- Email: [email protected]
RESPONSE TO SINGLE DOSE OF TETANUS VACCINE IN SUBJECTS WITH NATURALLY ACQUIRED TETANUS ANTITOXIN
219
evidence for the presence of this new peptidergic component of the autonomic system in man.5 VIP was first discovered and isolated because of its very potent vasodilatory action.13Investigation of its effect on
RESPONSE TO SINGLE DOSE OF TETANUS VACCINE IN SUBJECTS WITH NATURALLY ACQUIRED TETANUS ANTITOXIN
organ blood-flow led to the demonstration ofa role of VIP as a neurotransmitter.14,IS It has now been established that VIP is responsible for several atropine-resistant vasodilatory
FARAM D. DASTUR VEENA P. AWATRAMANI SHAILA K. DIXIT
which occur after parasympathetic nerve stimulation. 15,16 These responses can also be mimicked by the local injection of very low concentrations of pure VIP. VIP concentrations were particularly high in the pudendal arteries as well as in the erectile tissue of the corpus cavernosum. The high concentrations of VIP in the male genital tract are comparable to those found in the hypothalamus,17 which is a crucial control centre for neuroendocrine regulation of sexual behaviour. The finding of VIP immunoreactive nerves within the muscular cushions of the pudendal arteries is relevant to the need for rapid dilation of the blood vessels at the start of erection (opening the "sluice-gates") and could also be important in the maintenance of active arterial dilation. VIP-immunostained local ganglia were detected and were concentrated mainly in the corpus cavernosum. This accords with the general observation that peripheral VIP nerves often originate from local ganglia.1S,19 The, finding of VIP immunoreactive fibres in the circular muscle lining the inner face of the albuginea of the testis suggests that VIP could also have a role in the control of testicular temperature. Changes in the scrotal surface area (cold contraction, heat relaxation) which are largely responsible for heat dispersion or conservation are under nervous control. 20 The role of the classic adrenergic and cholinergic nerves in the control of ejaculation is well established, 20 though only ganglion-blocking agents reliably result in impotence. 21,22 The present demonstration of an extensive VIP innervation in the circular muscle of the corpus spongiosum and the epithelium of the vas deferens adds another factor to our knowledge of the nervous control of male external genitalia.
Seth G.S. Medical College and King Edward VII Memorial Hospital, Bombay
Department of Medicine,
responses
Requests for reprints should be addressed to S. R. B., Department of Atedicine, Hammersmith Hospital, Du Cane Road, London W 12 OHS. REFERENCES overview In: Bloom SR, Polak JM, eds. Gut hormones. 2nd ed. Edinburgh Churchill Livingstone, 1981; 379-84. 2 Said SI Vasoactive intestinal polypeptide (VIP) as a neural peptide. In: Miyoshi A, eds. Gut peptides Tokyo Kodansha. Amsterdam Elsevier, 1979, 268-74. 3 Polak JM, Bloom SR The distribution and significance of the vipergic system in man and other mammals. Endocr Jap 1980, Suppl 1: 11-22 4 Alm P, Alumets J, Hakanson R, Sundler F Peptidergic (vasoactive intestinal peptide)
1. Said SI VIP
Neuroscience 1977; 2: 751-54 containing vasoactive intestinal polypeptide immunoreactivity m the male genital tract. Life Sci 1977; 21: 503-08. 6 Bloom W, Fawcett DW Male reproductive system. In: Bloom W, Fawcett DW, eds. A textbook of histology. 10th ed. Philadelphia Saunders WB, 1975; 805-57. 7 Mitchell SJ, Bloom SR. Measurement of fasting and postprandial plasma VIP in man. Gut 1978, 19: 1043-48. 8 Bishop AE, Polak JM, Bloom SR, Pearse AGE. A new universal technique for the immunocytochemical localisation of peptidergic innervation. J Endocr 1978; 77: nerves
in the genito-urinary
5 Larsson L-I. Occurrence of
10 11
12
13
NOSHIR D. COOVERJI
M. PAUL ANAND Glaxo Laboratories (India)
Ltd, Bombay, India
Tests among 410 Indians not artificially immunised against tetanus showed that 80% had measurable antitoxin. Single doses (100 Lfor 250 Lf) of a potent tetanus toxoid were given to such individuals with naturally acquired antitoxin. The 100 Lf dose produced on average a ten-fold rise in antibody level, and the 250 Lf dose a twenty-fold rise. In adults who had been artificially immunised, a 5 Lf dose produced a four-fold to ten-fold rise in antibody level. In infants three doses of triple vaccine produced satisfactory antitoxin concentrations. The levels of antibody achieved after a single 250 Lf dose should protect for 5 years. Single-dose vaccination may be better than the conventional three-dose scheme for a population that is unlikely to comply with a three-dose regimen and in whom naturally acquired antitoxin is associated with partial tolerance to tetanus toxoid. Naturally acquired antitoxin in Indians is probably the result of chronic clostridial contamination of the small bowel. This contamination can induce immune tolerance in the gut and systemically and may be the reason for the poor responses to vaccination in all except infants.
Summary
Introduction THE past decade has shown that tetanus antitoxin can be found in individuals who have neither been artificially immunised against tetanus nor had the disease. Protective levels of tetanus antitoxin (0 - 01 IU/ml) have been found in people living in rural areas and in domestic and farm animals in Brazil. u2 In India the antitoxin titres have been mostly well below the protective level. 3-6 Nevertheless, if naturally acquired antitoxin is widespread in the community, even at a low level, it can be of great significance in conferring
tract
nerves
25-26 9
TOSEPH A. D’SA
Coons AH, Leduc EH, Connolly JM Studies on antibody production I. A method for the histochemical demonstration of specific antibody and its application to a study of the hyperimmune rabbit J Exp Med 1955; 102: 49-59. Sternberger LA The unlabelled antibody enzyme method. In- Sternberger LA, ed. Immunocytochemistry. New Jersey. Prentice-Hall, 1974; 129-71. El-Badawi A, Schenk EA Histochemical methods for separate, consecutive and simultaneous demonstration of acetylcholinesterase and norepinephrine in cryostat sections J Histochem Cytochem 1967; 15: 580-88. de la Torre JC, Surgeon JW A methodological approach to rapid and sensitive monoamine histofluorescence using a modified glyoxylic acid technique: the SPG method Histochemistry 1976; 49: 81-93. Said SI, Mutt V Isolation from porcine intestinal wall ofa vasoactive octacosapeptide related to secretin and glucagon Eur J Biochem 1972, 28: 199-204.
Fahrenkrug J Physiological role of VIP in digestion. In: Bloom SR, Polak JM, eds. Gut hormones. 2nd ed. Edinburgh. Churchill Livingstone, 1981, 385-91. 15. Bloom SR, Edwards AV. Vasoactive intestinal peptide in relation to atropine resistant vasodilatation in the submaxillary gland of the cat. J Physiol 1980; 300: 41-53 16. Lundberg JM, Ähggard A, Fahrenkrug J, Hökfelt T, Mutt V. Vasoactive intestinal polypeptide in cholinergic neurons of exocrine glands functional significance of 14.
coexisting transmitters for vasodilation and secretion. Proc Nat Acad Sci USA 1980; 77: 1651-55 17. Roberts GW, Woodhams PL, Bryant MG, Crow TJ, Bloom SR, Polak JM VIP in the rat brain evidence for a major pathway linking the amygdala and hypothalamus via the stria terminalis Histochemistry 1980, 65: 103-19 18. Jesson KR, Polak JM, Van Noorden S, Bloom SR, Burnstock G. Peptide-containing neurones connect the two ganglionated plexuses of the enteric nervous system Nature 1980, 283: 391-93. 19. Bishop AE, Polak JM, Green IC, Bryant MG, Bloom SR. The location of VIP in the pancreas of man and rat Diabetologia 1980, 18: 73-78 20. MacLeod J Reproduction in the male. In: Ruch TC, Patton HD, eds Physiology and biophysics III Digestion, metabolism, endocrine, function and reproduction 20th ed. Philadelphia. Saunders WB, 1973; 340-78. 21. Cole NJ. Drugs causing sexual problems. Pharmacy Int 1981, 2: 63-67. 22 Horowitz JD, Goble AJ. Drugs and impaired male sexual function Drugs 1979; 18: 206-17.
220
protection. Tetanus toxoid has to be given in three doses at spaced intervals, a scheme that does not receive the cooperation of a large proportion of the population. 30 000 to 60 000 Indians get tetanus every urban survey showed that only 10% of people year,’ have protective levels of antitoxin.s However, if in most of the population the immune system is already sensitised to tetanus antigen, one dose of a potent toxoid may boost low titres to protective levels for a considerable period.
Consequently and
an
Patients and Methods
Subjects Various groups of individuals
were
studied
to answer
certain
Fig. 1-Basal antitoxin levels in 410 unimmunised individuals.
questions.
_
What percentage of urban dwellers have naturally acquired antitoxin and in what percentage the levels are protective.-Antitoxin levels were measured in 410 (254 males, 156 females) non-immunised inpatients at the King Edward VII Hospital in Bombay who ranged in age from newly born to 65 years. Whether one dose of a potent tetanus toxoid (TT) induces long-term immunity in unimmunised persons who possess acquired antitoxin.-100 Lf TT was given to 131 adults. 90 were patients awaiting cold orthopaedic surgery and 41 were students. Postimmunisation levels on the 8th day and at one month were measured. 30 patients were followed up for 3 years. 250 LfTT was given to 38 children aged 6-16 years. Their 8th day and 1 month postimmunisation levels were measured. All children are still being followed up to determine the duration, of protection afforded. What rise in antibody level occurs with a single dose of 5 Lf TTgiven .to previously artifically immunised persons.-5 LfTT was given to 30 junior hospital staff members. All had had primary immunisation (three doses in infancy) and some had had boosters. Antibody levels on the 8th day and at 1 month were measured. What tetanus antitoxin titres are reached after three doses of triple vaccine (DPT) given to Indian infants.-30 children attending the well baby clinic of the King Edward VII Memorial Hospital, which serves the lower socioeconomic classes, had received three doses of DPT at the 3rd, 4th, and 5th months of life.. Antitoxin levels were measured over 18 months, whenever the children presented to the clinic.
Tetanus Toxoid Adsorbed tetanus toxoid was used in all studies. 100 Lfand 250 Lf were supplied by Glaxo Laboratories (India) Ltd. The vaccines were adsorbed on 2’5 mg of aluminium phosphate and concentrated into 0 -5ml volumes. They were stored at 4°C before use. Experience has shown the vaccines to be free of side-effects.
strengths
Antitoxin Measurement
protective. The earliest age at which naturally acquired antibody was detected was 1 year. Fig. 2 shows the basal antibody levels in those given 100 Lf TT or 250 LfTT. On the 8th day the levels (not shown) were double the basal reading. At 1 month the levels had risen by ten fold and twenty fold, respectively, for each vaccine. In the 30 previously immunised individuals concentrations rose four fold in 26 subjects and ten fold in 4 individuals 1 month 5 Lf booster. Fig. 3 shows antitoxin levels in Indian children who received three doses of triple vaccine. The average level in American children after three doses is also indicated for
after
a
comparison. 133 Discussion
Acquired antitoxin was detected in 80% of 410 unimmunised inpatients in a city hospital, although in only 3% did the concentration reach protective levels. Our findings indicate that urban dwellers, like rural dwellers, 1-6 are sensitised to tetanus antigen. The 100 Lf vaccine given to 131 unimmunised adults and the 250 Lf vaccine given to 38 children produced protective levels of antibody in all. However, the antibody levels at 1 month rose by only ten fold after the 100 Lf dose and by twenty fold after the 250 Lf dose. There was no booster response (a steep rise in antibody level in the first week), and the 8th day level showed only a doubling of the basal concentration. Similar observations after a single-dose vaccine have been reported elsewhere from India.4 When immunised individuals were given a standard 5 Lf TT
antitoxin levels were measured by the Blood cells were tanned with tannic acid, coated with concentrated tetanus toxoid (40 Lf/ml), and under precisely buffered conditions exposed to serial dilutions of the antitoxin being measured. The toxoid used contained 2000 Lf7mg of protein nitrogen. All subjects who received 250 Lf and 5 Lf doses also had the preimmunisation antibody levels checked by the standard mouse neutralisation test,1O which measures only biologically active antitoxin. The findings by the haemagglutination test showed agreement with those obtained by the mouse neutralisation test, but only the former are presented here because the neutralisation method could not detect concentrations below 0’005 IU/ml. All post-immunisation levels were measured by the mouse neutralisation test; after immunisation the haemagglutination test may be unreliable because of the induction of IgM 11and other short-term non-toxin neutralising antibodies. 12
Preimmunisation
tetanus
passive haemagglutination technique.9
Results
Fig.
1 shows that 80% of the 410 inpatients had measurable levels. In 307o the concentration was
tetanus antitoxin
Fig. 2-Response to a single dose of tetanus toxoid of different potency ’
in 3 groups of individuals. (a) Those given 5 LF had been artificially immunised before. (b) Those given 100 LF and 250 LF had not been artificially immunised ,
221
inability of hyperimmunised Indian Army recruits to produce sufficient antitoxin for the collection of human The
immune globulin can now be understood.z9 The is further supported by the data on infant immunisation. Here three doses of triple vaccine yielded satisfactory antitoxin titres. At this young age tolerance resulting from gut contamination has not had sufficient time tetanus
hypothesis
to
Fig. 3-Antitoxin titres in Indian children given triple vaccine at 3, 4, and 5 months of age.
Open circles indicate those who received triple vaccine; closed circles indicate those who received booster dose as well. Horizontal line indicates average levels I in American children after 3 doses of triple vaccine.
reinforcing dose the pattern was unchanged-there was nc booster response and at 1 month the levels rose four-fold in 26 and ten-fold in 4 individuals. Laboratory studies have shown that after a 5 Lf TT reinforcing dose T-helper cells are rapidly recruited to induce specific clones of B cells to secrete antitoxin14 so that a 10-100 fold rise in titre results within 7 days. 15 The magnitude of the response is enhanced by previous decay in the antitoxin level and by a significant time lapse’following receipt of the previous dose.16 Despite these conditions being satisfied in most individuals the responses observed were less than those in Western subjects Why? Certain factors may be excluded as causes of the relatively low responses. Firstly, abnormal immune status of the subjects given a 100 Lf dose is unlikely because, although some patients showed impaired T-cell function, their responses to the toxoid mimicked those of the students.18 Secondly, the subjects are unlikely to be "poor responders" to TT, since poor responders tend to have distinct HL-A antigens (B-5 and DHO);19 in a separate study there was no preponderance of these haplotypes among tetanus patients and normal Indian controls.2° Thirdly, inadequacy of the 5 Lf dose vaccine (lower fiducial limit approximately 50 IU) is excluded by its ability to immunise infants satisfactorily when incorporated into triple vaccine (DPT). We believe that the most plausible explanation for our data is immune tolerance to tetanus toxoid resulting from chronic clostridial contamination of the small intestine. The Indian jejunal mucosa is histologically abnormal by Western criteria. The abnormalities are not genetic, since similar changes have been found in American Peace Corps workers living in India for more than 6 months.2I The abnormalities seem to be related to chronic microbial contamination of the small bowel.z2 Experimentally, certain clostridial organisms stimulate B and T cells in Peyer’s patches.23 Such sensitised cells induce systemic immunity when transported to the spleen and mesenteric lymph nodes.24 Chronic Cl. tetani contamination of the small bowel may be the reason for the presence oflow levels of tetanus antitoxin in Indians. Chronic antigenic feeding by the oral route is now known to lead not only to local immune tolerance in the gut, but also to specific systemic tolerance, if the antigen is subsequently given parenterally, as in immunisation.25-28
develop.
The value of single-dose tetanus toxoids must be assessed by the period of protection they provide. With the 100 Lf dose the level remained protective for 3 years. The follow-up after the 250 Lf dose is in progress, but protection in excess of 5 years is expected. The 5 Lf dose currently being given in India is only adequate when compliance with the three-dose regimen can be ensured-for example, in the Armed Forces. The general population in India does not comply with a three-dose regimen, hence the innumerable immunisation failures. When compliance is so poor, the single 250 Lf dose may be useful. It would allow a wider coverage of the population and guarantee immunity for people particularly at risk. In India this would mean the pregnant female, her offspring, and the growing child, for tetanus most commonly afflicts the young. Reimmunisation might be needed at intervals but further studies are necessary to establish the frequency with which boosters have to be given. The study was supported by a grant from the Research Society, Seth G.S. Medical College and King Edward VII Memorial Hospital, and by Glaxo Laboratories (India) Ltd, Bombay. Requests for reprints should be addressed to F. D. D., Department of Medicine, Seth G.S. Medical College and King Edward VII Memorial Hospital, Parel, Bombay, 400012, India. REFERENCES 1. Veronesi R. New
approaches on tetanus immunisation: naturally acquired immunity. Preliminary report. Rev Hosp Clin Fac Med Sao Paulo 1973; 28: 313-18 2. Veronesi R, Correia A, Ferreira H, et al. Naturally acquired tetanus immunity further evidences in humans and animals. Lyon: Dakar Senegal Foundation Merieux. Proc IV Int Conf on Tetanus Dakar 1975; 2: 613-26 3. Vakil BJ, Tulpule TH, Rao SS, Borker MB. A comparison of 1500 units and 5000 units of
simultaneous active and passive immunization against 56: 1188-201. 4. Kielmann AA, Vohra RS. Control of tetanus neonatorum in rural communitiesimmunisation effects of high dose calcium phosphate adsorbed tetanus toxoid. Ind J Med Res 1977; 66: 906-16. 5. Ray SN, Grover SS, Ray K, Regis ML. Sero-survey of rhesus monkeys for bacterial and viral antibodies. Ind J Med Res 1978; 67: 354-57. 6. Ray SN, Ray K, Grover SS, Sharma RS, Sharma SP. Sero-survey of diphtheria and tetanus antitoxin. Ind J Med Res 1978; 68: 901-04. 7. Dastur FD, D’Sa JA. Tetanus-present knowledge and experience in India. In: Ahuja MMS, ed. Progress in clinical medicine in India, Third Series. New Delhi: Arnold-Heinemann, 1979: 68-88. 8. D’Sa JA. Tetanus antitoxin in human serum. J Postgrad Med 1974; 20: 15-20. 9. Levine L, Wyman L, Broderick EJ, Ipsen G. Haemagglutination titration for diphtheria and tetanus antitoxin. J Paediatr 1960; 57: 836-41. 10. Glenny DT, Stevens MF The laboratory control of tetanus prophylaxis. J Roy Army Med Corps 1938; 70: 308-20. 11. Thiele CJ, Stevens RH. Antibody potential of human peripheral blood lymphocytes, differentially expressing surface membrane IgM. J Immunology 1980; 124: 1898-903. 12. Edsall G. Problems in the immunology and control of tetanus. Med J Aust 1976, 2: tetanus
tetanus.
antitoxin
in
Res 1968; Ind Med J
216-20. 13. Peebles TC, Levine
L, Eldred MC, Edsall G. Tetanus toxoid emergency boosters. N
Engl J Med 1969; 280:
575-81.
HR, Saxon A. Control of antitetanus toxoid antibody production after booster immunization. J Clin Invest 1978; 62: 1154-60. 15. Edsall G. Immunological principles in active immunization against tetanus. In: Echmann L, ed. Proceedings ofthe 2nd International Conference on Tetanus. Bern. 14. Stevens
Hans Huber 1966: 225-36. 16. Adams EB, Laurence DR, Smith JWG Tetanus. Oxford: Blackwell, 1969: 63-66. 17. Bainton D, Freeman M, Magrath DI, Sheffield F, Smith JWG. Immunity of children to diphtheria, tetanus and polio Br Med J 1979; i: 854-57. 18 Gaitonde BB, Chanderkar NG, Saldanha FL, et al. Immune response in tetanus. J Ass Phys Ind 1979; 27: 699-705. 19. Sazazuki T, Kohno Y, Iwamoto I, Tanimura M, Naito S. Association between an HLA haplotype and low responsiveness to tetanus toxoid in man. Nature 1978; 272: 356-63 20. Bale UM, Mehta MM, Contractor NM, Bhatia HM, Dastur FD. HLA antigens and E-Rosettes in tetanus patients. Tiss Antigens 1980; 16: 181-86
222
NON-PARENTERAL TRANSMISSION OF CYTOMEGALOVIRUS IN A NEONATAL INTENSIVE CARE UNIT INGE GUREVICH
BURKE A. CUNHA
Infection Control Section, Infectious Disease Division, Department of Medicine, Nassau Hospital, Mineola, New York, U.S.A.
Summary
genital CMV
Cytomegalovirus (CMV) was transmitted non-parenterally from an infant with conwho lived only 8 h to four other infants who
A pregnant nurse in an adjacent nursery was instructed the NICU. She was advised to have CMV titres measured through the hospital’s Employee Health Service, but she preferred to deal directly with her own obstetrician. The baby’s mother was placed on gown and glove isolation. Serial CMV titres (IgG) measured every 5 weeks remained negative in a pregnant nurse who had had contact with the lochia. CMV titre (IgG) measured in the cord blood of the baby was 1:160. The mother’s CMV titre measured on the same day was 1:640. Titres of other antibodies are given in table I.
the
baby.
not to enter
TABLE I-TITRES OF CASE
1 AND MOTHER
in the neonatal intensive care unit at the same time. Two infants with cytomegalovirus died. The dizygotic twin of one of the dead infants presented with a cytomegalovirus-specific IgG titre of 1:640 at 4 months of age, while the mother of the twins had a negative titre. Direct or indirect contact was thought to be the mode of spread in this outbreak of CMV.
were
Introduction PERINATAL acquisition of cytomegalovirus (CMV) infection has been extensively investigated and reported. Infections during gestation can be apparent or inapparent, and can be the result of a primary process, 1- 3 reinfection,4,5 or reactivation of a previous infection. 6, Viral infection can also be acquired during passage through the birth cana1.s Postnatally infants can acquire CMV by close contact with mothers who are shedding the virus in the urine, or possibly from breast milk.9 The virus is often transmitted via transfusion of blood or blood products. 10 Between 0’5% and 2-4% of neonates have congenital CMV infection.",12 Therefore, neonates are a constant reservoir for CMV, irrespective of their developinga specific immune response or the presence of maternal antibody.13,14 Outbreak and Index Case
Investigation
An increase in the baby’s non-specific IgM concentration to 59 mg/dl strongly indicated an infection. Since maternal titres were determined in a single serum sample, and no other titres were available for comparison, they indicated only that an infection had taken place at some time. It was not known whether this was a primary infection, reinfection, or an episode of reactivation of a latent infection. It would have been useful to look for CMV-specific IgM which, if positive, might have indicated a primary infection. This test, however, was not performed. The baby died on June 5, 1980, 8 h after birth and, at necropsy, widely disseminated infection, as evidenced by CMV inclusion bodies, was found in the kidneys, liver, brain, lung, heart, pancreas, and the placenta. Viral cultures were not done. During this period, there were seven other infants in the same nursery. Their approximate position is shown in fig. 1. Babies were
often moved around within the nursery, and it is therefore difficult to determine their exact location. Birth and discharge dates are indicated for those babies in whom CMV titres were subsequently measured, and for the two babies in whom CMV inclusion bodies were found at necropsy.
(Infant 1)
On June 5, 1980, at 6 A.M., a term female infant was delivered to a mother who was gravida II para I. The baby weighed 3000 g and had an Apgar score of 1 at 1 min and 5 min. She was covered with petechiae and presented with shock, disseminated intravascular coagulation, and seizures. The baby was intubated and taken to the neonatal intensive care unit (NICU) where she died 8 h later. At 10.30 A.M., 41/2 h after the baby was admitted to the unit, Infection Control was notified of the birth of a baby with probable congenital CMV. The chief of infectious diseases, who is also chairman of the Infection Control Committee, requested that the infant be nursed in strict isolation. Since life support systems are available only in the NICU, isolation was instituted within that unit: masks, gowns, and gloves were worn by those in contact with
SJ, Mathan VI Tropical enteropathy and tropical sprue. Am J Clin Nutr 1972; 25: 1047-55. 22. Bhat P, Shantakumari S, Rajan D, et al. Bacterial flora of the gastrointestinal tract in Southern Indian control subjects and patients with tropical sprue. Gastroenterology 1972; 62: 11-15. 23. Muller-Schoop JW, Good RA. Functional studies of Peyer’s patches. Evidence for their participation in intestinal immune response. J Immunol 1975; 114: 1757-60. 24. Rothberg RM, Kraft SG, Michalek SM. Systemic immunity after local antigenic stimulation of the lymphoid tissue of the gastrointestinal tract. J Immunol 1973; 111: 1906-13. 25. Swarbrick ET, Stokes CR, Soothill JF. Absorption of antigens after oral immunization and the simultaneous induction of specific systemic tolerance Gut 1979; 20: 121-25. 26. Annotation. Gut reaction to antigen. Lancet 1979; i: 763. 27. Hemmings WA. Gut reaction to antigen. Lancet 1979, ii: 874. 28. Tomasi TB. Oral tolerance-an overview. Transplantation 1980; 29: 353-56. 29. Varma RN, Murthy RGS, Boparai MS, Chanderkar NG. Measurement of tetanus immunity in army personnel. Ind J Med Res 1975; 63: 1204-08.
Fatal Cases
Infant 2-On April 20, 1980, a set of dizygotic male twins were born, and because of their low birth-weight, they were nursed in the NICU. They were 45 days old when the index baby was admitted. On June 7, a pustule which grew Staphylococcus aureus, developed
21. Baker
Fig. 1—Neonatat intensive care unit showing placement of and other infants.
index cast
evidence for the presence of this new peptidergic component of the autonomic system in man.5 VIP was first discovered and isolated because of its very potent vasodilatory action.13Investigation of its effect on
RESPONSE TO SINGLE DOSE OF TETANUS VACCINE IN SUBJECTS WITH NATURALLY ACQUIRED TETANUS ANTITOXIN
organ blood-flow led to the demonstration ofa role of VIP as a neurotransmitter.14,IS It has now been established that VIP is responsible for several atropine-resistant vasodilatory
FARAM D. DASTUR VEENA P. AWATRAMANI SHAILA K. DIXIT
which occur after parasympathetic nerve stimulation. 15,16 These responses can also be mimicked by the local injection of very low concentrations of pure VIP. VIP concentrations were particularly high in the pudendal arteries as well as in the erectile tissue of the corpus cavernosum. The high concentrations of VIP in the male genital tract are comparable to those found in the hypothalamus,17 which is a crucial control centre for neuroendocrine regulation of sexual behaviour. The finding of VIP immunoreactive nerves within the muscular cushions of the pudendal arteries is relevant to the need for rapid dilation of the blood vessels at the start of erection (opening the "sluice-gates") and could also be important in the maintenance of active arterial dilation. VIP-immunostained local ganglia were detected and were concentrated mainly in the corpus cavernosum. This accords with the general observation that peripheral VIP nerves often originate from local ganglia.1S,19 The, finding of VIP immunoreactive fibres in the circular muscle lining the inner face of the albuginea of the testis suggests that VIP could also have a role in the control of testicular temperature. Changes in the scrotal surface area (cold contraction, heat relaxation) which are largely responsible for heat dispersion or conservation are under nervous control. 20 The role of the classic adrenergic and cholinergic nerves in the control of ejaculation is well established, 20 though only ganglion-blocking agents reliably result in impotence. 21,22 The present demonstration of an extensive VIP innervation in the circular muscle of the corpus spongiosum and the epithelium of the vas deferens adds another factor to our knowledge of the nervous control of male external genitalia.
Seth G.S. Medical College and King Edward VII Memorial Hospital, Bombay
Department of Medicine,
responses
Requests for reprints should be addressed to S. R. B., Department of Atedicine, Hammersmith Hospital, Du Cane Road, London W 12 OHS. REFERENCES overview In: Bloom SR, Polak JM, eds. Gut hormones. 2nd ed. Edinburgh Churchill Livingstone, 1981; 379-84. 2 Said SI Vasoactive intestinal polypeptide (VIP) as a neural peptide. In: Miyoshi A, eds. Gut peptides Tokyo Kodansha. Amsterdam Elsevier, 1979, 268-74. 3 Polak JM, Bloom SR The distribution and significance of the vipergic system in man and other mammals. Endocr Jap 1980, Suppl 1: 11-22 4 Alm P, Alumets J, Hakanson R, Sundler F Peptidergic (vasoactive intestinal peptide)
1. Said SI VIP
Neuroscience 1977; 2: 751-54 containing vasoactive intestinal polypeptide immunoreactivity m the male genital tract. Life Sci 1977; 21: 503-08. 6 Bloom W, Fawcett DW Male reproductive system. In: Bloom W, Fawcett DW, eds. A textbook of histology. 10th ed. Philadelphia Saunders WB, 1975; 805-57. 7 Mitchell SJ, Bloom SR. Measurement of fasting and postprandial plasma VIP in man. Gut 1978, 19: 1043-48. 8 Bishop AE, Polak JM, Bloom SR, Pearse AGE. A new universal technique for the immunocytochemical localisation of peptidergic innervation. J Endocr 1978; 77: nerves
in the genito-urinary
5 Larsson L-I. Occurrence of
10 11
12
13
NOSHIR D. COOVERJI
M. PAUL ANAND Glaxo Laboratories (India)
Ltd, Bombay, India
Tests among 410 Indians not artificially immunised against tetanus showed that 80% had measurable antitoxin. Single doses (100 Lfor 250 Lf) of a potent tetanus toxoid were given to such individuals with naturally acquired antitoxin. The 100 Lf dose produced on average a ten-fold rise in antibody level, and the 250 Lf dose a twenty-fold rise. In adults who had been artificially immunised, a 5 Lf dose produced a four-fold to ten-fold rise in antibody level. In infants three doses of triple vaccine produced satisfactory antitoxin concentrations. The levels of antibody achieved after a single 250 Lf dose should protect for 5 years. Single-dose vaccination may be better than the conventional three-dose scheme for a population that is unlikely to comply with a three-dose regimen and in whom naturally acquired antitoxin is associated with partial tolerance to tetanus toxoid. Naturally acquired antitoxin in Indians is probably the result of chronic clostridial contamination of the small bowel. This contamination can induce immune tolerance in the gut and systemically and may be the reason for the poor responses to vaccination in all except infants.
Summary
Introduction THE past decade has shown that tetanus antitoxin can be found in individuals who have neither been artificially immunised against tetanus nor had the disease. Protective levels of tetanus antitoxin (0 - 01 IU/ml) have been found in people living in rural areas and in domestic and farm animals in Brazil. u2 In India the antitoxin titres have been mostly well below the protective level. 3-6 Nevertheless, if naturally acquired antitoxin is widespread in the community, even at a low level, it can be of great significance in conferring
tract
nerves
25-26 9
TOSEPH A. D’SA
Coons AH, Leduc EH, Connolly JM Studies on antibody production I. A method for the histochemical demonstration of specific antibody and its application to a study of the hyperimmune rabbit J Exp Med 1955; 102: 49-59. Sternberger LA The unlabelled antibody enzyme method. In- Sternberger LA, ed. Immunocytochemistry. New Jersey. Prentice-Hall, 1974; 129-71. El-Badawi A, Schenk EA Histochemical methods for separate, consecutive and simultaneous demonstration of acetylcholinesterase and norepinephrine in cryostat sections J Histochem Cytochem 1967; 15: 580-88. de la Torre JC, Surgeon JW A methodological approach to rapid and sensitive monoamine histofluorescence using a modified glyoxylic acid technique: the SPG method Histochemistry 1976; 49: 81-93. Said SI, Mutt V Isolation from porcine intestinal wall ofa vasoactive octacosapeptide related to secretin and glucagon Eur J Biochem 1972, 28: 199-204.
Fahrenkrug J Physiological role of VIP in digestion. In: Bloom SR, Polak JM, eds. Gut hormones. 2nd ed. Edinburgh. Churchill Livingstone, 1981, 385-91. 15. Bloom SR, Edwards AV. Vasoactive intestinal peptide in relation to atropine resistant vasodilatation in the submaxillary gland of the cat. J Physiol 1980; 300: 41-53 16. Lundberg JM, Ähggard A, Fahrenkrug J, Hökfelt T, Mutt V. Vasoactive intestinal polypeptide in cholinergic neurons of exocrine glands functional significance of 14.
coexisting transmitters for vasodilation and secretion. Proc Nat Acad Sci USA 1980; 77: 1651-55 17. Roberts GW, Woodhams PL, Bryant MG, Crow TJ, Bloom SR, Polak JM VIP in the rat brain evidence for a major pathway linking the amygdala and hypothalamus via the stria terminalis Histochemistry 1980, 65: 103-19 18. Jesson KR, Polak JM, Van Noorden S, Bloom SR, Burnstock G. Peptide-containing neurones connect the two ganglionated plexuses of the enteric nervous system Nature 1980, 283: 391-93. 19. Bishop AE, Polak JM, Green IC, Bryant MG, Bloom SR. The location of VIP in the pancreas of man and rat Diabetologia 1980, 18: 73-78 20. MacLeod J Reproduction in the male. In: Ruch TC, Patton HD, eds Physiology and biophysics III Digestion, metabolism, endocrine, function and reproduction 20th ed. Philadelphia. Saunders WB, 1973; 340-78. 21. Cole NJ. Drugs causing sexual problems. Pharmacy Int 1981, 2: 63-67. 22 Horowitz JD, Goble AJ. Drugs and impaired male sexual function Drugs 1979; 18: 206-17.
220
protection. Tetanus toxoid has to be given in three doses at spaced intervals, a scheme that does not receive the cooperation of a large proportion of the population. 30 000 to 60 000 Indians get tetanus every urban survey showed that only 10% of people year,’ have protective levels of antitoxin.s However, if in most of the population the immune system is already sensitised to tetanus antigen, one dose of a potent toxoid may boost low titres to protective levels for a considerable period.
Consequently and
an
Patients and Methods
Subjects Various groups of individuals
were
studied
to answer
certain
Fig. 1-Basal antitoxin levels in 410 unimmunised individuals.
questions.
_
What percentage of urban dwellers have naturally acquired antitoxin and in what percentage the levels are protective.-Antitoxin levels were measured in 410 (254 males, 156 females) non-immunised inpatients at the King Edward VII Hospital in Bombay who ranged in age from newly born to 65 years. Whether one dose of a potent tetanus toxoid (TT) induces long-term immunity in unimmunised persons who possess acquired antitoxin.-100 Lf TT was given to 131 adults. 90 were patients awaiting cold orthopaedic surgery and 41 were students. Postimmunisation levels on the 8th day and at one month were measured. 30 patients were followed up for 3 years. 250 LfTT was given to 38 children aged 6-16 years. Their 8th day and 1 month postimmunisation levels were measured. All children are still being followed up to determine the duration, of protection afforded. What rise in antibody level occurs with a single dose of 5 Lf TTgiven .to previously artifically immunised persons.-5 LfTT was given to 30 junior hospital staff members. All had had primary immunisation (three doses in infancy) and some had had boosters. Antibody levels on the 8th day and at 1 month were measured. What tetanus antitoxin titres are reached after three doses of triple vaccine (DPT) given to Indian infants.-30 children attending the well baby clinic of the King Edward VII Memorial Hospital, which serves the lower socioeconomic classes, had received three doses of DPT at the 3rd, 4th, and 5th months of life.. Antitoxin levels were measured over 18 months, whenever the children presented to the clinic.
Tetanus Toxoid Adsorbed tetanus toxoid was used in all studies. 100 Lfand 250 Lf were supplied by Glaxo Laboratories (India) Ltd. The vaccines were adsorbed on 2’5 mg of aluminium phosphate and concentrated into 0 -5ml volumes. They were stored at 4°C before use. Experience has shown the vaccines to be free of side-effects.
strengths
Antitoxin Measurement
protective. The earliest age at which naturally acquired antibody was detected was 1 year. Fig. 2 shows the basal antibody levels in those given 100 Lf TT or 250 LfTT. On the 8th day the levels (not shown) were double the basal reading. At 1 month the levels had risen by ten fold and twenty fold, respectively, for each vaccine. In the 30 previously immunised individuals concentrations rose four fold in 26 subjects and ten fold in 4 individuals 1 month 5 Lf booster. Fig. 3 shows antitoxin levels in Indian children who received three doses of triple vaccine. The average level in American children after three doses is also indicated for
after
a
comparison. 133 Discussion
Acquired antitoxin was detected in 80% of 410 unimmunised inpatients in a city hospital, although in only 3% did the concentration reach protective levels. Our findings indicate that urban dwellers, like rural dwellers, 1-6 are sensitised to tetanus antigen. The 100 Lf vaccine given to 131 unimmunised adults and the 250 Lf vaccine given to 38 children produced protective levels of antibody in all. However, the antibody levels at 1 month rose by only ten fold after the 100 Lf dose and by twenty fold after the 250 Lf dose. There was no booster response (a steep rise in antibody level in the first week), and the 8th day level showed only a doubling of the basal concentration. Similar observations after a single-dose vaccine have been reported elsewhere from India.4 When immunised individuals were given a standard 5 Lf TT
antitoxin levels were measured by the Blood cells were tanned with tannic acid, coated with concentrated tetanus toxoid (40 Lf/ml), and under precisely buffered conditions exposed to serial dilutions of the antitoxin being measured. The toxoid used contained 2000 Lf7mg of protein nitrogen. All subjects who received 250 Lf and 5 Lf doses also had the preimmunisation antibody levels checked by the standard mouse neutralisation test,1O which measures only biologically active antitoxin. The findings by the haemagglutination test showed agreement with those obtained by the mouse neutralisation test, but only the former are presented here because the neutralisation method could not detect concentrations below 0’005 IU/ml. All post-immunisation levels were measured by the mouse neutralisation test; after immunisation the haemagglutination test may be unreliable because of the induction of IgM 11and other short-term non-toxin neutralising antibodies. 12
Preimmunisation
tetanus
passive haemagglutination technique.9
Results
Fig.
1 shows that 80% of the 410 inpatients had measurable levels. In 307o the concentration was
tetanus antitoxin
Fig. 2-Response to a single dose of tetanus toxoid of different potency ’
in 3 groups of individuals. (a) Those given 5 LF had been artificially immunised before. (b) Those given 100 LF and 250 LF had not been artificially immunised ,
221
inability of hyperimmunised Indian Army recruits to produce sufficient antitoxin for the collection of human The
immune globulin can now be understood.z9 The is further supported by the data on infant immunisation. Here three doses of triple vaccine yielded satisfactory antitoxin titres. At this young age tolerance resulting from gut contamination has not had sufficient time tetanus
hypothesis
to
Fig. 3-Antitoxin titres in Indian children given triple vaccine at 3, 4, and 5 months of age.
Open circles indicate those who received triple vaccine; closed circles indicate those who received booster dose as well. Horizontal line indicates average levels I in American children after 3 doses of triple vaccine.
reinforcing dose the pattern was unchanged-there was nc booster response and at 1 month the levels rose four-fold in 26 and ten-fold in 4 individuals. Laboratory studies have shown that after a 5 Lf TT reinforcing dose T-helper cells are rapidly recruited to induce specific clones of B cells to secrete antitoxin14 so that a 10-100 fold rise in titre results within 7 days. 15 The magnitude of the response is enhanced by previous decay in the antitoxin level and by a significant time lapse’following receipt of the previous dose.16 Despite these conditions being satisfied in most individuals the responses observed were less than those in Western subjects Why? Certain factors may be excluded as causes of the relatively low responses. Firstly, abnormal immune status of the subjects given a 100 Lf dose is unlikely because, although some patients showed impaired T-cell function, their responses to the toxoid mimicked those of the students.18 Secondly, the subjects are unlikely to be "poor responders" to TT, since poor responders tend to have distinct HL-A antigens (B-5 and DHO);19 in a separate study there was no preponderance of these haplotypes among tetanus patients and normal Indian controls.2° Thirdly, inadequacy of the 5 Lf dose vaccine (lower fiducial limit approximately 50 IU) is excluded by its ability to immunise infants satisfactorily when incorporated into triple vaccine (DPT). We believe that the most plausible explanation for our data is immune tolerance to tetanus toxoid resulting from chronic clostridial contamination of the small intestine. The Indian jejunal mucosa is histologically abnormal by Western criteria. The abnormalities are not genetic, since similar changes have been found in American Peace Corps workers living in India for more than 6 months.2I The abnormalities seem to be related to chronic microbial contamination of the small bowel.z2 Experimentally, certain clostridial organisms stimulate B and T cells in Peyer’s patches.23 Such sensitised cells induce systemic immunity when transported to the spleen and mesenteric lymph nodes.24 Chronic Cl. tetani contamination of the small bowel may be the reason for the presence oflow levels of tetanus antitoxin in Indians. Chronic antigenic feeding by the oral route is now known to lead not only to local immune tolerance in the gut, but also to specific systemic tolerance, if the antigen is subsequently given parenterally, as in immunisation.25-28
develop.
The value of single-dose tetanus toxoids must be assessed by the period of protection they provide. With the 100 Lf dose the level remained protective for 3 years. The follow-up after the 250 Lf dose is in progress, but protection in excess of 5 years is expected. The 5 Lf dose currently being given in India is only adequate when compliance with the three-dose regimen can be ensured-for example, in the Armed Forces. The general population in India does not comply with a three-dose regimen, hence the innumerable immunisation failures. When compliance is so poor, the single 250 Lf dose may be useful. It would allow a wider coverage of the population and guarantee immunity for people particularly at risk. In India this would mean the pregnant female, her offspring, and the growing child, for tetanus most commonly afflicts the young. Reimmunisation might be needed at intervals but further studies are necessary to establish the frequency with which boosters have to be given. The study was supported by a grant from the Research Society, Seth G.S. Medical College and King Edward VII Memorial Hospital, and by Glaxo Laboratories (India) Ltd, Bombay. Requests for reprints should be addressed to F. D. D., Department of Medicine, Seth G.S. Medical College and King Edward VII Memorial Hospital, Parel, Bombay, 400012, India. REFERENCES 1. Veronesi R. New
approaches on tetanus immunisation: naturally acquired immunity. Preliminary report. Rev Hosp Clin Fac Med Sao Paulo 1973; 28: 313-18 2. Veronesi R, Correia A, Ferreira H, et al. Naturally acquired tetanus immunity further evidences in humans and animals. Lyon: Dakar Senegal Foundation Merieux. Proc IV Int Conf on Tetanus Dakar 1975; 2: 613-26 3. Vakil BJ, Tulpule TH, Rao SS, Borker MB. A comparison of 1500 units and 5000 units of
simultaneous active and passive immunization against 56: 1188-201. 4. Kielmann AA, Vohra RS. Control of tetanus neonatorum in rural communitiesimmunisation effects of high dose calcium phosphate adsorbed tetanus toxoid. Ind J Med Res 1977; 66: 906-16. 5. Ray SN, Grover SS, Ray K, Regis ML. Sero-survey of rhesus monkeys for bacterial and viral antibodies. Ind J Med Res 1978; 67: 354-57. 6. Ray SN, Ray K, Grover SS, Sharma RS, Sharma SP. Sero-survey of diphtheria and tetanus antitoxin. Ind J Med Res 1978; 68: 901-04. 7. Dastur FD, D’Sa JA. Tetanus-present knowledge and experience in India. In: Ahuja MMS, ed. Progress in clinical medicine in India, Third Series. New Delhi: Arnold-Heinemann, 1979: 68-88. 8. D’Sa JA. Tetanus antitoxin in human serum. J Postgrad Med 1974; 20: 15-20. 9. Levine L, Wyman L, Broderick EJ, Ipsen G. Haemagglutination titration for diphtheria and tetanus antitoxin. J Paediatr 1960; 57: 836-41. 10. Glenny DT, Stevens MF The laboratory control of tetanus prophylaxis. J Roy Army Med Corps 1938; 70: 308-20. 11. Thiele CJ, Stevens RH. Antibody potential of human peripheral blood lymphocytes, differentially expressing surface membrane IgM. J Immunology 1980; 124: 1898-903. 12. Edsall G. Problems in the immunology and control of tetanus. Med J Aust 1976, 2: tetanus
tetanus.
antitoxin
in
Res 1968; Ind Med J
216-20. 13. Peebles TC, Levine
L, Eldred MC, Edsall G. Tetanus toxoid emergency boosters. N
Engl J Med 1969; 280:
575-81.
HR, Saxon A. Control of antitetanus toxoid antibody production after booster immunization. J Clin Invest 1978; 62: 1154-60. 15. Edsall G. Immunological principles in active immunization against tetanus. In: Echmann L, ed. Proceedings ofthe 2nd International Conference on Tetanus. Bern. 14. Stevens
Hans Huber 1966: 225-36. 16. Adams EB, Laurence DR, Smith JWG Tetanus. Oxford: Blackwell, 1969: 63-66. 17. Bainton D, Freeman M, Magrath DI, Sheffield F, Smith JWG. Immunity of children to diphtheria, tetanus and polio Br Med J 1979; i: 854-57. 18 Gaitonde BB, Chanderkar NG, Saldanha FL, et al. Immune response in tetanus. J Ass Phys Ind 1979; 27: 699-705. 19. Sazazuki T, Kohno Y, Iwamoto I, Tanimura M, Naito S. Association between an HLA haplotype and low responsiveness to tetanus toxoid in man. Nature 1978; 272: 356-63 20. Bale UM, Mehta MM, Contractor NM, Bhatia HM, Dastur FD. HLA antigens and E-Rosettes in tetanus patients. Tiss Antigens 1980; 16: 181-86
222
NON-PARENTERAL TRANSMISSION OF CYTOMEGALOVIRUS IN A NEONATAL INTENSIVE CARE UNIT INGE GUREVICH
BURKE A. CUNHA
Infection Control Section, Infectious Disease Division, Department of Medicine, Nassau Hospital, Mineola, New York, U.S.A.
Summary
genital CMV
Cytomegalovirus (CMV) was transmitted non-parenterally from an infant with conwho lived only 8 h to four other infants who
A pregnant nurse in an adjacent nursery was instructed the NICU. She was advised to have CMV titres measured through the hospital’s Employee Health Service, but she preferred to deal directly with her own obstetrician. The baby’s mother was placed on gown and glove isolation. Serial CMV titres (IgG) measured every 5 weeks remained negative in a pregnant nurse who had had contact with the lochia. CMV titre (IgG) measured in the cord blood of the baby was 1:160. The mother’s CMV titre measured on the same day was 1:640. Titres of other antibodies are given in table I.
the
baby.
not to enter
TABLE I-TITRES OF CASE
1 AND MOTHER
in the neonatal intensive care unit at the same time. Two infants with cytomegalovirus died. The dizygotic twin of one of the dead infants presented with a cytomegalovirus-specific IgG titre of 1:640 at 4 months of age, while the mother of the twins had a negative titre. Direct or indirect contact was thought to be the mode of spread in this outbreak of CMV.
were
Introduction PERINATAL acquisition of cytomegalovirus (CMV) infection has been extensively investigated and reported. Infections during gestation can be apparent or inapparent, and can be the result of a primary process, 1- 3 reinfection,4,5 or reactivation of a previous infection. 6, Viral infection can also be acquired during passage through the birth cana1.s Postnatally infants can acquire CMV by close contact with mothers who are shedding the virus in the urine, or possibly from breast milk.9 The virus is often transmitted via transfusion of blood or blood products. 10 Between 0’5% and 2-4% of neonates have congenital CMV infection.",12 Therefore, neonates are a constant reservoir for CMV, irrespective of their developinga specific immune response or the presence of maternal antibody.13,14 Outbreak and Index Case
Investigation
An increase in the baby’s non-specific IgM concentration to 59 mg/dl strongly indicated an infection. Since maternal titres were determined in a single serum sample, and no other titres were available for comparison, they indicated only that an infection had taken place at some time. It was not known whether this was a primary infection, reinfection, or an episode of reactivation of a latent infection. It would have been useful to look for CMV-specific IgM which, if positive, might have indicated a primary infection. This test, however, was not performed. The baby died on June 5, 1980, 8 h after birth and, at necropsy, widely disseminated infection, as evidenced by CMV inclusion bodies, was found in the kidneys, liver, brain, lung, heart, pancreas, and the placenta. Viral cultures were not done. During this period, there were seven other infants in the same nursery. Their approximate position is shown in fig. 1. Babies were
often moved around within the nursery, and it is therefore difficult to determine their exact location. Birth and discharge dates are indicated for those babies in whom CMV titres were subsequently measured, and for the two babies in whom CMV inclusion bodies were found at necropsy.
(Infant 1)
On June 5, 1980, at 6 A.M., a term female infant was delivered to a mother who was gravida II para I. The baby weighed 3000 g and had an Apgar score of 1 at 1 min and 5 min. She was covered with petechiae and presented with shock, disseminated intravascular coagulation, and seizures. The baby was intubated and taken to the neonatal intensive care unit (NICU) where she died 8 h later. At 10.30 A.M., 41/2 h after the baby was admitted to the unit, Infection Control was notified of the birth of a baby with probable congenital CMV. The chief of infectious diseases, who is also chairman of the Infection Control Committee, requested that the infant be nursed in strict isolation. Since life support systems are available only in the NICU, isolation was instituted within that unit: masks, gowns, and gloves were worn by those in contact with
SJ, Mathan VI Tropical enteropathy and tropical sprue. Am J Clin Nutr 1972; 25: 1047-55. 22. Bhat P, Shantakumari S, Rajan D, et al. Bacterial flora of the gastrointestinal tract in Southern Indian control subjects and patients with tropical sprue. Gastroenterology 1972; 62: 11-15. 23. Muller-Schoop JW, Good RA. Functional studies of Peyer’s patches. Evidence for their participation in intestinal immune response. J Immunol 1975; 114: 1757-60. 24. Rothberg RM, Kraft SG, Michalek SM. Systemic immunity after local antigenic stimulation of the lymphoid tissue of the gastrointestinal tract. J Immunol 1973; 111: 1906-13. 25. Swarbrick ET, Stokes CR, Soothill JF. Absorption of antigens after oral immunization and the simultaneous induction of specific systemic tolerance Gut 1979; 20: 121-25. 26. Annotation. Gut reaction to antigen. Lancet 1979; i: 763. 27. Hemmings WA. Gut reaction to antigen. Lancet 1979, ii: 874. 28. Tomasi TB. Oral tolerance-an overview. Transplantation 1980; 29: 353-56. 29. Varma RN, Murthy RGS, Boparai MS, Chanderkar NG. Measurement of tetanus immunity in army personnel. Ind J Med Res 1975; 63: 1204-08.
Fatal Cases
Infant 2-On April 20, 1980, a set of dizygotic male twins were born, and because of their low birth-weight, they were nursed in the NICU. They were 45 days old when the index baby was admitted. On June 7, a pustule which grew Staphylococcus aureus, developed
21. Baker
Fig. 1—Neonatat intensive care unit showing placement of and other infants.
index cast