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An explosive point-source measles outbreak in a highly vaccinated population
23 Infectious Diseases Newsletter 8(3) March 1989 infection--through underlying, noninfectious diseases and therapies directed at ameliorating these diseases--to the very locations where antimicrobic-resistant microorganisms predominate. Differences in nosocomial infections according to surgical or medical care include twice higher incidence and more frequent causation by Enterococcus spp., antimicrobicresistant Enterobacteriaceae, Pseudomonas aeruginosa, and Candida albicans in the former. It appears that more frequent use of invasive devices by surgeons is an important factor, possibly aided by more intense pressure from frequent use of multiple antibacterial antimicrobics. Preventive strategies include vigilant practice of hygiene--especially hand-washing by personnel. Intensive topical decontamination of patients is under study; apparently effective, it is an approach that remains to be proved cost-effective and safe. Use of matedais that are inimical to colonization by microorganisms for the construction of invasive devices has not been fully explored. Better diagnostic tests for early warning of complicating infections, more thoughtful use of antimicrobics, and education in infection control are desirable.
Comment This article is a thoughtful and thorough overview of the present state and the future directions of infection control in intensive care units. PDH []
Chen RT, Goldbaum GM, Wassilak GF, et al: An explosive point-source measles outbreak in a highly vaccinated population. Am J Epidemiol 129:173-182, 1989. A 16-year-old female 10th grade student attended classes despite having cough, rhinorrhea, conjunctivitis, and sore throat on April 12, a Friday.
Her cough was hacking, and she had a skin rash on April 15, the following Monday, when she again attended classes. She traveled to and from school on city buses. A clinical diagnosis of measles was made on April 16 and was confirmed by serological testing. A total of 69 secondary cases occurred, all in one generation. By interview of 58 of these patients, 11 recalled exposure to the index case; through epidemic modeling, 22% to 65% of the secondary cases probably had at least one person-to-person contact with the index case. Of the 1,873 students in the school, 99.7% were vaccinated against measles, according to the school records. The authors concluded that the number of secondary cases and the single-generation aspect of the outbreak suggested that airborne transmission as well as person-to-person transmission occurred; it was held possible that the school records of vaccination may have been in error and that immunity may have waned in persons vaccinated at a young age.
Comment Person-to-person spread of measles has been thought to require either actual contact or proximity ~<1 meter (the range of large droplets of respiratory tract secretions bearing measles virus). However, it has been suggested, and the outbreak described by Chen et al appears to be conf'Lrrnatory, that airborne droplet nuclei might also serve to transmit measles. If the recorded figure for vaccination is accepted, 0.3% of 1,872 students, i.e., five to six students, would have been susceptible through lack of vaccination. The fact that 69 secondary cases occurred asserts that solid immunity was not achieved in all putative recipients of measles vaccine. However, the apparent lack of tertiary cases asserts that, for the most part, immunity was solid. The secondary cases tended to occur in students vaccinated at ages 12 to 14 months--an important consideration © 1989 Elsevier Science Publishing Co., Inc. 0278-2316/89/$0.00 + 2.20
because it is known that measles vaccination at or before the child's first birthday may not provoke immunity. PDH []
Westblom TU, Belshe RB: Clindamycin therapy of cerebral toxoplasmosis in an AIDS patient. Scand J Infect Dis 20:561-563, 1988. Because of skin rash, treatment of biopsy proven cerebral (vicinal to the left internal capsule) toxoplasmosis with pyrimethamine plus sulfadiazine was abandoned in a 47-year-old homosexual man with acquired immunodeficiency syndrome. The rash was maculopapular and had advanced to cover >90% of the body. It was assumed that the rash was caused by the sulfadiazine, the treatment was continued using pyrimethamine plus clindamycin. Clinical improvement after 3 weeks was supported by demonstration of decreased density of the lesion with loss of midline shift (CT scan). Follow-up CT 3 months after completion of 37 days of treatment showed resolution of the cerebral mass. Several months later, the patient died of sepsis; nodules were found in the brain that contained cyst forms of
Toxoplasma gondii. Comment The good effect of clindamycin on cerebral toxoplasmosis reported by Westblom and Belshe is unexpected in view of the failure of entry of the drug into the central nervous system even in the presence of inflammation. Moreover, in tissue culture systems, clindamycin is not active against T. gondii, whereas in experimental animals infected by intraperitoneal inoculation, the drug prevents death. Perhaps a metabolite of clindamycin is actively antitoxoplasmal (in humans, about 85% of a dose is metabolized) and also enters the central nervous system. PDH
Comment This article is a thoughtful and thorough overview of the present state and the future directions of infection control in intensive care units. PDH []
Chen RT, Goldbaum GM, Wassilak GF, et al: An explosive point-source measles outbreak in a highly vaccinated population. Am J Epidemiol 129:173-182, 1989. A 16-year-old female 10th grade student attended classes despite having cough, rhinorrhea, conjunctivitis, and sore throat on April 12, a Friday.
Her cough was hacking, and she had a skin rash on April 15, the following Monday, when she again attended classes. She traveled to and from school on city buses. A clinical diagnosis of measles was made on April 16 and was confirmed by serological testing. A total of 69 secondary cases occurred, all in one generation. By interview of 58 of these patients, 11 recalled exposure to the index case; through epidemic modeling, 22% to 65% of the secondary cases probably had at least one person-to-person contact with the index case. Of the 1,873 students in the school, 99.7% were vaccinated against measles, according to the school records. The authors concluded that the number of secondary cases and the single-generation aspect of the outbreak suggested that airborne transmission as well as person-to-person transmission occurred; it was held possible that the school records of vaccination may have been in error and that immunity may have waned in persons vaccinated at a young age.
Comment Person-to-person spread of measles has been thought to require either actual contact or proximity ~<1 meter (the range of large droplets of respiratory tract secretions bearing measles virus). However, it has been suggested, and the outbreak described by Chen et al appears to be conf'Lrrnatory, that airborne droplet nuclei might also serve to transmit measles. If the recorded figure for vaccination is accepted, 0.3% of 1,872 students, i.e., five to six students, would have been susceptible through lack of vaccination. The fact that 69 secondary cases occurred asserts that solid immunity was not achieved in all putative recipients of measles vaccine. However, the apparent lack of tertiary cases asserts that, for the most part, immunity was solid. The secondary cases tended to occur in students vaccinated at ages 12 to 14 months--an important consideration © 1989 Elsevier Science Publishing Co., Inc. 0278-2316/89/$0.00 + 2.20
because it is known that measles vaccination at or before the child's first birthday may not provoke immunity. PDH []
Westblom TU, Belshe RB: Clindamycin therapy of cerebral toxoplasmosis in an AIDS patient. Scand J Infect Dis 20:561-563, 1988. Because of skin rash, treatment of biopsy proven cerebral (vicinal to the left internal capsule) toxoplasmosis with pyrimethamine plus sulfadiazine was abandoned in a 47-year-old homosexual man with acquired immunodeficiency syndrome. The rash was maculopapular and had advanced to cover >90% of the body. It was assumed that the rash was caused by the sulfadiazine, the treatment was continued using pyrimethamine plus clindamycin. Clinical improvement after 3 weeks was supported by demonstration of decreased density of the lesion with loss of midline shift (CT scan). Follow-up CT 3 months after completion of 37 days of treatment showed resolution of the cerebral mass. Several months later, the patient died of sepsis; nodules were found in the brain that contained cyst forms of
Toxoplasma gondii. Comment The good effect of clindamycin on cerebral toxoplasmosis reported by Westblom and Belshe is unexpected in view of the failure of entry of the drug into the central nervous system even in the presence of inflammation. Moreover, in tissue culture systems, clindamycin is not active against T. gondii, whereas in experimental animals infected by intraperitoneal inoculation, the drug prevents death. Perhaps a metabolite of clindamycin is actively antitoxoplasmal (in humans, about 85% of a dose is metabolized) and also enters the central nervous system. PDH