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FASTIDIOUS ADENOVIRUSES
51 FASTIDIOUS ADENOVIRUSES
SIR,-In their studies of fastidious enteric adenoviruses, Dr Petric and his colleagues (May 8, p. 1074) tested, by electron microscopy, nasopharyngeal secretions and stools from gastroenteritis patients who shed adenovirus particles in stools and found two distinct patterns of adenovirus-specific fluorescence, based on the degree of spread of infection to adjacent cells in inoculated human amnion monolayers. One pattern (with little spread of fluorescence to adjacent cells) was attributed to the fastidious enteric adenoviruses, and complete absence of fluorescent foci from nasopharyngeal secretions of these patients was taken to suggest that "enteric adenoviruses are limited to the gastrointestinal tract alone". We are concerned about this interpretation. Firstly, it is possible that some of the adenoviruses in stool which gave rise to fluorescent foci with little spread were strains of common serotypes. Some of these viruses can take up to 4 weeks to establish themselves in cell culture, and might give the same apparently "abortive" fluorescence picture if the inoculated cultures were fixed too early. The fastidious adenovirus species can now be typed by neutralisation,l and we are surprised that Petric did not use his neutralising human serum2for this purpose. Even if the adenoviruses in stool giving the abortive pattern of fluorescence were members of the new species, they must be present in numbers of at least 106 particles/ml stool extract to be seen by electron microscopy.3We have seen the same abortive fluorescence picture using KB cells,4and the particle number to infectivity ratio (measured by electron and immunofluorescence, respectively) can be very high, with few fluorescent foci. It is difficult to see how a nasal wash could contain 106 particles/ml and so give a similar number of fluorescent foci as the corresponding stool. Therefore, fastidious adenoviruses might be present in respiratory secretions but not be detected by immunofluorescence. There is also a possibility that these viruses could elicit a strong secretory antibody response in the respiratory tract, which would prevent their detection by immunofluorescence. The fastidious adenoviruses are not only adenovirus species to be detected solely from the gastrointestinal tract. Some highernumbered adenovirus serotypes (species) have been isolated exclusively or almost exclusively from the faeces. We therefore suggest that "enteric" is too wide a term for the recently discovered fastidious adenoviruses, and look forward to their numerical designation. Until then, interpretations based on few data will be premature: they can only confuse the clinician, and misconceptions can be difficult to reverse. Department of Virology, University of the Witwatersrand, National Institute for Virology, Sandringham 2131, South Africa
A. H. KIDD B. D. SCHOUB
THYROID FOLLOW-UP REGISTERS
SIR,-The article by S. J. Jones and colleagues (May 29, p. 1229) to show that the cost of follow-up of patients registered
purports
with the Scottish Automated Thyroid Follow-up Register is less than that of a comparison group not so registered. This may well be so, but the article does not prove it. Apart from the marked disparity of the two groups, both geographically and in treatment, the means of estimating medical work are very different. In group 2 (patients on the automated registry) the general practitioners are asked for additional contacts with patients specifically for thyroid assessment, whereas in group 1 the questionnaire completed by the GP asks for an estimate from his records of the number of contacts for thyroid assessment, even though the contact may not be specifically for thyroid assessment. This could well account for the apparent difference in contact rates 1. Kidd AH,
Cosgrove BP, Brown RA, Madeley CR. Faecal adenoviruses from Glasgow babies: Studies on culture and identity. J Hyg (Camb) (in press). 2. Retter M, Middleton PJ, Tam JS, Petric M. Enteric adenoviruses: Detection, replication and significance. J Clin Microbiol 1979; 10: 574-78. 3. Madeley CR. Viruses in the stools. J Clin Pathol 1979; 32: 1-10. 4 Kidd AH, Madeley CR. In vitro growth of some fastidious adenoviruses from stool specimens. J Clin Pathol 1981, 34: 213-16.
between the two groups. If we are measuring medical workload the total number of contacts for each group should have been recorded. This would not make any allowance for differences in consulting rates between different areas, but at least would have been a more valid method than that used. We have been one of the practices participating in the Scottish Automated Thyroid Follow-up Register scheme, and feel that it is useful in that it ensures adequate follow-up. I think it highly unlikely, however, that it reduces the GP’s workload; the completion of the form, examination of the patient, and blood sampling take longer than the average GP consultation. In addition, with postal charges increasing and with more GPs having access to a laboratory van collection service, it may well be that the most costefficient service might be for each district biochemistry laboratory to maintain a computer file of patients who should have long-term ’
thyroid follow-up. 85
Mitngavte Road,
Bearsden,
GlasgowG612DN
K. A. HARDEN
SIR,-The paper by S. J. Jones and colleagues was of great interest we have recently completed a study in the South-East region of Scotland which is in many ways complementary. Because our audit of thyroid follow-up was designed to introduce a group of trainee general practitioners to the principles of research within the short space of a single academic year, our population of patients was small (125) and selected (women aged 50-59) and, of course, drawn whooly from training practices. Of the 125 patients 62 were on thyroxine and 63 were not and the 28 who had had 131therapy were directly comparable with those in the study Jones and colleagues describe. All 10 patients (8%) had "low T4" estimates and 3 of these were in the 28 1311-treated patients (11%), a figure closer to that for the automated follow-up patients than for the others in Weir’s report. We agree about the consequences of poor follow-up. 54 of our 125 patients (44%) were not being reviewed regularly and 8 of the low
because
T4 values were in this group-a 15% "failure" rate. On the other hand 71 patients of 125 (56%) were being regularly assessed either in hospital (27), through Scottish Automated Follow-up Register (4 only), or by their general practitioners (40), and all but 2 (3%) were properly controlled. Our conclusions overlap those of the Nottingham/Aberdeen workers. Patients with thyroid disease do need a positive system for adequate surveillance. The apparent morbidity in patients not properly followed up seems to be about 15%. But properly organised follow-up care, either in general practice or in hospital, does seem able to produce results as satisfactory as those achieved by the Scottish Automated Follow-up Registry. Department of General Practice, University of Edinburgh, 23 Chalmers Street, Edinburgh EH3 9REW
J. G. R. HOWIE A. J. M. BUTT
KAPOSI SARCOMA IN HOMOSEXUAL MEN: IS IT A NEW DISEASE?
SiR,-Six Danish colleagues (May 1, p. 1027), raising the above question have, in support of the answer yes, pointed to an absence of misdiagnosed cases filed in the Danish Cancer Registry during 1963-77 for males aged 15-44. They assume, not without justification, that cases ofKaposi’s sarcoma, if misdiagnosed, might have been registered as sarcoma or as malignant lymphoma. However, in the absence of numbers for the cases correctly diagnosed and notified, the letter may be misinterpreted as implying that no such cases have been recorded at the registry since it began in 1942.
During the period when I was in charge, up to December, 1979, of Kaposi sarcoma were grouped under the designation "4: particular specification" as an alternative to the possibilities under the same digit as those mentioned, and under "site:skin".1 Forty
cases
J. Statistical studies in the etiology of malignant neoplasms Vol. I Acta Pathol Microbiol Scand 1965; suppl. 174: 42, 26.
1. Clemmesen
SIR,-In their studies of fastidious enteric adenoviruses, Dr Petric and his colleagues (May 8, p. 1074) tested, by electron microscopy, nasopharyngeal secretions and stools from gastroenteritis patients who shed adenovirus particles in stools and found two distinct patterns of adenovirus-specific fluorescence, based on the degree of spread of infection to adjacent cells in inoculated human amnion monolayers. One pattern (with little spread of fluorescence to adjacent cells) was attributed to the fastidious enteric adenoviruses, and complete absence of fluorescent foci from nasopharyngeal secretions of these patients was taken to suggest that "enteric adenoviruses are limited to the gastrointestinal tract alone". We are concerned about this interpretation. Firstly, it is possible that some of the adenoviruses in stool which gave rise to fluorescent foci with little spread were strains of common serotypes. Some of these viruses can take up to 4 weeks to establish themselves in cell culture, and might give the same apparently "abortive" fluorescence picture if the inoculated cultures were fixed too early. The fastidious adenovirus species can now be typed by neutralisation,l and we are surprised that Petric did not use his neutralising human serum2for this purpose. Even if the adenoviruses in stool giving the abortive pattern of fluorescence were members of the new species, they must be present in numbers of at least 106 particles/ml stool extract to be seen by electron microscopy.3We have seen the same abortive fluorescence picture using KB cells,4and the particle number to infectivity ratio (measured by electron and immunofluorescence, respectively) can be very high, with few fluorescent foci. It is difficult to see how a nasal wash could contain 106 particles/ml and so give a similar number of fluorescent foci as the corresponding stool. Therefore, fastidious adenoviruses might be present in respiratory secretions but not be detected by immunofluorescence. There is also a possibility that these viruses could elicit a strong secretory antibody response in the respiratory tract, which would prevent their detection by immunofluorescence. The fastidious adenoviruses are not only adenovirus species to be detected solely from the gastrointestinal tract. Some highernumbered adenovirus serotypes (species) have been isolated exclusively or almost exclusively from the faeces. We therefore suggest that "enteric" is too wide a term for the recently discovered fastidious adenoviruses, and look forward to their numerical designation. Until then, interpretations based on few data will be premature: they can only confuse the clinician, and misconceptions can be difficult to reverse. Department of Virology, University of the Witwatersrand, National Institute for Virology, Sandringham 2131, South Africa
A. H. KIDD B. D. SCHOUB
THYROID FOLLOW-UP REGISTERS
SIR,-The article by S. J. Jones and colleagues (May 29, p. 1229) to show that the cost of follow-up of patients registered
purports
with the Scottish Automated Thyroid Follow-up Register is less than that of a comparison group not so registered. This may well be so, but the article does not prove it. Apart from the marked disparity of the two groups, both geographically and in treatment, the means of estimating medical work are very different. In group 2 (patients on the automated registry) the general practitioners are asked for additional contacts with patients specifically for thyroid assessment, whereas in group 1 the questionnaire completed by the GP asks for an estimate from his records of the number of contacts for thyroid assessment, even though the contact may not be specifically for thyroid assessment. This could well account for the apparent difference in contact rates 1. Kidd AH,
Cosgrove BP, Brown RA, Madeley CR. Faecal adenoviruses from Glasgow babies: Studies on culture and identity. J Hyg (Camb) (in press). 2. Retter M, Middleton PJ, Tam JS, Petric M. Enteric adenoviruses: Detection, replication and significance. J Clin Microbiol 1979; 10: 574-78. 3. Madeley CR. Viruses in the stools. J Clin Pathol 1979; 32: 1-10. 4 Kidd AH, Madeley CR. In vitro growth of some fastidious adenoviruses from stool specimens. J Clin Pathol 1981, 34: 213-16.
between the two groups. If we are measuring medical workload the total number of contacts for each group should have been recorded. This would not make any allowance for differences in consulting rates between different areas, but at least would have been a more valid method than that used. We have been one of the practices participating in the Scottish Automated Thyroid Follow-up Register scheme, and feel that it is useful in that it ensures adequate follow-up. I think it highly unlikely, however, that it reduces the GP’s workload; the completion of the form, examination of the patient, and blood sampling take longer than the average GP consultation. In addition, with postal charges increasing and with more GPs having access to a laboratory van collection service, it may well be that the most costefficient service might be for each district biochemistry laboratory to maintain a computer file of patients who should have long-term ’
thyroid follow-up. 85
Mitngavte Road,
Bearsden,
GlasgowG612DN
K. A. HARDEN
SIR,-The paper by S. J. Jones and colleagues was of great interest we have recently completed a study in the South-East region of Scotland which is in many ways complementary. Because our audit of thyroid follow-up was designed to introduce a group of trainee general practitioners to the principles of research within the short space of a single academic year, our population of patients was small (125) and selected (women aged 50-59) and, of course, drawn whooly from training practices. Of the 125 patients 62 were on thyroxine and 63 were not and the 28 who had had 131therapy were directly comparable with those in the study Jones and colleagues describe. All 10 patients (8%) had "low T4" estimates and 3 of these were in the 28 1311-treated patients (11%), a figure closer to that for the automated follow-up patients than for the others in Weir’s report. We agree about the consequences of poor follow-up. 54 of our 125 patients (44%) were not being reviewed regularly and 8 of the low
because
T4 values were in this group-a 15% "failure" rate. On the other hand 71 patients of 125 (56%) were being regularly assessed either in hospital (27), through Scottish Automated Follow-up Register (4 only), or by their general practitioners (40), and all but 2 (3%) were properly controlled. Our conclusions overlap those of the Nottingham/Aberdeen workers. Patients with thyroid disease do need a positive system for adequate surveillance. The apparent morbidity in patients not properly followed up seems to be about 15%. But properly organised follow-up care, either in general practice or in hospital, does seem able to produce results as satisfactory as those achieved by the Scottish Automated Follow-up Registry. Department of General Practice, University of Edinburgh, 23 Chalmers Street, Edinburgh EH3 9REW
J. G. R. HOWIE A. J. M. BUTT
KAPOSI SARCOMA IN HOMOSEXUAL MEN: IS IT A NEW DISEASE?
SiR,-Six Danish colleagues (May 1, p. 1027), raising the above question have, in support of the answer yes, pointed to an absence of misdiagnosed cases filed in the Danish Cancer Registry during 1963-77 for males aged 15-44. They assume, not without justification, that cases ofKaposi’s sarcoma, if misdiagnosed, might have been registered as sarcoma or as malignant lymphoma. However, in the absence of numbers for the cases correctly diagnosed and notified, the letter may be misinterpreted as implying that no such cases have been recorded at the registry since it began in 1942.
During the period when I was in charge, up to December, 1979, of Kaposi sarcoma were grouped under the designation "4: particular specification" as an alternative to the possibilities under the same digit as those mentioned, and under "site:skin".1 Forty
cases
J. Statistical studies in the etiology of malignant neoplasms Vol. I Acta Pathol Microbiol Scand 1965; suppl. 174: 42, 26.
1. Clemmesen