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SKIN INFECTION AND THE KIDNEY
390
monitor animal colonies and stocks to see which organisms they are carrying, and animal users know only too well that the animals they buy are not always as free of disease as they are supposed to be. Many of the more important diseases of animals are due to viruses and, with the exception of the mouse pox virus and the rabbit myxoma virus, animals are not screened for pathogenic viruses under the L.A.C. accreditation scheme. According to the survey, over half of the 5 to 6 million animals used during 1972 were mice, more than a quarter were rats, guineapigs, rabbits, or hamsters, and about a sixth were chickens, embryonated eggs, frogs, or fish. The total numbers of monkeys, cats, and dogs used were around 7000,11,000, and 12,000, respectively. Undoubtedly the most disturbing finding in the survey was that 24% of the cats and 30% of the dogs were not bred specially for research but were purchased from animal dealers not included in the accreditation or recognition schemes operated by the L.A.C. The mixed and uncertain origins and health status of such animals render them unsuitable for many forms of research, and the near certainty that some of them have been obtained dishonestly by the dealers who sell them suggests that it is high time such trading was made illegal.
SKIN INFECTION AND THE KIDNEY
As a complication of streptococcal infection, acute glomerulonephritis, in contrast to rheumatic fever, still arises in epidemic form. Epidemics of up to a thousand clinical cases (and equal numbers of subclinical ones) crop up in hot places such as Trinidad, Israel, and the Southern United States, and they follow skin infection rather than tonsillitis. Glomeruloan is disorder and both immune-complex nephritis clinical and subclinical cases are characterised by low serum-complement (&bgr;1C) concentrations. The kidney is affected soon after the pyoderma, so the causal bacteria can often be isolated and typed. Streptococci of Lancefield group A, types Ml and 12-the original " " strains-are rarely encountered nephritogenic but the advent of more potent and specific today, antisera has led to definition of several new serotypes; such as M49, 55, 57, and 60, and has facilitated epidemiological surveys. Pyoderma is common among children in large families of low socioeconomic status. The sexes are affected equally until the age of 6, but thereafter there is an excess in boys, particularly striking in Israel,l which suggests that minor trauma (such as thorns in fields) and close contact (fighting) predispose to it; so does the occurrence of lesions among soldiers in the jungle.2 Heat, humidity, arthropod bites, and crowded living conditions are all important epidemiological factors. Prospective investigations in the Red Lake Indian reservation, in Trinidad, in Lasch, E. E., Frankel, V., Vardy, P. A., Bergner-Rabinowitz, S., Ofek, K., Rabinowitz, K. J. infect. Dis. 1971, 124, 141. 2. Taplin, D., Lansdell, L., Allen, A. M., Rodriguez, R., Cortes, A. Lancet, 1973, i, 501. 3. Dillon, H. C. in Streptococci and Streptococcal Diseases (edited by L. W. Wannamaker and J. W. Matsen); p. 571. New York, 1.
1972.
Alabama, and in Columbia showed that streptococci the commonest bacteria in the lesions, often associated with staphylococci, while staphylococci alone were less frequent. The streptococci are from a defined number of serotypes, which includes the nephritogenic strains, and can pass from the skin to the respiratory tract but rarely go the other way. In fact, different strains can coexist in the skin lesions and throat. Viable bacteria have repeatedly been isolated from the unbroken skin, but their presence may reflect recurrent contamination rather than growth. Streptococci can be eliminated from lesions by systemic penicillin therapy, but this does not necessarily prevent kidney disease-indeed, half the Israeli glomerulonephritis patients had received some were
chemotherapy. of substantial outbreaks of gloareas, and the realisation that treatment of established skin lesions may not prevent the disease, have directed attention to prophylaxis of pyoderma. Two groups have looked at this problem and both experimented with injections’of benzathine penicillin. Ferrieri, Dajani, and Wannamaker4 studied 78 children from eighteen families of Red Lake Indians. 11 children were allergic to penicillin and had no treatment; the remainder were divided by family into two groups and given penicillin or saline followed six weeks later by the alternative injection. The antibiotic protected against lesions for up to three weeks in the under-6s, who received 6 x 105 units, and for up to five weeks in the over-6s, who were given 12 x 106 units. Reinfections rapidly ensued, however, and the untreated children did not seem to benefit from the treatment of their siblings. Sharrett and his co-workers5 studied 135 children in seventeen families from poor villages in rural Trinidad. There was no piped water, the children went barelegged, and an abundance of mosquitoes ensured plenty of minor trauma. They compared the effects of washing with plain or hexachlorophane soap, and also of two injections of benzathine penicillin (1-2 x 106 units) or placebo a month apart. The occurrence of skin lesions was unaltered by any of these measures, although hexachlorophane reduced the numbers of streptococci present and penicillin eliminated these organisms altogether; recolonisation took place within six weeks. Thus neither investigation revealed more than a temporary control of streptococci, and in Trinidad, where perhaps the environment was the more hostile, skin lesions were not controlled. Eradication of skin streptococci from a community might be possible by repeated injections of benzathine penicillin in higher dosage, but penicillin allergy and antipathy to multiple jabs would present problems. Furthermore, even if the human reservoir were eliminated, there must be a substantial loading of the environment with dried streptococci, and the role of this secondary reservoir in the ultimate recolonisation of traumatic lesions remains to be defined. Although short-term or individual protection from glomerulonephritis could be achieved, The
recurrence
merulonephritis in well-defined
mass 4. 5.
prophylaxis
seems
sadly impracticable.
Ferrieri, P., Dajani, A. S., Wannamaker, L. W. J. infect. Dis. 1974, 129, 429. Sharrett, A. R., Finklea, J. F., Potter, E. V., Poon-King, T., Earle, D. E. Am. J. Epidemiol. 1974, 99, 408.
monitor animal colonies and stocks to see which organisms they are carrying, and animal users know only too well that the animals they buy are not always as free of disease as they are supposed to be. Many of the more important diseases of animals are due to viruses and, with the exception of the mouse pox virus and the rabbit myxoma virus, animals are not screened for pathogenic viruses under the L.A.C. accreditation scheme. According to the survey, over half of the 5 to 6 million animals used during 1972 were mice, more than a quarter were rats, guineapigs, rabbits, or hamsters, and about a sixth were chickens, embryonated eggs, frogs, or fish. The total numbers of monkeys, cats, and dogs used were around 7000,11,000, and 12,000, respectively. Undoubtedly the most disturbing finding in the survey was that 24% of the cats and 30% of the dogs were not bred specially for research but were purchased from animal dealers not included in the accreditation or recognition schemes operated by the L.A.C. The mixed and uncertain origins and health status of such animals render them unsuitable for many forms of research, and the near certainty that some of them have been obtained dishonestly by the dealers who sell them suggests that it is high time such trading was made illegal.
SKIN INFECTION AND THE KIDNEY
As a complication of streptococcal infection, acute glomerulonephritis, in contrast to rheumatic fever, still arises in epidemic form. Epidemics of up to a thousand clinical cases (and equal numbers of subclinical ones) crop up in hot places such as Trinidad, Israel, and the Southern United States, and they follow skin infection rather than tonsillitis. Glomeruloan is disorder and both immune-complex nephritis clinical and subclinical cases are characterised by low serum-complement (&bgr;1C) concentrations. The kidney is affected soon after the pyoderma, so the causal bacteria can often be isolated and typed. Streptococci of Lancefield group A, types Ml and 12-the original " " strains-are rarely encountered nephritogenic but the advent of more potent and specific today, antisera has led to definition of several new serotypes; such as M49, 55, 57, and 60, and has facilitated epidemiological surveys. Pyoderma is common among children in large families of low socioeconomic status. The sexes are affected equally until the age of 6, but thereafter there is an excess in boys, particularly striking in Israel,l which suggests that minor trauma (such as thorns in fields) and close contact (fighting) predispose to it; so does the occurrence of lesions among soldiers in the jungle.2 Heat, humidity, arthropod bites, and crowded living conditions are all important epidemiological factors. Prospective investigations in the Red Lake Indian reservation, in Trinidad, in Lasch, E. E., Frankel, V., Vardy, P. A., Bergner-Rabinowitz, S., Ofek, K., Rabinowitz, K. J. infect. Dis. 1971, 124, 141. 2. Taplin, D., Lansdell, L., Allen, A. M., Rodriguez, R., Cortes, A. Lancet, 1973, i, 501. 3. Dillon, H. C. in Streptococci and Streptococcal Diseases (edited by L. W. Wannamaker and J. W. Matsen); p. 571. New York, 1.
1972.
Alabama, and in Columbia showed that streptococci the commonest bacteria in the lesions, often associated with staphylococci, while staphylococci alone were less frequent. The streptococci are from a defined number of serotypes, which includes the nephritogenic strains, and can pass from the skin to the respiratory tract but rarely go the other way. In fact, different strains can coexist in the skin lesions and throat. Viable bacteria have repeatedly been isolated from the unbroken skin, but their presence may reflect recurrent contamination rather than growth. Streptococci can be eliminated from lesions by systemic penicillin therapy, but this does not necessarily prevent kidney disease-indeed, half the Israeli glomerulonephritis patients had received some were
chemotherapy. of substantial outbreaks of gloareas, and the realisation that treatment of established skin lesions may not prevent the disease, have directed attention to prophylaxis of pyoderma. Two groups have looked at this problem and both experimented with injections’of benzathine penicillin. Ferrieri, Dajani, and Wannamaker4 studied 78 children from eighteen families of Red Lake Indians. 11 children were allergic to penicillin and had no treatment; the remainder were divided by family into two groups and given penicillin or saline followed six weeks later by the alternative injection. The antibiotic protected against lesions for up to three weeks in the under-6s, who received 6 x 105 units, and for up to five weeks in the over-6s, who were given 12 x 106 units. Reinfections rapidly ensued, however, and the untreated children did not seem to benefit from the treatment of their siblings. Sharrett and his co-workers5 studied 135 children in seventeen families from poor villages in rural Trinidad. There was no piped water, the children went barelegged, and an abundance of mosquitoes ensured plenty of minor trauma. They compared the effects of washing with plain or hexachlorophane soap, and also of two injections of benzathine penicillin (1-2 x 106 units) or placebo a month apart. The occurrence of skin lesions was unaltered by any of these measures, although hexachlorophane reduced the numbers of streptococci present and penicillin eliminated these organisms altogether; recolonisation took place within six weeks. Thus neither investigation revealed more than a temporary control of streptococci, and in Trinidad, where perhaps the environment was the more hostile, skin lesions were not controlled. Eradication of skin streptococci from a community might be possible by repeated injections of benzathine penicillin in higher dosage, but penicillin allergy and antipathy to multiple jabs would present problems. Furthermore, even if the human reservoir were eliminated, there must be a substantial loading of the environment with dried streptococci, and the role of this secondary reservoir in the ultimate recolonisation of traumatic lesions remains to be defined. Although short-term or individual protection from glomerulonephritis could be achieved, The
recurrence
merulonephritis in well-defined
mass 4. 5.
prophylaxis
seems
sadly impracticable.
Ferrieri, P., Dajani, A. S., Wannamaker, L. W. J. infect. Dis. 1974, 129, 429. Sharrett, A. R., Finklea, J. F., Potter, E. V., Poon-King, T., Earle, D. E. Am. J. Epidemiol. 1974, 99, 408.