Circumcision and infectious diseases

To The Editors:

The two recent articles on circumcision might, at first glance, be seen as factual yet opposing representations of circumcision. Nothing could be further from the truth. Weiss[1] enthusiastically promotes circumcision sometimes based on scant evidence, whereas Van Howe[2] in his "factual refutation" severely distorts evidence, even going so far as to misrepresent some of his references. As Weiss' article has already been thoroughly criticized by Van Howe, with varying degrees of validity, this letter analyzes Van Howe's article.

Van Howe takes exception to Weiss's calling the preputial cavity a "cesspool" and instead speaks of it as being "self-cleaning." He ignores an enormous body of evidence. Wiswell et al.[3] found the periurethral area to contain from 20 530 to 130 000 aerobic bacterial colonies in healthy uncircumcised male infants compared with only 540 to 13 150 in circumcised males. Furthermore uropathogens, including Escherichia coli, were present significantly more often in the uncircumcisedvs. the circumcised. Proteus mirabilis is a frequent cause of urinary tract infections in boys[4]; among 184 boys 6 weeks to 14 years old, Glennon et al.[5] found its presence in 22.6% of healthy uncircumcised boys but in only 1.7% of circumcised boys. Where hygiene is incomplete or where phimosis prevents hygiene, the preputial cavity does indeed accumulate smegma and other substances, more than Van Howe would admit. In what is likely the largest study of its kind, a study of 3000 German young men mostly between 18 and 22 years old, Schoberlein[6] found smegma in 19.2% including one-third with a "large amount." Phimosis, defined by Schoberlein as a prepuce that is rigid (unretractable) or retractable only with difficulty, was reported in 8.8% of the sample population. Furthermore salts found in urine combine with smegma to form preputial calculi which, in a phimotic prepuce, can grow quite large and painful.[7]

Regarding the experimental production of cancer tumors by smegma, Van Howe uses selection bias. In addition to the studies of Plaut and Kohn-Speyer[8] cited by Weiss, Pratt-Thomas et al.[9] were also able to produce cancer, the latter study using human smegma. The fact that others were unable to produce cancerous tumors may possibly relate to insufficient time exposure; invasive penile cancer is rare in humans (occurring mainly in older age) and the longevity of mice is not as great as for humans.

Van Howe's most serious distortions involves the sexually transmitted disease and HIV evidence. Van Howe claims that the studies of Donovan, Laumann and Urassa et al. support an increased incidence of sexually transmitted diseases in circumcised men. This is absolutely false. Donovan et al.[10] found that no sexually transmitted disease were more common to a statistically significant degree in circumcised men. Laumann et al.[11] state "We find no significant differences between circumcised and uncircumcised men in their likelihood of contracting sexually transmitted diseases." After adjusting for confounding factors Urassa et al.[12] found the same.

Van Howe claims "large random cross-sectional studies which have the least degree of bias have found that circumcised men are more likely to develop or transmit HIV infection." Van Howe makes another false statement concerning his references. Urassa et al.[12] reported the complete opposite:"After controlling for confounding variables, however, there was a modest but significant reduction of the HIV prevalence among circumcised men... Male circumcision has a protective effect against HIV infection in this population." In all but one of Van Howe's remaining references, after any adjustments were made, there was no statistically significant association between HIV and circumcision.[13-15] In the study by Chao et al.[16] insufficient control of confounding variables was exercised, "few partners in our study were circumcised (6%) and they may constitute a population with high-risk sexual behaviour. It is also likely that some men were circumcised as a result of treatment for venereal disease. However we did not collect data on the reason for or age at circumcision." Inexplicably Van Howe fails to mention that the preponderance of studies support the increased risk of HIV among uncircumcised men. The Canadian/African team of Moses et al.[17] extensively reviewed the findings and reported that 27 of 33 studies demonstrated that male circumcision reduces the risk of HIV infection.

Many other distortions exist in Van Howe's article, especially on urinary tract infections where again he turns reality upside down, but space considerations preclude further discussion. Distortions and misrepresentations are to be expected in anti-circumcision propaganda on the Internet; however, such deceptive tactics have no place in a scientific journal article.

References

1. Weiss GN. Prophylactic neonatal surgery and infectious diseases. Pediatr Infect Dis J 1997;16:727-34.
2. Van Howe RS. Circumcision and infectious diseases revisited. Pediatr Infect Dis J 1998;17:1-6.
3. Wiswell TE, Miller GM, Gelston HM, Jones SK, Clemmings AF. Effect of circumcision status on periurethral bacterial flora during the first year of life. J Pediatr 1988;13:442-6.
4. Hallett RJ, Peade L, Maskell R. Urinary infection in boys. Lancet 1976;21107-10.
5. Glennon J, Ryan PJ, Keane CT, Rees JPR. Circumcision and periurethral carriage of Proteus mirabilis in boys. Arch Dis Child 1988;63:556-7.
6. Schoberlein W. Bedeutung und haufigkeit von phimose und smegma. (Significance and incidence of phimosis and smegma). Munch Med Wochenschr 1966;7:373-7.
7. Sharma SK, Bapna BC. Preputial calculi. Int Surg 1977;62:553-4.
8. Plaut A, Kohn-Speyer AC. The carcinogenic action of smegma. Science 1947;105:391-2.
9. Pratt-Thomas HR, Heins HC, Latham E, Dennis EJ, McIver FA. The carcinogenic effect of human smegma: an experimental study. Cancer 1956;9:671-80.
10. Donovan B, Bassett I, Bodsworth NJ. Male circumcision and common sexually transmissible diseases in a developed nation setting. Genitourin Med 1994;70:317-20.
11. Laumann EO, Masi CM, Zuckerman MA. Circumcision in the United States: prevalence, prophylactic effects, and sexual practice. JAMA 1997;277:1052-7.
12. Urassa M, Todd J, Boerma JT, Hayes R, Isingo R. Male circumcision and susceptibility to HIV infection among men in Tanzania. AIDS 1997;11:73-80.
13. Grosskurth H, Mosha F, Todd J, et al. A community trial of the impact of improved sexually transmitted disease treatment on the HIV epidemic in rural Tanzania: 2. Baseline survey results. AIDS 1995;9:927-34.
14. Barongo LR, Borgdorff MW, Mosha FF, et al. The epidemiology of HIV-1 infection in urban areas, roadside settlements and rural villages in Mwanza Region, Tanzania. AIDS 1992;6:1521-8.
15. Van de Perre P, Carael M, NzVanaramba D, Zissis G, Kayihigi J, Butzler JP. Risk factors for HIV seropositivity in selected urgan-based Rwandese adults. AIDS 1987;1:207-11.
16. Chao A, Bulterys M, Musanganire F, et al. Risk factors associated with prevalent HIV-1 infection among pregnant women in Rwanda. Int J Epidemiol 1994;23:371-80.
17. Moses S, Plummer FA, Bradley JE, Ndinya-Achola, Nagelkerke NJD, Ronald AR. Association between lack of male circumcision and risk for HIV infection: review of the epidemiological evidence [Abstract We. C.452]. Presented at the Eleventh International Conference on AIDS, Vancouver, Canada, July 7 to 12, 1996.