Vasectomy and prostate cancer

WHO News and activities (Austria, Bulgaria, Czechoslovakia, Hungary, Poland, Romania, Yugoslavia) and Greece. The outbreaks waned in February, and by March influenza was sporadic. In eight countries which provided information on age distribution there was a predominance of cases among pre-school and schoolchildren, adoles- cents and young adults. About half of all cases noti- fied in Hungary and Poland were under 15 years of age and at the peak of the epidemic in Czechoslova- kia, 6% of children under 15 years of age were affec- ted. High absenteeism was noted in schools; Hunga- ry reported absenteeism rates reaching 70% in some classes, and Sweden, 50%. Influenza A (H3N2) predominated initially in all countries but in Belgium influenza A (HINI) viruses soon became commoner than the H3N2 subtype. Influenza A (HINI) viruses were also associated with local outbreaks and sporadic cases in other European countries, particularly towards the end of the season. Only sporadic cases of influenza B were reported in the 1991-92 influenza season in Europe. Oceania Influenza activity was reported in Australia, Fiji, New Zealand and Papua New Guinea during the 1991-92 season. Only New Zealand reported wide- spread activity. Fiji experienced an outbreak from February to April, whereas Australia and Papua New Guinea reported the presence of influenza viruses almost every month in 1992, in general, in sporadic cases. Influenza A (H3N2) viruses were found in Australia and Fiji, whereas the major influenza type during the epidemic in New Zealand was influ- enza A (HINI). Diagnosis of intestinal helminths A set of four bench aids for the diagnosis of intesti- nal helminths has been prepared by the WHO Pro- gramme of Intestinal Parasitic Infections. These are intended both as a guide for laboratory and field workers in endemic countries and as a teaching aid for students and trainees. The bench aids are in A4 size and have been produced in a robust, waterproof, plastic sealed cover. On the front are large, coloured photomicrographs of the diagnostic stages of the most common intestinal parasites including nema- todes, cestodes, schistosomes and other trematodes. Some of the diagnostic stages are also presented as they appear in the Kato-Katz preparations. A short explanatory legend is added to each of the 36 figures. On the reverse, the three recommended diagnostic techniques are explained in detail and a synoptic table with the size of the different eggs is included. Single copies of the bench aids will be distributed free of charge on request, with priority to health institutions in developing countries. Requests should be addressed to: Programme of Intestinal Parasitic Infections, Division of Communi- cable Diseases, World Health Organization, 1211 Geneva 27, Switzerland. Vasectomy and prostate cancer It has been estimated that about 42 million couples rely on vasectomy as their method of family plan- ning. WHO and other agencies have consistently monitored the safety of this method and of other contraceptive methods. Studies in the 1980s and 1990s have indicated that the procedure is safe. However, epidemiological investigations conducted in the USA in 1990 suggested a possible increase in the risk of prostate cancer a long time after vasec- tomy. In 1991 a WHO consultation concluded that no such causal relationship existed, that there was no known biological mechanism to suggest such a relationship, and that no change in family planning policy regarding vasectomy was warranted.c Two recently published U.S. studies have again suggest- ed an increased risk of prostate cancer (1.6 times) following vasectomy, with a relative risk of about 1.9 among men vasectomized at least 20 years pre- viously.d,e These studies and others as yet un- published were reviewed at a National Institutes of Health (NIH) meeting, with WHO participation, on 1-2 March 1993. It was concluded that, because the results of current research on vasectomy and prostate cancer are inconsistent, and the associations that have been found are weak, there is insufficient basis for recommending a change in clinical and public health practice. In particular, in countries where prostate cancer is rare, the relationship observed in the USA, even if real, would be of little significance to individual or public health. Family planning pro- viders should continue to offer vasectomy and per- form the procedure. A detailed discussion of the issue will appear in the next issue of the Bulletin. c Vasectomy and cancer. Lancet, 338: 1586 (1991). d Giovannucci, E. et al. A prospective cohort study of vasecto- my and prostate cancer in U.S. men. Journal of the American Medical Association, 269: 873-877 (1993). e Giovannucci, E. et al. A retrospective cohort study of vasecto- my and prostate cancer in U.S. men. Journal of the American Medical Association, 269: 878-882 (1993). 262 WHO Bulletin OMS. Vol 71 1993 Notes et activit6s OMS Oceanie Une activite grippale a et6 signalee en Australie, a Fidji, en Nouvelle-Zelande et en Papouasie-Nouvelle- Guinee pendant la saison 1991-1992. Seule la Nouvelle-Zalande a notifei une activite tres repan- due. Fidji a connu une flambee de fevrier a avril, tan- dis que I'Australie et la Papouasie-Nouvelle-Guin6e signalaient la presence de virus grippaux presque tous les mois en 1992, s'agissant generalement de cas sporadiques. Des virus de la grippe A(H3N2) ont et6 depistes en Australie et 'a Fidji, tandis que le type grippal principal lors de 1'epidemie en Nouvelle-Zelande etait le type A(HIN1). Diagnostic des helminthiases Le programme OMS de lutte contre les parasitoses intestinales a mis au point un jeu de quatre planches pour le diagnostic des helminthiases, qui serviront de guide aux techniciens de laboratoire et aux agents de terrain qui travaillent dans les pays d'endemicite et d'auxiliaires pedagogiques aux etudiants et aux sta- giaires. Ces quatre planches sont de format A4 et sont plastifiees donc impermeables. Au recto figu- rent de grandes microphotographies en couleur des differents stades utilises pour le diagnostic des para- sitoses intestinales les plus courantes - nematodoses, cestodoses, schistosomiases et autres trdmatodoses. Certains stades tels qu'ils apparaissent selon la tech- nique de Kato-Katz sont egalement presentes. Une breve legende explicative accompagne chacune des 36 figures. Au verso, les trois techniques diagnos- tiques recommandees sont expliquees en detail et sont accompagnees d'un tableau synoptique donnant la taille des differents aeufs. Ces planches sont distri- buees gratuitement sur demande, la priorite allant aux etablissements de sante des pays en developpement. Les demandes doivent etre envoyees 'a l'adresse suivante: Programme de Lutte contre les Parasitoses intestinales, Division des Maladies transmissibles, Organisation mondiale de la Sante, 1211 Geneve 27, Suisse. Vasectomie et cancer de la prostate On estime a environ 42 millions le nombre de couples qui ont recours a la vasectomie comme moyen de planification familiale. L'OMS et d'autres organismes ont soumis cette methode a une sur- veillance continue pour s'assurer de son innocuite, comme ils l'ont fait pour d'autres methodes contra- ceptives. Des etudes menees dans les annees 80 et 90 ont montre que cette intervention etait sans danger. Neanmoins, des etudes epid6miologiques entreprises aux Etats-Unis d'Amerique en 1991 semblaient indi- quer une faible augmentation du risque a long terme de cancer de la prostate apres vasectomie. En 1991, une consultation OMS a conclu qu'il n'existait aucun lien de causalit6 entre les deux, qu'aucun mecanisme biologique connu ne suggerait un tel lien, et que par consequent, aucun changement de politique en ce qui conceme la vasectomie n'etait justifie.c Deux etudes americaines parues recemment evoquent a nouveau un risque accru de cancer de la prostate (1,6 fois) apres vasectomie, avec un risque relatif d'environ 1,9 chez des hommes ayant subi une vasectomie 20 ans ou plus auparavant.de Les conclusions de ces etudes ainsi que d'autres a paralitre ont ete examinees lors d'une reunion des National Institutes of Health (NIH) avec la participation de 1'OMS (les ler et 2 mars 1993). I1 a ete conclu lors de cette reunion que, etant donne que les resultats des recherches sur la vasectomie et le cancer de la prostate menees actuel- lement ne concordent pas et que les associations observees sont faibles, il n'y a pas lieu pour l'instant de recommander des changements dans la pratique clinique et en sante publique. En particulier, dans les pays oui le cancer de la prostate est rare, le lien observe aux Etats-Unis, meme s'il se confirmait, aurait une importance minime au niveau des indivi- dus comme de la sante publique. Les services de pla- nification familiale doivent continuer a offrir et a pratiquer des vasectomies. La question fait l'objet d'une analyse detaillee dans un article a paraitre dans un prochain numero du Bulletin. c Vasectomy and cancer. Lancet, 338: 1586 (1991). d Glovannucci, E. et al. A prospective cohort study of vasecto- my and prostate cancer in U.S. men. Journal of the American Medical Association, 269: 873-877 (1993). e Glovannucci, E. et al. A retrospective cohort study of vasecto- my and prostate cancer in U.S. men. Journal of the American Medical Association, 269: 878-882 (1993). Notice necrologique Dr James Haworth Nous avons le regret d'annoncer le deces soudain du Dr James ("Jim") Haworth survenu le 5 octobre 1992. Il avait 72 ans. Ne a Lancaster, Jim Haworth fait ses etudes de medecine et de chirurgie 'a 'Universite d'Edimbourg oui il est diplome en 1942 et s'engage dans le Royal Army Medical Corps. Apres la guerre, il entre dans le service colonial et obtient un diplome de medecine et d'hygiene tropicale de l'Universite de Liverpool