Epidemiology of bacterial meningitis among children in Brazil, 1997-1998.

OBJECTIVE: To document the incidence and the descriptive epidemiology of bacterial meningitis among individuals under age 20 in a geographically defined region in Brazil during the two-year period immediately preceding the introduction of Haemophilus influenzae type b (Hib) vaccines into the national immunization program of Brazil. METHODS: Population-based epidemiological study of all cases of bacterial meningitis reported among residents of Campinas, Brazil, under age 20 (n=316,570) during the period of 1997-98, using comprehensive surveillance records compiled by the Campinas Health Department from cases reported among hospital inpatients, outpatients, emergency room visits, death certificates, and autopsy reports. RESULTS: The incidence of bacterial meningitis (n=274) was 334.9, 115 and 43.5 cases/10(5) person-years (pys) for residents of Campinas under age 1, 5 and 20, respectively. All cases were hospitalized, with an average length of stay of 12 days. Documented prior antibiotic use was 4.0%. The case-fatality rate of bacterial meningitis in individuals under age 20 was 9% (24/274) with 75% of deaths occurring in children under the age of five. The incidence of Hib meningitis (n=26) was 62.8 and 17 cases/10(5) pys in children age <1 and <5, respectively. CONCLUSIONS: The incidence of Hib meningitis in children under the age of 5 in Campinas during 1997-98 was similar to that reported in the US, Western Europe, and Israel prior to widespread Hib vaccine use in those regions. This study provides a baseline for later studies to evaluate changes in the etiology and incidence of bacterial meningitis in children after introduction of routine Hib vaccination in Brazil.

Human immunodeficiency virus infection in Mexico City. Rectal bleeding and anal warts as risk factors among men reporting sex with men.

The objectives of this study were to evaluate the frequency and determinants of rectal bleeding and the association between rectal bleeding and risk of human immunodeficiency virus (HIV) infection among homosexual/ bisexual men in Mexico City. Men who requested anonymous HIV testing at a public clinic in Mexico City and who reported engaging in any homosexual behavior were eligible to participate in this study. Trained staff collected information on demographic factors, sexual behavior, psychological states, and HIV serostatus from all consenting, eligible clients. Logistic regression modeling was used to investigate the independent effect of risk factors among 2,758 men who were tested between June 1991 and December 1992. Bleeding during anal intercourse was a common occurrence: More than one third of the men in the study reported some bleeding, and 8% reported bleeding in half or more of their intercourse episodes. The prevalence of HIV infection among bleeders was 42% as compared with 28% in nonbleeders (p < 0.0001), and the adjusted odds ratio was 1.8 (95% confidence interval (CI) 1.1-2.8) for men who bled in more than half of their anal intercourse episodes relative to nonbleeders. There was a trend of increasing HIV seroprevalence with increasing frequency of rectal bleeding (p = 0.001). Nine percent of all HIV infections and 42% of infections among frequent bleeders were attributable to rectal bleeding. Men who reported both rectal bleeding and anal warts were 3.5 (95% CI 2.1-5.8) times more likely to be HIV-infected in multivariate analysis than men reporting neither rectal bleeding nor anal warts. Determinants of rectal bleeding included older age, more education, more receptive anal intercourse than insertive intercourse, receptive digital-anal contact, anal warts, and genital ulcers. Among men reporting sex with men in Mexico City, rectal bleeding is common. It is an independent risk factor for HIV infection, and warrants attention in acquired immunodeficiency syndrome prevention efforts. Rectal bleeding that results from rupture of anal warts may be an especially effective portal of HIV transmission.

PIP: During June 1991 to December 1992, 68.8% of all men who gave informed consent for HIV testing at a public health clinic in Mexico City and for participation in this study had ever had sexual intercourse with men. The final sample size was 2758 men. The study examined the reported frequency of rectal bleeding, the determinants of rectal bleeding, and the interactions between rectal bleeding and other risk factors with HIV infection among homosexual/bisexual men. It also aimed to determine whether rectal bleeding is an independent risk factor for HIV transmission. 32.8% had HIV infection. 39% reported some rectal bleeding during anal intercourse. 8% experienced rectal bleeding during at least 50% of intercourse episodes. Overall, bleeders were more likely to be HIV infected than nonbleeders (42% vs. 28%; p 0.0001; adjusted odds ratio [AOR] = 1.8 for men who bled in more than 50% of anal intercourse episodes; AOR = 1.3 for men who sometimes bled). The odds ratios increased as the frequency of reported rectal bleeding increased (p = 0.001). Condom use during receptive anal intercourse did not affect the association between rectal bleeding and HIV infection. 9% of all HIV infections were attributable to rectal bleeding. 42% of HIV infections among bleeders were attributable to rectal bleeding. In the multivariate analysis, men with both rectal bleeding and anal warts were more likely to have HIV infection than men who had neither (67.9% vs. 27.2%; AOR = 3.5). Significant predictors of rectal bleeding were older age (i.e., =or 30) (AOR = 1.5), more education (AOR = 1.4-1.5), more receptive anal intercourse than insertive intercourse (AOR = 5.3-16.1), receptive digital-anal contact (AOR = 1.6), anal warts (AOR = 1.9), and genital ulcers (AOR = 2). These findings show that rectal bleeding is an independent risk factor for HIV infection. Rupture of anal warts is an especially effective portal of HIV transmission.