GB virus C during the natural course of HIV-1 infection: viremia at diagnosis does not predict mortality.

OBJECTIVE: To investigate whether GBV-C viremia at diagnosis of HIV-1 infection predicts disease outcome in patients not receiving combination antiretroviral therapy (ART), and whether longitudinal changes in GBV-C viremia are associated with disease progression. DESIGN: Prospective cohort study. METHODS: 230 patients with a serum sample available for testing obtained within 2 years of HIV-1 diagnosis were followed until either initiation of ART, death, or their last visit to our clinic (median follow-up 4.3 years). Baseline and follow-up serum samples (available from 163 patients) were tested for GBV-C RNA and antibodies against GBV-C envelope E2 protein (anti-E2; signifying resolved GBV-C viremia). RESULTS: At inclusion, 62 patients (27%) had GBV-C viremia and 69 (30%) had anti-E2. Baseline GBV-C status was not associated with all-cause mortality (P = 0.12), HIV-related mortality (P = 0.18), or development of AIDS (P = 0.84). However, GBV-C RNA was less prevalent in patients with AIDS at inclusion (P = 0.008). Eleven of 44 patients with baseline GBV-C viremia lost GBV-C RNA during follow-up without showing anti-E2 seroconversion. In comparison with anti-E2-negative patients with either persistent absence, persistent presence, or acquisition of GBV-C viremia, these subjects had significantly increased all-cause mortality (P = 0.018), HIV-related mortality (P = 0.007), and AIDS incidence (P < 0.001). CONCLUSIONS: GBV-C status at diagnosis did not predict disease outcome in this HIV cohort. GBV-C viremia was rare in patients with AIDS, and tended to disappear without occurrence of anti-E2 in patients with progressive disease. This suggests that the GBV-C status of HIV-1-infected patients could be a phenomenon secondary to HIV progression, rather than an independent prognostic factor.

Tuberculosis in Bissau: incidence and risk factors in an urban community in sub-Saharan Africa.

BACKGROUND: Despite the long history of tuberculosis (TB) research, population-based studies from developing countries are rare. METHODS: In a prospective community study in Bissau, the capital of Guinea-Bissau, we assessed the impact of demographic, socioeconomic and cultural risk factors on active TB. A surveillance system in four districts of the capital identified 247 adult (>or=15 years) cases of intrathoracic TB between May 1996 and June 1998. Risk factors were evaluated comparing cases with the 25,189 adults living in the area in May 1997. RESULTS: The incidence of intrathoracic TB in the adult population was 471 per 100 000 person-years. Significant risk factors in a multivariate analysis were increasing age (P < 0.0001), male sex (odds ratio [OR] = 2.58, 95% CI: 1.85, 3.60), ethnic group other than the largest group (Pepel) (OR = 1.64, 95% CI: 1.20, 2.22), adult crowding (OR = 1.68, 95% CI: 1.18, 2.39 for >2 adults in household), and poor quality of housing (OR = 1.66, 95% CI: 1.24, 2.22). Household type was important; adults living alone or with adults of their own sex only, had a higher risk of developing TB than households with husband and wife present, the adjusted OR being 1.76 (95% CI: 1.11, 2.78) for male households and 3.80 (95% CI: 1.69, 8.56) for female households. In a multivariate analysis excluding household type, child crowding was a protective factor, the OR being 0.68 (95% CI: 0.51, 0.90) for households with >2 children per household. CONCLUSIONS: Bissau has a very high incidence of intrathoracic TB. Human immunodeficiency virus (HIV), increasing age, male sex, ethnicity, adult crowding, family structure, and poor housing conditions were independent risk factors for TB. Apart from HIV prevention, TB control programmes need to emphasize risk factors such as socioeconomic inequality, ethnic differences, crowding, and gender.

High sexual risk taking and diverging trends of HIV-1 and HIV-2 in the military of Guinea Bissau.

BACKGROUND: HIV and other sexually transmitted infections are a growing problem in the military personnel of Africa, and information about this problem in Guinea-Bissau is lacking. The aims of this study were to determine the prevalence and trends of the HIV epidemics in the military forces of Guinea Bissau and to explore possible risk factors for HIV infection. METHODOLOGY: Repeated cross-sectional surveys of HIV-1 and HIV-2 were conducted between 1992 and 2005, and knowledge, sexual behaviour and risk factors for HIV-1 and HIV-2 in military personnel in Guinea-Bissau were assessed. RESULTS: The seroprevalence of HIV-1, HIV-2 and HIV-1+HIV-2 dual reactivity was 1.1%, 8.4% and 0.1% in 1992-95, and in 2005 7.7%, 5.1% and 1.9%, respectively. Both the increase of HIV-1 and the decline of HIV-2 between 1992-95 and 2005 were significant when adjusted for age (p < 0.001 for both changes). Only a minority did not know how HIV transmits, but sexual risk taking was high. Several significant risk factors were found in univariate analyses for HIV-1 and HIV-2, but the only risk factor that remained significant after multivariate regression analysis was previous contact with a prostitute among HIV-1-positive subjects (single and dually reactive) (p < 0.01). CONCLUSION: The increasing trend of HIV-1 and the high risky sexual behavior illustrate the need for improvement in HIV/AIDS prevention efforts among military personnel in Guinea Bissau.

Risk factors for positive tuberculin skin test in Guinea-Bissau.

BACKGROUND: The tuberculin skin test is used for tracing of tuberculosis transmission and identifying individuals in need of prophylactic treatment. METHODS: Using a case-control study design, we recruited 220 smear-positive tuberculosis cases and 223 randomly selected healthy community controls in Bissau, Guinea-Bissau, during 1999-2000. Tuberculin skin tests were performed on family members of cases and controls (n = 1059 and n = 921, respectively). Induration of 10 mm or greater was considered positive. Risk factors were calculated for children (<15 years) and adults separately in multivariate logistic regression analysis. RESULTS: The prevalence of positive tuberculin skin test was 41% in case-contacts compared with 22% in control-contacts, resulting in a prevalence ratio of 1.48 (95% confidence interval = 1.37-1.60). Positive skin tests among case-contacts increased with age for children, as well as with proximity to a case during the night, for both children and adults. A Bacille Calmette Guerin scar increased the likelihood of having a positive tuberculin skin test for adults in case households, but not in other categories of contacts. Among control-contacts the prevalence of positive skin test was associated with older age in children, history of tuberculosis in the family, and a positive tuberculin skin test of the control person. CONCLUSIONS: Risk factors for a positive tuberculin skin test among case- and control-contacts are closely related to tuberculosis exposure. Having a BCG scar did not increase the risk of positive skin test in unexposed individuals. Tuberculin skin testing remains a useful tool for diagnosing tuberculosis infection.

Social network, social support and the rate of decline of CD4 lymphocytes in asymptomatic HIV-positive homosexual men.

AIMS: To test a stress-disease hypothesis by investigating the influence of social network and social support factors on the course over time of the CD4 lymphocytes in an HIV-positive population of gay men. METHODS: The study is a prospective cohort study of a representative population of HIV-positive gay men, undertaken at the Department of Infectious Diseases, Malmö University Hospital. This is the only clinic providing care for HIV-positive individuals in the city of Malmö in southern Sweden (population 248,000). A total of 115 HIV-positive homosexual men, who had not received an AIDS diagnosis, were invited to take part in the study. Seventy-five men (65%) accepted to be interviewed and 64 men (56%) fulfilled the inclusion criteria for the statistical analysis. RESULTS: In a multivariate analysis adjustments were made for age, level of the first CD4 count and time since first contact with the clinic. Men with high family contact frequency had a longer half-life (20.3 years) of the CD4 lymphocyte count than men with a low family contact frequency (7.4 years) (p = 0.03). Men with high social participation also had a longer half-life of CD4 lymphocyte count (14.7 years), compared with men with low social participation (6.3 years, p = 0.10). CONCLUSIONS: The findings of this study imply the importance of social support and social network factors as modifiers of the rate of decline of the CD4 lymphocyte level, which is an important prognostic marker of survival in HIV-positive homosexual men.