High mortality and severe immunosuppression in hospitalized patients with pulmonary tuberculosis and HIV-2 infection in Guinea-Bissau

Mortality associated with HIV-1, HIV-2, and HTLV-I single and dual infections in a middle-aged and older population in Guinea-Bissau

BACKGROUND

In Guinea-Bissau HIV-1, HIV-2, and HTLV-I are prevalent in the general population. The natural history of HIV/HTLV-I single and dual infections has not been fully elucidated in this population. Previous studies have shown that combinations of these infections are more common in older women than in men. The present study compares mortality associated with HIV-1, HIV-2, and HTLV-I single and dual infections in individuals over 35 years of age within an urban community-based cohort in Guinea-Bissau.

RESULTS

A total of 2,839 and 1,075 individuals were included in the HIV and HTLV-I mortality analyses respectively. Compared with HIV-negative individuals, adjusted mortality rate ratios (MRRs) were 4.9 (95% confidence interval (CI): 2.3, 10.4) for HIV-1, 1.8 (95%CI: 1.5, 2.3) for HIV-2, and 5.9 (2.4, 14.3) for HIV-1/HIV-2 dual infections. MRR for HTLV-I-positive compared with HTLV-I-negative individuals was 1.7 (1.1, 2.7). Excluding all HIV-positive individuals from the analysis, the HTLV-I MRR was 2.3 (1.3, 3.8). The MRR of HTLV-I/HIV-2 dually infected individuals was 1.7 (0.7, 4.3), compared with HIV/HTLV-I-negative individuals. No statistically significant differences were found in retrovirus-associated mortality between men and women.

CONCLUSION

HIV-1-associated excess mortality was low compared with community studies from other parts of Africa, presumably because this population was older and the introduction of HIV-1 into the community recent. HIV-2 and HTLV-I-associated mortality was 2-fold higher than the mortality in uninfected individuals. We found no significant differences between the mortality risk for HIV-2 and HTLV-I single infection, respectively, and HIV-2/HTLV-I dual infection. The higher prevalence of retroviral dual infections in older women is not explained by differential retrovirus-associated mortality for men and women.

Parenteral transmission during excision and treatment of tuberculosis and trypanosomiasis may be responsible for the HIV-2 epidemic in Guinea-Bissau

BACKGROUND AND OBJECTIVE

The factors that led to the simultaneous emergence, decades ago, of HIV-1 in central Africa and HIV-2 in West Africa remain unclear. The low HIV-2-associated mortality enables epidemiological assessment of risk factors potentially relevant in the early stages of the epidemic. In Guinea-Bissau, its epicentre, HIV-2 became highly prevalent (approximately 15%) in cohorts of individuals born before 1962, but is now disappearing whereas HIV-1 prevalence is increasing. We sought to verify the hypothesis that parenteral transmission was the key factor in the building-up of the HIV-2 epidemic.

DESIGN

Cross-sectional community survey of 1608 individuals aged > or = 50 years in Bissau.

METHODS

Capillary blood was obtained for HIV serology. Associations between HIV-2 (alone or in dual HIV-1/HIV-2 infections) and exposures were measured with crude and adjusted odds ratios (AOR) and 95% confidence intervals (CI).

RESULTS

Prevalence of HIV-2 was higher in women (160/1063; 15.1%) than men (45/545; 8.3%, P < 0.001). Among women, excision (AOR, 1.54; 95% CI, 1.08-2.18) was independently associated with HIV-2, as were age and being widowed (AOR, 1.88; 95% CI, 1.29-2.74). Among men, HIV-2 was not associated with sexually transmitted infections or transactional sex. In an analysis comprising men and women that was adjusted for age, sex, ethnic group and marital status, HIV-2 was associated with having received injections for the treatment of tuberculosis (AOR, 2.12; 95% CI, 1.11-4.05) or trypanosomiasis (AOR, 1.75; 95% CI, 1.03-2.97).

CONCLUSIONS

Parenteral transmission through ritual excision and multiple injections during treatment of tuberculosis and trypanosomiasis contributed to the emergence of HIV-2 in Guinea-Bissau.

Incidence of tuberculosis and survival after its diagnosis in patients infected with HIV-1 and HIV-2

BACKGROUND

In sub-Saharan Africa, tuberculosis (TB) is the most frequently diagnosed opportunistic infection and cause of death among HIV-infected patients. HIV-2 has been associated with less immune suppression, slower disease progression and longer survival.

OBJECTIVE

To examine whether the incidence of TB and survival after TB are associated with CD4 cell count rather than HIV type.

METHODS

Clinical and immunological data were retrospectively evaluated among an open clinic-based cohort of HIV-1- and HIV-2-infected patients to determine incidence of TB (first diagnosis > 28 days after HIV diagnosis) and subsequent mortality. Patients were grouped by CD4 cell count into those with < 200, 200-500 and > 500 x 10 cells/l.

RESULTS

Incident TB was diagnosed among 159 of 2012 patients, with 4973 person-years of observation time. In 105/159 (66.0%), the diagnosis was confirmed by direct microscopy or culture. Incidence of TB was highest in the group with < 200 x 10 cells/l (9.1/100 and 8.8/100 person-years in HIV-1 and HIV-2, respectively). Adjusted for CD4 cell count, there was no significant difference in incidence or mortality following TB between HIV-1- and HIV-2-infected patients. Mortality rate was higher in those with incident TB and HIV infection, most markedly in the group with the highest CD4 cell count (hazard ratio, 10.0; 95% confidence interval, 5.1-19.7).

CONCLUSION

Adjusted for CD4 cell count, incidence of TB was similar among HIV-1- and HIV-2-infected patients. Mortality rates after TB diagnosis were similar in both groups and high compared with those without TB.

Smear microscopy to diagnose tuberculosis early and prevent further transmission in a population with a high prevalence of HIV infection

In western Europe, Portugal has the highest incidence of tuberculosis (TB). The quickest way to diagnose TB is with a positive smear. To evaluate the usefulness of smear microscopy in a population with a high HIV seroprevalence, TB patients admitted during the year 2000 were retrospectively analyzed. Of the 74 TB patients admitted, 45 (61%) had pulmonary TB, 11 having multiresistant (MR)-TB. Considering that only half of the patients with pulmonary TB had a positive smear, a high degree of clinical suspicion is of great importance. Appropriate isolation facilities for TB are much needed, in order to prevent nosocomial TB spread.