HIV incidence and HIV-associated mortality in a cohort of factory workers and their spouses in Tanzania, 1991 through 1996.

OBJECTIVE: To describe HIV incidence and HIV-associated mortality in a cohort of factory workers and their spouses with access to adequate sexually transmitted diseases (STD) treatment services and moderate exposure to sexual health interventions. METHODS: Follow-up visits at 4-month intervals and home follow-up of those who failed to keep appointments were used to estimate HIV incidence and mortality in a cohort of factory workers and their spouses in Mwanza, Tanzania, during 1991 to 1996. RESULTS: HIV prevalence at intake was 10.5% and 15.3% among 1,594 men and 880 women, respectively. HIV incidence was just over 1/100 person-years (PY) in 1,427 men and 1.9/100 PY in 745 women. The main risk factors were related to sexual behavior and clinical evidence of an STD, although only one seventh of those with HIV seroconversions had had an STD during the period following the second-from-last follow-up visit. HIV incidence among discordant couples was 5.0 and 8.3/100 PY for 41 men and 37 women, respectively. Mortality rates were 9.0 and 7.8/1,000 PY for men and women, respectively, and 65% of male and 60% of female deaths were attributable to HIV infection. CONCLUSIONS: In this factory population with good access to and use of STD treatment and with a moderate level of exposure to HIV prevention education, HIV incidence among men and women is still over 1/100 PY, which suggests a relatively high level of program effort is needed to lower incidence. More than half of all adult deaths were attributable to HIV, but greater increases in HIV-associated mortality are likely.

HIV infection and sexual behaviour among women with infertility in Tanzania: a hospital-based study.

BACKGROUND: Infertility is common in Africa, but virtually no data exist on HIV prevalence among infertile women. Mainly anthropological studies in Africa have shown that infertile women have higher risks of marital instability and possibly also have more sexual partners than fertile women. METHOD: This study was conducted in a hospital in northwest Tanzania during 1994 and 1995. Women presenting themselves with infertility problems to the outpatient clinic were interviewed, examined and blood was drawn. Women who came to deliver in the hospital, excluding primiparae, were taken as a control group. The analysis was limited to women > or = 24 years. In total 154 infertile and 259 fertile women were included in the study. RESULTS: HIV prevalence was markedly higher among infertile women than among fertile women: 18.2% and 6.6% respectively (adjusted odds ratio [OR] for age, residence and occupation 2.7; 95%-confidence interval [CI]: 1.4-5.3). Data on past sexual behaviour showed that infertile women had more marital breakdowns, more lifetime sexual partners and a higher level of exposure to sexually transmitted diseases (STD). CONCLUSION: Women with fertility problems appear to have higher HIV prevalence, which justifies more attention for such women in the context of AIDS programmes. In addition, caution is needed when using sentinel surveillance data from antenatal clinics to monitor HIV prevalence.

PIP: Infertility is common in Africa. Anthropological studies conducted on the continent have found infertile women to have higher risks of marital instability and possibly more sex partners than fertile women. Findings are reported from a study conducted during 1994 and 1995 in a hospital in northwest Tanzania to determine the prevalence of HIV infection among infertile women. Women presenting with infertility problems to the outpatient clinic were interviewed, examined, and blood was drawn. Women who came to deliver in the hospital, excluding primiparae, comprised the control group. A total of 154 infertile and 259 fertile women were included in the study, all age 24 years and older. 18.2% of infertile women and 6.6% of fertile women were infected with HIV. Data on past sex behavior indicated that infertile women had more marital breakdowns, more lifetime sex partners, and a higher level of exposure to sexually transmitted diseases.

HIV-1 incidence and HIV-1 associated mortality in a cohort of urban factory workers in Tanzania.

OBJECTIVE: To determine HIV-1 incidence and HIV-1 associated mortality in a prospective cohort study. To determine whether the cohort is suitable for studies aiming to determine the impact of interventions on HIV-1 incidence. METHODS: The study population was a cohort of 1772 urban factory workers (1478 men and 294 women) in northwest Tanzania. The study took place from October 1991 to September 1993. Outcome measures were HIV-1 seroconversion and death. RESULTS: HIV-1 incidence was 1.2 (95% CI 0.7-2.0) per 100 person-years (pyr). Crude annual mortality was 4.9 per 100 pyr in those with and 0.3 in those without HIV-1 infection, giving an age and sex adjusted mortality ratio of 12.9 (95% CI 5.4-30.7). Of all deaths, 62% were attributable to HIV-1 infection. CONCLUSION: HIV-1 infection was a major public health problem, being the major cause of death in this adult population. At an HIV-1 incidence of 1.2 per 100 pyr, a large cohort size would be required to evaluate the impact of interventions on HIV-1 incidence.

PIP: The objectives were to determine HIV-1 incidence and HIV-1 associated mortality in a prospective cohort study and to determine whether the cohort is suitable for studies attempting to determine the impact of interventions on HIV-1 incidence. The study population was a cohort of 2038 urban factory workers in northwest Tanzania of whom 1772 workers (1478 men or 87% and 294 women or 89%) had enrolled in the study during October 1991 to September 1993. 471 (27%) of the total study population were lost to follow-up by the end of the study period. Outcome measures were HIV-1 seroconversion and death. At intake, 153 of 1478 (10.4%) men and 52 of 294 (17.7%) women were infected with HIV-1. In the study period, 17 seroconversions took place in 1365.9 person years of follow-up giving an HIV-1 incidence rate of 1.2/100 person-years of follow-up. No association was found between seroconversion and age or sex. The crude annual mortality rate was 4.9/100 person-years in those with and 0.3/100 person-years in those without HIV-1 infection, giving an age- and sex-adjusted mortality ratio of 12.9. The age- and sex-adjusted population attributable risk was 0.5/100 person-years, and of all deaths, 62% were attributable to HIV-1 infection. Of the 14 HIV-1 infected people who died, 9 met the criteria of the 1987 revised Centers for Disease Control/World Health Organization AIDS case definition: one had cryptococcal meningitis and eight HIV wasting syndrome. Two others had had weight loss and fever, but the evidence was inadequate to make or reject the diagnosis of AIDS. The remaining three without an AIDS diagnosis had pulmonary tuberculosis, diarrhea, and pyomyositis, respectively. HIV-1 infection was a major cause of death in this adult population. At an HIV-1 incidence of 1.2/100 person-years, a large cohort size would be required to evaluate the impact of interventions on HIV-1 incidence.

Reducing the cost of HIV-testing through use of the IgG antibody captured particle adherence test (GACPAT) in district hospitals.

Though the World Health Organization (WHO) has acted to reduce the price of anti-HIV assays for developing countries, the cost of the large-scale testing to be done may still be prohibitive to the health budget of these countries. GACPAT, a modified commercial particle assay, is ten times cheaper than the WHO price of ELISAs. In this study GACPAT was introduced in three district hospital laboratories (DHL) in Tanzania, and the results compared with those on the same sera in a reference laboratory (RL). Sensitivity and specificity were 92.6% and 98.7%, respectively at DHL. It is concluded that GACPAT is a valid, feasible and cheap alternative for ELISA anti-HIV-testing also at district hospital laboratory level.

PIP: In developing countries, routine HIV testing has largely been used in the screening of blood donors, sentinel surveillance, and for epidemiological purposes. There is, however, an increasing individual demand for voluntary HIV testing and diagnostic HIV testing in hospitals. Testing remains very expensive in developing countries relative to available resources. The IgG antibody captured particle adherence test (GACPAT) is a modification of the Serodia particle agglutination test. This modification substantially lowers the cost per HIV antibody test without loss of specificity and sensitivity; the GACPAT is 10 times cheaper than the World Health Organization price for ELISAs. Using plates coated at a regional reference laboratory, GACPAT was evaluated in a government district hospital, a voluntary agency district hospital, and a designated district hospital. Test sensitivity and specificity were 92.6% and 98.7%, respectively in the district hospital laboratories. The authors deem GACPAT to be a valid, feasible, and cheap alternative for ELISA anti-HIV testing also at the district hospital laboratory level.

Secondary school students: a safer blood donor population in an urban with high HIV prevalence in east Africa.

We evaluated the enrollment of secondary school students as voluntary unremunerated blood donors in a city where the HIV-1 prevalence among the adult population is 11.8%. Between 1st July, 1992 and 1st December, 1993, consecutive blood donors were screened for anti-HIV-1, TPHA, HBsAg and anti-HBc. Test results were related to age, sex, voluntary or relative donor status. 525 (22.4%) of 2345 were voluntary donors aged 24 years or less and 529 (29.6%) of 1820 of the relative donors were of the same age group. Voluntary donors had statistically significant lower prevalence rates of anti-HIV-1, TPHA, and anti-HBc, 1.5%, 2.1% and 50.2% respectively, compared to relative donors of the same age group, 4.7%, 9.0% and 70.3% respectively. We conclude that secondary school students constituted a safer donor population. The student population offered the additional advantage of being easily accessible for donation and lesser blood units needed to be discarded. For a blood transfusion centre in an urban settlement, recruitment of secondary school students as voluntary unremunerated blood donors should be considered as a cost-effective strategy.

Intake of a cohort study of urban factory workers in northwest Tanzania. Risk factors for HIV-1 infection.

A cohort study has been started of urban factory workers and their spouses in Tanzania, in order to 1) identify risk factors for HIV-1 seroconversion, and 2) document changes over time in risk behaviour, in particular condom use and partner change, and determine whether these are associated with a reduced incidence of HIV-1 and other sexually transmitted diseases. We report findings at intake from October 1991 to March 1992. Study participants were interviewed, examined, and screened for HIV-1 and syphilis. HIV-1 prevalence was 91/926 (10%) in males and 36/217 (17%) in females. Statistically significant risk factors for HIV-1 infection in males were age group, region of birth, not being married for more than 5 years, being uncircumcised, having had a genital ulcer in the past four months, and having received injections from medical staff in the past four months. HIV-1 incidence in this group is expected to be between 1% and 2% per year. It is concluded that a longitudinal study is needed to assess the importance of partner change. This cohort appears to be suitable for such a study as HIV-1 incidence is expected to be fairly high, HIV-1 prevalence and risk factors are comparable to those of the general population and cooperation of the factory workers is good.

HIV-1 infection as a risk factor for leprosy; a case-control study in Tanzania.

A case-control study was carried out in Tanzania to determine the relative risk of those with HIV-1 infection for getting leprosy. Cases were 93 consecutively diagnosed patients with leprosy aged 15-54 years from the Mwanza Region. Controls were a representative population sample of 4161 people drawn from a stratified cluster sample from urban areas, roadside settlements, and rural villages. HIV-1 infection was determined by enzyme-linked immunosorbent assay (ELISA); Western blot was used when the ELISA result was indeterminate. The HIV-1 prevalence in leprosy cases was 10% in rural (7 of 72) and in roadside and urban areas (2 of 21); in controls these prevalences were 3.4% and 9.9%, respectively. The relative risk of HIV-1 infection for the development of leprosy was estimated to be 2.2 [95% confidence interval (CI) = 1.0-4.7; p = 0.07]. HIV-1 infection was significantly associated with multibacillary (MB) leprosy (odds ratio 4.6; CI = 1.3-13.2) but not with paucibacillary leprosy (odds ratio 1.4; 95% CI = 0.4-3.8). The population etiological fraction for the development of MB leprosy attributable to HIV-1 infection in this population is estimated to be 13% (95% CI = 4%-23%). We conclude that HIV-1 is a risk factor for the development of MB leprosy. The impact of the HIV-1 epidemic on the incidence of leprosy so far has been limited since HIV-1 occurs mainly in urban areas and leprosy in rural areas.

HIV-1 infection as a risk factor for the development of tuberculosis: a case-control study in Tanzania.

A population-based case-control study was carried out in Mwanza Region, Tanzania, to determine the relative and population attributable risk of human immunodeficiency virus type 1 (HIV-1) infection for developing active tuberculosis. Cases were 441 consecutively diagnosed patients with tuberculosis (all types), aged 15-54 years. Controls were a representative population sample of 4161 people, drawn in a stratified cluster sample from urban areas, roadside settlements, and rural villages. HIV-1 infection was determined by ELISA and if the ELISA result was indeterminate by Western Blot. The HIV-1 prevalence in cases was 23.0% in rural, 32.1% in roadside, and 54.1% in urban areas, while in controls these prevalences were 3.4%, 7.2% and 12.1% respectively. The relative risk (RR) of HIV-1 infection for the development of active tuberculosis was estimated to be 8.3 (95% confidence interval [CI] 6.4-11.0). This risk varied little by sex or residence, but appeared to be more pronounced in the age group 25-34 years. The case detection rate of tuberculosis in those aged 15-54 years was 125/100,000 people per year. The population attributable risk was 36/100,000 people per year, implying that 29% of tuberculosis cases at present may be attributable to HIV-1 infection. It is concluded that HIV-1 infection is a major contributing factor to the increased case detection rate of tuberculosis observed over the past 10 years in Mwanza Region. If the prevalence of HIV-1 continues to increase, the incidence of tuberculosis will continue to rise as well.(ABSTRACT TRUNCATED AT 250 WORDS)

PIP: This population-based case-control study in Mwanza Region of Tanzania determined the relative and population-attributable risk of HIV-1 infection for developing active tuberculosis (TB). 441 TB patients aged 15-54 years were considered as cases. 4161 controls constituting a representative population sample were drawn in a stratified cluster sample from urban areas, roadside settlements, and rural villages. HIV-1 was identified among 23.0% of cases in rural, 32.1% in roadside, and 54.1% in urban areas. HIV-1 prevalences among controls were 3.4%, 7.2%, and 12.1%, respectively. The relative risk of HIV infection for the development of active tuberculosis is estimated to be 8.3 with little variation by sex or residence. Risk did, however, seem to be more evident in the age group of 25.34 years. The case detection rate of TB among individuals aged 15-54 years was 125/100,000 people per year. Further, the population-attributable risk was found to be 36/100,000 people per year; this implies that 29% of current TB cases may be attributable to HIV-1 infection. The authors conclude that HIV-1 infection is a major contributing factor to the increased case detection rate of TB observed over the past 10 years in Mwanza Region and that the incidence of TB should continue to increase along with that for HIV-1. Efforts should therefore be made to maintain a high cure rate for TB in the interest of preventing an increased risk of TB infection among HIV-1 infected and uninfected people.

The epidemiology of HIV-1 infection in urban areas, roadside settlements and rural villages in Mwanza Region, Tanzania.

OBJECTIVE: To determine the prevalence of HIV-1 infection and to identify the most important risk factors for infection. DESIGN: A cross-sectional population survey carried out in 1990 and 1991 in Mwanza Region, Tanzania. METHODS: Adults aged 15-54 years were selected from the region (population, 2 million) by stratified random cluster sampling: 2434 from 20 rural villages, 1157 from 20 roadside settlements and 1554 from 20 urban wards. Risk factor information was obtained from interviews. All sera were tested for HIV-1 antibodies using enzyme-linked immunosorbent assay (ELISA); sera non-negative on ELISA were also tested by Western blot. RESULTS: The response rate was 81%. HIV-1 infection was 1.5 times more common in women than in men; 2.5% of the adult population in rural villages, 7.3% in roadside settlements and 11.8% in town were infected. HIV-1 infection occurred mostly in women aged 15-34 years and men aged 25-44 years. It was associated with being separated or widowed, multiple sex partners, presence of syphilis antibodies, history of genital discharge or genital ulcer, travel to Mwanza town, and receiving injections during the previous 12 months, but not with male circumcision. CONCLUSION: This study confirms that HIV-1 infection in this region in East Africa is more common in women than in men. The results are consistent with the spread of HIV-1 infection along the main roads. There is no evidence that lack of circumcision is a risk factor in this population.

PIP: Between August 1990 and February 1991, health workers took blood samples from, and trained interviewers spoke to, 5145 15-to-54-year-old adults living in either an urban area (1554), in a rural village (2434), or in a roadside settlement (1157) in the Mwanza Region of Tanzania to determine the prevalence of HIV-1 infection and its most significant risk factors. The prevalence rate of HIV-1 infection was highest in urban areas, lower in roadside settlements, and lowest in rural areas (11.8%, 7.3%, and 2.5%, respectively), suggesting that HIV-1 had spread along main roads. Yet, there were as many people infected with HIV-1 in rural areas of the Mwanza Region as there were in Mwanza town. Women were 1.2 (rural) to 1.7 (urban) times more likely to be infected with HIV-1 than were men, indicating greater efficiency of HIV-1 transmission from men to women than from women to men. HIV-1 infection peaked in the 15-to-34-year-old group in women and in the 25-to-44-year-old group in men. Separated, divorced, or widowed men and women were at increased risk of being HIV-1 infected, even when controlled for numerous factors (odds ratio (OR) = 3.4 and 1.6, respectively). This may have been an indication of multiple partners, since the question concerning multiple partners was vague. Other important risk factors for women and men were syphilis antibodies (OR = 1.7 and 1.85), history of genital discharge or chancroid (OR = 2, 1.6 and 2.7, 1.6), travel to Mwanza town (OR = 2.1 and 1.7), and receiving injections during the previous 12 months (OR = 1.5 and 1.9). There was no link between male circumcision and HIV-1 infection. In fact, there seemed to be a moderate protective effect (OR = 0.8). This effect may be even more likely since urban men, who were at greatest risk of HIV-1 infection (8.7% vs. 5.4% [roadside] and 2.4% [rural]), had the highest rate of circumcision (61% vs. 29% and 17%, respectively).