Angela Obasi

Biological and behavioural impact of an adolescent sexual health intervention in Tanzania : a community-randomized trial

Objective:The impact of a multicomponent intervention programme on the sexual health of adolescents was assessed in rural Tanzania. Design:A community-randomized trial. Methods:Twenty communities were randomly allocated to receive either a specially designed programme of interventions (intervention group) or standard activities (comparison group). The intervention had four components: community activities; teacher-led, peer-assisted sexual health education in years 5–7 of primary school; training and supervision of health workers to provide ‘youth-friendly’ sexual health services; and peer condom social marketing. Impacts on HIV incidence, herpes simplex virus 2 (HSV2) and other sexual health outcomes were evaluated over approximately 3 years in 9645 adolescents recruited in late 1998 before entering years 5, 6 or 7 of primary school. Results:The intervention had a significant impact on knowledge and reported attitudes, reported sexually transmitted infection symptoms, and several behavioural outcomes. Only five HIV seroconversions occurred in boys, whereas in girls the adjusted rate ratio (intervention versus comparison) was 0.75 [95% confidence interval (CI) 0.34, 1.66]. Overall HSV2 prevalences at follow-up were 11.9% in male and 21.1% in female participants, with adjusted prevalence ratios of 0.92 (CI 0.69, 1.22) and 1.05 (CI 0.83, 1.32), respectively. There was no consistent beneficial or adverse impact on other biological outcomes. The beneficial impact on knowledge and reported attitudes was confirmed by results of a school examination in a separate group of students in mid-2002. Conclusion:The intervention substantially improved knowledge, reported attitudes and some reported sexual behaviours, especially in boys, but had no consistent impact on biological outcomes within the 3-year trial period.

A bit more truthful: the validity of adolescent sexual behaviour data collected in rural northern Tanzania using five methods.

Objective: To assess the validity of sexual behaviour data collected from African adolescents using five methods. Methods: 9280 Tanzanian adolescents participated in a biological marker and face to face questionnaire survey and 6079 in an assisted self-completion questionnaire survey; 74 participated in in-depth interviews and 56 person weeks of participant observation were conducted. Results: 38% of males and 59% of females reporting sexual activity did so in only one of the two 1998 questionnaires. Only 58% of males and 29% of females with biological markers consistently reported sexual activity in both questionnaires. Nine of 11 (82%) in-depth interview respondents who had had biological markers provided an invalid series of responses about sex in the survey and in-depth interview series. Only one of six female in-depth interview respondents with an STI reported sex in any of the four surveys, but five reported it in the in-depth interviews. Conclusion: In this low prevalence population, biological markers on their own revealed that a few adolescents had had sex, but in combination with in-depth interviews they may be useful in identifying risk factors for STIs. Self-reported sexual behaviour data were fraught with inconsistencies. In-depth interviews seem to be more effective than assisted self-completion questionnaires and face to face questionnaires in promoting honest responses among females with STIs. Participant observation was the most useful method for understanding the nature, complexity, and extent of sexual behaviour.

Antibody to Herpes Simplex Virus Type 2 as a Marker of Sexual Risk Behavior in Rural Tanzania

A serosurvey was conducted in a random sample of 259 women and 231 men in 12 rural communities in Mwanza Region, Tanzania, using a type-specific ELISA for Herpes simplex virus type 2 (HSV-2) infection. Seroprevalence rose steeply with age to approximately 75% in women >=25 years old and 60% in men >=30. After adjusting for age and residence, HSV-2 prevalence was higher in women who were married, in a polygamous marriage, Treponema pallidum hemagglutination assay (TPHA)-positive, had more lifetime sex partners, or who had not traveled. Prevalence was higher in men who were married, had lived elsewhere, had more lifetime partners, had used condoms, or were TPHA-positive. HSV-2 infection was significantly associated with recent history of genital ulcer. The association between HSV-2 infection and lifetime sex partners was strongest in those <25 years old in both sexes. This association supports the use of HSV-2 serology as a marker of risk behavior in this population, particularly among young people.

Herpes simplex virus type 2 infection increases HIV incidence: a prospective study in rural Tanzania

Objectives To quantify the association between prevalent or incident Herpes simplex virus type-2 (HSV2) infection and the incidence of HIV seroconversion among adults in the general population in rural Tanzania. Study population Adults aged 15–54 years sampled randomly from 12 rural communities in Mwanza Region, Tanzania and recruited to a randomized trial of improved treatment of sexually transmitted diseases. Study design Unmatched case–control study nested within trial cohort. Methods Participants included 127 cases who seroconverted to HIV during the 2-year follow-up period and 636 randomly selected controls who remained HIV negative. Subjects were tested for HSV2 serology at baseline and follow-up, and associations between HIV and HSV2 were analysed with adjustment for socio-demographic and behavioural factors. Results After adjusting for confounding factors, a strong association between HSV2 infection and HIV seroconversion was observed in men (test for trend:P < 0.001), with adjusted odds ratios (OR) of 6.12 [95% confidence interval (CI), 2.52–14.9] in those HSV2 positive at baseline, and 16.8 (95% CI, 6.06–46.3) in those acquiring HSV2 infection during follow-up. A weaker association was observed in women (tests for trend:P = 0.14), with adjusted OR of 1.32 (95% CI, 0.62–2.78) and 2.36 (95% CI, 0.81–6.84), respectively. Population attributable fractions of incident HIV infection due to HSV2 were estimated as 74% in men and 22% in women. Conclusions The results suggest that HSV2 plays an important role in the transmission of HIV infection in this population. There is an urgent need to identify effective HSV2 control measures in order to reduce HIV incidence in Africa.

Disease progression and survival in HIV-1-infected Africans in London

Objective:To examine differences in progression to AIDS and death between HIV-1-positive Africans (most infected in sub-Saharan Africa and therefore with non-B subtypes) and HIV-1-positive non-Africans in London. Design:Retrospective cohort study of 2048 HIV-1-positive individuals. Setting:HIV-1-infected individuals attending 11 of the largest HIV/AIDS units in London. Patients:Subjects were 1056 Africans and 992 non-Africans seen between 1982–1995. Results:There were no differences in crude survival from presentation to death between Africans and non-Africans (median 82 and 78 months, respectively; P = 0.22). Africans progressed more rapidly to AIDS [hazard ratio (HR), 1.21; 95% confidence interval (CI), 1.02–1.45] but after adjustment for age, sex, Centers for Disease Control and Prevention category B symptoms and CD4+ lymphocyte count at presentation, year of HIV diagnosis and hospital attended, this difference was no longer significant (adjusted HR, 1.15; 95% CI, 0.93–1.43). Africans with AIDS had a reduced risk of death compared with non-Africans (HR, 0.78; 95% CI, 0.63–0.96) but not after adjustment for age, CD4+ lymphocyte count at AIDS, initial AIDS-defining conditions (ADC) and hospital attended (HR, 0.98; 95% CI, 0.76–1.27). Tuberculosis as the first ADC was associated with a 64% reduction in the risk of death. CD4+ lymphocyte decline was not significantly different between Africans and non-Africans (P = 0.18). Conclusions:Differences in progression to AIDS and death and CD4+ lymphocyte decline between HIV-1-infected Africans and non-Africans in London could not be attributed to ethnicity or different viral subtypes. Age and the clinical and immunological stage at presentation, or AIDS, were the major determinants of outcome. Compared with other diagnoses, tuberculosis as the initial ADC was associated with increased survival. Lack of access to health care and exposure to environmental pathogens are the most likely causes of reduced survival with AIDS in Africa, rather than inherently different rates of progression of immune deficiency due to racial differences or viral subtypes.

Disease progression and survival following specific AIDS-defining conditions: a retrospective cohort study of 2048 HIV-infected persons in London.

Objective: To assess the impact of specific AIDS‐defining conditions on survival in HIV‐infected persons, with emphasis on the effect of tuberculosis. Methods: A retrospective cohort analysis of HIV‐infected Africans and non‐Africans attending 11 specialist HIV/AIDS units in London enrolled for a comparison of the natural history of HIV/AIDS in different ethnic groups. Results: A total of 2048 patients were studied of whom 627 (31%) developed 1306 different AIDS indicator diseases. Pneumocystis carinii pneumonia accounted for 159 (25%) of initial AIDS episodes and tuberculosis for 103 (16%). In patients with HIV disease, tuberculosis had the lowest risk [relative risk (RR), 1.11; 95% confidence interval (CI), 0.75–1.63], and high‐grade lymphoma had the highest risk (RR, 20.56; 95% CI, 2.70–156.54) for death. For patients with a prior AIDS‐defining illness, the development of subsequent AIDS indicator diseases such as Pneumocystis carinii pneumonia (RR, 1.18; 95% CI, 0.77–1.83) and tuberculosis (RR, 1.36; 95% CI, 0.76–2.47) had the best survival, and non‐Hodgkins lymphoma had the worst survival (RR, 9.67; 95% CI, 1.26–74.33). Patients with tuberculosis had a lower incidence of subsequent AIDS‐defining conditions than persons with other initial AIDS diagnoses (rate ratio, 0.47; 95% CI, 0.37–0.59). Conclusions: Considerable variation exists in the relative risk of death following different AIDS‐defining conditions. The development of any subsequent AIDS‐defining condition is associated with an increased risk of death that differs between diseases, and this risk should be considered when evaluating the impact of specific conditions. Like other AIDS‐defining conditions, incident tuberculosis was associated with adverse outcome compared with the absence of an AIDS‐defining event, but we found no evidence of major acceleration of HIV disease attributable to tuberculosis.

Spectrum of disease in Africans with AIDS in London

Objective: To compare the spectrum of disease, severity of immune deficiency and chemoprophylaxis prescribed in HIV‐infected African and non‐African patients in London. Design: Retrospective review of case notes of all HIV‐infected Africans and a comparison group of non‐Africans attending 11 specialist HIV/AIDS Units in London. Main outcome measures: Comparison of demographic information, first and subsequent AIDS‐defining conditions, levels of immune deficiency, and chemoprophylactic practices between the African and non‐African groups. Results: A total of 1056 Africans (313 developing AIDS) and 992 non‐Africans (314 developing AIDS) were studied. Africans presented later than non‐Africans (median CD4+ lymphocyte counts at diagnosis 238 and 371 × 106/l, respectively). Tuberculosis accounted for 27% of initial episodes of AIDS in Africans and 5% in non‐Africans; Pneumocystis carinii pneumonia (PCP) was the initial AIDS‐defining condition in 34% of non‐Africans and 17% of Africans. The incidence of tuberculosis in Africans with another AIDS‐indicator disease was 16 per 100 person‐years. PCP prophylaxis was prescribed for 40% Africans and 32% non‐Africans; only 8% of Africans received tuberculosis preventive therapy. Conclusions: HIV‐infected African patients presented at lower levels of CD4+ lymphocyte count, at a more advanced clinical stage, and with different AIDS‐indicator diseases as compared with non‐Africans. Prophylaxis against tuberculosis should be considered for all HIV‐infected African patients in industrialized countries. The high incidence of diseases that are indicative of advanced immunodeficiency (e.g., cytomegalovirus disease) in African patients contrasts with data from Africa, suggesting better survival chances in the UK.

Rationale and design of the MEMA kwa Vijana adolescent sexual and reproductive health intervention in Mwanza Region, Tanzania

Abstract Large-scale innovative, integrated, multifaceted adolescent sexual and reproductive health (ASRH) interventions are urgently needed in sub-Saharan Africa. Implementation through schools and health facilities may maximize intervention coverage and sustainability, however the impact of the use of these structures on intervention content and delivery is not well documented. This paper describes the rationale and design of a large-scale multifaceted ASRH intervention, which was developed and evaluated over three years in rural communities in Mwanza Region, North West Tanzania. The intervention comprised community mobilization, participatory reproductive health education in primary schools, youth-friendly reproductive health services and community-based condom provision for youth. We examine the effect of socioeconomic, cultural and infrastructural factors on intervention content and implementation. This paper demonstrates the means by which such interventions can be feasibly and sustainably implemented to a high standard through existing government health and school structures. However, the use of these structures involves compromise on some key aspects of intervention design and requires the development of complementary strategies to access out-of-school youth and the wider community.

Risk Factors Influencing HIV Infection Incidence in a Rural African Population: A Nested Case-Control Study

BACKGROUND Risk factors influencing the incidence of human immunodeficiency virus (HIV) infection were investigated in a case-control study nested within a community-randomized trial of treatment of syndromic sexually transmitted infections (STIs) in rural Tanzania. METHODS Case patients were persons who became HIV positive, and control subjects were randomly selected from among persons who remained HIV negative. For each sex, we obtained adjusted odds ratios (ORs) and population-attributable fractions (PAFs) for biomedical and behavioral factors. RESULTS We analyzed 92 case patients and 903 control subjects. In both sexes, the incidence of HIV infection was significantly higher in subjects with an HIV-positive spouse than in those with HIV-negative spouse (men: OR, 25.1; women: OR, 34.0). The incidence of HIV infection was significantly higher in those who became positive for herpes simplex virus type 2 (HSV-2) (men: OR, 5.60; women: OR, 4.76) and those who were HSV-2-positive at baseline (men: OR, 3.66; women: OR, 2.88) than in subjects who were HSV-2 negative. In women, living elsewhere (OR, 3.22) and never having given birth (OR, 4.27) were significant risk factors. After adjustment, the incidence of HIV infection was not significantly associated with a history of injections or STIs in either sex. CONCLUSION HSV-2 infection was the most important risk factor for HIV infection, which highlights the need for HSV-2 interventions in HIV infection control, and there were particularly strong associations with recent HSV-2 seroconversion. The PAF associated with having an HIV-positive spouse was low, but this is likely to increase during the epidemic.

Asking semi-literate adolescents about sexual behaviour: the validity of assisted self-completion questionnaire (ASCQ) data in rural Tanzania.

Objectives  To develop and test a sexual behaviour survey method for semi‐literate populations, combining the privacy of a self‐completion questionnaire (SCQ) with the clarity of a face‐to‐face questionnaire (FFQ).