Patterns of sexually transmitted infections in adolescents and youth in Dar es Salaam, Tanzania

BACKGROUND: Syndromic management of STIs has been advocated as simplified and cheap approach. Youth have been reported to be at increased risk of acquiring STIs which can facilitate HIV transmission. We have investigated the relationship between the syndromic management and specific aetiology diagnosis and its relationship with HIV infection and health seeking behaviour among youth attending a reproductive health clinic in Dar es Salaam, Tanzania. METHODS: Between September 1998 and February 1999 among 1895 adolescents and youth below 25 years seen in the clinic 199 (10.5%) were randomly selected and consented to participate in the study. A standard questionnaire was administered. Blood and vaginal or urethral specimens were taken and investigated for STI causative agents. RESULTS: Among a total of 199 studied adolescents and youth 22.6 % were teenagers, with fewer females 17.8% than males; 27.5% (p < 0.018). 20.8% of the females compared to 11.5% in males were HIV infected. Genital discharge was the most common complaint which was reported in 54.1% of male and 63.4 % of female patients. All males with gonorrhoea and four out of five with Chlamydia were given appropriate treatment with syndromic management, while 28% women with gonorrhoea or Chlamydia received appropriate treatment by syndromic management. All patients found with active syphilis by serology had not complained of genital ulcers and would not have been assigned to syndromic treatment for syphilis at the initial visit. CONCLUSION: The burden of STIs in this youth population is large indicating that youth are at increased risk of STIs and will certainly require youth friendly clinics. There is a need to refine the current syndromic management guidelines

Evaluation of simple rapid HIV assays and development of national rapid HIV test algorithms in Dar es Salaam, Tanzania

BACKGROUND: Suitable algorithms based on a combination of two or more simple rapid HIV assays have been shown to have a diagnostic accuracy comparable to double enzyme-linked immunosorbent assay (ELISA) or double ELISA with Western Blot strategies. The aims of this study were to evaluate the performance of five simple rapid HIV assays using whole blood samples from HIV-infected patients, pregnant women, voluntary counseling and testing attendees and blood donors, and to formulate an alternative confirmatory strategy based on rapid HIV testing algorithms suitable for use in Tanzania. METHODS: Five rapid HIV assays: Determine HIV-1/2 (Inverness Medical), SD Bioline HIV 1/2 3.0 (Standard Diagnostics Inc.), First Response HIV Card 1-2.0 (PMC Medical India Pvt Ltd), HIV1/2 Stat-Pak Dipstick (Chembio Diagnostic System, Inc) and Uni-Gold HIV-1/2 (Trinity Biotech) were evaluated between June and September 2006 using 1433 whole blood samples from hospital patients, pregnant women, voluntary counseling and testing attendees and blood donors. All samples that were reactive on all or any of the five rapid assays and 10% of non-reactive samples were tested on a confirmatory Inno-Lia HIV I/II immunoblot assay (Immunogenetics). RESULTS: Three hundred and ninety samples were confirmed HIV-1 antibody positive, while 1043 were HIV negative. The sensitivity at initial testing of Determine, SD Bioline and Uni-Gold was 100% (95% CI; 99.1-100) while First Response and Stat-Pak had sensitivity of 99.5% (95% CI; 98.2-99.9) and 97.7% (95% CI; 95.7-98.9), respectively, which increased to 100% (95% CI; 99.1-100) on repeat testing. The initial specificity of the Uni-Gold assay was 100% (95% CI; 99.6-100) while specificities were 99.6% (95% CI; 99-99.9), 99.4% (95% CI; 98.8-99.7), 99.6% (95% CI; 99-99.9) and 99.8% (95% CI; 99.3-99.9) for Determine, SD Bioline, First Response and Stat-Pak assays, respectively. There was no any sample which was concordantly false positive in Uni-Gold, Determine and SD Bioline assays. CONCLUSION: An alternative confirmatory HIV testing strategy based on initial testing on either SD Bioline or Determine assays followed by testing of reactive samples on the Determine or SD Bioline gave 100% sensitivity (95% CI; 99.1-100) and 100% specificity (95% CI; 96-99.1) with Uni-Gold as tiebreaker for discordant results

Studies on genital ulcer disease in Tanzania. Aetiology with special reference to Haemophilus ducreyi, association with human immunodeficiecy virus infection, and human papilloma virus

Genital ulcer diseases (GUD) caused by Haemophilus ducreyi, Treponema pallidum and herpessimplex type 2 (HSV-2) are an important health problem in many developing countries. Ulcerativesexually transmitted infections (STIs) have been associated with increased acquisition andtransmission of human immunodeficiency virus type 1 (HIV-1). Thus, the recognition and controlof GUD is important for the prevention of HIV-1.In the present thesis the aetiology of GUD with special reference to Haemophilus ducreyicausing chancroid, was investigated. Presence of antibodies to H. ducreyi cytolethal distendingtoxin (HdCDT) as a tool for the diagnosis of chancroid was determined. The seroprevalence of HIVand to human papilloma virus (HPV) infections was evaluated among patients with GUD andindividuals from the general population of urban Tanzania.Three hundred and two patients with GUD from two Tanzanian cities, representing high-riskgroups, were recruited in 1999 and in 2001 into the study. The sera from pregnant women and maleblood donors were used as a controls and represented individuals from the general population ofTanzania. We used a multiplex PCR to determine the aetiological agents, H. ducreyi, T. pallidumand HSV-2 in ulcer specimens. H. ducreyi was also cultured from the specimens. A randomamplified polymorphic DNA (RAPD) method with two primers was adapted to characterize 43 H.ducreyi isolates from Tanzania, Senegal, South East Asia, Europe and North America. An enzymeimmunosorbent assay (ELISA) was used to detect antibodies to HdCDT, HIV-1 and HPV in serafrom GUD patients, from pregnant women and from male blood donors.HSV-2 was the most common identified agent (49%), followed by H. ducreyi bacterium(12%) in the genital ulcer specimens. The RAPD method generated nine different banding profilesand the majority of African strains were clustered into two patterns for both primers.HIV-1 antibodies were detected in 49% of the GUD sera collected in 1999 and 62% inpatients recruited in 2001.The majority of patients with chancroid and blood donors had low levels of antibodies to HdCDT.However, 32 % of the chancroid patients had significantly higher levels of antibodies to the toxin ascompared to levels in sera from Tanzanian blood donors (4%) (p=0.001).The seroprevalence of HPV types 11, 16, 18, 31, 33, 35, 51 and 52 among the 200 GUD patientswas 11%, 58%, 28% 0%, 3%, 10%, 18% and 62%, respectively. For the pregnant women thehighest prevalence of antibodies was detected to HPV16 (40%) followed by HPV52 (38%) and forthe blood donors HPV16 (10%).To identify the causative agents of GUD is important, since treatment of each of thepathogen differs. The present study revealed that HSV-2 is the most common cause of GUD,followed by H. ducreyi and that the prevalence of HIV-1 is high among patients with STI. Thesefindings suggest the need for integrating diagnosis and HSV-2 treatment in the syndromicmanagement of GUD in Tanzania, in addition to other intervention measures. Treatment of STI,including HSV-2 could also play a role in preventing HIV-1 infection. The diagnosis of chancroidby culture is difficult and PCR method is a good alternative. The study showed a high prevalence ofoncogenic HPV types, 16, 18, 51 and 52 among high-risk group of STI as well as in women fromthe general population of Tanzania. The overload of STIs in high risk-group in Tanzania reinforcesthe need for appropriate strategy to control these infections

Mature Glycoprotein G Presents High Performance in Diagnosing Herpes Simplex Virus Type 2 Infection in Sera of Different Tanzanian Cohorts

Herpes simplex virus type 2 (HSV-2) is a common sexually transmitted infection in sub-Saharan Africa. Glycoprotein G (gG) of HSV-2 elicits a type-specific antibody response and is widely used for serodiagnosis. gG is cleaved into a secreted portion (sgG-2) and a highly O-glycosylated mature portion (mgG-2). The performances of these two native immunosorbent purified antigens were compared in an enzyme-linked immunosorbent assay (ELISA) format with a commercially available assay (FOCUS2) using sera from blood donors (n = 194) and individuals (n = 198) with genital ulcer disease (GUD) from Tanzania. Discordant results were resolved by Western blotting. The HSV-2 seroprevalence for blood donors was estimated as 42%, and that for the GUD cohort was estimated as 78%. The prevalence increased significantly with age for both cohorts and was higher among human immunodeficiency virus (HIV)-positive individuals than among HIV-negative subjects. In the GUD cohort with a high HSV-2 prevalence, all three assays showed statistically similar performances, with sensitivities between 97% and 99% and specificities in the range of 86% to 91%. In contrast, among blood donors with a lower seroprevalence, the mgG-2-based ELISA presented significantly higher specificity (97%) than the sgG-2 ELISA (89%) and FOCUS2 (74%). Overall, the mgG-2 ELISA gave a high performance, with negative and positive predictive values of 96% for blood donors and a negative predictive value of 95% and a positive predictive value of 97% for the GUD cohort. We conclude that native purified mgG-2 showed the highest accuracy for detection of HSV-2 in patient sera from Tanzania and is therefore suitable for seroprevalence studies as well as in clinical settings

Evaluation of simple rapid HIV assays and development of national rapid HIV test algorithms in Dar es Salaam, Tanzania

Abstract Background Suitable algorithms based on a combination of two or more simple rapid HIV assays have been shown to have a diagnostic accuracy comparable to double enzyme-linked immunosorbent assay (ELISA) or double ELISA with Western Blot strategies. The aims of this study were to evaluate the performance of five simple rapid HIV assays using whole blood samples from HIV-infected patients, pregnant women, voluntary counseling and testing attendees and blood donors, and to formulate an alternative confirmatory strategy based on rapid HIV testing algorithms suitable for use in Tanzania. Methods Five rapid HIV assays: Determine™ HIV-1/2 (Inverness Medical), SD Bioline HIV 1/2 3.0 (Standard Diagnostics Inc.), First Response HIV Card 1–2.0 (PMC Medical India Pvt Ltd), HIV1/2 Stat-Pak Dipstick (Chembio Diagnostic System, Inc) and Uni-Gold™ HIV-1/2 (Trinity Biotech) were evaluated between June and September 2006 using 1433 whole blood samples from hospital patients, pregnant women, voluntary counseling and testing attendees and blood donors. All samples that were reactive on all or any of the five rapid assays and 10% of non-reactive samples were tested on a confirmatory Inno-Lia HIV I/II immunoblot assay (Immunogenetics). Results Three hundred and ninety samples were confirmed HIV-1 antibody positive, while 1043 were HIV negative. The sensitivity at initial testing of Determine, SD Bioline and Uni-Gold™ was 100% (95% CI; 99.1–100) while First Response and Stat-Pak had sensitivity of 99.5% (95% CI; 98.2–99.9) and 97.7% (95% CI; 95.7–98.9), respectively, which increased to 100% (95% CI; 99.1–100) on repeat testing. The initial specificity of the Uni-Gold™ assay was 100% (95% CI; 99.6–100) while specificities were 99.6% (95% CI; 99–99.9), 99.4% (95% CI; 98.8–99.7), 99.6% (95% CI; 99–99.9) and 99.8% (95% CI; 99.3–99.9) for Determine, SD Bioline, First Response and Stat-Pak assays, respectively. There was no any sample which was concordantly false positive in Uni-Gold™, Determine and SD Bioline assays. Conclusion An alternative confirmatory HIV testing strategy based on initial testing on either SD Bioline or Determine assays followed by testing of reactive samples on the Determine or SD Bioline gave 100% sensitivity (95% CI; 99.1–100) and 100% specificity (95% CI; 96–99.1) with Uni-Gold™ as tiebreaker for discordant results.</p