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Genetic Characterization of Vibrio cholerae O1 isolates from outbreaks between 2011 and 2015 in Tanzania. BMC Infect Dis 2017; 17:157. [PMID: 28219321 PMCID: PMC5319185 DOI: 10.1186/s12879-017-2252-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 02/08/2017] [Indexed: 12/30/2022] Open
Abstract
Background Cholera outbreaks have occurred in Tanzania since 1974. To date, the genetic epidemiology of these outbreaks has not been assessed. Methods 96 Vibrio cholerae O1 isolates from five regions were characterized, and their genetic relatedness assessed using multi-locus variable-number tandem-repeat analysis (MLVA) and whole genome sequencing (WGS). Results Of the 48 MLVA genotypes observed, 3 were genetically unrelated to any others, while the remaining 45 genotypes separated into three MLVA clonal complexes (CCs) - each comprised of genotypes differing by a single allelic change. In Kigoma, two separate outbreaks, 4 months apart (January and May, 2015), were each caused by genetically distinct strains by MLVA and WGS. Remarkably, one MLVA CC contained isolates from both the May outbreak and ones from the 2011/2012 outbreak in Dar-es-Salaam. However, WGS revealed the isolates from the two outbreaks to be distinct clades. The outbreak that started in August 2015 in Dar-es-Salaam and spread to Morogoro, Singida and Mara was comprised of a single MLVA CC and WGS clade. Isolates from within an outbreak were closely related differing at fewer than 5 nucleotides. All isolates were part of the 3rd wave of the 7th pandemic and were found in four clades related to isolates from Kenya and Asia. Conclusions We conclude that genetically related V. cholerae cluster in outbreaks, and distinct strains circulate simultaneously. Electronic supplementary material The online version of this article (doi:10.1186/s12879-017-2252-9) contains supplementary material, which is available to authorized users.
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The Canadian Society for Epidemiology and Biostatistics 2016 National Student Conference001INVESTIGATING ECOLOGICAL DETERMINANTS OF MALARIA VECTOR DISTRIBUTION IN RURAL TANZANIA “A MULTI-SCALAR INVESTIGATION”002PREVALENCE AND RISK FACTORS OF TUBERCULOSIS INFECTION AMONG HEALTHCARE TRAINEES IN SOUTH INDIA003SPATIAL MODELLING OF LUNG AND THYROID CANCERS IN UNITED STATES COUNTIES004A MEDIATION ANALYSIS TO ASSESS THE IMPACT OF INHALED CORTICOSTEROIDS (ICSS) DURING PREGNANCY ON BIRTHWEIGHT005MODELLING HUMAN RISK OF WEST NILE VIRUS IN ONTARIO, 2002-2013: INCORPORATING SURVEILLANCE AND ENVIRONMENTAL DATA006EXPLORING THE HEALTH OUTCOMES OF VARIOUS PAN-CANADIAN CERVICAL CANCER SCREENING PROGRAMS USING MICROSIMULATION MODELING007INTEGRATIVE ANALYSIS OF MICRORNA AND GENE EXPRESSION DATA USING SPARSE CANONICAL CORRELATION ANALYSIS008CONDITIONAL DEPENDENCE MODELS UNDER COVARIATE MEASUREMENT ERROR009ASSOCIATION BETWEEN FOOD INSECURITY AND HIV VIRAL SUPPRESSION: A SYSTEMATIC REVIEW AND META-ANALYSIS010ANTIBIOTICS VERSUS APPENDECTOMY FOR UNCOMPLICATED APPENDICITIS: A GLOBAL HEALTH PERSPECTIVE. Am J Epidemiol 2016. [DOI: 10.1093/aje/kww058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Trends in the selection of insecticide resistance in Anopheles gambiae s.l. mosquitoes in northwest Tanzania during a community randomized trial of longlasting insecticidal nets and indoor residual spraying. MEDICAL AND VETERINARY ENTOMOLOGY 2015; 29:51-59. [PMID: 25537754 PMCID: PMC4359020 DOI: 10.1111/mve.12090] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 08/27/2014] [Accepted: 09/03/2014] [Indexed: 06/04/2023]
Abstract
Anopheles gambiae s.l. (Diptera: Culicidae) in Muleba, Tanzania has developed high levels of resistance to most insecticides currently advocated for malaria control. The kdr mutation has almost reached fixation in An. gambiae s.s. in Muleba. This change has the potential to jeopardize malaria control interventions carried out in the region. Trends in insecticide resistance were monitored in two intervention villages using World Health Organization (WHO) susceptibility test kits. Additional mechanisms contributing to observed phenotypic resistance were investigated using Centers for Disease Control (CDC) bottle bioassays with piperonylbutoxide (PBO) and S,S,S-tributyl phosphorotrithioate (DEF) synergists. Resistance genotyping for kdr and Ace-1 alleles was conducted using quantitative polymerase chain reaction (qPCR). In both study villages, high phenotypic resistance to several pyrethroids and DDT was observed, with mortality in the range of 12-23%. There was a sharp decrease in mortality in An. gambiae s.l. exposed to bendiocarb (carbamate) from 84% in November 2011 to 31% in December 2012 after two rounds of bendiocarb-based indoor residual spraying (IRS). Anopheles gambiae s.l. remained susceptible to pirimiphos-methyl (organophosphate). Bendiocarb-based IRS did not lead to the reversion of pyrethroid resistance. There was no evidence for selection for Ace-1 resistance alleles. The need to investigate the operational impact of the observed resistance selection on the effectiveness of longlasting insecticidal nets and IRS for malaria control is urgent.
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Distribution and spread of pyrethroid and DDT resistance among the Anopheles gambiae complex in Tanzania. MEDICAL AND VETERINARY ENTOMOLOGY 2014; 28:244-52. [PMID: 24192019 PMCID: PMC10884793 DOI: 10.1111/mve.12036] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Revised: 09/10/2013] [Accepted: 09/19/2013] [Indexed: 06/02/2023]
Abstract
The development of insecticide resistance is a threat to the control of malaria in Africa. We report the findings of a national survey carried out in Tanzania in 2011 to monitor the susceptibility of malaria vectors to pyrethroid, organophosphate, carbamate and DDT insecticides, and compare these findings with those identified in 2004 and 2010. Standard World Health Organization (WHO) methods were used to detect knock-down and mortality rates in wild female Anopheles gambiae s.l. (Diptera: Culicidae) collected from 14 sentinel districts. Diagnostic doses of the pyrethroids deltamethrin, lambdacyhalothrin and permethrin, the carbamate propoxur, the organophosphate fenitrothion and the organochlorine DDT were used. Anopheles gambiae s.l. was resistant to permethrin in Muleba, where a mortality rate of 11% [95% confidence interval (CI) 6-19%] was recorded, Muheza (mortality rate of 75%, 95% CI 66-83%), Moshi and Arumeru (mortality rates of 74% in both). Similarly, resistance was reported to lambdacyhalothrin in Muleba, Muheza, Moshi and Arumeru (mortality rates of 31-82%), and to deltamethrin in Muleba, Moshi and Muheza (mortality rates of 28-75%). Resistance to DDT was reported in Muleba. No resistance to the carbamate propoxur or the organophosphate fenitrothion was observed. Anopheles gambiae s.l. is becoming resistant to pyrethoids and DDT in several parts of Tanzania. This has coincided with the scaling up of vector control measures. Resistance may impair the effectiveness of these interventions and therefore demands close monitoring and the adoption of a resistance management strategy.
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Prevalence of genotypic resistance to antiretroviral drugs in treatment-naive youths infected with diverse HIV type 1 subtypes and recombinant forms in Dar es Salaam, Tanzania. AIDS Res Hum Retroviruses 2011; 27:377-82. [PMID: 20954839 DOI: 10.1089/aid.2010.0113] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
As human immunodeficiency virus (HIV) diversity may have an impact on both vaccine efficacy and drug resistance, it is important to have knowledge of circulating genetic variants. With widespread use of antiretroviral (ARV) drugs in Africa, one of the major potential challenges is the risk of emergence of ARV drug-resistant HIV strains. This study aimed to determine the circulating HIV subtypes and recombinant forms, as well as the prevalence of ARV drug resistance mutations, among 75 treatment-naive HIV-infected youths in Dar es Salaam, Tanzania. Gag (n = 48), partial pol (n = 44), and partial env (n = 35) sequencing was performed; all three regions were sequenced in 26 samples. Evidence of infection with recombinant viruses was found in 12 (46%) participants; AC recombinants were the most commonly detected and they were identified in six (23%) participants. Of individuals infected with nonrecombinant strains, subtype A was most commonly detected in seven (27%) participants, followed by subtype C detected in six (23%) participants and subtype D detected in one (4%) participant. Among the pol sequences from 44 individuals, three (7%) had resistance to nucleoside reverse transcriptase (RT) inhibitors and four (9%) had nonnucleoside RT inhibitor resistance mutations. Of these, three (7%) individuals were infected with viruses with cross-resistance mutations to both classes of RT inhibitors. These resistant mutations were all associated with drugs currently used in first-line therapy and in the prevention of vertical transmission. This high prevalence of resistance mutations is of considerable concern in apparently drug-naive populations as it may result in treatment failure and the spread of ARV-resistant strains.
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From strategy to action: The vital roles of trained field epidemiologists and laboratory management professionals in epidemic control and prevention in Tanzania. Int J Infect Dis 2010. [DOI: 10.1016/j.ijid.2010.02.579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Controlling persistent cholera outbreaks in Africa: Lessons from the recent Cholera Outbreak, West District Unguja Zanzibar, Tanzania, 2009. Int J Infect Dis 2010. [DOI: 10.1016/j.ijid.2010.02.1549] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Abstract
Data from studies in Mwanza Region in Tanzania suggest stabilising HIV prevalence. The objective was to determine the factors that may have contributed to the relatively stable pattern of the HIV prevalence observed in the comparison communities of the Mwanza STD treatment trial in rural Mwanza Region, Tanzania between 1991 and 2001. Socio-demographic, sexual behaviour and HIV prevalence data in two surveys conducted 10 years apart in the same communities using similar sampling schemes were compared. The age standardised HIV prevalence was 3.8% (95% CI: 3.2-4.6) in 1991 and 4.3% (95% CI: 2.8-6.4) in 2001 for males (Z= - 0.56, P= 0.58); and 4.5% (95% CI: 3.8-5.3) in 1991 and 3.9% (95% CI: 2.6-5.6) in 2001 for females (Z= 0.64, P = 0.52). Participants in the 2001 survey reported significantly fewer lifetime and recent sexual partners (12 months), Sexually Transmitted disease syndromes (12 months) and significantly more condom use at last sex with casual partners than those in the 1991 behaviour survey. We conclude that STD/HIV infection prevention activities in rural Mwanza may be responsible for changes in risky sexual behaviour and have successfully impeded the spread of HIV infection. These activities should therefore be enhanced to reduce HIV incidence even further. In addition, modelling studies are needed to assess whether mobility of HIV infected people out of rural communities may stabilise the prevalence of the HIV infection in the general populations.
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Vector species composition and malaria infectivity rates in Mkuzi, Muheza District, north-eastern Tanzania. ACTA ACUST UNITED AC 2008; 10:46-9. [DOI: 10.4314/thrb.v10i1.14341] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Evaluation of the effectiveness of a clean delivery kit intervention in preventing cord infection and puerperal sepsis among neonates and their mothers in rural Mwanza Region, Tanzania. ACTA ACUST UNITED AC 2006; 7:185-8. [PMID: 16941946 DOI: 10.4314/thrb.v7i3.14258] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A study was carried out in Misungwi and Kwimba Districts, Tanzania to determine the effectiveness of clean delivery kits in preventing cord infection and puerperal sepsis and to provide qualitative information on community acceptability, correct use, and appropriateness of the kits. This study involved pregnant women aged 18-45 years old. In the delivery kit intervention population, the Maternal and Child Health Aide (MCHA) assigned to the health facility provided pregnant mothers with a clean delivery kit on their first antenatal visit. She explained how to use each of the kit components, with the aid of pictorial instructions included in the kit. The pregnant mothers were asked to convey the information to whoever assisted them during delivery. The MCHA also gave them health education based on the principles of the "six cleans" recognized by WHO (i.e., clean hands, clean perineum, clean delivery surface, clean cord cutting and tying instruments, clean cutting surface). Women received the clean delivery kit free of charge in accordance with the randomised stepped-wedge design schedule. During the first week following delivery, the Village Health Workers (VHWs) from both the intervention and control groups made two visits to the households of mothers who had delivered. They administered questionnaire about delivery to mother and birth attendant. During the two scheduled postpartum visits, those who were suspected to have puerperal sepsis or cord infection of the baby were referred to the health facility clinician for confirmation. Results indicated that use of clean delivery kit had a positive effect on reducing both cord infection and puerperal sepsis. The use of a clean home delivery kit coupled with an educational intervention about the "six cleans" had a significant effect on reducing the incidence of cord infection and puerperal sepsis among women enrolled in the study. In low resource settings where home birth is common and clean delivery supplies are scarce, disposable kits can be made available through health clinics, markets, pharmacies or other channels to help reduce rates of infection.
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Abstract
BACKGROUND/OBJECTIVES There is an urgent need for effective interventions to improve the sexual and reproductive health of adolescents. Reliable data on the sexual health of adolescents are needed to guide the development of such interventions. The aim was to describe the sexual health of pupils in years 4 to 6 of 121 rural primary schools in north western Tanzania, before the implementation of an innovative sexual health intervention in 58 of the schools. METHODS A cross sectional survey of primary school pupils in rural Tanzania was carried out. The study population comprised pupils registered in years 4 to 6 of 121 primary schools in 20 rural communities in 1998. Basic demographic information was collected from all pupils seen. Those born before 1 January 1985 (aged approximately 14 years and over) were invited to participate in the survey, and asked about their knowledge and attitudes towards sexual health issues, and their sexual experience. A urine specimen was requested and tested for HIV, Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and, for females, pregnancy. RESULTS 9283 pupils born before 1 January 1985 were enrolled and provided demographic information and a urine sample. Male pupils were significantly older than females (mean age 15.5 years v 14.8 years, p<0.001), but all other demographic characteristics were similar between the sexes. 14 (0.2%) of the enrolled pupils (four male and 10 female) were HIV positive, 83 (0.9%) were positive for CT, and 12 (0.1%) for NG. 32 female pupils (0.8%) were positive by pregnancy test. Sexual experience was reported by one fifth of primary school girls, and by almost half of boys. Only 45/114 (39%) girls with biological markers of sexual activity reported having had sex. CONCLUSIONS HIV, CT, NG, and pregnancy were present though at relatively low levels among pupils in years 4 to 6 of primary school. A high proportion of pupils with a biological marker of sexual activity denied ever having had sex. Alternative ways of collecting sensitive data about the sexual behaviour of school pupils should be explored.
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How many patients with a sexually transmitted infection are cured by health services? A study from Mwanza region, Tanzania. Trop Med Int Health 2001; 6:971-9. [PMID: 11737832 DOI: 10.1046/j.1365-3156.2001.00809.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVES To estimate the proportion of symptomatic patients with a bacterial sexually transmitted infection (STI) cured by primary health care services in Mwanza Region, Tanzania, and to compare the cure rate achieved by health centres before and after the introduction of improved STI treatment services. METHODS A model was used that describes the different hurdles patients with an STI take before they can be considered cured by the health services. The values for the input parameters for the model were taken from different studies. Data from an intervention trial as well as from a population-based study on male urethritis were used to estimate the proportion of symptomatic patients with an STI who seek care from a health centre. An observational study in four health centres where improved STI treatment services had been introduced provided estimates of the proportions of patients with an STI correctly diagnosed and treated. Patients who returned to the health centres after 1 week were interviewed about compliance. An estimate of the efficacy of treatments prescribed for STIs in health centres before the introduction of improved STI services was obtained from a study on prescription patterns for genital discharge syndrome (GDS) and genital ulcer disease (GUD). RESULTS It was estimated that in the catchment area of health centres offering improved STI services, 51-72% of patients with STI symptoms sought care from those health centres. About 76-85% of cases were correctly diagnosed, and of these 69-80% received efficacious treatment. Compliance with full treatment was estimated at 84%. The estimated overall cure rate achieved by the health centres offering improved STI services ranged between 23 and 41%. The proportion of symptomatic STI patients who attended a health centre before improved STI services were introduced was estimated at 39%. The estimated efficacy of the treatments prescribed was 28%. The overall cure rate achieved by these health centres was less than 10%. CONCLUSIONS When assessing the performance of STI case detection and management all steps have to be taken into account that are taken by patients with an STI before they can be considered cured by the health services. The intervention to improve STI services in Mwanza Region has resulted in an improvement of the cure rate of STIs achieved by primary health care centres.
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Abstract
OBJECTIVE To estimate the prevalence of HIV and Chlamydia trachomatis (CT) infections amongst adolescents in rural Mwanza Region, Tanzania and their association with demographic variables. DESIGN Population-based cross-sectional survey. METHODS All 15--19-year olds living in households selected by random cluster sampling were invited to participate. After interview, urine was tested for HIV and CT. RESULTS 9445 15--19-year olds were enrolled. HIV prevalence was 0.6% (95% CI: 0.4--0.8%) in males and 2.4% (95% CI: 2.0--2.8%) in females, and increased steeply with age (trend: P < 0.006 and P < 0.001, respectively). After adjustment for age, risk of HIV infection was significantly associated with female sex (OR=4.3), never having been to primary school in males (OR=2.7), and current symptoms of genital discharge (OR=2.3) or genital ulcer (OR=5.3) in females. The prevalence of CT was 1.0% (95% CI: 0.8--1.4%) in males and 2.4% (95% CI: 2.0-2.9%) in females. After adjustment for age, CT infection was associated with female sex (OR=2.4), reported current symptoms of STD (males OR=2.5, females OR=1.9) and positive leucocyte esterase (LE) test (males OR=3.1, females OR=2.6). Eighty-two percent of males and 79% of females with CT were asymptomatic. There was no association between CT and HIV infection in either sex. CONCLUSIONS There is a high prevalence of HIV and CT amongst adolescents, especially young women, in this rural population, highlighting the need for effective interventions to improve adolescent reproductive health. The high rates of asymptomatic infection imply that innovative strategies are needed to reach and treat young people with STD.
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Risk factors for active syphilis and TPHA seroconversion in a rural African population. Sex Transm Infect 2001; 77:37-45. [PMID: 11158690 PMCID: PMC1758332 DOI: 10.1136/sti.77.1.37] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVES Syphilis is an important cause of morbidity in sub-Saharan Africa, and a cofactor for the sexual transmission of HIV. A better understanding of the prevalence and risk factors of syphilis in African populations would help to formulate effective interventions for its prevention and treatment. METHODS The prevalence and incidence of syphilis were obtained from a cohort recruited in Mwanza, Tanzania. Two unmatched case-control studies nested within the cohort provide information on potential risk factors. RESULTS The prevalence of active syphilis (TPHA positive and RPR positive any titre) was 7.5% in men and 9.1% in women, but in youths (aged 15-19 years) the prevalence was higher in women (6.6%) than in men (2.0%). The incidence of TPHA seroconversion was highest in women aged 15-19 at 3.4% per year, and around 2% per year at all ages among men. A higher prevalence of syphilis was found in those currently divorced or widowed (men: OR=1.61, women: OR=2.78), and those previously divorced or widowed (men: OR=1.51, women: OR=1.85). Among men, prevalence was associated with lack of circumcision (OR=1.89), traditional religion (OR=1.55), and reporting five or more partners during the past year (OR=1.81) while incidence was associated with no primary education (OR=2.17), farming (OR=3.85), and a self perceived high risk of STD (OR=3.56). In women, prevalence was associated with no primary education (OR=2.13), early sexual debut (OR=1.59), and a self perceived high risk of STD (OR=3.57), while incidence was associated with living away from the community (OR=2.72). CONCLUSION The prevalence and incidence of syphilis remain high in this rural African population. More effort is needed to promote safer sexual behaviour, and to provide effective, accessible treatment. The high incidence of syphilis in young women calls for sexual health interventions targeted at adolescents.
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High prevalence of trichomoniasis in rural men in Mwanza, Tanzania: results from a population based study. Sex Transm Infect 2000; 76:355-62. [PMID: 11141851 PMCID: PMC1744211 DOI: 10.1136/sti.76.5.355] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
OBJECTIVES To measure the prevalence of urethral infections including trichomoniasis in rural Tanzanian men, to assess the prevalence of symptoms and signs among men with Trichomonas vaginalis, and to analyse the risk factors for trichomoniasis. DESIGN A cross sectional study of 1004 men aged 15-54 years in a rural community in north west Tanzania. METHODS Participants were interviewed about sexual behaviour and symptoms of sexually transmitted diseases. First fraction urine samples and urethral swabs were collected and used to test for T vaginalis by wet preparation and culture, Neisseria gonorrhoeae by culture, Chlamydia trachomatis by ligase chain reaction and non-specific urethritis by Gram stain. Urine was also tested for the presence of leucocytes using a leucocyte esterase dipstick. Men were re-interviewed 2 weeks later to document new symptoms and signs of urethritis. RESULTS Complete laboratory results were available on 980 men. One in four men had laboratory evidence of urethritis. T vaginalis was found in 109 individuals (11%), gonorrhoea in eight (0.8%), and chlamydial infection in 15 (1.5%). Over 50% of men with urethritis were asymptomatic. The prevalence of signs and symptoms was similar among men with T vaginalis alone compared with men with other urethral infections. The sensitivity and specificity of the leucocyte esterase dipstick (LED) test for detecting T vaginalis were 80% and 48% respectively in symptomatic men and 60% and 68% in asymptomatic men. Factors associated with trichomoniasis included religion, type of employment, and marital status. CONCLUSIONS A high prevalence of urethritis was found in men in this community based study. More than half of the urethral infections detected were asymptomatic. The most prevalent pathogen was T vaginalis. Studies are needed on the prevalence of trichomoniasis in men presenting to health services with complaints suggestive of urethritis since treatment for T vaginalis is not included in the syndromic management of urethritis in most countries. The performance of the LED test as a screening test for trichomoniasis was unsatisfactory in both symptomatic and asymptomatic men. Improved screening tests are urgently needed to identify urethral infections that are asymptomatic and which are not covered by current syndromic management algorithms.
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Syndromic treatment of sexually transmitted diseases reduces the proportion of incident HIV infections attributable to these diseases in rural Tanzania. AIDS 2000; 14:1429-37. [PMID: 10930159 DOI: 10.1097/00002030-200007070-00017] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To compare the proportion of HIV seroconversions attributable to other sexually transmitted diseases in the intervention and comparison arms of the Mwanza sexually transmitted diseases (STD) intervention trial. DESIGN Case-control study of 96 cases of HIV seroconversion and 974 HIV-negative controls, nested within the Mwanza trial cohort. METHODS Data on reported STD symptoms during 2 years of follow-up, and serological evidence of recent syphilis, were used to obtain odds ratios (ORs) for HIV seroconversion, adjusted for community, age, marital status, sex partners and travel. Population-attributable fractions (PAF) of HIV seroconversions associated with these STD exposures were calculated separately for the intervention and comparison arms, and for men and women. RESULTS In men in the comparison arm, adjusted ORs for ulcers (14.8), discharge (3.3), any symptom (4.1) and any STD (4.0) were highly significant. There were no significant associations between HIV incidence and STD exposures in the intervention arm. The PAF were consistently higher in the comparison arm than the intervention arm. In men, the PAF for any STD was 39.6% [95% confidence interval (CI), 12.4-58.3)] in the comparison arm but only 12.0% (CI, 0.0-35.9) in the intervention arm. The PAF for women were lower than for men. CONCLUSIONS These are minimal PAF estimates and they do not account for STD effects on HIV infectiousness. Nevertheless, a substantial proportion of new HIV infections in men in the comparison arm were attributable to STD. Lower PAF in the intervention arm than in the comparison arm for men provide further evidence of the role of STD cofactors in HIV transmission, supporting the hypothesis that the Mwanza intervention reduced the duration of symptomatic STD, thus reducing the HIV risk associated with such STD.
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Livestock management and malaria prevention in irrigation schemes. PARASITOLOGY TODAY (PERSONAL ED.) 1999; 15:394-5. [PMID: 10481148 DOI: 10.1016/s0169-4758(99)01522-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Antibody to herpes simplex virus type 2 as a marker of sexual risk behavior in rural Tanzania. J Infect Dis 1999; 179:16-24. [PMID: 9841817 DOI: 10.1086/314555] [Citation(s) in RCA: 130] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
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.
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Cost-effectiveness of improved treatment services for sexually transmitted diseases in preventing HIV-1 infection in Mwanza Region, Tanzania. Lancet 1997; 350:1805-9. [PMID: 9428251 DOI: 10.1016/s0140-6736(97)08222-6] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND A community-randomised trial was undertaken to assess the impact, cost, and cost-effectiveness of averting HIV-1 infection through improved management of sexually transmitted diseases (STDs) by primary-health-care workers in Mwanza Region, Tanzania. METHODS The impact of improved treatment services for STDs on HIV-1 incidence was assessed by comparison of six intervention communities with six matched communities. We followed up a random cohort of 12,537 adults aged 15-54 years for 2 years to record incidence of HIV-1 infection. The total and incremental costs of the intervention were estimated (ingredients approach) and used to calculate the total cost per case treated, the incremental cost per HIV-1 infection averted, and the incremental cost per disability-adjusted life-year (DALY) saved. FINDINGS During 2 years of follow-up, 11,632 cases of STDs were treated in the intervention health units. The baseline prevalence of HIV-1 infection was 4%. The incidence of HIV-1 infection during the 2 years was 1.16% in the intervention communities and 1.86% in the comparison communities. An estimated 252 HIV-1 infections were averted each year. The total annual cost of the intervention was US$59,060 (1993 prices), equivalent to $0.39 per head of population served. The cost for STD case treated was $10.15, of which the drug cost was $2.11. The incremental annual cost of the intervention was $54,839, equivalent to $217.62 per HIV-1 infection averted and $10.33 per DALY saved (based on Tanzanian life expectancy) or $9.45 per DALY saved (based on the assumptions of the World Development Report). In a sensitivity analysis of factors influencing cost-effectiveness, cost per DALY saved ranged from $2.51 to $47.86. INTERPRETATION Improved management of STDs in rural health units reduced the incidence of HIV-1 infection in the general population by about 40%. The estimated cost-effectiveness of this intervention ($10 per DALY) compares favourably with that of, for example, childhood immunisation programmes ($12-17 per DALY). Cost-effectiveness should be further improved when the intervention is applied on a larger scale. Resources should be made available for this highly cost-effective HIV control strategy.
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Improved treatment services significantly reduce the prevalence of sexually transmitted diseases in rural Tanzania: results of a randomized controlled trial. AIDS 1997; 11:1873-80. [PMID: 9412707 DOI: 10.1097/00002030-199715000-00013] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To evaluate the impact of improved case management for sexually transmitted diseases (STD) at the primary health care level on the incidence and prevalence of STD. DESIGN Community-randomized controlled trial. SETTING Mwanza region, Tanzania. SUBJECTS A random cohort of about 1000 adults aged 15-54 years from each of 12 communities, in six matched pairs. One member of each pair was assigned at random to receive the intervention, and the others served as a comparison community. This cohort was surveyed at baseline and at follow-up 2 years later. About 100 antenatal clinic attenders were also studied in each community on two occasions: the first shortly after the implementation of the intervention, and the second approximately 1 year later. INTERVENTION Improved services were established for the management of STD, using the syndromic approach, in rural health units. RESULTS A total of 12,534 individuals were enrolled in the cohort study, of whom 8844 (71%) were seen again 2 years later. The prevalence of serological syphilis (rapid plasma reagin titre > or = 1:8, Treponema pallidum haemagglutinin assay positive) was 6.2% in both intervention and comparison communities at baseline. At follow-up it was 5.0% in the intervention community and 7.0% in the comparison community [adjusted relative risk (RR), 0.71; 95% confidence interval (CI), 0.54-0.93; P < 0.02]. The prevalence of urethritis in males did not differ significantly between intervention and comparison groups at follow-up, but the prevalence of symptomatic urethritis was reduced by about 50% (adjusted RR, 0.51; 95% CI, 0.24-1.10; P = 0.08). There was no significant difference between the groups in the incidence of self-reported STD symptoms over the last year of the follow-up period, or in the prevalence of any STD in antenatal clinic attenders. CONCLUSION The reduction in HIV incidence previously reported in this intervention study can be attributed to a reduction in the duration, and hence the prevalence of symptomatic STD.
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Abstract
OBJECTIVE To measure HIV-associated adult mortality in a rural population in Tanzania. To record the signs and symptoms associated with deaths of HIV-positive adults. DESIGN Prospective cohort study conducted in the context of a randomized controlled trial to evaluate the impact of a sexually transmitted disease treatment programme. METHODS A cohort consisting of a random sample of 12501 adults aged 15-54 years was recruited from 12 rural communities in Mwanza region, Tanzania in 1991/1992. Baseline HIV prevalence was 4.0%. The cohort was followed up after 2 years to record mortality according to baseline HIV status. A verbal autopsy questionnaire was administered for each of the deaths reported. RESULTS A total of 196 deaths were recorded, of which 73 (37%) occurred in HIV-positive individuals. Mortality rates per 1000 person-years were 6.0 in HIV-negatives and 93.5 in HIV-positives. The age-adjusted mortality rate ratio was 15.68 (95% confidence interval, 11.18-21.03). The proportion of adult deaths attributed to HIV infection was 35% overall and 53% in those aged 20-29 years. Verbal autopsies showed that HIV-positive deaths were significantly associated with fever, rash, weight loss, anaemia, cough, chest pain, abdominal pain and headache, but the specificity of individual symptoms was low. The World Health Organization clinical case definition of AIDS was satisfied for only 13 deaths, of which seven were HIV-positive at baseline. Only seven respondents reported that the death was associated with HIV or AIDS. CONCLUSIONS This study confirms the strong association of HIV infection and mortality in rural Africa, with an annual death rate in adult seropositives of over 9%. In this rural population with a relatively low HIV prevalence of 4%, HIV has increased overall adult mortality by more than 50%. Signs and symptoms associated with HIV deaths were non-specific, and the population seemed largely unaware of the contribution of HIV to mortality, an important obstacle to prevention efforts.
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Abstract
The HIV epidemic in sub-Saharan Africa has been characterised by the predominance of heterosexual transmission. Patterns of sexual behaviour have been implicated in the spread of the epidemic, but few quantitative data are available on sexual behaviour in rural populations in Africa. This paper reports data from a survey of 1117 adults aged 15-54 years selected randomly from twelve rural communities in Mwanza Region, Tanzania. Sexual debut occurred early, 50% of women and 46% of men reporting first sex before age 16. On average, women married 1.8 years and men 6.1 years after their sexual debut. In women, age at sexual debut appears to have increased over time, in parallel with an increase in age at first marriage. Men were generally married later, to women around five to ten years younger than themselves. Marital dissolution and remarriage were common in both sexes. Reported numbers of sexual partners were compared with those recorded in a population survey in Britain. More men reported 10 or more lifetime partners, or three or more partners in the past year, in rural Mwanza (48% and 29%) than in Britain (24% and 6%). Women reported fewer partners, and results were broadly similar to British data. Casual sex during the past year was reported by 53% of the men and 15% of the women, but only 2% of men reported sexual contact with bar girls or commercial sex workers. Only 20% of men and 3% of women had ever used a condom. Interventions are needed to reduce the high levels of sexual partner change and casual sex, and low levels of condom use, recorded in this rural population. Targeting of interventions to traditional "core groups" may be of limited value in rural areas, and additional strategies are needed, focusing particularly on teenagers who are at high risk of HIV and other sexually transmitted diseases.
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Abstract
OBJECTIVE To examine the association between HIV infection and patterns of sexual behaviour and other risk factors in a rural Tanzanian population in a case-control study, nested within a randomized trial of improved sexually transmitted disease treatment. METHODS All HIV-positive patients from the baseline survey of the randomized trial were eligible as cases. Cases (n = 338) and controls (a random sample of one in eight HIV-negative persons; n = 1078) were interviewed about risk factors for HIV infection using a structured questionnaire. RESULTS A significantly higher HIV prevalence was found among men and women not currently employed in farming [men: odds ratio (OR), 2.08; women: OR, 3.65], women who had travelled (OR, 3.27), educated women (OR, 4.51), and widowed/ divorced people compared with those currently married (men: OR, 3.10; women: OR, 3.54). Two spouse-related factors were significantly associated with HIV, even after adjustment for the sexual behaviour of the index case: HIV was more prevalent in men with younger spouses (P = 0.020 for trend) and in women married to men currently employed in manual work, office work or business (OR, 2.20). In women only, blood transfusions were associated with a higher HIV prevalence (OR, 2.40), but only a small population attributable fraction (4%). There was an increased HIV prevalence associated with increasing numbers of injections. Reported number of lifetime sexual partners was significantly associated with HIV infection (women: OR, 7.33 if > or = 10 lifetime partners compared with < or = 1; men: OR, 4.35 for > or = 50 compared with < or = 1). After adjustment for confounders, male circumcision was associated with a lower HIV prevalence (OR, 0.65; P = 0.11). CONCLUSIONS In these rural communities, many HIV infections occur through sexual transmission. Some people are at high risk of HIV infection through large numbers of sex partners, whereas some are at risk through their spouse or regular partner. The role of circumcision in HIV transmission is unclear. Commercial sex seems to play a negligible role in HIV transmission in these communities. Our results confirm marked heterogeneity in HIV risk, indicating the scope for risk reduction strategies.
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Asymptomatic gonorrhoea and chlamydial infection in rural Tanzanian men. BMJ (CLINICAL RESEARCH ED.) 1996; 312:277-80. [PMID: 8611782 PMCID: PMC2349889 DOI: 10.1136/bmj.312.7026.277] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVE To measure the prevalence of urethritis due to Neisseria gonorrhoeae and Chlamydial infection trachomatis in rural Tanzanian men DESIGN About 500 men aged 15-54 years were selected from each of 12 rural communities by random cluster sampling; interviewed concerning past or present symptoms of sexually transmitted diseases; and asked to provide a first catch urine specimen, which was tested for pyuria with a leucocyte esterase dipstick test. Subjects with symptoms or with a positive result on testing were examined, and urethral swabs were taken for detection of N gonorrhoeae by gram stain and of C trachomatis by antigen detection immunoassay. SETTING Mwanza region, north western Tanzania. SUBJECTS 5876 men aged 15-54 years. MAIN OUTCOME MEASURES Prevalence of urethral symptoms, observed urethral discharge, pyuria, urethritis ( > 4 pus cells per high power field on urethral smear), N gonorrhoeae infection (intracellular gram negative diplococci), and C trachomatis infection (IDEIA antigen detection assay). RESULTS 1618 (28%) subjects reported ever having a urethral discharge. Current discharge was reported by 149 (2.5%) and observed on examination in 207 (3.5%). Gonorrhoea was found in 128 subjects (2.2%) and chlamydial infection in 39 (0.7%). Only 24 of 158 infected subjects complained of urethral discharge at the time of interview (15%). CONCLUSION Infection with N gonorrhoeae and C trachomatis is commonly asymptomatic among men in this rural African population. This has important implications for the design of control programmes for sexually transmitted disease.
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Abstract
A randomised trial was done to evaluate the impact of improved sexually transmitted disease (STD) case management at primary health care level on the incidence of HIV infection in the rural Mwanza region of Tanzania. HIV incidence was compared in six intervention communities and six pair-matched comparison communities. A random cohort of about 1000 adults aged 15-54 years from each community was surveyed at baseline and at follow-up 2 years later. Intervention consisted of establishment of an STD reference clinic, staff training, regular supply of drugs, regular supervisory visits to health facilities, and health education about STDs. 12,537 individuals were recruited. Baseline HIV prevalences were 3.8% and 4.4% in the intervention and comparison communities, respectively. At follow-up, 8845 (71%) of the cohort were seen. Of those initially seronegative, the proportions seroconverting over 2 years were 48 of 4149 (1.2%) in the intervention communities and 82 of 4400 (1.9%) in the comparison communities. HIV incidence was consistently lower in the intervention communities in all six matched pairs. Allowing for the community-randomised design and the effects of confounding factors, the estimated risk ratio was 0.58 (95% CI 0.42-0.79, p = 0.007). No change in reported sexual behaviour was observed in either group. We conclude that improved STD treatment reduced HIV incidence by about 40% in this rural population. This is the first randomised trial to demonstrate an impact of a preventive intervention on HIV incidence in a general population.
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A community trial of the impact of improved sexually transmitted disease treatment on the HIV epidemic in rural Tanzania: 1. Design. AIDS 1995; 9:919-26. [PMID: 7576328 DOI: 10.1097/00002030-199508000-00014] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
OBJECTIVE To describe the rationale and design of a randomized trial of the impact of improved services for the treatment of sexually transmitted diseases (STD) on the incidence of HIV infection in Mwanza Region, Tanzania. METHODS The likely impact of improved STD treatment services on HIV incidence, and the need for empirical information on the effectiveness of this intervention strategy, are discussed. The rationale and design of such an intervention programme in Mwanza Region, and of a community-randomized trial to measure the impact of the programme on HIV and other STD, are presented. Problems in the design and interpretation of the trial are reviewed. RESULTS Results of the baseline survey of the cohort of over 12,000 adults in 12 communities are presented in a companion paper. CONCLUSION There is an urgent need for effective preventive measures against the HIV epidemic in sub-Saharan Africa and other developing regions. Improved STD treatment has been promoted as a potentially effective strategy, but there is little empirical information on its impact. The trial in Mwanza Region is the first randomized study of this intervention and should provide valuable data for health policy makers.
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A community trial of the impact of improved sexually transmitted disease treatment on the HIV epidemic in rural Tanzania: 2. Baseline survey results. AIDS 1995; 9:927-34. [PMID: 7576329 DOI: 10.1097/00002030-199508000-00015] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
OBJECTIVES To determine baseline HIV prevalence in a trial of improved sexually transmitted disease (STD) treatment, and to investigate risk factors for HIV. To assess comparability of intervention and comparison communities with respect to HIV/STD prevalence and risk factors. To assess adequacy of sample size. SETTING Twelve communities in Mwanza Region, Tanzania: one matched pair of roadside communities, four pairs of rural communities, and one pair of island communities. One community from each pair was randomly allocated to receive the STD intervention following the baseline survey. METHODS Approximately 1000 adults aged 15-54 years were randomly sampled from each community. Subjects were interviewed, and HIV and syphilis serology performed. Men with a positive leucocyte esterase dipstick test on urine, or reporting a current STD, were tested for urethral infections. RESULTS A total of 12,534 adults were enrolled. Baseline HIV prevalences were 7.7% (roadside), 3.8% (rural) and 1.8% (islands). Associations were observed with marital status, injections, education, travel, history of STD and syphilis serology. Prevalence was higher in circumcised men, but not significantly after adjusting for confounders. Intervention and comparison communities were similar in the prevalence of HIV (3.8 versus 4.4%), active syphilis (8.7 versus 8.2%), and most recorded risk factors. Within-pair variability in HIV prevalence was close to the value assumed for sample size calculations. CONCLUSIONS The trial cohort was successfully established. Comparability of intervention and comparison communities at baseline was confirmed for most factors. Matching appears to have achieved a trial of adequate sample size. The apparent lack of a protective effect of male circumcision contrasts with other studies in Africa.
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A population-based study of syphilis and sexually transmitted disease syndromes in north-western Tanzania. 1. Prevalence and incidence. Genitourin Med 1993; 69:415-20. [PMID: 8282291 PMCID: PMC1195142 DOI: 10.1136/sti.69.6.415] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVE To determine the prevalence of syphilis and the prevalence and incidence of self-reported STD syndromes in the population of Mwanza Region, North-Western Tanzania. METHODS A population-based random cluster sample survey, stratified by rural, roadside or urban residence, of 4173 individuals aged 15-54 years was performed in 1990-91. The seroprevalence of syphilis (using TPHA and RPR) and the prevalence and incidence of self-reported genital ulcer syndrome (GUS) and genital discharge syndrome (GDS) were determined. RESULTS Active syphilis was detected in 9% of the adult population, while 15% had serological evidence of past or current infection. Seroprevalence was significantly lower in the rural than in the roadside and urban populations, but there was little difference between men and women. Amongst men, a history of GDS was reported by 28%, and a history of GUS by 14%, with point prevalences of 2.3% and 1.3% respectively. Annual incidence among men were 6.8% for GDS and 3.6% for GUS. Women reported these conditions less frequently. There was little difference between the strata in the prevalence or incidence of reported STD syndromes. CONCLUSION Sexually transmitted diseases represent a major public health problem in both the rural and urban populations of Mwanza Region.
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A population-based study of syphilis and sexually transmitted disease syndromes in north-western Tanzania. 2. Risk factors and health seeking behaviour. Genitourin Med 1993; 69:421-6. [PMID: 8282292 PMCID: PMC1195143 DOI: 10.1136/sti.69.6.421] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVE To determine risk factors for syphilis and sexually transmitted disease (STD) syndromes, and to study health seeking behaviour among those with STD syndromes, in the population of Mwanza Region, North-Western Tanzania. METHODS A population-based random cluster sample survey, stratified by rural, roadside or urban residence, of 4173 individuals aged 15-54 years was performed in 1990-91. The seroprevalence of syphilis and the prevalence and incidence of self-reported genital ulcer syndrome (GUS) and genital discharge syndrome (GDS) are reported in the accompanying paper. This paper reports on risk factors for these conditions and on health seeking behaviour among those reporting them. RESULTS In both sexes, the risk of STDs increased with the reported number of sexual partners in the previous five years. Men who were separated, divorced or widowed were at increased risk of STDs, but this was not the case among women. Higher educational status was associated with an increased risk of urethral discharge in males but with a decreased prevalence of syphilis in females. Male circumcision was associated with an increased risk of urethral discharge but a reduced prevalence of syphilis. Nearly all men, and 90% of women, reporting symptoms of genital discharge or ulceration had sought treatment. Of these, approximately 70% of males and 60% of females had sought treatment in the official health sector. CONCLUSIONS Targetted health education concerning risk reduction for HIV infection and other STDs should be a high priority in this population. Improved case management of STDs in health centres and dispensaries may have a substantial impact on the incidence of these infections.
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Sentinel surveillance for HIV-1 infection: how representative are blood donors, outpatients with fever, anaemia, or sexually transmitted diseases, and antenatal clinic attenders in Mwanza Region, Tanzania? AIDS 1993; 7:567-72. [PMID: 8507421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVE To assess the validity of extrapolation from sentinel data by comparing the HIV-1 prevalence of various sentinel groups with that of the general population in Mwanza Region, Tanzania. METHODS In a population survey, 4161 individuals were selected in a stratified random cluster sample. Sentinel groups (all in the age group 15-54 years) included blood donors (n = 1090); patients examined at district hospitals for the presence of malaria parasites (n = 1488), anaemia (n = 1339), or syphilis (n = 33); and antenatal clinic attenders (n = 1193). The HIV-1 serostatus of individuals selected from the population survey was tested using enzyme-linked immunosorbent assay (ELISA) and Western blot; 51% of the blood donors were tested using HIVCHEK, and all others using ELISA. HIV-1 prevalence was standardized for age, sex, and urban/non-urban location. RESULTS HIV-1 prevalence (standardized by age, sex, and residence) in Mwanza Region was 4.0% (3.0% in non-urban areas and 11.3% in town). The standardized HIV-1 prevalences in the sentinel groups were: blood donors, 4.5%; patients with fever, 11.6%; patients with anaemia, 8.9%; urban sexually transmitted disease patients, 27.1%; urban antenatal clinic attenders, 11.8%. The crude prevalence in blood donors was 6.0%. CONCLUSION Blood donors who are related to blood recipients appear to be a representative sentinel group in this region, provided that data are standardized for age, sex, and urban/non-urban location. Patients with fever and antenatal clinic attenders may reflect trends, but data from patients with fever markedly overestimate, and data from antenatal clinic attenders underestimate, population HIV-1 prevalence. Because self-selection of blood donors may become more pronounced, this comparison should be repeated later or elsewhere, should the opportunity arise.
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