The burden and determinants of HIV and sexually transmitted infections in a population-based sample of female sex workers in Goa, India.

BACKGROUND: Interventions targeting sex workers are central to the National AIDS Control programme of India's third 5-year plan. Understanding the way in which societal and individual factors interact to shape sex workers' vulnerability would better inform interventions. METHODS: 326 female sex workers, recruited throughout Goa using respondent-driven sampling, completed interviewer-administered questionnaires. Biological samples were tested for Trichomonas vaginalis, Neisseria gonorrhoea, Chlamydia trachomatis and antibodies to herpes simplex virus type 2 (HSV-2) and HIV. Multivariate analysis was used to define the determinants of HIV infection and any bacterial sexually transmitted infection (STI). RESULTS: Infections were common, with 25.7% prevalence of HIV and 22.5% prevalence of bacterial STI; chlamydia 7.3%, gonorrhoea 8.9% and trichomonas 9.4%. Antibodies to HSV-2 were detected in 57.2% of women. STI were independently associated with factors reflecting gender disadvantage and disempowerment, namely young age, lack of schooling, no financial autonomy, deliberate self-harm, sexual abuse and sex work-related factors, such as having regular customers and working on the streets. Other factors associated with STI were Goan ethnicity, not having an intimate partner and being asymptomatic. Having knowledge about HIV and access to free STI services were associated with a lower likelihood of STI. HIV was independently associated with being Hindu, recent migration to Goa, lodge or brothel-based sex work and dysuria. CONCLUSION: Sex workers working in medium prevalence states of India are highly vulnerable to HIV and STI and need to be rapidly incorporated into existing interventions. Structural and gender-based determinants of HIV and STI are integral to HIV prevention strategies.

Modelling the cost effectiveness of rapid point of care diagnostic tests for the control of HIV and other sexually transmitted infections among female sex workers.

BACKGROUND: In sub-Saharan Africa, gonococcal and chlamydial infections are usually managed using the syndromic approach. However, many infections are asymptomatic in women, and the syndromic algorithm has poor sensitivity and specificity for infections caused by Neisseria gonorrhoeae (Ng) and Chlamydia trachomatis (Ct). Because of this, rapid point of care (POC) tests for Ct/Ng could improve sexually transmitted infection (STI) management in women. This study uses mathematical modelling to estimate the incremental cost effectiveness of using POC tests to diagnose Ng/Ct instead of the current syndromic approach used by the SIDA2 HIV/STI prevention project for female sex workers in Cotonou, Benin. METHODS: A dynamic mathematical model was used with data from Cotonou to estimate the HIV impact of the existing SIDA2 project (1995-8), and to project how impact would change if POC tests had been used. As observed in test evaluations, the POC tests were assumed to have high specificity, but a range of sensitivities. The incremental economic cost effectiveness of using POC tests was modelled using data on intervention costs and an evaluation of an Ng POC test in Cotonou in 2004. All costs were in 2004 US dollars. RESULTS: The model estimated the STI treatment aspect of the intervention averted 18 553 Ng/Ct and 359 HIV infections over 4 years when the syndromic approach was used. In contrast, if Ng/Ct had been diagnosed with a 70-80% sensitive and 95% specific POC test then 24-31% fewer clinic attenders would have been treated, 40-60% more Ng/Ct and HIV infections would have been averted, and the incremental cost effectiveness of using them would have been 107-151 dollars per HIV infection averted if the POC tests cost 2 dollars and 58-81 dollars if they cost 1 dollar. CONCLUSIONS: POC tests can be a cost effective strategy for substantially increasing the impact on HIV transmission, and decreasing the degree of inappropriate treatment of STI treatment interventions that use syndromic management to diagnose Ng/Ct.

The burden and determinants of reproductive tract infections in India: a population based study of women in Goa, India.

BACKGROUND/OBJECTIVE: Reproductive tract infections (RTI) present major health, social, and economic problems in developing countries. Our objective was to describe the prevalence and risk factors of RTIs in a population based sample of women aged 18-45 years. METHOD: 2494 women of 3000 randomly selected from the population defined by a primary health centre catchment area consented to participate. Participants were interviewed regarding complaints and risk factors. Laboratory specimens were collected for the diagnosis of RTIs. Analyses of risk factors were carried out separately for the outcomes of sexually transmitted infections: chlamydia, gonorrhoea, trichomoniasis; and endogenous infections: bacterial vaginosis (BV) and candida. RESULTS: Endogenous infections were relatively common (BV 17.8%; candida 8.5%), and sexually transmitted infections (STI) were infrequent (4.2%). Factors indicative of poverty and marginalisation were associated with STIs and BV. Gender disadvantage, particularly spousal violence, was associated with BV, while concern about a husband's extramarital relationships, an indicator of sexual risk, was associated with STI. Husband's discharge was strongly associated with STI, and a non-white vaginal discharge was associated with both STI and BV. Condom use and oral contraceptive use were associated with a reduced risk of BV. CONCLUSIONS: Most of the population burden of RTIs is attributed to endogenous infections. Socioeconomic deprivation and gender disadvantage are associated with raised risk for BV, while the risk factors for STIs indicated that disadvantaged women were likely to be infected by their husbands.

Modelling the cost-effectiveness of introducing rapid syphilis tests into an antenatal syphilis screening programme in Mwanza, Tanzania.

OBJECTIVES: A study found screening (with rapid plasma reagin (RPR)) pregnant women for maternal syphilis was cost-effective in Mwanza, Tanzania. Recently, four rapid point-of-care (POC) syphilis tests were evaluated in Mwanza, and found to have reasonable sensitivity/specificity. This analysis estimates the relative cost-effectiveness of using these POC tests in the Mwanza syphilis screening intervention. METHODS: Empirical cost and epidemiological data were used to model the potential benefit of using POC tests instead of RPR. Reductions in costs relating to training, supplies, and equipment were estimated, and any changes in impact due to test sensitivity were included. Additional modelling explored how the results vary with prevalence of past infection, misclassified RPR results, and if not all women return for treatment. RESULTS: The cost-effectiveness of using POC tests is mainly dependent on their cost and sensitivity for high titre active syphilis (HTAS). Savings due to reductions in training and equipment are small. Current POC tests may save more disability-adjusted life years (DALYs) than the RPR test in Mwanza, but the test cost needs to be <0.63 US dollars to be as cost-effective as RPR. However, the cost-effectiveness of the RPR test worsens by 15% if its HTAS sensitivity had been 75% instead of 86%, and by 25-65% if 20-40% of women had not returned for treatment. In such settings, POC tests could improve cost-effectiveness. Lastly, the cost-effectiveness of POC tests is affected little by the prevalence of syphilis, false RPR-positives, and past infections. DISCUSSION: Although the price of most POC tests needs to be reduced to make them as cost-effective as RPR, their simplicity and limited requirements for electricity/equipment suggest their use could improve the coverage of antenatal syphilis screening in developing countries.

Is antenatal syphilis screening still cost effective in sub-Saharan Africa.

OBJECTIVES: To estimate the cost effectiveness of on-site antenatal syphilis screening and treatment in Mwanza, Tanzania. To compare this intervention with other antenatal and child health interventions, specifically the prevention of mother to child transmission of HIV (PMTCT). METHODS: The economic costs of adding the intervention to routine antenatal care were assessed. Cost effectiveness (CE) ratios of the intervention were obtained for low birth weight (LBW) live births and stillbirths averted and cost per DALY saved. Cost per DALY saved was also estimated for previous CE studies of syphilis screening. The CE of the intervention at different syphilis prevalence rates was modelled. RESULTS: The economic cost of the intervention is $1.44 per woman screened, $20 per woman treated, and $187 per adverse birth outcome averted. The cost per DALY saved is $110 with LBW as the only adverse outcome. When including stillbirth, this estimate improves 10-fold to $10.56 per DALY saved. The cost per DALY saved from all syphilis screening studies ranged from $3.97 to $18.73. CONCLUSIONS: Syphilis screening is shown to be at least as cost effective as PMTCT and more cost effective than many widely implemented interventions. There is urgent need for scaling up syphilis screening and treatment in high prevalence areas. The CE of screening interventions is highly dependent on disease prevalence. In combination, PMTCT and syphilis screening and treatment interventions may achieve economies of scope and thus improved efficiency.

Operational performance of an STD control programme in Mwanza Region, Tanzania.

OBJECTIVES: To describe important details of the design and operational features of the Mwanza sexually transmitted diseases (STD) control programme. To assess the feasibility of the intervention, the distribution of STD syndromes observed, the clinical effectiveness of syndromic STD case management, the utilisation of STD services by the population, and the quality of syndromic STD services delivered at rural health units. METHODS: The intervention was integrated into rural primary healthcare (PHC) units. It comprised improved STD case management using the syndromic approach, facilitated by a regional programme office which ensured the training of health workers, a reliable supply of effective drugs, and regular support supervision. Five studies were performed to evaluate operational performance: (i) a survey of register books to collect data on patients presenting with STDs and reproductive tract infections (RTIs) to rural health units with improved STD services, (ii) a survey of register books from health units in communities without improved services, (iii) a survey of register books from referral clinics, (iv) a home based cross sectional study of STD patients who did not return to the intervention health units for follow up, (v) a cross sectional survey of reported STD treatment seeking behaviour in a random cohort of 8845 adults served by rural health units. RESULTS: During the 2 years of the Mwanza trial, 12,895 STD syndromes were treated at the 25 intervention health units. The most common syndromes were urethral discharge (67%) and genital ulcers (26%) in men and vaginal discharge (50%), lower abdominal tenderness (33%), and genital ulcers (13%) in women. Clinical treatment effectiveness was high in patients from whom complete follow up data were available, reaching between 81% and 98% after first line treatment and 97%-99% after first, second, and third line treatment. Only 26% of patients referred to higher levels of health care had presented to their referral institutions. During the trial period, data from the cohort showed that 12.8% of men and 8.6% of women in the intervention communities experienced at least one STD syndrome. Based on various approaches, utilisation of the improved health units by symptomatic STD patients in these communities was estimated at between 50% and 75%. During the first 6 months of intervention attendance at intervention units increased by 53%. Thereafter, the average attendance rate was about 25% higher than in comparison communities. Home visits to 367 non-returners revealed that 89% had been free of symptoms after treatment, but 28% became symptomatic again within 3 months of treatment. 100% of these patients reported that they had received treatment, but only 74% had been examined, only 57% had been given health education, and only 30% were offered condoms. Patients did not fully recall which treatment they had been given, but possibly only 63% had been treated exactly according to guidelines. CONCLUSIONS: This study demonstrated that it is feasible to integrate effective STD services into the existing PHC structure of a developing country. Improved services attract more patients, but additional educational efforts are needed to further improve treatment seeking behaviour. Furthermore, clear treatment guidelines, a reliable drug supply system, and regular supervision are critical. All efforts should be made to treat patients on the spot, without delay, as referral to higher levels of care led to a high number of dropouts. The syndromic approach to STD control should be supported by at least one reference clinic and laboratory per country to ensure monitoring of prevalent aetiologies, of the development of bacterial resistance, and of the effectiveness of the syndromic algorithms in use.

Reproductive-tract infections in women in low-income, low-prevalence situations: assessment of syndromic management in Matlab, Bangladesh.

BACKGROUND: In the control of reproductive-tract infections, including sexually transmitted infections (STIs), in low-income and middle-income countries, WHO recommends syndromic management for individuals with symptoms. This intervention was initially developed in areas where prevalence of such infections is high. We investigated the clinical effectiveness and cost of this approach among a group of women with a low prevalence of infection. METHODS: During a 5-month period, we investigated all women complaining of abnormal vaginal discharge and seeking care at maternal and child health/family-planning centres in Matlab, Bangladesh, for the presence of laboratory-diagnosed reproductive-tract infections and STIs. Syndromic diagnoses made by trained health-care workers were compared with laboratory diagnosis of infection. We then calculated the costs of treating women by means of the recommended WHO algorithm and an adapted algorithm incorporating use of a speculum and simple diagnostic tests. FINDINGS: The prevalence of endogenous infections among 320 women seen was 30%. Cervical infections (Neisseria gonorrhoeae and Chlamydia trachomatis) were found in only three women. The WHO algorithm had a high sensitivity (100%) but a low specificity (zero for bacterial vaginosis, candida, and Trichomonas vaginalis). The speculum-based algorithm had a low sensitivity (between zero and 59%) but a higher specificity (79-97%). Between 36% and 87% of costs would have been spent on uninfected women. INTERPRETATION: The high rate of overtreatment in the population studied carries both financial and social costs--the latter in potentially exposing women misdiagnosed as having an STI to threats of domestic disruption or even violence. We make recommendations for management programmes in areas of low STI prevalence and low income.

PIP: This paper presents a study on the syndromic management of reproductive tract infections among women in low-income and low-prevalence situations. Women complaining of abnormal vaginal discharge and seeking care at health centers in Matlab, Bangladesh, were examined for the presence of laboratory-diagnosed reproductive tract infections and sexually transmitted infections. In the results, 30% of 320 women were diagnosed as having endogenous infections. Overall result of the study revealed a low prevalence of sexually transmitted infections among these women. The WHO algorithm had 100% sensitivity but a low specificity, while the speculum-based algorithm had a low sensitivity (0-59%) but a higher specificity (79-97%). Cost analysis indicated that 87% of expenditure was wasted on overtreatment under the WHO algorithm, while only 36% of expenditure was wasted on overtreatment using the speculum-based algorithm. In conclusion, the development of simple, affordable and effective diagnostic tests should be prioritized by policymakers and public health specialists to ensure the provision of adequate services among the higher risk groups in society.

The availability and cost of antibiotics for treating PID in the Central Region of Ghana and implications for compliance with national treatment guidelines.

The availability and cost of antibiotics for treating pelvic inflammatory disease (PID) were assessed in 17 drug-dispensing outlets in 5 districts of the Central Region, Ghana. The outlets included the dispensaries of 2 regional and 4 district hospitals, 4 privately-owned pharmacies and 7 chemical seller shops. The most common antibiotics available, including co-trimoxazole, metronidazole, benzylpenicillin, amoxycillin, chloramphenicol and gentamicin, were also the lowest-priced drugs. Conversely, the most expensive antibiotics including ceftriaxone, ciprofloxacin, cefuroxime and spectinomycin, were also the least commonly available. Recommended anti-gonococcal antibiotics (ciprofloxacin, ceftriaxone) may not be prescribed if they are not available in the districts.

PIP: This paper assessed the availability and cost of antibiotics used for treating pelvic inflammatory disease in 17 drug-dispensing outlets in five districts of the Central Region, Ghana. The outlets included the dispensaries of 2 regional and 4 district hospitals, 4 privately owned pharmacies, and 7 chemical seller shops. The most common antibiotics available, including cotrimoxazole, metronidazole, benzylpenicillin, amoxycillin, chloramphenicol, and gentamicin, were also the lowest priced drugs. In contrast, the most expensive antibiotics, including ceftriaxone, ciprofloxacin, cefuroxime, and spectinomycin, were also the least commonly available. Recommended anti-gonococcal antibiotics (ciprofloxacin, ceftriaxone) may not be prescribed if they are not available in the districts.

Validation of a WHO algorithm with risk assessment for the clinical management of vaginal discharge in Mwanza, Tanzania.

OBJECTIVES: (i) To determine the microbial aetiologies of vaginal discharge in STD clinic and antenatal clinic (ANC) attenders; (ii) to evaluate the performance and costs of a new WHO algorithm for the detection of gonococcal and chlamydial infections in women complaining of vaginal discharge and/or genital itching, using a risk assessment. METHODS: Two groups were enrolled: (i) 395 consecutive female patients attending a hospital outpatient clinic complaining of genital discharge or itching; and (ii) 628 consecutive pregnant women reporting at an urban ANC these symptoms. Patients were interviewed by a nurse, who applied the WHO risk score. They were then referred to the study room for interview concerning the same and other risk factors, examined, and sampled for Neisseria gonorrhoeae (NG), Chlamydia trachomatis (CT), Trichomonas vaginalis (TV), and Candida albicans (CA). Sensitivity, specificity, positive predictive value, overtreatment and correct treatment rates, and cost of drugs per true case treated were estimated. RESULTS: The prevalence of NG and/or CT infections was 11.4% and 8% at the STD clinic and the ANC respectively. The most prevalent pathogens were CA (38% at both clinics) and TV (25% at the STD clinic and 34% at the ANC). The sensitivity of the WHO algorithm for NG and/or CT was 62% at the STD clinic and 46% at the ANC, and the specificities were 64% and 84% respectively. The operational feasibility of the method was good. The cost of drugs per true case treated in applying the risk assessment approach was $3.5 among nonpregnant women and $5.0 among pregnant women. This compared favourably with respective costs of $8.8 and $25.0 in applying the syndromic management alone. CONCLUSIONS: The WHO risk assessment algorithm for the diagnosis of NG and/or CT infections among women complaining of genital discharge can considerably reduce overtreatment of NG and/or CT in both pregnant and non-pregnant women, but in this study it failed to identify 38% of non-pregnant and 54% of pregnant women with these infections. The elements of the risk score may need adjustment in different settings.

STD rapid assessment in Rwandan refugee camps in Tanzania.

OBJECTIVE: To obtain baseline information on sexually transmitted diseases (STDs) in the Rwandan refugees camps in Tanzania, prior to establishment of STD services. SETTING: The largest camps of Rwandan refugees in the Ngara District of Tanzania (estimated population 300,000). The study was carried out in 8 days in August 1994. SUBJECTS AND METHODS: A rapid assessment technique was used to measure STD prevalences among: (i) 100 antenatal clinic attenders (ANC); (ii) 239 men from outpatient clinics (OPD); and (iii) 289 men from the community. Interviews (by questionnaire) and genital examination were performed for all participants; sampling for females included genital swabs for the the diagnosis of Neisseria gonorrhoeae (NG), Candida albicans (CA), Trichomonas vaginalis (TV), bacterial vaginosis (BV) and a blood sample for syphilis serology. Men provided urine samples which were screened for leucocytes using the leucocyte esterase (LE) dipstick; urethral swabs for Gram stain were taken from men with a reactive LE test and from those with symptoms or signs of urethritis. OPD males provided a blood sample for syphilis serology. RESULTS: All groups reported frequent experience with STDs and engaging in risky sexual behaviour prior to the survey. During the establishment of the camps, sexual activity was reportedly low. Over 50% of ANC attenders were infected with agents causing vaginitis (TV/BV/CA) and 3% were infected with NG. The prevalence of active syphilis was 4%. In the male outpatients, the prevalence of urethritis was 2.6% and of serological syphilis was 6.1%. Among males in the community, the prevalence of urethritis was 2.9% (the majority being asymptomatic infections). We noted frequent over-reporting of STD symptoms, unconfirmed clinically or biologically. CONCLUSIONS: STD case detection and management should be improved by training health workers in using the WHO syndromic approach, and through IEC campaigns encouraging attendance at clinics. Rapid epidemiological methods provide quick and useful information at low cost in refugee camps.

Cost-effectiveness of improved treatment services for sexually transmitted diseases in preventing HIV-1 infection in Mwanza Region, Tanzania.

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.

PIP: Improved management of sexually transmitted diseases (STDs) is consistently advocated as an effective strategy for HIV prevention. The impact, cost, and cost-effectiveness of this approach were evaluated in a prospective, comparative study of six communities in Tanzania's Mwanza Region in which primary health care center workers were trained to provide improved STD treatment and six matched non-intervention communities. The baseline prevalence of HIV was 4% in both groups. During the 2-year study period, 11,632 cases of STDs were treated in the intervention health units. The HIV seroconversion rate was 1.16% in the intervention communities and 1.86% in the comparison communities--a difference in HIV incidence of 0.70 (95% confidence interval, 0.37-1.09) and a reduction of about 40%. The total annual cost of the intervention was US$59,060 ($0.39 per person served). The cost of STD treatment was $10.15 per case. An estimated 252 HIV-1 infections were averted each year. The incremental annual cost of the program was $54,839, equivalent to $217.62 per HIV infection averted and $10.33 per disability-adjusted-life-year (DALY) saved. The estimated cost-effectiveness compares favorably with that of childhood immunization programs ($12-17 per DALY saved) and could be further enhanced through implementation of the intervention on a wider scale. The intervention subsequently has been expanded to encompass 65 health units in Mwanza Region, with no increase in investment costs.

Analysis of the household distribution of trachoma in a Gambian village using a Monte Carlo simulation procedure.

Studies on the household distribution of trachoma have reached conflicting conclusions. This paper describes a cross-sectional survey of endemic trachoma in a Gambian village. Cases of active trachoma were mapped, and the compound and household distribution of the disease analysed by a Monte Carlo simulation procedure which takes into account differences in the size and age distribution within individual households. Significant clustering of active trachoma cases both by village compound (p less than 0.0001) and bedroom (less than 0.05) were detected supporting the concept that intra-familial transmission of trachoma is important. There was no evidence of spatial clustering of rooms with higher than expected prevalence of trachoma. Clustering of disease in space or time provides important evidence of infectious aetiology and route of transmission. The methods discussed here are generally applicable in the study of other infectious diseases.