How many patients with a sexually transmitted infection are cured by health services? A study from Mwanza region, Tanzania

Real-time PCR detection of mixed Plasmodium ovale curtisi and wallikeri species infections in human and mosquito hosts

Plasmodium ovale curtisi (Poc) and Plasmodium ovale wallikeri (Pow) represent distinct non-recombining malaria species that are increasing in prevalence in sub-Saharan Africa. Though they circulate sympatrically, co-infection within human and mosquito hosts has rarely been described. Separate 18S rRNA real-time PCR assays that detect Poc and Pow were modified to allow species determination in parallel under identical cycling conditions. The lower limit of detection was 0.6 plasmid copies/μL (95% CI 0.4-1.6) for Poc and 4.5 plasmid copies/μL (95% CI( 2.7- 18) for Pow, or 0.1 and 0.8 parasites/μL, respectively, assuming 6 copies of 18s rRNA per genome. However, the assays showed cross-reactivity at concentrations greater than 103 plasmid copies/μL (roughly 200 parasites/μL). Mock mixtures were used to establish criteria for classifying mixed Poc/Pow infections that prevented false-positive detection while maintaining sensitive detection of the minority ovale species down to 10° copies/μL (<1 parasite/μL). When the modified real-time PCR assays were applied to field-collected blood samples from Tanzania and Cameroon, species identification by real-time PCR was concordant with nested PCR, but additionally detected two mixed Poc/Pow infections where nested PCR detected a single Po species. When real-time PCR was applied to 14 oocyst-positive Anopheles midguts saved from mosquitoes fed on P. ovate-infected persons, mixed Poc/Pow infections were detected in 11 (79%). Based on these results, 8/9 P. ovate carriers transmitted both P. ovate species to mosquitoes, though both Po species could only be detected in the blood of two carriers. The described real-time PCR approach can be used to identify the natural occurrence of mixed Poc/Pow infections in human and mosquito hosts and reveals that such co-infections and co-transmission are likely more common than appreciated.

Assessment of syndromic management of curable sexually transmitted and reproductive tract infections among pregnant women: an observational cross-sectional study

Background

This study estimated the prevalence of curable sexually transmitted and reproductive tract infections (STIs/RTIs) among pregnant women attending antenatal care (ANC) in rural Zambia, evaluated the effectiveness of syndromic management of STIs/RTIs versus reference-standard laboratory diagnoses, and identified determinants of curable STIs/RTIs during pregnancy.

Methods

A total of 1086 pregnant women were enrolled at ANC booking, socio-demographic information and biological samples were collected, and the provision of syndromic management based care was documented. The Piot-Fransen model was used to evaluate the effectiveness of syndromic management versus etiological testing, and univariate and multivariate logistic regression analyses were used to identify determinants of STIs/RTIs.

Results

Participants had a mean age of 25.6 years and a mean gestational age of 22.0 weeks. Of 1084 women, 700 had at least one STI/RTI (64.6%; 95% confidence interval [CI], 61.7, 67.4). Only 10.2% of infected women received any treatment for a curable STI/RTI (excluding syphilis). Treatment was given to 0 of 56 women with chlamydia (prevalence 5.2%; 95% CI, 4.0, 6.6), 14.7% of participants with gonorrhoea (prevalence 3.1%; 95% CI, 2.2, 4.4), 7.8% of trichomoniasis positives (prevalence 24.8%; 95% CI, 22.3, 27.5) and 7.5% of women with bacterial vaginosis (prevalence 48.7%; 95% CI, 45.2, 51.2). An estimated 7.1% (95% CI, 5.6, 8.7) of participants had syphilis and received treatment. Women < 20 years old were more likely (adjusted odds ratio [aOR] = 5.01; 95% CI: 1.23, 19.44) to have gonorrhoea compared to women ≥30. The odds of trichomoniasis infection were highest among primigravidae (aOR = 2.40; 95% CI: 1.69, 3.40), decreasing with each subsequent pregnancy. Women 20 to 29 years old were more likely to be diagnosed with bacterial vaginosis compared to women ≥30 (aOR = 1.58; 95% CI: 1.19, 2.10). Women aged 20 to 29 and ≥ 30 years had higher odds of infection with syphilis, aOR = 3.96; 95% CI: 1.40, 11.20 and aOR = 3.29; 95% CI: 1.11, 9.74 respectively, compared to women under 20.

Conclusions

Curable STIs/RTIs were common and the majority of cases were undetected and untreated. Alternative approaches are urgently needed in the ANC setting in rural Zambia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03573-3.

Determinants of Malaria Transmission at the Population Level

Transmission of malaria from man to mosquito defines the human infectious reservoir of malaria. At the population level this is influenced by a variety of human, parasite, and mosquito vector factors some or all of which may vary depending on the epidemiological setting. Here, we review our current state of knowledge related to human infectiousness to mosquitoes and how current malaria control strategies might be adapted to focus on reducing this. While much progress has been made in malaria control, we argue that an improved understanding of human infectivity will allow more effective use of current control tools and make elimination a more feasible goal.

Dynamics of the Human Infectious Reservoir for Malaria Determined by Mosquito Feeding Assays and Ultrasensitive Malaria Diagnosis in Burkina Faso

BACKGROUND

Plasmodium falciparum gametocytes are essential for malaria transmission. Malaria control measures that aim at reducing transmission require an accurate characterization of the human infectious reservoir.

METHODS

We longitudinally determined human infectiousness to mosquitoes and P. falciparum carriage by an ultrasensitive RNA-based diagnostics in 130 randomly selected inhabitants of an endemic area.

RESULTS

At least 1 mosquito was infected by 32.6% (100 of 307) of the blood samples; in total, 7.6% of mosquitoes (916 of 12 079) were infected. The proportion of infectious individuals and infected mosquitoes were negatively associated with age and positively with asexual parasites (P < .001). Human infectiousness was higher at the start of the wet season and subsequently declined at the peak of the wet season (adjusted odds ratio, 0.52; P = .06) and in the dry season (0.23; P < .001). Overall, microscopy-negative individuals were responsible for 28.7% of infectious individuals (25 of 87) and 17.0% of mosquito infections (145 of 855).

CONCLUSIONS

Our study reveals that the infectious reservoir peaks at the start of the wet season, with prominent roles for infections in children and submicroscopic infections. These findings have important consequences for strategies and the timing of interventions, which need to include submicroscopic infections and be implemented in the dry season.

A study of 113 cases of genital ulcerative disease and urethral discharge syndrome with validation of syndromic management of sexually transmitted diseases

AIMS

To validate syndromic management of cases having genital ulcerative disease (GUD) and urethral discharge syndrome (UDS).

MATERIALS AND METHODS

A study of 113 cases of GUD and UDS was carried out in the Department of Skin and VD from March 2011 to August 2012. All cases having history and clinical evidence suggestive of GUD and UDS were included in the study.

RESULTS

According to syndromic diagnosis, GUD herpetic syndrome was the most common 71 (62.27%), followed by GUD non-herpetic syndrome 25 (21.89%) and UDS 17 (14.91%). Out of 71 cases clinically diagnosed as GUD herpetic, 16 (22.53%) were validated by immunoglobulin M (IgM) anti herpes simplex virus-2 (HSV) serology, 14 (19.71%) by Tzanck smear and 3 (4.22%) by both. 24 (33.80%) were Reactive plasma Reagin (RPR)(<1:8) reactive and trepenomma palidum haem-agglutination positive. Out of total 25 clinically diagnosed GUD non herpetic cases, 22 (88%) were validated by laboratory tests Out of 17 cases of UDS, 15 (88%) were validated by smear.

CONCLUSION

Sensitivity and specificity of clinically diagnosed syndrome is not so high particularly for GUD herpetic syndrome Continuous monitoring of diagnostic component of syndromic approach is key to success of STD control program.

Missed opportunities: poor linkage into ongoing care for HIV-positive pregnant women in Mwanza, Tanzania

Background

Global coverage of prevention of mother-to-child (PMTCT) services reached 53% in 2009. However the number of pregnant women who test positive for HIV in antenatal clinics and who link into long-term HIV care is not known in many resource-poor countries. We measured the proportion of HIV-positive pregnant women in Mwanza city, Tanzania, who completed the cascade of care from antenatal HIV diagnosis to assessment and engagement in care in adult HIV clinics.

Methods

Thirty antenatal and maternity ward health workers were interviewed about PMTCT activities. Nine antenatal HIV education sessions were observed. A prospective cohort of 403 HIV-positive women was enrolled by specially-trained clinicians and nurses on admission to delivery and followed for four months post-partum. Information was collected on referral and attendance at adult HIV clinics, eligibility for highly active antiretroviral therapy (HAART) and reasons for lack of attendance.

Results

Overall, 70% of PMTCT health workers referred HIV-positive pregnant women to the HIV clinic for assessment and care. Antenatal HIV education sessions did not cover on-going care for HIV-infected women. Of 310 cohort participants tested in pregnancy, 51% had received an HIV clinic referral pre-delivery. Only 32% of 244 women followed to four months post-partum had attended an HIV clinic and been assessed for HAART eligibility. Non-attendance for HIV care was independently associated with fewer antenatal visits, poor PMTCT prophylaxis compliance, non-disclosure of HIV status, and non-Sukuma ethnicity.

Conclusion

Most women identified as HIV-positive during pregnancy were not assessed for HAART eligibility during pregnancy or in the first four months post-partum. Initiating HAART at the antenatal clinic, improved counselling and linkages to care between PMTCT and adult HIV treatment services and reducing stigma surrounding disclosure of HIV results would benefit on-going care of HIV-positive pregnant women.

Operational assessment of access to ART in rural Africa: the example of Kisantu in Democratic Republic of the Congo

Despite the availability of large funds and considerable efforts to improve access to antiretroviral therapy (ART), coverage of treatment with ART remains low in Democratic Republic of the Congo (DRC). We identified the bottlenecks for adults' access to ART in a semi-rural health zone in DRC, compared ART coverage in the urban and rural area and described the outcomes and yield of different HIV testing settings. An operational model was used to examine bottlenecks in the flow of patients. The study period covered the start of the HIV care programme in April 2006, until December 2008. An estimated 505 People Living With HIV/AIDS (PLWHA), of whom 201 were in need of ART, lived in the health zone. The proportion of PLWHA in need of ART who were actually receiving ART was estimated at 53%. About 6451 adults were tested for HIV, 266 of them were HIV-positive and 163 accessed the HIV care programme. About 106 of the 126-159 eligible patients initiated ART. The main bottleneck was situated at HIV detection. Access to the HIV care programme for the patients testing HIV-positive was identified as the second biggest bottleneck. About 41% of the PLWHA identified in urban areas accessed the HIV care programme, versus 11% of the rural PLWHA, showing a serious inequity. The tuberculosis (TB) programme detected 75% of the total estimated 92 co-infected patients of the health zone. Only 13% of women testing positive in the Prevention of Mother-To-Child Transmission programme accessed the HIV care programme, showing that this bottleneck is greatly accentuated in this specific group. By testing all pregnant women and all TB patients in the health zone, 28% of all PLWHA could potentially be detected in a period of 33 months, showing its great potential in settings with a relatively low HIV prevalence.

Treatment of sexually transmitted infections for HIV prevention: end of the road or new beginning?

Observational and biological data provide compelling evidence of the importance of sexually transmitted infections (STIs) in HIV transmission, but only one of nine intervention trials has shown an effect. This article reviews the observational studies, critically examines the nine randomized controlled trials evaluating the impact of STI treatment interventions on HIV incidence, and discusses implications for HIV prevention policy, programs and future research. The role of other vaginal infections is also briefly considered. In aggregate, the evidence strongly supports the concept that STI treatment prevents HIV infection. However, issues in trial design and conduct, including HIV epidemic phase, STI prevalence, intervention in comparison groups, and power have affected five of the six trials of treatment of curable STIs. In the three herpes intervention trials, antivirals for HSV suppression were insufficiently potent to alleviate persistent genital inflammation in HIV-negative HSV2-positive persons, and the reduction in HIV levels in HIV-positive persons was insufficient to reduce HIV transmission. It is time for a new phase of exploration of how, when, and in whom to include STI control as a key component of HIV prevention, driven by basic research to elucidate the mechanisms by which STIs and vaginal infections facilitate HIV transmission. From a policy perspective, treatment of curable STIs is an essential part of primary healthcare and is a cheap, simple, and effective intervention when appropriately targeted and delivered. It should be promoted as an essential component of HIV control programs in communities in which the burden of STIs is substantial.

The effect of syndromic management interventions on the prevalence of sexually transmitted infections in South Africa

OBJECTIVES

Few studies have assessed the effect of syndromic management interventions on the prevalence of sexually transmitted infections (STIs) at a population level. This study aims to determine the effect of syndromic management protocols that have been introduced in South Africa since 1994.

STUDY DESIGN

A mathematical model of sexual behaviour patterns in South Africa was used to model the incidence of HIV, genital herpes, syphilis, chancroid, gonorrhoea, chlamydial infection, trichomoniasis, bacterial vaginosis and vaginal candidiasis. Assumptions about health seeking behaviour and treatment effectiveness were based on South African survey data. The model was fitted to available STI prevalence data.

MAIN OUTCOME MEASURES

Reductions in STI prevalence due to syndromic management.

RESULTS

Between 1995 and 2005, there were significant reductions in the prevalence of syphilis, chancroid, gonorrhoea, trichomoniasis and chlamydial infection. In women aged between 15 and 49, syndromic management resulted in a 33% (95% CI: 23-43%) decline in syphilis prevalence, a 6% (95% CI: 3-11%) reduction in gonorrhoea prevalence, a 5% (95% CI: 1-13%) reduction in the prevalence of bacterial vaginosis and a substantial decline in chancroid. However, syndromic management did not significantly reduce the prevalence of other STIs. For all STIs, much of the modelled reduction in STI prevalence between 1995 and 2005 can be attributed to either increased condom usage or AIDS mortality.

CONCLUSIONS

Syndromic management of STIs can be expected to decrease the prevalence of curable STIs that tend to become symptomatic, but has little effect on the prevalence of STIs that are mostly asymptomatic.

Community Effectiveness of Artemisinin-Based Combination Therapy for Malaria in Rural Southwestern Nigeria

A descriptive cross sectional survey using an interviewer-administered questionnaire was carried out among 700 caregivers whose children had fever during the previous two weeks. The aim was to determine the community effectiveness of malaria treatment using arthemeter-lumefantrine (AL) among under-5-year-olds in a rural community in southwestern Nigeria. A total of 353 (50.9%) children received AL. About half of these children (49%) were said to have been treated within 24 hours of onset of symptoms; 44% took the drug for the stipulated period of time; 42% received the correct dosage; and only 4% received all the treatment steps. With a drug efficacy of 100%, AL achieved a community effectiveness of 4%. The greatest effort in the home management of malaria strategy should be in reducing delay in treatment and improving dosage and duration of treatment.

HIV control in low-income countries in sub-Saharan Africa: are the right things done?

HIV control efforts in sub-Saharan Africa meet with difficulties. Incidence and prevalence remains high, and little behaviour change seems to have taken place. The focus on HIV control has shifted to anti-retroviral therapy (ART), although this is unlikely either to be cost-effective or the reduce the incidence of HIV. There is reason to change the current approach. Three questions arise: Is there a need to adjust the view on the determinants of the HIV epidemic in sub-Saharan Africa? Are the right things being done to control HIV? Are the things that are being done, done in the right way? We try to answer these questions. The determinants of the epidemic are reviewed and summarized in Figure 2. The need to adjust the view on the determinants and get rid of myths is stressed. A possible, locally adaptable intervention mix is outlined. Male circumcision is a key intervention where socially acceptable. Operationalisation and organisational changes are briefly discussed. Conclusively, the need for a "social revolution" through the opening up of a discussion on sexuality in the community, as well as a focus on cost-effective interventions and a slimmed down, more effective organisation is underlined. Such steps might make it possible to considerably reduce HIV-incidence, even in low-income countries.

Low effectiveness of syndromic treatment services for curable sexually transmitted infections in rural South Africa

Objectives:

Syndromic sexually transmitted infection (STI) treatment remains a cost-saving HIV prevention intervention in many countries in Africa. We estimate the effectiveness of syndromic treatment for curable STIs in rural KwaZulu-Natal, South Africa, and the trend in STI prevalences before and after the introduction of syndromic treatment in 1995.

Methods:

Data were available from various clinical studies, surveys of public and private health providers, the general population and women attending antenatal, family planning and child immunisation clinics in rural northern KwaZulu-Natal between 1987 and 2004. Overall effectiveness was defined as the estimated proportion of the annual number of symptomatic curable STI episodes cured by syndromic treatment based on separate estimates for six curable STI aetiologies by gender.

Results:

Median overall effectiveness was 13.1% (95% CI 8.9 to 17.8%) of symptomatic curable STI episodes cured. Effectiveness increased to 25.0% (95% CI 17.3 to 33.8%), 47.6% (95% CI 44.5 to 50.8%) or 14.3% (95% CI 9.9 to 19.4%) if 100% treatment seeking, 100% correct treatment provision or 100% cure were assumed, respectively. Time-trends were difficult to assess formally but there was little evidence of decreasing STI prevalences. Including incurable but treatable herpes simplex virus (HSV)-2 ulcers in the effectiveness calculation would halve the proportion of ulcers cured or correctly treated, but this reduction could be entirely countered by including episodic antiviral treatment in the national guidelines.

Conclusion:

Overall effectiveness of syndromic treatment for curable STIs in rural KwaZulu-Natal remains low and there is little evidence of reduced curable STI prevalences. As syndromic treatment is likely to be a cost-saving HIV prevention intervention in South Africa, innovative strategies are urgently needed to increase rates of treatment seeking and correct treatment provision.

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

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

Sexual and reproductive health: a matter of life and death

Despite the call for universal access to reproductive health at the 4th International Conference on Population and Development in Cairo in 1994, sexual and reproductive health was omitted from the Millennium Development Goals and remains neglected (panel 1). Unsafe sex is the second most important risk factor for disability and death in the world's poorest communities and the ninth most important in developed countries. Cheap effective interventions are available to prevent unintended pregnancy, provide safe abortions, help women safely through pregnancy and child birth, and prevent and treat sexually transmitted infections. Yet every year, more than 120 million couples have an unmet need for contraception, 80 million women have unintended pregnancies (45 million of which end in abortion), more than half a million women die from complications associated with pregnancy, childbirth, and the postpartum period, and 340 million people acquire new gonorrhoea, syphilis, chlamydia, or trichomonas infections. Sexual and reproductive ill-health mostly affects women and adolescents. Women are disempowered in much of the developing world and adolescents, arguably, are disempowered everywhere. Sexual and reproductive health services are absent or of poor quality and underused in many countries because discussion of issues such as sexual intercourse and sexuality make people feel uncomfortable. The increasing influence of conservative political, religious, and cultural forces around the world threatens to undermine progress made since 1994, and arguably provides the best example of the detrimental intrusion of politics into public health.

Empirical Observations Underestimate the Proportion of Human Immunodeficiency Virus Infections Attributable to Sexually Transmitted Diseases in the Mwanza and Rakai Sexually Transmitted Disease Treatment Trials: Simulation Results

BACKGROUND AND OBJECTIVES

Population attributable fractions (PAF) from observational studies may under- or overestimate the contribution of cofactor sexually transmitted disease (STD) to human immunodeficiency virus (HIV) spread. Empirical PAF estimates from the Mwanza and Rakai trials indicated the proportion of HIV infections attributable to STDs was higher in Mwanza than Rakai.

GOAL OF THIS STUDY

Estimate the "true" proportion (PAFM) of HIV infections attributable to STDs in the Mwanza and Rakai STD trial populations and explore how the evaluated interventions prevented HIV infections.

STUDY DESIGN

The STDSIM model was used to simulate the 2 populations at the baseline of the trials (with no STD treatment interventions) and counterfactual scenarios in which STD cofactor effects on HIV spread were removed either at the start of the trials or 2, 10, and 20 years into the HIV epidemics. Similar methods were used to quantify the contribution of the cure of each STD to overall HIV impact in each site.

RESULTS

: In Mwanza, the highest PAFM for the effect of any single STD over the 2 years of the trial was due to chancroid (40%). The PAFM for all curable STD was 65%. In Rakai, herpes simplex virus type 2 (HSV-2) was the most important STD (PAFM = 23%); the PAFM for curable STD was 20%. In both sites, the proportion of new infections due to treatable STD decreased over time. The decrease was greater for Rakai, where a behavioral risk reduction that preceded the trial reduced STD prevalence. In both sites, the importance of HSV-2 increased later in the HIV epidemics and STD increased transmission of HIV more than acquisition of HIV. In the Mwanza trial, treatment of chancroid contributed most to preventing new HIV infections.

CONCLUSIONS

PAFs calculated from empirical data underestimated the contribution of STD to HIV spread in the Mwanza and Rakai trial populations because STD effects on HIV transmission (as opposed to acquisition) were not captured in the observationally based studies.

Can malaria be controlled where basic health services are not used?

OBJECTIVE

To assess the potential of integrating malaria control interventions in underused health services.

METHODS

Using the Piot predictive model, we estimated malaria cure rates by deriving parameters influencing treatment at home and in health facilities from the best-performing African malaria programmes and applying them to Yanfolila district, Mali.

RESULTS

Without any malaria control intervention, the population cure rate is 8.4% with home treatment, but would be 13% if access to timely treatment were improved (as in Kenya). A further 3.2% of malaria patients could be cured in institutional settings with more sensitive diagnosis, timely start of treatment, better compliance (as in Uganda, Tanzania, Ghana) and 80% chloroquine efficacy. Applied in a setting where 7.6% of malaria patients seek institutional care, these assumptions would result in a total population cure rate of 14.5%. Increasing the health service user rate from 0.17 in Yanfolila to 0.95 new cases/inhabitant/year (as in Namibia) would result in half of all malaria patients attending professional services, raising the cure rate to 26.1%.

CONCLUSION

If malaria patients are to be treated and followed-up early and appropriately, basic health services need to deliver integrated care and be attended by an adequate pool of users. Improved service user rates and case management can increase malaria cure rates far more than isolated control interventions can. This has implications for international policies endorsing a narrow disease-based approach.

Can population differences explain the contrasting results of the Mwanza, Rakai, and Masaka HIV/sexually transmitted disease intervention trials?: A modeling study

OBJECTIVE

To determine whether population differences can explain the contrasting impacts on HIV observed in the Mwanza trial of sexually transmitted disease (STD) syndromic treatment (ST), the Rakai trial of STD mass treatment (MT), and the Masaka trial of information, education, and communication (IEC) with and without ST as well as to predict the effectiveness of each intervention strategy in each population.

METHODS

Stochastic modeling of the transmission of HIV and 6 STDs was used with parameters fitted to demographic, sexual behavior, and epidemiological data from the trials and general review of STD/HIV biology.

RESULTS

The baseline trial populations could be simulated by assuming higher risk behavior in Uganda compared with Mwanza in the 1980s, followed by reductions in risk behavior in Uganda preceding the trials. In line with trial observations, the projected HIV impacts were larger for the ST intervention in Mwanza than for the MT intervention in Rakai or the IEC and IEC + ST interventions in Masaka. All 4 simulated intervention strategies were more effective in reducing incidence of HIV infection in Mwanza than in either Rakai or Masaka.

CONCLUSIONS

Population differences in sexual behavior, curable STD rates, and HIV epidemic stage can explain most of the contrast in HIV impact observed between the 3 trials. This study supports the hypothesis that STD management is an effective HIV prevention strategy in populations with a high prevalence of curable STDs, particularly in an early HIV epidemic.

Community effectiveness of malaria treatment in Uganda--a long way to Abuja targets

INTRODUCTION

At the Roll Back Malaria summit for African countries in Abuja, the heads of state committed to ensure that by the year 2005 at least 60% of those suffering from malaria would have access to effective treatment within 24 hours of onset of symptoms.

AIM

The aim of the study was to assess community effectiveness of malaria treatment in children.

METHOD

A community-based survey of 500 households was undertaken in western Uganda.

RESULTS

A total of 260 (52%) children were reported to have had fever within the previous 2 weeks: 87% received some kind of treatment, 44% were said to have been treated within 24 hours of onset of symptoms, 47% received appropriate anti-malarials, 25% received the correct dosage, and 24% took the drug for the recommended period of time; altogether, only 7% received all the treatment steps.

CONCLUSION

With drug efficacies of 50-90%, we estimate a community effectiveness of 4-6%, which is far from the 2005 Abuja target. The greatest need for improvement in the Home Based Fever Management strategy is in reducing delay in treatment and improving dosage and duration of treatment.

Patterns of uptake of treatment for self reported sexually transmitted infection symptoms in rural Zimbabwe

OBJECTIVES

To determine the extent of self reported symptoms perceived to be related to sexually transmitted infections and the patterns of subsequent treatment seeking behaviour in a predominantly rural population of Zimbabwe.

METHODS

A population based survey of 4331 men and 5149 women was conducted in rural Zimbabwe during 1998-2000. Structured confidential interviews collected data on self reported sexually transmitted infection symptoms, treatment seeking behaviour, sociodemographic characteristics, and sexual behaviour.

RESULTS

25% of men aged 17-54 years report experiencing genital sores and 25% of men report experiencing urethral discharge; 30% of women aged 15-44 years report experiencing vaginal discharge. The lifetime number of sexual partners, age, and years of sexual activity were all significant predictors of symptoms for both men and women (all p values <0.001). 92% of men and 62% of women had sought treatment for their symptoms in the past year (p value <0.001). Men and women were equally likely to have sought treatment at a local hospital or clinic, but women were much less likely than men to have sought treatment at a different hospital or clinic. Among those who had sought treatment, men sought treatment faster than women and were more likely to report being "very satisfied" with their treatment than women.

CONCLUSIONS

The gender differences in treatment seeking are of major concern for control efforts and further work on determining the reasons for these should be a priority. This would inform the likely impact of both increasing availability of local services and further reducing the stigma faced by those wishing to access such services.

Chlamydia and gonorrhoea in pregnancy: effectiveness of diagnosis and treatment in Botswana

BACKGROUND

Millions of patients are prescribed drugs for sexually transmitted infections (STIs) in developing countries each year, yet the treatment effect of these prescriptions is largely unknown.

OBJECTIVES

To determine if the prescribing of erythromycin and ceftriaxone to pregnant women with STI symptoms leads to a reduction in the prevalence among these women of chlamydia and gonorrhoea, respectively.

METHODS

We compared the prevalence of chlamydia among 116 pregnant women who had been prescribed erythromycin for a history of STI symptoms in their current pregnancy with the prevalence in a control group of 557 pregnant women who had not been prescribed this drug. Similarly we compared the prevalence of gonorrhoea among 110 pregnant women who had and 561 women who had not been prescribed ceftriaxone.

RESULTS

There was no significant difference in the prevalence of chlamydia among the women who had and the women who had not been prescribed erythromycin four times daily for 10 days (7% v 8%). Contrarily, none of the women who had been prescribed a single dose of ceftriaxone had gonorrhoea, whereas 4% of the women who had not had this drug prescribed did have gonorrhoea.

CONCLUSIONS

The prescribing of erythromycin seems to have had a limited effect on chlamydia in this population, whereas the prescribing of ceftriaxone led to the curing of gonorrhoea. Ceftriaxone is provided as a single dose injection at the point of care, and the differential effectiveness between the two drugs may reflect low compliance with the complex erythromycin regimen. Interventions to increase compliance could improve cure rates. The use of a simpler drug regimen should be considered when low compliance is likely.

The effectiveness of active population screening and treatment for sleeping sickness control in the Democratic Republic of Congo

BACKGROUND

The human African trypanosomiasis (HAT) control programme of the Democratic Republic of Congo (DRC) uses mass screening with the card agglutination test for trypanosomes (CATT). We looked at the contribution of CATT and improved parasitological confirmation to the effectiveness of screening and treatment.

METHOD

The effectiveness of the screening and treatment process is measured by the percentage of HAT cases that is effectively cured after a single round of screening. The process is analysed in five steps: (i) the attendance at the screening, (ii) the sensitivity of the screening procedure, (iii) the sensitivity of the parasitological confirmation, (iv) the proportion of the confirmed cases that effectively receive treatment and (v) the cure rate of the treatment. We used a simplified model that multiplies proportions of infected persons that go through each step. We estimated these parameters using a combination of routine data collected by the national control programme over the period January 1997 to December 1998 and published data. For varying attendance rates we compared the effectiveness of screening strategies based on CATT or on CATT combined with improved parasitological confirmation by mini anion exchange column technique (mAECT) with the previously used strategy based on palpation of neck glands and microscopy alone.

RESULTS

The model shows that overall effectiveness of the active case detection and treatment strategy is <50% under most scenarios. Attendance rates averaged 74% but showed considerable regional variability and are a major problem in some areas of DRC. The CATT and replacing traditional parasitology by mAECT increases the sensitivity of the screening but a substantial part of the gains are lost at other stages of the screening process.

CONCLUSION

Improvements of the HAT screening process such as introduction of CATT or mAECT only make sense if other parameters and attendance rate in particular are optimized at the same time.

Infectivity of asymptomatic Plasmodium-infected human populations to Anopheles dirus mosquitoes in western Thailand

The infectivity of Plasmodium-infected humans in western Thailand was estimated by feeding laboratory-reared Anopheles dirus Peyton and Harrison mosquitoes on venous blood placed in a membrane-feeding apparatus. Between May 2000 and November 2001, a total of 6,494 blood films collected during an active malaria surveillance program were checked by microscopy for the presence of Plasmodium parasites: 3.3, 4.5, and 0.1% of slides were P. falciparum- (Pf), P. vivax- (Pv), and P. malariae (Pm)-positive. Venous blood was collected from 70, 52, 6, and 4 individuals infected with Pf, Pv, Pm, and mixed Pf/Pv, respectively, with 167 uninfected individuals serving as negative controls. Only 10% (7/70), 13% (7/52), and 0% (0/6) of membrane feeds conducted on Pf-, Pv-, and Pm-infected blood yielded infected mosquitoes. One percent (2/167) of microscope-negative samples infected mosquitoes; however, both samples were subsequently determined to be Pf-positive by polymerase chain reaction. Gametocytes were observed in only 29% (4/14) of the infectious samples. All infections resulted in low oocyst loads (average of 1.2 oocysts per positive mosquito). Only 4.5% (10/222) of mosquitoes fed on the seven infectious Pf samples developed oocysts, whereas 2.9% (9/311) of mosquitoes fed on the seven infectious Pv samples developed oocysts. The probability of a mosquito becoming infected with Pf or Pv after a blood meal on a member of the human population in Kong Mong Tha was estimated to be 1 in 6,700 and 1 in 5,700, respectively. The implications toward malaria transmission in western Thailand are discussed.

Stronger health systems for more effective HIV/AIDS prevention and care

Of the 42 million living with HIV/AIDS world-wide some 90% live in developing countries. The international community acknowledges the devastating impact of HIV/AIDS on development and over the past few years resources to control HIV/AIDS have increased considerably. We argue that strengthening of health systems is a necessary prerequisite for improving the prevention of HIV infection and the care of HIV-infected persons. Sexual behaviour change requires a multidisciplinary approach, but health services play a crucial role in detection and treatment of other sexually transmitted infections; HIV counselling and testing; prevention of mother-to-child transmission of HIV; and care of HIV-infected patients. Increasing access to antiretroviral treatment especially poses formidable challenges to health authorities in developing countries. Additional resources for the prevention of HIV-infection and the care of HIV-infected persons may not have the desired impact if health systems in developing countries are not strengthened. Further, any activity in the area of HIV/AIDS prevention and care, carried out within health services, can have a positive ripple effect on other health care activities and vice versa. This interactive effect needs to be acknowledged and built on.

A Piot model to analyse case management in malaria control programmes

At the beginning of the 21st century, malaria remains one of the most important public health problems in the world. An important control strategy to address this burden is adequate case management of malaria patients. The success of this strategy, however, does not solely depend on diagnosis and treatment, but also on a sequence of steps that patients have to take when they are ill. Only when patients go through all these steps successfully will they be cured. In this paper, a model is presented in which these steps are described. The model provides a framework for analysing this type of malaria control strategy and for identifying the most critical challenges faced. Furthermore, the model is used to analyse recent literature on case management as part of malaria control programmes in order to highlight current knowledge, core issues and constraints, and to make recommendations for programme development and research.

HIV dynamics and behaviour change as determinants of the impact of sexually transmitted disease treatment on HIV transmission in the context of the Rakai trial

OBJECTIVE

To assess how the impact of sexually transmitted disease (STD) treatment on HIV incidence varies between stages of the HIV epidemic.

METHODS

We simulated the spread of curable STD, herpes simplex virus type 2 and HIV in the dynamic transmission model. Parameters were quantified to represent a severe HIV epidemic as in Rakai, Uganda, using demographic, behavioural and epidemiological data from a recent STD treatment trial.

RESULTS

The model fitted the HIV epidemic in Rakai if we assumed a considerable behavioural risk reduction, starting at the end of the Ugandan civil war in 1986. An improvement in STD treatment reduced HIV incidence in this population by 35% over 2 years if implemented in 1981, but only by 11 and 8% in 1988 or 1998. This trend resulted partly from the hypothesized behaviour change, which markedly reduced the prevalences of bacterial STD. In a simulated epidemic without behavioural change, the corresponding treatment impacts in 1988 and 1998 would be 19 and 15%. Enhanced herpetic ulceration in immunocompromised HIV patients contributed little to the reduced impact of treatment of bacterial STD over time.

CONCLUSION

In HIV epidemics beyond the first decade, the impact of STD treatment programmes on HIV transmission may depend more on behavioural risk reduction than on the stage of the epidemic. Preceding behavioural change associated with restored civil stability may have contributed to the lack of impact of STD treatment on HIV in the Rakai trial. In advanced epidemics with less behaviour change, STD treatment may still be important for HIV prevention.

HIV-1/AIDS and the control of other infectious diseases in Africa

The effect of HIV-1 on other infectious diseases in Africa is an increasing public health concern. In this review, we describe the role that three major infectious diseases--malaria, sexually transmitted diseases (STDs), and tuberculosis--have had in the HIV-1 epidemic. The high prevalence of untreated STD infections has been a major factor facilitating the spread of HIV-1 in Africa; with the synergistic interaction between HIV-1 transmission and genital herpes being of special concern for control of both diseases. Increased susceptibility to tuberculosis after infection with HIV-1 has led to a rising incidence and threat of increased transmission of tuberculosis. Clinical malaria occurs with an increased frequency and severity in HIV-1-infected individuals, especially during pregnancy. As with tuberculosis, STDs, and other communicable HIV-1-associated diseases, the net effect of HIV-1 might include increased rates of malaria transmission across communities. In addition to enhancing access to HIV-1 prevention and care, public health surveillance and control programmes should be greatly intensified to cope with the new realities of infectious disease control in Africa.

The spread and effect of HIV-1 infection in sub-Saharan Africa

Africa is the continent most severely affected by the global HIV-1 epidemic, with east and southern Africa in general more severely affected than west and central Africa. Differences in the spread of the epidemic can be accounted for by a complex interplay of sexual behaviour and biological factors that affect the probability of HIV-1 transmission per sex act. Sexual behaviour patterns are determined by cultural and socioeconomic contexts. In sub-Saharan Africa, some traditions and socioeconomic developments have contributed to the extensive spread of HIV-1 infection, including the subordinate position of women, impoverishment and decline of social services, rapid urbanisation and modernisation, and wars and conflicts. Populations in many parts of Africa are becoming trapped in a vicious circle as the HIV-1 epidemic leads to high mortality rates in young and economically productive age groups, and thus leads to further impoverishment. Interventions to control HIV-1 should not only target individuals, but also aim to change those aspects of cultural and socioeconomic context that increase the vulnerability to HIV-1 of people and communities.