Genital schistosomiasis in women: a clinical 12-month in vivo study following treatment with praziquantel

Predictors for participation in mass-treatment and female genital schistosomiasis re-investigation, and the effect of praziquantel treatment in South African adolescents

OBJECTIVE

Female Genital Schistosomiasis (FGS) causes intravaginal lesions and symptoms that could be mistaken for sexually transmitted diseases or cancer. In adults, FGS lesions [grainy sandy patches (GSP), homogenous yellow patches (HYP), abnormal blood vessels and rubbery papules] are refractory to treatment. The effect of treatment has never been explored in young women; it is unclear if gynaecological investigation will be possible in this young age group (16-23 years). We explored the predictors for accepting anti-schistosomal treatment and/or gynaecological reinvestigation in young women, and the effects of anti-schistosomal mass-treatment (praziquantel) on the clinical manifestations of FGS at an adolescent age.

METHOD

The study was conducted between 2011 and 2013 in randomly selected, rural, high schools in Ilembe, uThungulu and Ugu Districts, KwaZulu-Natal Province, East Coast of South Africa. At baseline, gynaecological investigations were conducted in female learners in grades 8 to 12, aged 16-23 years (n = 2293). Mass-treatment was offered in the low-transmission season between May and August (a few in September, n = 48), in accordance with WHO recommendations. Reinvestigation was offered after a median of 9 months (range 5-14 months). Univariate, multivariable and logistic regression analysis were used to measure the association between variables.

RESULTS

Prevalence: Of the 2293 learners who came for baseline gynaecological investigations, 1045 (46%) had FGS lesions and/or schistosomiasis, 209/1045 (20%) had GSP; 208/1045 (20%) HYP; 772/1045 (74%) had abnormal blood vessels; and 404/1045 (39%) were urine positive. Overall participation rate for mass treatment and gynaecological investigation: Only 26% (587/2293) learners participated in the mass treatment and 17% (401/2293) participated in the follow up gynaecological reinvestigations. Loss to follow-up among those with FGS: More than 70% of learners with FGS lesions at baseline were lost to follow-up for gynaecological investigations: 156/209 (75%) GSP; 154/208 (74%) HYP; 539/722 (75%) abnormal blood vessels; 238/404 (59%) urine positive. The grade 12 pupil had left school and did not participate in the reinvestigations (n = 375; 16%). Follow-up findings: Amongst those with lesions who came for both treatment and reinvestigation, 12/19 still had GSP, 8/28 had HYP, and 54/90 had abnormal blood vessels. Only 3/55 remained positive for S. haematobium ova. Factors influencing treatment and follow-up gynaecological investigation: HIV, current water contact, water contact as a toddler and urinary schistosomiasis influenced participation in mass treatment. Grainy sandy patches, abnormal blood vessels, HYP, previous pregnancy, current water contact, water contact as a toddler and father present in the family were strongly associated with coming back for follow-up gynaecological investigation. Challenges in sample size for follow-up analysis of the effect of treatment: The low mass treatment uptake and loss to follow up among those who had baseline FGS reduced the chances of a larger sample size at follow up investigation. However, multivariable analysis showed that treatment had effect on the abnormal blood vessels (adjusted odds ratio = 2.1, 95% CI 1.1-3.9 and p = 0.018).

CONCLUSION

Compliance to treatment and gynaecological reinvestigation was very low. There is need to embark on large scale awareness and advocacy in schools and communities before implementing mass-treatment and investigation studies. Despite challenges in sample size and significant loss to follow-up, limiting the ability to fully understand the treatment's effect, multivariable analysis demonstrated a significant treatment effect on abnormal blood vessels.

Integration of female genital schistosomiasis into HIV/sexual and reproductive health and rights and neglected tropical diseases programmes and services: a scoping review

Female genital schistosomiasis (FGS) affects approximately 56 million women and girls across sub-Saharan Africa and is associated with up to a threefold increased prevalence of HIV. Integrating FGS with HIV programmes as part of comprehensive sexual and reproductive health (SRH) services may be one of the most significant missed opportunities for preventing HIV incidence among girls and women. A search of studies published until October 2021 via Scopus and ProQuest was conducted using PRISMA guidelines to assess how FGS can be integrated into HIV/SRH and neglected tropical diseases (NTDs) programmes and services. Data extraction included studies that integrated interventions and described the opportunities and challenges. A total of 334 studies were identified, with 22 eligible for analysis and summarised conducting a descriptive numerical analysis and qualitative review. We adapted a framework for integrated implementation of FGS, HIV, and HPV/cervical cancer to thematically organise the results, classifying them into five themes: awareness and community engagement, diagnosis, treatment, burden assessment, and economic evaluation. Most activities pertained to awareness and community engagement (n = 9), diagnosis (n = 9) and were primarily connected to HIV/AIDS (n = 8) and school-based services and programming (n = 8). The studies mainly described the opportunities and challenges for integration, rather than presenting results from implemented integration interventions, highlighting an evidence gap on FGS integration into HIV/SRH and NTD programmes. Investments are needed to realise the potential of FGS integration to address the burden of this neglected disease and improve HIV and SRH outcomes for millions of women and girls at risk.

Urogenital schistosomiasis (UGS) and female genital schistosomiasis (FGS) in Cameroon: an observational assessment of key reproductive health determinants of girls and women in the Matta Health Area

OBJECTIVES AND SETTING

Across sub-Saharan Africa, urogenital schistosomiasis (UGS), in particular female genital schistosomiasis (FGS), is a significant waterborne parasitic disease, with its direct burden on the sexual and reproductive health (SRH) of sufferers infrequently measured. UGS has an established control plan, which in most endemic regions as in Cameroon, still excludes FGS considerations. Highlighting existent associations between UGS and FGS could increase the management of FGS within UGS interventions. This study seeks to identify current associations among FGS and UGS with some reproductive health indicators, to provide formative information for better integrated control.

PARTICIPANTS

304 females aged 5-69 years were all examined for UGS by urine filtration and microscopy. Among these, 193 women and girls were eligible for clinical FGS assessment based on age (>13). After selective questioning for FGS symptoms, a subgroup of 67 women and girls consented for clinical examination for FGS using portable colposcopy, with observed sequelae classified according to the WHO FGS pocket atlas.

OUTCOME

Overall UGS and FGS prevalence was measured, with FGS-related/UGS-related reproductive health symptoms recorded. Associations between FGS and UGS were investigated by univariate and multivariate logistic regression analyses.

RESULTS

Overall UGS prevalence was 63.8% (194/304), where FGS prevalence (subgroup) was 50.7% (34/67). FGS manifestation increased significantly with increasing age, while a significant decrease with ascending age was observed for UGS. Lower abdominal pain (LAP) vaginal itches (VI) and coital pain (CP) were identified as the main significant shared symptoms of both FGS and UGS, while LAP with menstrual irregularity (MI) appeared a strong symptomatic indicator for FGS.

CONCLUSION

LAP, MI, CP and VI are the potential SRH indicators that could be exploited in future for targeting of praziquantel provision to FGS sufferers within primary care, complementary with existing praziquantel distribution for UGS sufferers in Schistosoma haematobium endemic areas.

Female Genital Schistosomiasis Lesions Explored Using Circulating Anodic Antigen as an Indicator for Live Schistosoma Worms

Background

In areas where reinfection with schistosomiasis is rampant, it is not known if the lesions of Female Genital Schistosomaisis are a consequence of live worms, or caused by dead ova. Live schistosome worms regurgitate Circulating Anodic Antigen (CAA). We sought to explore the association between the different lesions of FGS (grainy sandy patches, homogenous yellow patches, rubbery papules and abnormal blood vessels) and the presence of live worms as indicated by S. haematobium-derived CAA in blood.

Materials and Methods

In this cross-sectional study, rural high schools were randomly selected from Ilembe, uThungulu and Ugu Districts on the East Coast of South Africa, KwaZulu-Natal Province. Serum samples for CAA analysis were collected from 246 female learners aged 16 - 23 years. Uncorrected chi-square and odds ratio with 95% confidence interval (CI) were used to evaluate the null hypothesis.

Results

CAA was positive in 82/246 (33%) of the participants. Sandy patches were found in 123 (50%) of the study population. Grainy sandy patches were significantly associated with CAA even after controlling for age (Adjusted Odds Ratio (AOR) 4.2, 95% CI 2.3 - 7.9, p < 0.001). Likewise, abnormal blood vessels were associated with CAA (AOR 3.0, 95% CI 1.5-4.5, p = 0.001) whereas homogenous yellow patches were not associated with CAA (p = 0.57). Rubbery papules were not found in this study population.

Conclusion

Grainy sandy patches and abnormal blood vessels are found more commonly in women who harbour live Schistosoma haematobium worms whilst homogenous yellow patches may indicate chronic tissue damage due to dead ova.

An update on female and male genital schistosomiasis and a call to integrate efforts to escalate diagnosis, treatment and awareness in endemic and non-endemic settings: The time is now

The last decades have brought important insight and updates in the diagnosis, management and immunopathology of female genital schistosomiasis (FGS) and male genital schistosomiasis (MGS). Despite sharing a common parasitic aetiological agent, FGS and MGS have typically been studied separately. Infection with Schistosoma haematobium manifests with gender-specific clinical manifestations and consequences of infection, albeit having a similar pathogenesis within the human genital tract. Schistosoma haematobium is a known urinary bladder carcinogen, but its potential causative role in other types of neoplasia, such as cervical cancer, is not fully understood. Furthermore, the impact of praziquantel treatment on clinical outcomes remains largely underexplored, as is the interplay of FGS/MGS with relevant reproductive tract infections such as HIV and Human Papillomavirus. In non-endemic settings, travel and immigrant health clinics need better guidance to correctly identify and treat FGS and MGS. Our review outlines the latest advances and remaining knowledge gaps in FGS and MGS research. We aim to pave a way forward to formulate more effective control measures and discuss elimination targets. With a growing community awareness in health practitioners, scientists and epidemiologists, alongside the sufferers from these diseases, we aspire to witness a new generation of young women and men free from the downstream disabling manifestations of disease.

The parasitology of female genital schistosomiasis

Female genital schistosomiasis (FGS) is the gynaecological presentation of Schistosoma haematobium infection, resulting from egg deposition in the female genital tract. Despite the fact that this condition has been reported in the early days of the discovery of S. haematobium in Egypt, its existence has been grossly neglected, causing many women in schistosomiasis-endemic areas to go through a preventable, debilitating, and stigmatizing presentation of FGS. To prevent this, increasing awareness of FGS is necessary for all, especially healthcare providers, to improve the diagnosis, management, and treatment. As proposed by the FAST package project, several healthcare professionals with different specializations are expected to be involved in the management of FGS. It is therefore important that basic updated knowledge on the parasitology of the disease be acquired by healthcare professionals. This review provides basic information necessary to improve the knowledge of FGS among healthcare professionals in areas endemic to schistosomiasis. Armed with these basic details, healthcare professionals can improve their confidence in the management and treatment of FGS, contributing significantly to the control and prevention of FGS in endemic areas.

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A review of female genital schistosomiasis.

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Data on the life-cycle of Schistosoma haematobium, and pathogenesis and clinical features of female genital schistosomiasis.

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Summary of diagnostic methods and treatment, control and prevention of female genital schistosomiasis.

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Increasing awareness among healthcare workers is key to the management, control, and prevention of the disease.

Cervicovaginal Immune Activation in Zambian Women With Female Genital Schistosomiasis

HIV-1 infection disproportionately affects women in sub-Saharan Africa, where areas of high HIV-1 prevalence and Schistosoma haematobium endemicity largely overlap. Female genital schistosomiasis (FGS), an inflammatory disease caused by S. haematobium egg deposition in the genital tract, has been associated with prevalent HIV-1 infection. Elevated levels of the chemokines MIP-1α (CCL-3), MIP-1β (CCL-4), IP-10 (CXCL-10), and IL-8 (CXCL-8) in cervicovaginal lavage (CVL) have been associated with HIV-1 acquisition. We hypothesize that levels of cervicovaginal cytokines may be raised in FGS and could provide a causal mechanism for the association between FGS and HIV-1. In the cross-sectional BILHIV study, specimens were collected from 603 female participants who were aged 18–31 years, sexually active, not pregnant and participated in the HPTN 071 (PopART) HIV-1 prevention trial in Zambia. Participants self-collected urine, and vaginal and cervical swabs, while CVLs were clinically obtained. Microscopy and Schistosoma circulating anodic antigen (CAA) were performed on urine. Genital samples were examined for parasite-specific DNA by PCR. Women with FGS (n=28), defined as a positive Schistosoma PCR from any genital sample were frequency age-matched with 159 FGS negative (defined as negative Schistosoma PCR, urine CAA, urine microscopy, and colposcopy imaging) women. Participants with probable FGS (n=25) (defined as the presence of either urine CAA or microscopy in combination with one of four clinical findings suggestive of FGS on colposcope-obtained photographs) were also included, for a total sample size of 212. The concentrations of 17 soluble cytokines and chemokines were quantified by a multiplex bead-based immunoassay. There was no difference in the concentrations of cytokines or chemokines between participants with and without FGS. An exploratory analysis of those women with a higher FGS burden, defined by ≥2 genital specimens with detectable Schistosoma DNA (n=15) showed, after adjusting for potential confounders, a higher Th2 (IL-4, IL-5, and IL-13) and pro-inflammatory (IL-15) expression pattern in comparison to FGS negative women, with differences unlikely to be due to chance (p=0.037 for IL-4 and p<0.001 for IL-5 after adjusting for multiple testing). FGS may alter the female genital tract immune environment, but larger studies in areas of varying endemicity are needed to evaluate the association with HIV-1 vulnerability.

Beyond the barrier: Female Genital Schistosomiasis as a potential risk factor for HIV-1 acquisition

Female genital schistosomiasis (FGS) results from egg-deposition in the female reproductive tract primarily by the waterborne parasite Schistosoma (S.) haematobium, and less commonly by Schistosoma (S.) mansoni. FGS affects an estimated 20-56 million women worldwide, mostly in sub-Saharan Africa. There is cross-sectional evidence of increased HIV-1 prevalence in schistosomiasis-infected women, but a causal relationship between FGS and either HIV-1 acquisition or transmission has not been fully established. Beyond the pathognomonic breach in the cervicovaginal barrier caused by FGS, this narrative review explores potential mechanisms for a synergistic relationship between S. haematobium infection, FGS, and HIV-1 acquisition through vaginal inflammation and target cell recruitment.

Integration of prevention and control measures for female genital schistosomiasis, HIV and cervical cancer

Female genital schistosomiasis as a result of chronic infection with Schistosoma haematobium (commonly known as bilharzia) continues to be largely ignored by national and global health policy-makers. International attention for large-scale action against the disease focuses on whether it is a risk factor for the transmission of human immunodeficiency virus (HIV). Yet female genital schistosomiasis itself is linked to pain, bleeding and sub- or infertility, leading to social stigma, and is a common issue for women in schistosomiasis-endemic areas in sub-Saharan Africa. The disease should therefore be recognized as another component of a comprehensive health and human rights agenda for women and girls in Africa, alongside HIV and cervical cancer. Each of these three diseases has a targeted and proven preventive intervention: antiretroviral therapy and pre-exposure prophylaxis for HIV; human papilloma virus vaccine for cervical cancer; and praziquantel treatment for female genital schistosomiasis. We discuss how female genital schistosomiasis control can be integrated with HIV and cervical cancer care. Such a programme will be part of a broader framework of sexual and reproductive health and rights, women's empowerment and social justice in Africa. Integrated approaches that join up multiple public health programmes have the potential to expand or create opportunities to reach more girls and women throughout their life course. We outline a pragmatic operational research agenda that has the potential to optimize joint implementation of a package of measures responding to the specific needs of girls and women.

Genital self-sampling compared with cervicovaginal lavage for the diagnosis of female genital schistosomiasis in Zambian women: The BILHIV study

BACKGROUND

Given the potentially causal association of female genital schistosomiasis (FGS) with HIV-1 infection, improved diagnostics are urgently needed to scale-up FGS surveillance. The BILHIV (bilharzia and HIV) study assessed the performance of home-based self-collection methods (cervical and vaginal swabs) compared to cervicovaginal lavage (CVL) for the detection of Schistosoma DNA by real-time polymerase chain reaction (PCR).

METHODS

Between January and August 2018, a consecutive series of female participants from the Population-Cohort of the previous HIV prevention trial HPTN 071 (PopART), resident in Livingstone, Zambia were invited to take part in BILHIV if they were 18-31 years old, non-pregnant and sexually active. Genital self-collected swabs and a urine specimen were obtained and a questionnaire completed at home visits. CVL was obtained at clinic follow-up.

RESULTS

603 women self-collected genital swabs. Of these, 527 women had CVL performed by a mid-wife during clinic follow-up. Schistosoma DNA was more frequently detected in genital self-collected specimens (24/603, 4.0%) compared to CVL (14/527, 2.7%). Overall, 5.0% (30/603) women had female genital schistosomiasis, defined as a positive PCR by any genital sampling method (cervical swab PCR, vaginal swab PCR, or CVL PCR) and 95% (573/603) did not have a positive genital PCR. The sensitivity of any positive genital self-collected swab against CVL was 57.1% (95% CI 28.9-82.3%), specificity 97.3% (95.5-98.5%). In a subset of participants with active schistosome infection, determined by detectable urine Circulating Anodic Antigen (CAA) (15.1%, 91/601), positive PCR (4.3%, 26/601), or positive microscopy (5.5%, 33/603), the sensitivity of any positive self-collected specimen against CVL was 88.9% (51.8-99.7%).

CONCLUSIONS

Genital self-sampling increased the overall number of PCR-based FGS diagnoses in a field setting, compared with CVL. Home-based sampling may represent a scalable alternative method for FGS community-based diagnosis in endemic resource limited settings.

Prevalence and intensity of neglected tropical diseases (schistosomiasis and soil-transmitted helminths) amongst rural female pupils in Ugu district, KwaZulu-Natal, South Africa

Background

Inadequate water supply and sanitation adversely affects the health and socio-economic development of communities and places them at risk of contracting schistosomiasis and soil-transmitted helminths (STHs). The aim of this study was to quantify the prevalence and intensity of schistosomiasis (bilharzia) and STHs amongst female school-going pupils in Ugu district.

Methods

A descriptive cross-sectional study was conducted in Ugu district amongst primary school pupils from 18 randomly selected schools in 2010. A structured questionnaire was used to collect information on the history and knowledge of bilharzia of 1057 pupils. One stool and 3 consecutive days of urine samples were collected per participant and screened for helminth ova. Findings were compared with those reported by the parasite control programme, which collected data in the same area in 1998.

Results

The prevalence of Ascaris lumbricoides and Trichuris trichiura was 25% and 26%, respectively, and their corresponding mean intensities of infection were 21 and 26 eggs per gram. The prevalence of Schistosoma haematobium was 32%, and its mean intensity of infection was 52 eggs per 10 mL urine. Of the pupils, 60% knew about schistosomiasis, 9% reported red urine in the past week and 22% had had dysuria before. Although the prevalence of ascariasis and trichuriasis had decreased since 1998 (62% and 59%, respectively), the prevalence of schistosomiasis had increased to 32% (p < 0.05).

Conclusion

Female pupils in rural schools remain at risk. A mass treatment campaign, increased public awareness and improved sanitation are required to reduce these infections and sustain a reduction of STHs and schistosomiasis.

Keywords

prevalence; intensity; schistosomiasis; soil-transmitted helminths; Ascaris lumbricoides; Trichuris trichiura; Schistosoma haematobium; parasite control programme; water contact.

Associations between schistosomiasis and HIV-1 acquisition risk in four prospective cohorts: a nested case-control analysis

INTRODUCTION

Globally, schistosomes infect approximately 200 million people, with 90% of infections in sub-Saharan Africa. Schistosomiasis is hypothesized to increase HIV-1 acquisition risk, and multiple cross-sectional studies reported strong associations. We evaluated this hypothesis within four large prospective cohorts.

METHODS

We conducted nested case-control analyses within three longitudinal cohorts of heterosexual HIV-1 serodiscordant couples and one female sex worker (FSW) cohort from Kenya and Uganda. The serodiscordant couples studies were conducted between 2004 and 2012 while the FSW cohort analysis included participant follow-up from 1993 to 2014. Cases HIV-1 seroconverted during prospective follow-up; three controls were selected per case. The presence of circulating anodic antigen in archived serum, collected prior to HIV-1 seroconversion, identified participants with active schistosomiasis; immunoblots determined the schistosome species. Data from serodiscordant couples cohorts were pooled, while the FSW cohort was analysed separately to permit appropriate confounder adjustment.

RESULTS

We included 245 HIV-1 seroconverters and 713 controls from the serodiscordant couples cohorts and 330 HIV-1 seroconverters and 962 controls from the FSW cohort. The prevalence of active schistosomiasis was 20% among serodiscordant couples and 22% among FSWs. We found no association between schistosomiasis and HIV-1 acquisition risk among males (adjusted odds ratio (aOR) = 0.99, 95% CI 0.59 to 1.67) or females (aOR = 1.21, 95% CI 0.64 to 2.30) in serodiscordant couples. Similarly, in the FSW cohort we detected no association (adjusted incidence rate ratio (aIRR) = 1.11, 95% CI 0.83 to 1.50). Exploring schistosome species-specific effects, there was no statistically significant association between HIV-1 acquisition risk and Schistosoma mansoni (serodiscordant couples: aOR = 0.90, 95% CI 0.56 to 1.44; FSW: aIRR = 0.83, 95% CI 0.53 to 1.20) or Schistosoma haematobium (serodiscordant couples: aOR = 1.06, 95% CI 0.46 to 2.40; FSW: aIRR = 1.64, 95% CI 0.93 to 2.87) infection.

CONCLUSIONS

Schistosomiasis was not a strong risk factor for HIV-1 acquisition in these four prospective studies. S. mansoni was responsible for the majority of schistosomiasis in these cohorts, and our results do not support the hypothesis that S. mansoni infection is associated with increased HIV-1 acquisition risk. S. haematobium infection was associated with a point estimate of elevated HIV-1 risk in the FSW cohort that was not statistically significant, and there was no trend towards a positive association in the serodiscordant couples cohorts.

Schistosomiasis: Still a Cause of Significant Morbidity and Mortality

Tropical diseases remain severe threats to global health with acute or chronic debility. Public health issues are regularly monitored and reported by the WHO. Conditions with high prevalence and virulence such as Schistosomiasis or Malaria still need active treatment. Advances over the decades in the treatment and management of Schistosomiasis have reduced morbidity and mortality in patients. However, poverty, adverse environments, lack of education and awareness, with parasites and vectors that can thrive if uncontrolled, remain issues for the successful global eradication of Schistosomiasis. From the disease's discovery in 1850, the author relates historical details to its current status. Several countries previously affected, including Japan and Tunisia, have eliminated the disease while others seek the same goal. Africa remains the most severely affected continent with vulnerable women and children, although the infection persists in South America and the Far East of Asia as well. Realistic improvements for continuing health conditions are vogue and emphasized for those at risk or afflicted by the infection, illustrating success models of concerted efforts of extirpation. Constant proximity to infected water, with a parasite host, are hurdles in reducing exposure. Effective medication for acute treatment is available, and prophylaxis by vaccination is promising. Where endemic Schistosomiasis is prevalent, significant morbidity and mortality have far-reaching complications in multiple human organ systems, including irreversible pulmonary hypertension, renal, genitourinary, central nervous system conditions, and neoplasia. Two hundred and thirty million people are estimated to have contracted Schistosomiasis globally, with up to 700 million still at risk of infection, and 200,000 deaths occur annually. The disease may be more prevalent than thought after newer tests have shown increased sensitivity to pathological antigens. The author discusses infectivity risks, investigations, prognosis, treatment, and management, as well as morbidity and mortality.

Female Genital Schistosomiasis and HIV: Research Urgently Needed to Improve Understanding of the Health Impacts of This Important Coinfection

Evidence suggests that there are important interactions between HIV and female genital schistosomiasis (FGS) that may have significant effects on individual and population health. However, the exact way they interact and the health impacts of the interactions are not well understood. In this article, we discuss what is known about the interactions between FGS and HIV, and the potential impact of the interactions. This includes the likelihood that FGS is an important health problem for HIV-positive women in Schistosoma-endemic areas potentially associated with an increased risk of mortality, cancer, and infertility. In addition, it may be significantly impacting the HIV epidemic in sub-Saharan Africa by making young women more susceptible to HIV. We call for immediate action and argue that research is urgently required to address these knowledge gaps and propose a research agenda to achieve this.

Determinants of Urogenital Schistosomiasis Among Pregnant Women and its Association With Pregnancy Outcomes, Neonatal Deaths, and Child Growth

Background

Schistosoma haematobium is a parasitic helminth that causes urogenital pathology. The impact of urogenital schistosomiasis during pregnancy on birth outcomes and child growth is poorly understood.

Methods

Risk factors for urogenital schistosomiasis were characterized among 4437 pregnant women enrolled in a cluster-randomized community-based trial in rural Zimbabwe. Infection was defined via urine microscopy (≥1 S. haematobium egg) and urinalysis (hematuria). Associations between infection and pregnancy outcomes were assessed in case-control analyses using conditional logistic regression. The association of maternal infection with birthweight and length-for-age Z scores (LAZ) at 1 and 18 months of age were assessed using generalized estimating equations.

Results

Urogenital schistosomiasis (egg positive and/or hematuria positive) was detected in 26.8% of pregnant women. Risk factors significantly associated with infection were maternal age, education, marital status, and religion; household drinking water source and latrine; study region; and season. Urogenital schistosomiasis was not significantly associated with adverse pregnancy outcomes (miscarriage, stillbirth, preterm, and small-for-gestational age), birthweight, neonatal death, or LAZ.

Conclusions

Including pregnant women in antihelminthic treatment programs would benefit a large number of women in rural Zimbabwe. However, clearance of the low-intensity infections that predominate in this context is unlikely to have additive benefits for pregnancy outcomes or child growth.

Clinical Trials Registration

NCT01824940.

Schistosomiasis is associated with incident HIV transmission and death in Zambia

Background

We examined relationships between schistosome infection, HIV transmission or acquisition, and all-cause death.

Methods

We retrospectively tested baseline sera from a heterosexual HIV-discordant couple cohort in Lusaka, Zambia with follow-up from 1994–2012 in a nested case-control design. Schistosome-specific antibody levels were measured by ELISA. Associations between baseline antibody response to schistosome antigens and incident HIV transmission, acquisition, and all-cause death stratified by gender and HIV status were assessed. In a subset of HIV- women and HIV+ men, we performed immunoblots to evaluate associations between Schistosoma haematobium or Schistosoma mansoni infection history and HIV incidence.

Results

Of 2,145 individuals, 59% had positive baseline schistosome-specific antibody responses. In HIV+ women and men, baseline schistosome-specific antibodies were associated with HIV transmission to partners (adjusted hazard ratio [aHR] = 1.8, p<0.005 and aHR = 1.4, p<0.05, respectively) and death in HIV+ women (aHR = 2.2, p<0.001). In 250 HIV- women, presence of S. haematobium-specific antibodies was associated with increased risk of HIV acquisition (aHR = 1.4, p<0.05).

Conclusion

Schistosome infections were associated with increased transmission of HIV from both sexes, acquisition of HIV in women, and increased progression to death in HIV+ women. Establishing effective prevention and treatment strategies for schistosomiasis, including in urban adults, may reduce HIV incidence and death in HIV+ persons living in endemic areas.

This study explored the association between schistosome infections (a disease caused by parasitic flatworms, also known as ‘snail fever’, which is very common throughout sub-Saharan Africa) and human immunodeficiency virus (HIV). We found in Lusaka, the capital of Zambia, that schistosome infections were associated with transmission of HIV from adult men and women, and schistosome infections were also associated with increased HIV acquisition in adult women. We additionally found that schistosome infections were associated with death in HIV+ adult women. Since treatment of schistosome infections with praziquantel is inexpensive, effective, and safe, schistosomiasis prevention and treatment strategies may be a cost-effective way to reduce not only the symptoms associated with the infection, but also new cases of HIV and death among HIV+ persons. Though often viewed as an infection of predominantly rural areas and children, this study highlights that schistosomiasis prevention and treatment efforts are also needed in urban areas and among adults.

Advancing the Development of a Human Schistosomiasis Vaccine

Three vaccines against human schistosomiasis are in different phases of clinical development, and a fourth is expected to enter the clinic soon. Successful introduction of an efficacious preventive human schistosomiasis vaccine will require integration into existing health systems such as those that deliver childhood vaccines or mass drug administration programs.

HIV-1 Viral Loads Are Not Elevated in Individuals Co-infected With Schistosoma spp. After Adjustment for Duration of HIV-1 Infection

Studies of the role of Schistosoma co-infections on plasma HIV-1 RNA (HIV-1 viral load) have yielded incongruent results. The role of duration of HIV-1 infection on the link between Schistosoma and HIV-1 viral load has not been previously investigated. We aimed to assess the impact of HIV-1/Schistosoma co-infections on viral load in Antiretroviral Treatment (ART)-naïve HIV-1 infected people taking into account the duration of HIV-1 infection. We describe 79 HIV-infected outpatients greater than 18 years of age who had never used ART in Mwanza, Tanzania. Schistosomiasis testing was done by urine and stool microscopy and by serum Schistosoma circulating anodic antigen (CAA) testing. Schistosoma positivity was defined as having either test positive. We conducted univariable and multivariable linear regressions to assess the relationship between Schistosoma infection and the log₁₀ of viral load. Duration of HIV infection was calculated using the first measured CD4⁺ T-cell (CD4) count as a function of normal CD4 count decay per calendar year in drug naïve individuals. An active Schistosoma infection was demonstrated in 46.8% of the patients. The median log₁₀ viral load was 4.5[3.4–4.9] log₁₀ copies/mL in Schistosoma uninfected patients and 4.3[3.7–4.6] log₁₀ copies/mL in Schistosoma infected patients. Schistosoma co-infection was negatively associated with the log₁₀ of viral load after adjustment for Schistosoma intensity as measured by CAA, CD4 counts at time of testing, and duration of HIV-1 infection (β = −0.7[−1.3;−0.1], p = 0.022). Schistosoma co-infection was not associated with viral load in univariable analysis. There was also no interaction between Schistosoma positivity and duration of HIV-1 infection. Our study is the first, to our knowledge, to report adjustment for duration of HIV-1 infection when analyzing the relationship between HIV-1 viral load and Schistosoma spp. We found that time infected with HIV-1 has a major effect on the relationship between HIV-1 viral load and Schistosoma infection and may be a critical explanatory factor in the disparate findings of studies on HIV-1 viral load and schistosomiasis. The log₁₀ viral load difference found indicates that Schistosoma co-infection does not make HIV progression worse, and could possibly lead to slower HIV disease progression.

Inflammation dynamics after praziquantel treatment of Schistosoma haematobium reflected by urinary eosinophil cationic protein

Background

This cohort study assessed urinary eosinophil cationic protein (ECP) as an indicator for urinary tract morbidity and inflammation indication related to single-dose or dual-dose praziquantel (PZQ) treatment.

Methods

Urinary ECP was measured at baseline, 24 h and 9 weeks after treatment (baseline 305, follow-up 204 participants, ages 2-40 years).

Results

ECP was significantly associated with the intensity of infection at baseline (p<0.05). Levels at baseline were 8.31 times higher (p<0.01) in participants with bladder morbidity than in those without. There was no correlation with kidney morbidity and no significant effect of a repeated dose of PZQ 40 mg/kg. Baseline ECP and ECP after 9 weeks were associated with microhaematuria (geometric mean ratio at baseline 7.56 [95% confidence limit {CL} 2.34-24.45]; p<0.01) and macrohaematuria (geometric mean ratio at baseline 6.22 [95% CL 2.71-14.24]; p<0.001). Mean levels of ECP dropped significantly during the first follow-up period and far less so in the second follow-up period (mean ECP at baseline: 70.8 ng/mL; ECP at 24 h: 24.5 ng/mL; ECP at 9 weeks: 14.6 ng/mL).

Conclusion

The urine ECP decrease happened immediately after treatment, reflecting the rapid action of PZQ on eggs in the bladder tissue. ECP in urine can be used as an indirect marker of the degree of local inflammatory reaction in the bladder and is not significantly affected by a repeated dose of PZQ.

Schistosomiasis in the first 1000 days

Infections during the first 1000 days-the period from conception to a child's second birthday-can have lifelong effects on health, because this is a crucial phase of growth and development. There is increasing recognition of the burden and potential effects of schistosomiasis in women of reproductive age and young children. Exposure to schistosomes during pregnancy can modulate infant immune development and schistosomiasis can occur from early infancy, such that the high disease burden found in adolescents is often due to accumulation of infections with long-lived schistosomes from early life. Women of reproductive age and young children are largely neglected in mass drug administration programmes, but early treatment could avert subsequent disease. We evaluate the evidence that early schistosomiasis has adverse effects on birth, growth, and development. We also discuss the case for expanding public health interventions for schistosomiasis in women of reproductive age and preschool-age children, and the need for further research to evaluate the potential of treating women pre-conception to maximise health across the life course.

Schistosomiasis and Infertility in East Africa

Case reports and pathology series suggest associations of female genital schistosomiasis (Schistosoma haematobium) with infertility and ectopic pregnancy. Differential geographic distribution of infertility is not explained by analyses of known risk factors. In this cross-sectional multilevel semi-ecologic study, interpolated prevalence maps for S. haematobium and Schistosoma mansoni in East Africa were created using data from two open-access Neglected Tropical Diseases Databases. Prevalence was extracted to georeferenced survey sample points for Demographic and Health Surveys for Ethiopia, Kenya, Tanzania, and Uganda for 2000 and 2010. Exploratory spatial analyses showed that infertility was not spatially random and mapped the clustering of infertility and its co-location with schistosomiasis. Multilevel logistic regression analysis demonstrated that women living in high compared with absent S. haematobium locations had significantly higher odds of infertility (2000 odds ratio [OR] = 1.5 [confidence interval95 = 1.3, 1.8]; 2010 OR = 1.2 [1.1, 1.5]). Women in high S. haematobium compared with high S. mansoni locations had significantly higher odds of infertility (2000 OR 1.4 [1.1, 1.9]; 2010 OR 1.4 [1.1, 1.8]). Living in high compared with absent S. mansoni locations did not affect the odds of infertility. Infertility appears to be associated spatially with S. haematobium.

Praziquantel for the treatment of schistosomiasis during human pregnancy

In 2014, an estimated 40 million women of reproductive age were infected with Schistosoma haematobium, S. japonicum and/or S. mansoni. In both 2003 and 2006, the World Health Organization (WHO) recommended that all schistosome-infected pregnant and breastfeeding women be offered treatment, with praziquantel, either individually or during treatment campaigns. In 2006, WHO also stated the need for randomized controlled trials to assess the safety and efficacy of such treatment. Some countries have yet to follow the recommendation on treatment and many programme managers and pregnant women in other countries remain reluctant to follow the recommended approach. Since 2006, two randomized controlled trials on the use of praziquantel during pregnancy have been conducted: one against S. mansoni in Uganda and the other against S. japonicum in the Philippines. In these trials, praziquantel treatment of pregnant women had no significant effect on birth weight, appeared safe and caused minimal side-effects that were similar to those seen in treated non-pregnant subjects. Having summarized the encouraging data, on efficacy, pharmacokinetics and safety, from these two trials and reviewed the safety data from non-interventional human studies, we recommend that all countries include pregnant women in praziquantel treatment campaigns. We identify the barriers to the treatment of pregnant women, in countries that already include such women in individual treatments and mass drug administration campaigns, and discuss ways to address these barriers.

Community engagement practices in Southern Africa: Review and thematic synthesis of studies done in Botswana, Zimbabwe and South Africa

Community Engagement (CE) is intended to enhance the participation of community stakeholders in research. CE is usually mentioned in publications as researchers discuss how they carried out community entry, consent and retained study participants but the actual CE activities are not always well documented. This paper reviews CE strategies employed in health research in Botswana, South Africa and Zimbabwe with reference to the development of a CE strategy for a multi-centre study to be conducted in these countries. The search was conducted using JANE (Journal/Author Name Estimator), Google Scholar and PubMed with known institutions and researchers providing context-specific material. The final synthesis includes 35 publications, 2 reports and 2 abstracts. There is evidence of CE being practiced in health research and eight closely related CE strategies were revealed. We conclude that since communities are heterogeneous and unique, CE activities will not have similar results in different settings. Even though there was insufficient evidence to determine which CE strategy is most effective, the review provides sufficient information to develop a CE strategy for a multi-centre study using the various strategies and activities described.

The cross-cutting contribution of the end of neglected tropical diseases to the sustainable development goals

The Sustainable Development Goals (SDGs) call for an integrated response, the kind that has defined Neglected Tropical Diseases (NTDs) efforts in the past decade.NTD interventions have the greatest relevance for SDG3, the health goal, where the focus on equity, and its commitment to reaching people in need of health services, wherever they may live and whatever their circumstances, is fundamentally aligned with the target of Universal Health Coverage. NTD interventions, however, also affect and are affected by many of the other development areas covered under the 2030 Agenda. Strategies such as mass drug administration or the programmatic integration of NTD and WASH activities (SDG6) are driven by effective global partnerships (SDG17). Intervention against the NTDs can also have an impact on poverty (SDG1) and hunger (SDG2), can improve education (SDG4), work and economic growth (SDG8), thereby reducing inequalities (SDG10). The community-led distribution of donated medicines to more than 1 billion people reinforces women's empowerment (SDG5), logistics infrastructure (SDG9) and non-discrimination against disability (SDG16). Interventions to curb mosquito-borne NTDs contribute to the goals of urban sustainability (SDG11) and resilience to climate change (SDG13), while the safe use of insecticides supports the goal of sustainable ecosystems (SDG15). Although indirectly, interventions to control water- and animal-related NTDs can facilitate the goals of small-scale fishing (SDG14) and sustainable hydroelectricity and biofuels (SDG7).NTDs proliferate in less developed areas in countries across the income spectrum, areas where large numbers of people have little or no access to adequate health care, clean water, sanitation, housing, education, transport and information. This scoping review assesses how in this context, ending the epidemic of the NTDs can impact and improve our prospects of attaining the SDGs.

Diagnosing Urogenital Schistosomiasis: Dealing with Diminishing Returns

Urogenital schistosomiasis, caused by Schistosoma haematobium, is the most prevalent form of schistosomiasis affecting humans, and can result in severe bladder, kidney, ureteral, and genital pathologies. Chronic infection with S. haematobium has been linked with bladder cancer and increased risk for HIV infection. As mass drug administration with praziquantel increases in an attempt to transition from control to elimination of schistosomiasis, the need for updated, more sensitive diagnostic tools becomes more apparent, especially for use in areas of low infection intensity and for individuals with light infections. Here, we review established and investigational diagnostic tests utilized for urogenital schistosomiasis, highlighting new insights and recent advances.

Cervical cytology as a diagnostic tool for female genital schistosomiasis: Correlation to cervical atypia and Schistosoma polymerase chain reaction

Background:

Female genital schistosomiasis (FGS) is a tissue reaction to lodged ova of Schistosoma haematobium in the genital mucosa. Lesions can make the mucosa friable and prone to bleeding and discharge. Women with FGS may have an increased risk of HIV acquisition, and FGS may act as a cofactor in the development of cervical cancer.

Objectives:

To explore cytology as a method for diagnosing FGS and to discuss the diagnostic challenges in low-resource rural areas. The correlation between FGS and squamous cell atypia (SCA) is also explored and discussed. Cytology results are compared to Schistosoma polymerase chain reaction (PCR) in vaginal lavage and urine and in urine microscopy.

Materials and Methods:

In a clinical study, 394 women aged between 16 and 23 years from rural high schools in KwaZulu-Natal, South Africa, underwent structured interviews and the following laboratory tests: Cytology Papanicolaou (Pap) smears for S. haematobium ova and cervical SCA, real-time PCR for Schistosoma-specific DNA in vaginal lavage and urine samples, and urine microscopy for the presence of S. haematobium ova.

Results:

In Pap smears, S. haematobium ova were detected in 8/394 (2.0%). SCA was found in 107/394 (27.1%), seven of these had high-grade squamous intraepithelial lesion (HSIL). Schistosoma specific DNA was detected in 38/394 (9.6%) of vaginal lavages and in 91/394 (23.0%) of urines. Ova were found microscopically in 78/394 (19.7%) of urines.

Conclusion:

Schistosoma PCR on lavage was a better way to diagnose FGS compared to cytology. There was a significant association between S. haematobium ova in Pap smears and the other diagnostic methods. In low-resource Schistosoma-endemic areas, it is important that cytology screeners are aware of diagnostic challenges in the identification of schistosomiasis in addition to the cytological diagnosis of SCA. Importantly, in this study, three of eight urines were negative but showed Schistosoma ova in their Pap smear, and one of them was also negative for Schistosoma DNA in urine. In this study, SCA was not significantly associated with schistosomiasis. HSIL detected in this young population might need future consideration.

Female genital schistosomiasis (FGS): from case reports to a call for concerted action against this neglected gynaecological disease

In recent years, control of neglected tropical diseases has been increasingly gaining momentum and interventions against schistosomiasis are being progressively scaled-up through expansion of donated praziquantel and preventive chemotherapy campaigns. However, the public health importance of female genital schistosomiasis is not fully recognised nor its control is adequately addressed. Taking a clinical and anatomopathological perspective, we evaluated the available literature to highlight the importance of female genital schistosomiasis and its connections with two sexually transmitted infections of global importance, Human Immunodeficiency Virus (HIV) and Human Papilloma Virus. Outside the long list of clinical descriptive reports beginning in 1899, there is presently a shocking gap in epidemiological assessment and a significant underestimation of the burden of FGS remains. The scarcity of integrated approaches to address female genital schistosomiasis calls for more concerted action in its detection, treatment and prevention alongside other concomitant women's health issues, otherwise female genital schistosomiasis will remain a neglected gynaecological disease.

Schistosomiasis elimination by 2020 or 2030?

Schistosomiasis has been a public health burden in a number of countries across the globe for centuries and probably beyond. The World Health Organization and partners are currently preparing to move towards elimination of this disease. However, given the historical challenges and barriers to ridding areas of this water-borne parasite infection, we question whether the current targets for eliminating schistosomiasis as a global health problem can be achieved.

Case-Control Study of Posttreatment Regression of Urinary Tract Morbidity Among Adults in Schistosoma haematobium-Endemic Communities in Kwale County, Kenya

Previous population-based studies have examined treatment impact on Schistosoma-associated urinary tract disease among children, but much less is known about longer-term treatment benefits for affected adult populations in areas where risk of recurrent infection is high. In communities in Msambweni, along the Kenya coast, we identified, using a portable ultrasound, 77 adults (aged 17-85) with moderate-to-severe obstructive uropathy or bladder disease due to Schistosoma haematobium. Treatment response was assessed by repeat ultrasound 1-2 years after praziquantel (PZQ) therapy and compared with interval changes among age- and sex-matched infected/treated control subjects who did not have urinary tract abnormalities at the time of initial examination. Of the 77 affected adults, 62 (81%) had improvement in bladder and/or kidney scores after treatment, 14 (18%) had no change, and one (1.3%) had progression of disease. Of the 77 controls, 75 (97%) remained disease free by ultrasound, while two (3%) had apparent progression with abnormal findings on follow-up examination. We conclude that PZQ therapy for S. haematobium is effective in significantly reducing urinary tract morbidity from urogenital schistosomiasis among adult age groups, and affected adults stand to benefit from inclusion in mass treatment campaigns.

Gynecological manifestations, histopathological findings, and schistosoma-specific polymerase chain reaction results among women with Schistosoma haematobium infection: a cross-sectional study in Madagascar

Background. The pathophysiology of female genital schistosomiasis (FGS) is only partially understood. This study aims to describe the histopathological findings, polymerase chain reaction (PCR) results, and gynecological manifestations of FGS in women with different intensities of Schistosoma haematobium infection.

Methods. Women aged 15–35 years living in an S. haematobium-endemic area in Madagascar underwent pelvic and colposcopic examinations. Small biopsy specimens were obtained from lesions and examined histopathologically. Schistosoma PCR was done on urine, biopsy, cervicovaginal lavage, and genital mucosal surface specimens.

Results. Sandy patches and rubbery papules were found in 41 of 118 women (35%). Rubbery papules reflected an intense cellular immune reaction dominated by eosinophils, epithelial erosion, and viable ova. There was a significant decrease in the prevalence of rubbery papules with age, even after adjustment for urinary ova excretion. The sandy patches with grains showed moderate cellular immune reaction and ova (viable and/or calcified). They were most prevalent in cases with low-intensity urinary S. haematobium infection. Forty-two percent of women with Schistosoma-negative urine specimens had at least 1 genital specimen test positive for Schistosoma by PCR.

Conclusions. The results indicate a diversity of lesions caused by S. haematobium and a dynamic evolution of the genital lesions. Schistosoma PCR may give an indication of the diagnosis.

Immune responses to Schistosoma haematobium infection

Urogenital schistosomiasis is one of the greatest single infectious sources of human morbidity and mortality known. Through a complex cycle of infection, migration and eventual maturation and mating, S. haematobium (the aetiological agent of urogenital schistosomiasis) deposits highly immunogenic eggs within the bladder and other pelvic organs, activating a wide range of immune programs that determine both infection outcome as well as downstream immunopathology. In this review, we discuss the experimental and observational bases for our current understanding of these immune programs, focusing specifically on how the balance of type 1 and type 2 responses governs subsequent immunopathology and clinical outcome.

Eosinophil granule proteins ECP and EPX as markers for a potential early-stage inflammatory lesion in female genital schistosomiasis (FGS)

Background

Genital granulomas induced by Schistosoma haematobium eggs can manifest as different lesion types visible by colposcopy; rubbery papules (RP), homogenous sandy patches (HSP) and grainy sandy patches (GSP). Pronounced tissue eosinophilia is a candidate marker for active S. haematobium pathology, as viable schistosome egg granulomas often are eosinophil rich. Here it was investigated whether eosinophil granule proteins ECP (eosinophil cationic protein) and EPX (eosinophil protein-X) in urine and genital lavage can be used as markers for active FGS lesions.

Methods

Uro-genital samples from 118 Malagasy women were analysed for ECP and EPX by standard sandwich avidin/biotin amplified ELISA.

Principal findings

The women with RP lesions had significantly higher levels of ECP and EPX in both lavage and urine. Furthermore, women with RP lesions were significantly younger than those with GSP. This could indicate that RP lesions might be more recently established and thus represent an earlier inflammatory lesion stage.

Conclusion

ECP in genital lavage might be a future tool aiding the identification of FGS pathology at a stage where reversibility remains a possibility following praziquantel treatment.

The blood-dwelling fluke Schistosoma haematobium produce eggs which can inflict lesions both in the urinary and genital tract. Lesions in the female genital tract have been hypothesised to confer higher risk of contraction of HIV and other genital infections. These epithelial genital lesions are visibly different and three types can be observed; rubbery papules, homologous sandy patches and grainy sandy patches. Like other helminths, active S. haematobium infection is associated with eosinophilia. Therefore eosinophil granule proteins might be useful markers for active inflammation related to female genital schistosomiasis lesions. This study identifies the rubbery papules as a potential early-stage inflammatory lesion type associated with high levels of eosinophil granule proteins in vaginal lavage. It may be advantageous to identify female genital lesions relatively early after infection as chronic inflammation stage lesions might not respond to praziquantel treatment.

Effect of female genital schistosomiasis and anti-schistosomal treatment on monocytes, CD4+ T-cells and CCR5 expression in the female genital tract

Background

Schistosoma haematobium is a waterborne parasite that may cause female genital schistosomiasis (FGS), characterized by genital mucosal lesions. There is clinical and epidemiological evidence for a relationship between FGS and HIV. We investigated the impact of FGS on HIV target cell density and expression of the HIV co-receptor CCR5 in blood and cervical cytobrush samples. Furthermore we evaluated the effect of anti-schistosomal treatment on these cell populations.

Design

The study followed a case-control design with post treatment follow-up, nested in an on-going field study on FGS.

Methods

Blood and cervical cytobrush samples were collected from FGS negative and positive women for flow cytometry analyses. Urine samples were investigated for schistosome ova by microscopy and polymerase chain reaction (PCR).

Results

FGS was associated with a higher frequency of CD14⁺ cells (monocytes) in blood (11.5% in FGS+ vs. 2.2% in FGS-, p = 0.042). Frequencies of CD4⁺ cells expressing CCR5 were higher in blood samples from FGS+ than from FGS- women (4.7% vs. 1.5%, p = 0.018). The CD14⁺ cell population decreased significantly in both compartments after anti-schistosomal treatment (p = 0.043). Although the frequency of CD4+ cells did not change after treatment, frequencies of CCR5 expression by CD4+ cells decreased significantly in both compartments (from 3.4% to 0.5% in blood, p = 0.036; and from 42.4% to 5.6% in genital samples, p = 0.025).

Conclusions

The results support the hypothesis that FGS may increase the risk of HIV acquisition, not only through damage of the mucosal epithelial barrier, but also by affecting HIV target cell populations, and that anti-schistosomal treatment can modify this.

Evaluating the potential impact of mass praziquantel administration for HIV prevention in Schistosoma haematobium high-risk communities

Genital infection with Schistosoma haematobium is prevalent in sub-Saharan Africa. Epidemiological studies have observed that genital schistosomiasis is associated with an increased odd of HIV infection among women. We used mathematical modeling to explore the potential impact of mass preventive chemotherapy against schistosomiasis on HIV transmission in three sub-Saharan Africa countries: Angola, Kenya, and Zambia. We developed a model of female genital schistosomiasis (FGS) and HIV transmission dynamics, fitting it to data of HIV and S. haematobium prevalences as well as co-infection. We simulated targeted mass drug administration (MDA) with praziquantel to school-age children and mass treatment of the entire community. We estimated that, in S. haematobium high-risk communities, targeted annual treatment of school-age children could reduce HIV prevalence by 20% (95% CI: 12-31%) in Angola, 16% (95% CI: 10-32%) in Kenya, and 6% (95% CI: 3-18%) in Zambia after the first 20 years of intervention; and would reduce HIV incidence by 15% (95% CI: 13-32%) in Angola, 22% (95% CI: 18-42%) in Kenya, and 9% (95% CI: 3-22%) in Zambia. Extending the intervention to adults could reduce HIV prevalence by an additional 2.2% (95% CI: 0.2-12.0%) in Angola, 1.8% (95% CI: 0.1-5.2%) in Kenya, and 0.3% (95% CI: 0.1-2.1%) in Zambia; and would reduce HIV incidence by an additional 1.8% (95% CI: 0.0-14.4%) in Angola, 6.1% (95% CI: 0.5-12.6%) in Kenya, and 0.8% (95% CI: 0.0-2.7%) in Zambia. We showed that the exacerbation of HIV transmission due to FGS and the probability of developing FGS as a result of childhood infection with S. haematobium, were the most important factors in determining the effectiveness of praziquantel MDA for reducing HIV transmission. Praziquantel MDA may be an innovative measure for reducing schistosomiasis and HIV transmission in sub-Saharan Africa, the effectiveness of which varies with HIV prevalence.

Impact of short-time urine freezing on the sensitivity of an established Schistosoma real-time PCR assay

Urogenital schistosomiaisis is a serious public health problem in sub-Saharan Africa. In this study, we have updated an established real-time polymerase chain reaction (PCR) routinely used in our laboratory. Schistosoma genus-specific real-time PCR was performed on DNA isolated from 85 urine samples and pellets obtained after centrifugation without and after frozen storage. The results revealed that concentration by centrifugation of the urine samples and freezing of the samples before extracting DNA improves the sensitivity of the PCR.

Real-time polymerase chain reaction for detection of Schistosoma DNA in small-volume urine samples reflects focal distribution of urogenital Schistosomiasis in primary school girls in KwaZulu Natal, South Africa

Schistosoma haematobium eggs and Schistosoma DNA levels were measured in urine samples from 708 girls recruited from 18 randomly sampled primary schools in South Africa. Microscopic analysis of two 10-mL urine subsamples collected on three consecutive days confirmed high day-to-day variation; 103 (14.5%) girls had positive results at all six examinations, and at least one positive sample was seen in 225 (31.8%) girls. Schistosoma-specific DNA, which was measured in a 200-μL urine subsample by using real-time polymerase chain reaction, was detected in 180 (25.4%) cases, and levels of DNA corresponded significantly with average urine egg excretion. In concordance with microscopic results, polymerase chain reaction results were significantly associated with history of gynecologic symptoms and confirmed highly focal distribution of urogenital schistosomiasis. Parasite-specific DNA detection has a sensitivity comparable to single urine microscopy and could be used as a standardized high-throughput procedure to assess distribution of urogenital schistosomiasis in relatively large study populations by using small sample volumes.

Detectable urogenital schistosome DNA and cervical abnormalities 6 months after single-dose praziquantel in women with Schistosoma haematobium infection

We explored response to single-dose praziquantel therapy in a cohort of 33 women with Schistosoma haematobium infection in rural Mwanza, Tanzania. Women with S. haematobium infection confirmed both by eggs in urine and by polymerase chain reaction (PCR) received single-dose praziquantel and treatment of concomitant sexually transmitted infections. Macroscopic cervical abnormalities were also quantified. After 6 months, microscopically detectable egg excretion was eliminated, but 8 of 33 women (24%) were persistently positive for S. haematobium by PCR, and 11 (33%) had cervical abnormalities potentially attributable to schistosomiasis. This suggests that praziquantel treatment more frequently than every 6 months may be necessary for complete elimination of the parasite and prevention of genital tissue pathology. This aggressive therapy may in turn play a key role decreasing HIV susceptibility in millions of people living in regions in which S. haematobium is endemic.

Exploring gender dimensions of treatment programmes for neglected tropical diseases in Uganda

Background

Gender remains a recognized but relatively unexamined aspect of the potential challenges for treatment programmes for Neglected Tropical Diseases (NTDs). We sought to explore the role of gender in access to treatment in the Uganda National Neglected Tropical Disease Control Programme.

Methodology/Principal Findings

Quantitative and qualitative data was collected in eight villages in Buyende and Kamuli districts, Eastern Uganda. Quantitative data on the number of persons treated by age and gender was identified from treatment registers in each village. Qualitative data was collected through semi-structured interviews with sub-county supervisors, participant observation and from focus group discussions with community leaders, community medicine distributors (CMDs), men, women who were pregnant or breastfeeding at the time of mass-treatment, and adolescent males and females. Findings include the following: (i) treatment registers are often incomplete making it difficult to obtain accurate estimates of the number of persons treated; (ii) males face more barriers to accessing treatment than women due to occupational roles which keep them away from households or villages for long periods, and males may be more distrustful of treatment; (iii) CMDs may be unaware of which medicines are safe for pregnant and breastfeeding women, resulting in women missing beneficial treatments.

Conclusions/Significance

Findings highlight the need to improve community-level training in drug distribution which should include gender-specific issues and guidelines for treating pregnant and breastfeeding women. Accurate age and sex disaggregated measures of the number of community members who swallow the medicines are also needed to ensure proper monitoring and evaluation of treatment programmes.

This study explored gender-related factors that may influence community member access and adherence to treatment programmes for NTDs in Uganda. A large number of previous studies have identified community-based mass-treatment programmes as an effective strategy to treat affected populations. However, limited evidence is available to discuss challenges to treatment access, adherence, delivery and monitoring at community level. Quantitative data from treatment registers suggested that men were less likely to access treatment than women in at least two villages. It also revealed difficulties in community-based monitoring of the programmes, creating challenges in ascertaining how many persons are able to access the programme. Qualitative data collected from district health workers, community leaders, community medicine distributors and community members suggested that socio-behavioural and structural barriers to treatment access may be present for both genders. Results of the study identify gender-based challenges to treatment access that should be considered in planning, implementing and evaluating national treatment programmes for NTDs.

The effects of schistosomiasis on HIV/AIDS infection, progression and transmission

PURPOSE OF REVIEW

The recent findings pertaining to the public health impact of schistosomiasis on the epidemiology of HIV/AIDS are summarized.

RECENT FINDINGS

Both empiric data and mathematical models support the hypothesis that schistosome infections lead to increased susceptibility to infection with HIV-1, a more rapid progression to disease through more vigorous viral replication and immunosuppression, and a higher likelihood of transmitting the infection to others through both vertical and horizontal routes. Different species of schistosome infection vary in the magnitude of their effects on these mechanisms with Schistosoma haematobium playing a greater role for increased susceptibility and transmission because of its association with urogenital disease.

SUMMARY

Schistosomiasis appears to be a cofactor in the spread and progression of HIV/AIDS in areas wherein both diseases are endemic; increased emphasis on treatment of schistosome infections in persons at risk of HIV/AIDS should be pursued.

Schistosoma mansoni enhances host susceptibility to mucosal but not intravenous challenge by R5 Clade C SHIV

Background

The high prevalence of HIV-1/AIDS in areas endemic for schistosomiasis and other helminthic infections has led to the hypothesis that parasites increase host susceptibility to immunodeficiency virus infection. We previously showed that rhesus macaques (RM) with active schistosomiasis were significantly more likely to become systemically infected after intrarectal (i.r.) exposure to an R5-tropic clade C simian-human immunodeficiency virus (SHIV-C) than were parasite-free controls. However, we could not address whether this was due to systemic or mucosal effects. If systemic immunoactivation resulted in increased susceptibility to SHIV-C acquisition, a similarly large difference in host susceptibility would be seen after intravenous (i.v.) SHIV-C challenge. Conversely, if increased host susceptibility was due to parasite-induced immunoactivation at the mucosal level, i.v. SHIV-C challenge would not result in significant differences between parasitized and parasite-free monkeys.

Methods and Findings

We enrolled two groups of RM and infected one group with Schistosoma mansoni; the other group was left parasite-free. Both groups were challenged i.v. with decreasing doses of SHIV-C. No statistically significant differences in 50% animal infectious doses (AID₅₀) or peak viremia were seen between the two groups. These data strongly contrast the earlier i.r. SHIV-C challenge (using the same virus stock) in the presence/absence of parasites, where we noted a 17-fold difference in AID₅₀ and one log higher peak viremia in parasitized monkeys (P<0.001 for both). The lack of significant differences after the i.v. challenge implies that the increased host susceptibility is predominantly due to parasite-mediated mucosal upregulation of virus replication and spread, rather than systemic effects.

Conclusions

The major impact of schistosome-induced increased host susceptibility is at the mucosal level. Given that >90% of all new HIV-1 infections worldwide are acquired through mucosal contact, parasitic infections that inflame mucosae may play an important role in the spread of HIV-1.

Parasitic infections have been postulated to increase host susceptibility to HIV-1. We previously demonstrated that rhesus monkeys with active schistosomiasis were significantly more likely to become systemically infected after intrarectal exposure to an R5-tropic clade C simian-human immunodeficiency virus then were parasite-free control animals. However, we could not address whether parasites exert their effect at the mucosal level or systemically. To address the latter possibility, we measured the virus doses needed to achieve systemic infection after intravenous exposure of parasite-free or parasite-positive monkeys using the identical virus stock. None of the viral parameters tested in these two groups of monkeys were statistically significantly different. These results suggest that schistosomiasis modulates susceptibility to immunodeficiency virus acquisition predominantly at the mucosal level. Treatment for parasitic infections in populations at higher risk for HIV-1 acquisition could represent a cost-effective approach to slow the spread of HIV-1, which is predominantly transmitted through mucosal routes.

A wake up call for urinary schistosomiasis: reconciling research effort with public health importance

This review considers the current status of urinary schistosomiasis, caused by infection with Schistosoma haematobium, and argues that greater research effort and focus are needed to improve understanding of this neglected tropical disease (NTD). The inappropriateness of relying solely on data concerning the much more extensively studied intestinal form of schistosomiasis caused by S. mansoni is highlighted. The current lack of genome and transcriptome information for S. haematobium is directly hindering further targeted research and must be quickly rectified. Recent molecular phylogenies caution the expectation of similarities between schistosome species and highlight the close relationships of species within the S. haematobium group. Treatment, current and prospective drugs and vaccines, together with diagnosis are considered, highlighting the differences associated with urinary schistosomiasis. This infection has a significant and specific impact on the urino-genital system and has a strong association with bladder cancer, leading to severe and chronic morbidity. There is a clear need for new clinical initiatives in this area to better quantify the disease burden. Furthermore, emerging associations with HIV and other pathogens need to be closely monitored. Research is urgently needed to improve current knowledge in order to develop the next generation of control tools.

Schistosomiasis: challenges for control, treatment and drug resistance

PURPOSE OF REVIEW

Schistosomiasis is a parasitic disease that has recently attracted increased focus and funding for control. Despite shifts in global health policy towards the implementation of mass chemotherapeutic control programmes at the national scale in sub-Saharan Africa, however, many challenges still exist.

RECENT FINDINGS

Publications reviewed for this article cover: the development of treatment strategies; the planning, implementation and impact of control programmes; the re-evaluation of the burden of schistosomiasis; improved tools for control; new drugs; the safety of treatment during pregnancy; and the development of resistance against praziquantel.

SUMMARY

The morbidity due to schistosomiasis has been shown to be greater than was previously thought. The reduction in morbidity of schistosomiasis by control programmes has been demonstrated, while new tools include a validated dose pole for delivering the correct treatment, geographical information systems mapping for determining high-risk areas, and Lot Quality Assurance Sampling for determining treatment strategies at the local level. Sustainability and future funding are issues to be addressed. Despite some positive results, myrrh is apparently ineffective against schistosomiasis, but fortunately no resistance to praziquantel has developed. We predict the impact of schistosomiasis control will be a healthier generation of children within 5 years.

Interactions between schistosomiasis and infection with HIV-1

In many regions of the world, both schistosomiasis and HIV/AIDS are endemic, resulting in patients harbouring co-infections. Because interaction with host CD4(+) T cells is a characteristic of schistosome as well as HIV-1 infections, bi-directional disease effects may be sufficiently different from sequelae caused by either infectious agent alone to warrant alteration of public health approaches in areas of co-endemnicity. Studies published over the past decade provide useful insights into interactions between schistosomiasis and infection with HIV-1, and overall support the hypothesis that special emphasis on treatment of schistosomiasis in populations with elevated prevalence or risk of HIV-1 infection is justified.