A synoptic inventory of needs for research on women and tropical parasitic diseases. II. Gender-related biases in the diagnosis and morbidity assessment of schistosomiasis in women

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.

Establishing and Integrating a Female Genital Schistosomiasis Control Programme into the Existing Health Care System

Female genital schistosomiasis (FGS) is a complication of Schistosoma haematobium infection, and imposes a health burden whose magnitude is not fully explored. It is estimated that up to 56 million women in sub-Saharan Africa have FGS, and almost 20 million more cases will occur in the next decade unless infected girls are treated. Schistosomiasis is reported throughout the year in South Africa in areas known to be endemic, but there is no control programme. We analyze five actions for both a better understanding of the burden of FGS and reducing its prevalence in Africa, namely: (1) schistosomiasis prevention by establishing a formal control programme and increasing access to treatment, (2) introducing FGS screening, (3) providing knowledge to health care workers and communities, (4) vector control, and (5) water, sanitation, and hygiene. Schistosomiasis is focal in South Africa, with most localities moderately affected (prevalence between 10% and 50%), and some pockets that are high risk (more than 50% prevalence). However, in order to progress towards elimination, the five actions are yet to be implemented in addition to the current (and only) control strategy of case-by-case treatment. The main challenge that South Africa faces is a lack of access to WHO-accredited donated medication for mass drug administration. The establishment of a formal and funded programme would address these issues and begin the implementation of the recommended actions.

Absence of lower genital tract lesions among women of reproductive age infected with Schistosoma mansoni: A cross-sectional study using a colposcope in Western Kenya

Background

Female genital schistosomiasis (FGS) constitutes four different lesions known to be caused by Schistosoma haematobium ova deposited in the genital tract. Schistosoma mansoni ova may also be found in the genital tract. However, it is not known if S. mansoni causes lower genital tract lesions characteristic of FGS.

Methodology

This study was conducted in 8 villages along the shores of Lake Victoria, western Kenya. Stool and urine samples, collected from women of reproductive age on three consecutive days, were analysed for S. mansoni and S. haematobium infection. S. mansoni positive and S. haematobium negative willing participants, aged 18–50 years were invited to answer a questionnaire (demographics, symptoms), undergo a gynaecological examination and cytology specimen collection by an FGS expert.

Principal findings

Gynaecologic investigations were conducted in 147 S. mansoni-positive women who had a mean infection intensity of 253.3 epg (95% CI: 194.8–311.9 epg). Nearly 90% of them used Lake Victoria as their main water source. None were found to have cervicovaginal grainy sandy patches or rubbery papules. Homogenous yellow patches were found in 12/147 (8.2%) women. Women with homogenous yellow patches were significantly older (47 years) than the rest (34 years, p = 0.001). No association was found between intensity of S. mansoni infection and homogenous yellow patches (p = 0.70) or abnormal blood vessels (p = 0.14). S. mansoni infection intensity was not associated with genital itch, bloody or malodorous vaginal discharge.

Conclusion

S. mansoni infection was neither associated with lower genital tract lesions nor symptoms typically found in women with FGS.

Comparing the accuracy of two diagnostic methods for detection of light Schistosoma haematobium infection in an elimination setting in Wolaita Zone, South Western Ethiopia

Reagent urinalysis dipstick and filtration have been recommended diagnostic methods for the detection of urogenital schistosomiasis. However, the accurate diagnosis of light infections using these methods presents a major challenge. This study evaluates the diagnosis accuracy of light infection with Schistosoma haematobium in study participants living in Wolaita Zone, an area targeted for sustainable control of Schistosomiasis, and ultimately interrupt transmission. Urine samples were collected from children and adults in surveys carried out during baseline and longitudinal sentinel site surveys conducted from 2018 to 2020. All urine samples were tested using a reagent urinalysis dipstick test (Haemastix) to detect microhaematuria with reference urine filtration technique as a proxy for S. haematobium infection. Sensitivity and specificity were determined in diagnosing urogenital schistosomiasis. Cohen’s Kappa statistics was done for the agreement of these diagnostic methods. A total of 12,102 participants were enrolled in the current baseline study. Among them, 285 (2.35%) samples tested positive for microhaematuria and 21 (0.20%) positive for S. haematobium eggs. A total of 4,357 samples were examined in year 1 and year 2 using urine dipsticks, and urine filtration 172 (3.95%) and 2 (0.05%) were positive for microhaematuria and S. haematobium eggs. The reagent urinalysis dipsticks showed the highest sensitivity and specificity for diagnosing light intensity of infection,100% (95% CI:85.18–100.00) and 97.4% (95% CI: 97.10–97.60), respectively. There is a slight agreement between the two methods (Kappa = 0.09, 95% CI: 0.01–0.18). The present study revealed very low prevalence and light intensity of S. haematobium infections. The study also highlights that the dipstick test is considered a useful adjunct diagnostic tool for population-based control of urogenital schistosomiasis.

The Case for Gender Equity in Health Research

Attention to health equity on the basis of economic class, caste or race has not spilled over to an effective consideration ofgender. Yet, social bias not only heavily influences health outcomes between women and men, it also affects our very understanding of biological differences with implications for understanding gender equity. Hence, when considering biological differences or special gender needs, it is necessary to be aware that biological 'givens' can also mask social norms that sanction discrimination and perpetuate health inequities. It is, therefore, particularly crucial to understand the nuances found in a gender and health equity approach and the consequences of not taking gender seriously in health research. These include the neglect of certain areas through resounding silences, the existence of misdirected or partial approaches, and the poor recognition of interactive pathways in terms of co-morbidity and multi ple social processes. After detailing this background we review the literature on the gender paradox' in health from an equity perspective. Finally, we discuss how research can contribute to improving gender equity and health by being conscious of potential biases in data, methodology and clinical research.

Meta-analysis of urine heme dipstick diagnosis of Schistosoma haematobium infection, including low-prevalence and previously-treated populations

BACKGROUND

Urogenital schistosomiasis remains highly endemic in Africa. Current control is based on drug administration, targeted either to school-age children or to high-risk communities at-large. Urine dipsticks for detection of microhematuria offer an inexpensive means for estimating infection prevalence. However, their diagnostic performance has not been systematically evaluated after community treatment, or in areas with continuing low prevalence. The objective of the present study was to perform meta-analysis of dipstick accuracy for S. haematobium infection in endemic regions, with special attention to performance where infection intensity or prevalence was low.

METHODOLOGY/PRINCIPAL FINDINGS

This review was registered at inception with PROSPERO (CRD42012002165). Included studies were identified by computerized search of online databases and hand search of bibliographies and existing study archives. Eligible studies included published or unpublished population surveys irrespective of date, location, or language that compared dipstick diagnosis of S. haematobium infection to standard egg-count parasitology. For 95 included surveys, variation in dipstick sensitivity and specificity were evaluated according to study size, age- and sex-specific participation, region, local prevalence, treatment status, and other factors potentially affecting test performance. Independent of prevalence, accuracy was greater in surveys of school-age children (vs. adults), whereas performance was less good in North Africa, as compared to other regions. By hierarchical ROC analysis, overall dipstick sensitivity and specificity for detection of egg-positive urine were estimated at 81% and 89%, respectively. Sensitivity was lower among treated populations (72%) and in population subgroups having lower intensity infection (65%). When the insensitivity of egg count testing was considered (and diagnosis inferred instead from combined hematuria and egg-count findings), overall dipstick sensitivity/specificity were 82%/97%, with significantly better sensitivity (92%) in high prevalence settings.

CONCLUSIONS/SIGNIFICANCE

This analysis suggests that dipsticks will continue to serve as very useful adjuncts for monitoring community prevalence following implementation of population-based control of urogenital schistosomiasis.

Prevalence of urinary schistosomiasis and HIV in females living in a rural community of Zimbabwe: does age matter?

A cross-sectional study was conducted on 544 women living in Mupfure rural area of Zimbabwe to determine whether infection with urinary schistosomiasis is associated with HIV infection. Schistosoma haematobium infection was examined in urine samples and HIV infection was determined in sera. The prevalence of S. haematobium infection was highest (60%) in women below 20 years of age and declined to 29% in the oldest age group (test for trends, P<0.001). Overall, women infected with urinary schistosomiasis had an HIV prevalence of 33.3%, whilst women without urinary schistosomiasis had an HIV prevalence of 25.6% (chi(2), P=0.053). Women above the age of 35 years and infected with urinary schistosomiasis had a significantly higher HIV prevalence (37.5%) than those without urinary schistosomiasis (16.8%; chi(2), P<0.001).

The social and economic context and determinants of schistosomiasis japonica

A variety of biological and social factors govern schistosomiasis japonica in China. Social factors include those at a national and regional level, such as policies and patterns of development, which impact on local economic activities, and affect community, household and personal risk factors of infection. Drawing on research conducted in China, we illustrate how social structural and related factors influence individual risk and prevalence of infection. At a macro-level, political changes have occurred resulting in the shift from collective to family-based production, leading to clustering of infection in families. Industrialization and urbanization, and associated increased population mobility, have also influenced patterns of transmission and infection. Types of activities and local production patterns determine the exposure of individuals to schistosome-infested water sources. Fishermen have the most frequent water contact, aquatic workers the second and farmers the third; the relative risk of Schistosoma japonicum infection follows the same order. Among farmers, human infection is significantly related to agricultural production in rice fields infested with the intermediate host snail, and to rates of the infection in livestock. Risk of S. japonicum infection is also influenced by the domestic environment, including both the location of the house in relation to snail-colonized water sources, access to safe water, and improved sanitation. Household wealth and income determine family ability to provide and maintain safe water and sanitation, while determining or interacting with other variables. At an individual level, sex, age, educational level and ethnicity are all associated with different patterns of water use and water contact behaviour thereby affecting infection rates. Schistosomiasis impairs the growth and nutrition of children and the physical work capacity of adults, and so affects economic development. Given this, we note the importance of further research and social and contextual aspects of schistosomiasis infection in order to develop and sustain sound control strategies.

Schistosomiasis haematobium as a cause of vulvar hypertrophy

Schistosomiasis is the most frequently imported helminthic infection in The Netherlands. Patients with Schistosoma haematobium infections usually present with fever, hematuria, dysuria, or urinary frequency. The ectopic localizations in female genital schistosomiasis are frequently misdiagnosed or confounded with sexually transmitted diseases or genital tract cancers. This paper describes a patient who presented with vulvar hypertrophy as a symptom of acute female genital schistosomiasis. The aim of this paper is to draw attention to a neglected parasitic disease that in the future will be encountered in increasing numbers in Western Europe.

Do young women in tropical regions constitute a recognized social category?

In most tropical regions there is little organized health care for young women, yet their household roles within contexts of worsening socio-economic situations create special health problems. In the area of sexual and reproductive health, the onset of reproductive roles does not entitle the young women to either maternal and child health services or family planning services unless they are married and have children under 5 years. Societal values and norms at macro and micro levels have prevented young women from benefiting from reproductive technology, although they are, at the same time, increasingly expected to spend a great deal of their youth in school and outside marriage. Young women thus live in paradoxical situations as indicated by the increasing levels of early teenage pregnancy, induced abortion and related complications, school drop-out and infection with sexually transmitted diseases including HIV/AIDS. Young women clearly constitute an unrecognized social category, and research focusing on them would be particularly rewarding because of the potential it offers for addressing the gender imbalances and their dynamics in health.

Urine reagent strips for diagnosis of schistosomiasis haematobium in women of fertile age

Hematuria, proteinuria and leukocyturia were semiquantitatively assessed by reagent strips in single morning urine of women of fertile age visiting the outpatient department of the Mangochi district hospital, Malawi. This was part of a diagnostic approach to female genital schistosomiasis (FGS). In 51 women ova of Schistosoma haematobium were detected in urine by a filtration technique. In 33 of these women ova were also present in genital tissue as demonstrated by microscopic examination of biopsies. In 209 women no ova were found in the single urine filtered. There were significantly higher scores for hematuria, proteinuria and leukocyturia as well as of the combined reagent strip index (RSI) in egg-excreting than in egg-negative women. The sensitivity of a single hematuria, proteinuria and leukocyturia reading was 98, 84 and 73%, respectively. However, the respective specificity was only 24, 22 and 23%. The best prediction of urinary schistosomiasis was achieved by a +2 score for hematuria, of which the sensitivity was 94% and the specificity was 61%. The high false-positive rates can probably be explained by contamination of urine by vaginal secretion. Moreover, cases of schistosomiasis have probably been overlooked because only a single morning urine sample was examined. The total absence of hematuria, proteinuria and leukocyturia, however, may be used to rule out heavy infections in community surveys. There was no difference in reagent strip scores between women with genital and urinary schistosomiasis as compared with those with urinary tract lesions alone. Thus urine analysis reagent strip readings do not help to discriminate between S. haematobium infected women with and without FGS.

Gender differentials in tuberculosis: the role of socio-economic and cultural factors

This paper reviews current knowledge about the role that socio-economic and cultural factors play in determining gender differentials in tuberculosis (TB) and tuberculosis control. The studies reviewed suggest that socio-economic and cultural factors may be important in two ways: first, they may play a role in determining overall gender differences in rates of infection and progression to disease, and second, they may lead to gender differentials in barriers to detection and successful treatment of TB. Both have implications for successful TB control programmes. The literature reviewed in this paper suggests the following: Gender differentials in social and economic roles and activities may lead to differential exposure to tuberculosis bacilli; The general health/nutritional status of TB-infected persons affects their rate of progression to disease. In areas where women's health is worse than men's (especially in terms of nutrition and human immunodeficiency virus status), women's risk of disease may be increased; A number of studies suggest that responses to illness differ in women and men, and that barriers to early detection and treatment of TB vary (and are probably greater) for women than for men. Gender differences also exist in rates of compliance with treatment; The fear and stigma associated with TB seems to have a greater impact on women than on men, often placing them in an economically or socially precarious position. Because the health and welfare of children is closely linked to that of their mothers, TB in women can have serious repercussions for families and households. The review points to the many gaps that exist in our knowledge and understanding of gender differentials in TB and TB control, and argues for increased efforts to identify and address gender differentials in the control of TB.

Human behavior, health education and schistosomiasis control: a review

This paper examines the role of human behavior in schistosomiasis transmission and control in relation to health education. The literature is reviewed to identify relevant behaviors and to examine progress and constraints in health education, using the primary health care approach. The behavior model by Dunn and the PRECEDE health education model by Green and coworkers are adapted for health education in schistosomiasis control. Because of its focus on the role of individual and community vs outside factors, deliberate vs non-deliberate behavior and health-enhancing and health-maintaining vs health-lowering behavior, Dunn's model can evaluate social, economic, cultural and political factors in schistosomiasis transmission and control that must be considered in health education. The PRECEDE model represents a suitable diagnostic tool for health education planning, intervention and evaluation.

Gender inequalities in health in the Third World: uncharted ground

Gender differences in health in developing countries have, until recently, received little attention from researchers, health programmes and international development efforts. This paper highlights several issues related to gender and health in the Third World on which information, especially of an empirical nature, is inadequate. These include certain health conditions and diseases for which gender differences remain largely uncharted, gender inequalities in the development of health and contraceptive technology, the lack of gender-sensitivity in the provision of health services, and gender inequalities in health policies, focusing mainly on structural adjustment. Questions urgently requiring research are identified and suggestions are made for improving the gender sensitivity of health policies and interventions.

Female genital schistosomiasis as a risk-factor for the transmission of HIV

Sexually transmitted diseases increase the probability for HIV transmission, presumably through lesions in the genital mucosa. Female genital schistosomiasis, a special form of urinary schistosomiasis due to infection with Schistosoma haematobium, may be another risk-factor for transmission of HIV. From published data there seem to be pathophysiological, immunological and epidemiological evidence for an association between genital ulcer disease due to S. haematobium and HIV-infection in women. Female genital schistosomiasis could be seen as an example of how an interaction between a parasitic disease and HIV facilitates the propagation of the latter. As long as the prevalence of HIV is low in the general population, interventions targeted to high risk groups will significantly delay, or even prevent, widespread dissemination of the HIV infection in the rest of the population. If female genital schistosomiasis is a risk factor for the spread of HIV like other genital ulcer diseases, there should be interesting ways to intervene from the public health point of view.

Evaluating agency initiatives: building social science capability in tropical disease research

In recent years, in an endeavour to increase social and economic research in tropical diseases, WHO/TDR has used a number of alternative models to develop social science research capability in countries endemic for the designated tropical diseases. These have included small grants schemes to encourage junior researchers to gain familiarity with the subject area and methods, and protocol development and methodology workshops, either for specific research topics (e.g. adolescent women's health; community perceptions of schistosomiasis) or for any topic of interest to the participants. Participants have included medical researchers, social science researchers, and interdisciplinary teams (e.g. a medical researcher and a collaborating social scientist). This paper develops a typology and critically analyses these alternative approaches to developing research capability, and assesses their effectiveness in terms of cost, short-term effectiveness, and sustainability of the initiative.

A synoptic inventory of needs for research on women and tropical parasitic diseases. I. Application to urinary and intestinal schistosomiasis

The determinants of major parasitic infections in women have never been studied systematically. Much work remains to be done before vital gaps in our knowledge will be filled. The protocol presented here categorizes the determinants of parasitic diseases, and functions as an inventory for research needs and priorities. In this paper, the synoptic inventory is tested by matching it against the scientific knowledge of schistosomiasis that is at hand. Available data and existing lacunae are discussed. We conclude that the environmental, economic, socio-cultural, nutritional, genetic, biological and immunological factors which determine schistosomiasis in women are largely unknown. There is an urgent need for systematic and interdisciplinary investigations before appropriate and sustainable interventions can be initiated.