Mass Drug Administration Campaigns Research Articles

Programmatic evaluation of mass drug administration for elimination of lymphatic filariasis and reasons for non-compliance in Gulbarga district, Karnataka in 2015

Background: Mass drug administration (MDA) to eliminate lymphatic filariasis (LF) is conducted once annually in the identified endemic districts of the country. MDA implementation is assessed by appointed independent teams within 2-3 weeks of the activity to suggest mid-term corrections and strengthen the on-going programme. This study was undertaken to assess the process of MDA implementation, drug coverage and compliance and to identify the reasons for non-compliance.Methods: A survey of four clusters comprising of three rural and one urban area was conducted in Gulbarga, during the third week following the MDA campaign in the district. Information pertaining to the MDA beneficiaries of the 124 evaluated households was collected over a period of three days using a structured proforma. The process of MDA implementation was evaluated at the district, taluk and primary health centre (PHC) levels.Results: From the information collected on 673 inmates of the households surveyed, the coverage and compliance rates of 87.5 and 60.9% respectively was found for diethylcarbamazine citrate and albendazole distribution and consumption. The important reasons for non–compliance to swallow the drugs identified were the beneficiaries being out of station during the campaign, was not aware of it, the drug distributer did not visit the beneficiaries house and fear of side effects of the drugs.Conclusions: Efforts to improve the compliance to consumption of the anti-filarial drugs at Gulbarga district is required for elimination of LF.

Community and Drug Distributor Perceptions and Experiences of Mass Drug Administration for the Elimination of Lymphatic Filariasis: A Rapid Review of Qualitative Research.

This article presents findings from a rapid review of qualitative research conducted to inform decision makers about community and drug distributor perceptions and experiences of mass drug administration campaigns for the elimination of lymphatic filariasis. We focused on questions related to acceptability of the mass drug administration campaigns within these groups and their thoughts around the feasibility of planning and carrying out the campaigns. We carried out a systematic search in five databases to identify potential studies. We included studies that focused on community members and drug distributors and used qualitative methods for data collection and analysis. We conducted a thematic framework analysis using the Supporting the Use of Research Evidence framework. Due to time constraints, one author conducted the screening, extraction and data analysis. Studies found that communities lack knowledge and information about lymphatic filariasis and the mass drug administration campaigns and that this can have an impact on how many community members choose to take medication. Health workers often had a good understanding that lymphatic filariasis was a problem in their setting, of its cause and mode of transmission and that hydrocele and elephantiasis had the same cause. However, this knowledge was not as prevalent amongst community drug distributors who often had misconceptions surrounding the topic. Furthermore, studies found that the length, timing, level of community and health system involvement, access to care for side effects, inadequate numbers of drug distributors and supervisors and motivation of drug distributors influenced participation in mass drug administration campaigns. Finally, the inadequate training of drug distributors could influence community trust in the mass drug administration program and the drug distributor themselves if there was a perception that the person was uninformed or not trained to carry out their tasks.

Filarial infection during pregnancy has profound consequences on immune response and disease outcome in children: A birth cohort study.

BackgroundCurrent Global Program to Eliminate Lymphatic Filariasis (GPELF) that prohibits pregnant mothers and children below two years of age from coverage targeted interruption of transmission after 5–6 rounds of annual mass drug administration (MDA). However, after more than 10 rounds of MDA in India the target has not been achieved, which poses challenge to the researchers and policy makers. Several studies have shown that in utero exposure to maternal filarial infections plays certain role in determining the susceptibility and disease outcome in children. But the mechanism of which has not been studied extensively. Therefore the present study was undertaken to understand the mechanism of immune modulation in children born to filarial infected mother in a MDA ongoing area.Methodology and principal findingTo our knowledge this is the first study to conduct both cellular and humoral immunological assays and follow up the children until older age in a W bancrofti endemic area,where the microfilariae (Mf) rate has come down to <1% after 10 rounds of MDA. A total 57 (32: born to infected, 25: born to uninfected mother) children were followed up. The infection status of children was measured by presence of Mf and circulating filarial antigen (CFA) assay. Filaria specific IgG1, IgG2, IgG3 and IgG4 responses were measured by ELISA. Plasma level of IL-10 and IFN-γ were evaluated by using commercially available ELISA kit. The study reveals a high rate of acquisition of filarial infection among the children born to infected mother compared to uninfected mothers. A significantly high level of IgG1 and IgG4 was observed in children born to infected mother, whereas high level of IgG3 was marked in children born to uninfected mother. Significantly high level of IL-10 positively correlated with IgG4 have been observed in infected children born to infected mother, while high level of IFN-γ positively correlated with IgG3 was found in infection free children born to mother free from infection at the time of pregnancy. Moreover a negative correlation between IL-10 and IFN-γ has been observed only among the infected children born to infected mother.Significance conclusionThe study shows a causal association between maternal filarial infection and impaired or altered immune response in children more susceptible to filarial infection during early childhood. As lymphatic damage that commences in childhood during asymptomatic stage has major implications from public health point of view, understanding maternal programming of the newborn immune system could provide a basis for interventions promoting child health by implementing MDA campaigns towards all women of childbearing age and young children in achieving the target of global elimination of LF.

Routine Surveillance Data as a Resource for Planning Integration of NTD Case Management

Background: There is a high burden of morbidity due to neglected tropical diseases. To help address this, the World Health Organization recommends integration of case management (CM). Here, we present a practical framework designed to identify areas that could benefit from an integrated CM strategy in Ghana. We also investigated the accessibility of primary health care (PHC) to CM cases, and the impact of this on morbidity at diagnosis. Methods: Routinely detected cases of Buruli ulcer (BU) and leprosy, and suspected lymphedema identified through morbidity surveys during mass drug administration campaigns in Ghana in 2014 were remotely georeferenced. We estimated distances from cases’ home communities to the nearest primary healthcare facility (PHC), and compared rates of reported disease, completeness of clinical information, and risk of more severe morbidity, relative to PHC accessibility. Results: We georeferenced communities of 295/350 reported leprosy cases, 240/333 BU cases, and 1,557/2383 instances of lymphedema. Overlap of these diseases was predominantly around Accra and in the Upper East Region. Rates of reported disease appeared higher in populations with higher accessibility to PHC, and leprosy cases living further from PHC had a higher risk of disability at diagnosis. Conclusions: This investigation demonstrates the feasibility and value of using routinely collected data to map CM-NTDs at low cost. The maps presented are intended to provide a resource for planning the implementation of integrated CM for NTDs in Ghana. This approach could be easily implemented by national health services in other endemic countries in the future.

Evaluation of mass drug administration against lymphatic filariasis in Bidar district, Karnataka, India

Background: Lymphatic filariasis is a major public health problem in India not only because it causes considerable suffering, deformity and disability but also due to social stigma and economic loss associated with it. The Government of India in 2004 began a nationwide mass drug administration (MDA) campaign in all the known endemic districts with the aim of eliminating it as a public health problem. However, even after a decade, uncertainty prevails about the coverage and compliance to MDA. Objectives of the study were to estimate coverage and compliance to mass drug administration (MDA) in Bidar district and to identify the various reasons for non-compliance to MDA.Methods: A cross sectional evaluation survey was conducted in the month of September 2016 in Bidar district using multi-stage cluster sampling technique. A total of 744 subjects were interviewed and information was collected in a predesigned questionnaire after taking an informed consent. Data thus obtained were entered and analyzed using Epi info software version 3.5.4.Results: The coverage, compliance and effective compliance to MDA in Bidar district were 82.1%, 72.3% and 59.4% respectively. The most common reasons for non-compliance to MDA were fear of side reactions followed by suffering from other chronic diseases and having no faith in tablets. The most common side reactions associated with drug intake were vomiting and fever.Conclusions: The present study demonstrates poor compliance to MDA in Bidar district despite good coverage, indicating an urgent need to revitalize the programme implementation.

Modelling local areas of exposure to Schistosoma japonicum in a limited survey data environment

BackgroundSpatial modelling studies of schistosomiasis (SCH) are now commonplace. Covariate values are commonly extracted at survey locations, where infection does not always take place, resulting in an unknown positional exposure mismatch. The present research aims to: (i) describe the nature of the positional exposure mismatch in modelling SCH helminth infections; (ii) delineate exposure areas to correct for such positional mismatch; and (iii) validate exposure areas using human positive cases.MethodsTo delineate exposure areas to Schistosoma japonicum, a spatial Bayesian network (sBN) was constructed. It uses data on exposure risk factors such as: potential sites for snails’ accessibility, geographical distribution of snail infection rate, and cost of the community to access nearby water bodies. Prior and conditional probabilities were obtained from the literature and inserted as weights based on their relative contribution to exposure; these probabilities were then used to calculate joint probabilities of exposure within the sBN.ResultsHigh values of probability of S. japonicum exposure correspond to polygons where snails could potentially be present, for instance in wet soils and areas with low slopes, but also where people can easily access water bodies. Low correlation (R2 = 0.3) was found between the percentage of human cases and the delineated probabilities of exposure when validation buffers are generated over the human cases.ConclusionsThe utility of a probabilistic method for the identification of exposure areas for S. japonicum, with wider application for other water-borne infections, was demonstrated. From a public health perspective, the schistosomiasis exposure sBN developed in this study could be used to guide local schistosomiasis control teams to specific potential areas of exposure, and improve efficiency of mass drug administration campaigns in places where people are likely to be exposed to the infection.

Integrating use of point-of-care circulating cathodic antigen rapid diagnostic tests by community health workers during mass drug administration campaigns to improve uptake of praziquantel treatment among the adult population at Kome Island, North-Western Tanzania: a cluster randomized community trial

BackgroundThe major drawback of the community-based mass drug administration (MDA) approach against schistosomiasis is that treatment is offered blindly without testing for the targeted infection. This partly contributes to the low treatment coverage. One approach to overcome this limitation is to introduce a diagnostic component in the treatment approach. This will improve drug uptake and compliance to treatment. This study is conducted to assess the feasibility and acceptability of integrating point-of-care Circulating Cathodic Antigen (POC-CCA) test to community-based directed MDA in improving treatment coverage and compliance with treatment among adults.MethodsThis is a randomized control community trial in which 30 clusters were randomly assigned to either an intervention or control arm to evaluate two interventions on treatment coverage and compliance with treatment. In each cluster, 150 adult participants were enrolled. Community Health Workers (CHW) in both arms were trained on all aspects of praziquantel (PZQ) distribution and management of mild side effects. In the intervention arm, CHWs had additional training on how to use POC-CCA to diagnose intestinal schistosomiasis. In the intervention arm, participants were tested using POC-CCA test for presence of intestinal schistosomiasis and treated based on test results, while in the control arm, participants were treated with PZQ without testing. The primary outcome measure was the proportion of participants provided with PZQ between the two arms and geographical clusters. Secondary outcomes were prevalence of S. mansoni infection based on the POC-CCA test conducted by CHWs, ability of CHWs to use the POC-CCA test accurately and safely and community acceptability of the POC-CCA test results from CHWs. Both quantitative and qualitative techniques have been used to collect data at study endpoint.DiscussionThe study will generate evidence on the importance of integrating a diagnostic component into the community directed MDA conducted by CHWs. Findings will generate discussion on the current MDA policy and practice in Tanzania.Trial registrationPACTR201804003343404 (25/4/2018).

Characterization of Divalent Metal Transporter 1 (DMT1) in Brugia malayi suggests an intestinal-associated pathway for iron absorption

Lymphatic filariasis and onchocerciasis are neglected parasitic diseases which pose a threat to public health in tropical and sub-tropical regions. Strategies for control and elimination of these diseases by mass drug administration (MDA) campaigns are designed to reduce symptoms of onchocerciasis and transmission of both parasites to eventually eliminate the burden on public health. Drugs used for MDA are predominantly microfilaricidal, and prolonged rounds of treatment are required for eradication. Understanding parasite biology is crucial to unravelling the complex processes involved in host-parasite interactions, disease transmission, parasite immune evasion, and the emergence of drug resistance. In nematode biology, large gaps still exist in our understanding of iron metabolism, iron-dependent processes and their regulation. The acquisition of iron from the host is a crucial determinant of the success of a parasitic infection. Here we identify a filarial ortholog of Divalent Metal Transporter 1 (DMT1), a member of a highly conserved family of NRAMP proteins that play an essential role in the transport of ferrous iron in many species. We cloned and expressed the B. malayi NRAMP ortholog in the iron-deficient fet3fet4 strain of Saccharomyces cerevisiae, performed qPCR to estimate stage-specific expression, and localized expression of this gene by immunohistochemistry. Results from functional iron uptake assays showed that expression of this gene in the iron transport-deficient yeast strain significantly rescued growth in low-iron medium. DMT1 was highly expressed in adult female and male B. malayi and Onchocerca volvulus. Immunolocalization revealed that DMT1 is expressed in the intestinal brush border, lateral chords, and reproductive tissues of males and females, areas also inhabited by Wolbachia. We hypothesize based on our results that DMT1 in B. malayi functions as an iron transporter. The presence of this transporter in the intestine supports the hypothesis that iron acquisition by adult females requires oral ingestion and suggests that the intestine plays a functional role in at least some aspects of nutrient uptake.

Infectivity of Chronic Malaria Infections and Its Consequences for Control and Elimination.

Assessing the importance of targeting the chronic Plasmodium falciparum malaria reservoir is pivotal as the world moves toward malaria eradication. Through the lens of a mathematical model, we show how, for a given malaria prevalence, the relative infectivity of chronic individuals determines what intervention tools are predicted be the most effective. Crucially, in a large part of the parameter space where elimination is theoretically possible, it can be achieved solely through improved case management. However, there are a significant number of settings where malaria elimination requires not only good vector control but also a mass drug administration campaign. Quantifying the relative infectiousness of chronic malaria across a range of epidemiological settings would provide essential information for the design of effective malaria elimination strategies. Given the difficulties obtaining this information, we also provide a set of epidemiological metrics that can be used to guide policy in the absence of such data.

Multiple Class I and Class II Haemophilus ducreyi Strains Cause Cutaneous Ulcers in Children on an Endemic Island.

Together with Treponema pallidum subspecies pertenue, Haemophilus ducreyi is a major cause of exudative cutaneous ulcers (CUs) in children. For H. ducreyi, both class I and class II strains, asymptomatic colonization, and environmental reservoirs have been found in endemic regions, but the epidemiology of this infection is unknown. Based on published whole-genome sequences of H. ducreyi CU strains, a single-locus typing system was developed and applied to H. ducreyi-positive CU samples obtained prior to, 1 year after, and 2 years after the initiation of a mass drug administration campaign to eradicate CU on Lihir Island in Papua New Guinea. DNA from the CU samples was amplified with class I and class II dsrA-specific primers and sequenced; the samples were classified into dsrA types, which were geospatially mapped. Selection pressure analysis was performed on the dsrA sequences. Thirty-seven samples contained class I sequences, 27 contained class II sequences, and 13 contained both. There were 5 class I and 4 class II types circulating on the island; 3 types accounted for approximately 87% of the strains. The composition and geospatial distribution of the types varied little over time and there was no evidence of selection pressure. Multiple strains of H. ducreyi cause CU on an endemic island and coinfections are common. In contrast to recent findings with T. pallidum pertenue, strain composition is not affected by antibiotic pressure, consistent with environmental reservoirs of H. ducreyi. Such reservoirs must be addressed to achieve eradication of H. ducreyi.

Impact of mass drug administration campaigns depends on interaction with seasonal human movement.

BackgroundMass drug administration (MDA) is a control and elimination tool for treating infectious diseases. For malaria, it is widely accepted that conducting MDA during the dry season results in the best outcomes. However, seasonal movement of populations into and out of MDA target areas is common in many places and could potentially fundamentally limit the ability of MDA campaigns to achieve elimination.MethodsA mathematical model was used to simulate malaria transmission in two villages connected to a high-risk area into and out of which 10% of villagers traveled seasonally. MDA was given only in the villages. Prevalence reduction under various possible timings of MDA and seasonal travel was predicted.ResultsMDA is most successful when distributed outside the traveling season and during the village low-transmission season. MDA is least successful when distributed during the traveling season and when traveling overlaps with the peak transmission season in the high-risk area. Mistiming MDA relative to seasonal travel resulted in much poorer outcomes than mistiming MDA relative to the peak transmission season within the villages.ConclusionsSeasonal movement patterns of high-risk groups should be taken into consideration when selecting the optimum timing of MDA campaigns.

Population-based coverage survey results following the mass drug administration of azithromycin for the treatment of trachoma in Amhara, Ethiopia.

BackgroundTrachoma is the leading infectious cause of blindness worldwide. In communities where the district level prevalence of trachomatous inflammation-follicular among children ages 1–9 years is ≥5%, WHO recommends annual mass drug administration (MDA) of antibiotics with the aim of at least 80% coverage. Population-based post-MDA coverage surveys are essential to understand the effectiveness of MDA programs, yet published reports from trachoma programs are rare.MethodsIn the Amhara region of Ethiopia, a population-based MDA coverage survey was conducted 3 weeks following the 2016 MDA to estimate the zonal prevalence of self-reported drug coverage in all 10 administrative zones. Survey households were selected using a multi-stage cluster random sampling design and all individuals in selected households were presented with a drug sample and asked about taking the drug during the campaign. Zonal estimates were weighted and confidence intervals were calculated using survey procedures. Self-reported drug coverage was then compared with regional reported administrative coverage.ResultsRegion-wide, 24,248 individuals were enumerated, of which, 20,942 (86.4%) individuals were present. The regional self-reported antibiotic coverage was 76.8% (95%Confidence Interval (CI):69.3–82.9%) in the population overall and 77.4% (95%CI = 65.7–85.9%) among children ages 1–9 years old. Zonal coverage ranged from 67.8% to 90.2%. Five out of 10 zones achieved a coverage >80%. In all zones, the reported administrative coverage was greater than 90% and was considerably higher than self-reported MDA coverage. Main reasons reported for MDA campaign non-attendance included being physically unable to get to MDA site (22.5%), traveling (20.6%), and not knowing about the campaign (21.0%). MDA refusal was low (2.8%) in this population.ConclusionsAlthough self-reported MDA coverage in Amhara was greater than 80% in some zones, programmatic improvements are warranted throughout Amhara to achieve higher coverage. These results will be used to enhance community mobilization and improve training for MDA distributors and supervisors to improve coverage in future MDAs.

Identifying co-endemic areas for major filarial infections in sub-Saharan Africa: seeking synergies and preventing severe adverse events during mass drug administration campaigns

BackgroundOnchocerciasis and lymphatic filariasis (LF) are major filarial infections targeted for elimination in most endemic sub-Saharan Africa (SSA) countries by 2020/2025. The current control strategies are built upon community-directed mass administration of ivermectin (CDTI) for onchocerciasis, and ivermectin plus albendazole for LF, with evidence pointing towards the potential for novel drug regimens. When distributing microfilaricides however, considerable care is needed to minimise the risk of severe adverse events (SAEs) in areas that are co-endemic for onchocerciasis or LF and loiasis. This work aims to combine previously published predictive risk maps for onchocerciasis, LF and loiasis to (i) explore the scale of spatial heterogeneity in co-distributions, (ii) delineate target populations for different treatment strategies, and (iii) quantify populations at risk of SAEs across the continent.MethodsGeographical co-endemicity of filarial infections prior to the implementation of large-scale mass treatment interventions was analysed by combining a contemporary LF endemicity map with predictive prevalence maps of onchocerciasis and loiasis. Potential treatment strategies were geographically delineated according to the level of co-endemicity and estimated transmission intensity.ResultsIn total, an estimated 251 million people live in areas of LF and/or onchocerciasis transmission in SSA, based on 2015 population estimates. Of these, 96 million live in areas co-endemic for both LF and onchocerciasis, providing opportunities for integrated control programmes, and 83 million live in LF-monoendemic areas potentially targetable for the novel ivermectin-diethylcarbamazine-albendazole (IDA) triple therapy. Only 4% of the at-risk population live in areas co-endemic with high loiasis transmission, representing up to 1.2 million individuals at high risk of experiencing SAEs if treated with ivermectin. In these areas, alternative treatment strategies should be explored, including biannual albendazole monotherapy for LF (1.4 million individuals) and ‘test-and-treat’ strategies (8.7 million individuals) for onchocerciasis.ConclusionsThese maps are intended to initiate discussion around the potential for tailored treatment strategies, and highlight populations at risk of SAEs. Further work is required to test and refine strategies in programmatic settings, providing the empirical evidence needed to guide efforts towards the 2020/2025 goals and beyond.

Understanding the relationship between egg- and antigen-based diagnostics of Schistosoma mansoni infection pre- and post-treatment in Uganda

BackgroundSchistosomiasis is a major socio-economic and public health problem in many sub-Saharan African countries. After large mass drug administration (MDA) campaigns, prevalence of infection rapidly returns to pre-treatment levels. The traditional egg-based diagnostic for schistosome infections, Kato-Katz, is being substituted in many settings by circulating antigen recognition-based diagnostics, usually the point-of-care circulating cathodic antigen test (CCA). The relationship between these diagnostics is poorly understood, particularly after treatment in both drug-efficacy studies and routine monitoring.ResultsWe created a model of schistosome infections to better understand and quantify the relationship between these two egg- and adult worm antigen-based diagnostics. We focused particularly on the interpretation of “trace” results after CCA testing. Our analyses suggest that CCA is generally a better predictor of prevalence, particularly after treatment, and that trace CCA results are typically associated with truly infected individuals.ConclusionsEven though prevalence rises to pre-treatment levels only six months after MDAs, our model suggests that the average intensity of infection is much lower, and is probably in part due to a small burden of surviving juveniles from when the treatment occurred. This work helps to better understand CCA diagnostics and the interpretation of post-treatment prevalence estimations.

Helen Keller International and its contribution to elimination of neglected tropical diseases

Helen Keller International (HKI) is a non-governmental organization, established in 1915. The mission is to save and improve the sight and lives of the world’s vulnerable by combatting the causes and consequences of blindness, poor health and malnutrition. HKI’s work on neglected tropical diseases (NTDs) dates back to 1950s with a pilot program to eliminate blinding trachoma in Taiwan. HKI’s work on trachoma in Tanzania in 1980s and in Morocco in 1990s contributed to the development of the World Health Organization-endorsed SAFE strategy (Surgery, Antibiotics, Facial cleanliness and Environmental improvement) and the creation of the International Trachoma Initiative dedicated to the elimination of trachoma. HKI is a leader in the control and elimination of onchocerciasis (river blindness) in Africa and played an important role in developing an innovative strategy: community-directed treatment with ivermectin (CDTI) to control onchocerciasis. For its multi-country support to control and eliminate onchocerciasis, HKI was awarded the AGFUND International Prize for Pioneering Development Projects for its “Sustainable Control of Onchocerciasis” program in Africa in 2009. With funding from donors such as USAID, DFID, the END Fund and many others, HKI currently supports 10 African countries to control and eliminate one or more of five major NTDs: lymphatic filariasis (LF), onchocerciasis, schistosomiasis, soil-transmitted helminthiasis (STH) and trachoma which includes leveraging medicines procured or donated from pharmaceutical companies. HKI aims to build the capacity of Ministries of Health to conduct community mobilization, mass drug administration campaigns, morbidity management, monitoring and evaluation. Over the past 10 years, through its integrated NTD programs, HKI has successfully supported Burkina Faso, Cameroon, Guinea, Mali, Niger, Nigeria, and Sierra Leone to complete NTD mapping, initiate MDA, scale up to national coverage, monitor the progress, evaluate the impact and scale down (stopping MDA) once objectives have been met. In 2017 alone, across Africa HKI supported the distribution of over 110 million MDA treatments for NTDs as well as the screening of nearly one million individuals for surgery including follow-up surgery for 36000 affected individuals. By 2018, stopping MDA criteria had been achieved for trachoma nationwide in Burkina Faso, Cameroon and Mali and in most endemic districts in Niger, and for LF nationwide in Mali and nearly in Cameroon and in most endemic districts in Burkina Faso, Niger and Sierra Leone. Prevalence levels for onchocerciasis, schistosomiasis and STH have also been significantly reduced in these countries. Moving forward, HKI will continue to collaborate with partners to support African governments to achieve NTD elimination goals and sustain the gains through mobilizing resources, building the capacity of Ministries of Health and strengthening existing health systems to integrate NTD activities. Joining this Alliance opens the door for HKI to collaborate with more partners on research and elimination of NTDs.

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.

Serology reflects a decline in the prevalence of trachoma in two regions of The Gambia

Trachoma is caused by Chlamydia trachomatis (Ct). It is targeted for global elimination as a public health problem. In 2014, a population-based cross-sectional study was performed in two previously trachoma-endemic areas of The Gambia. Participants of all ages from Lower River Region (LRR) (N = 1028) and Upper River Region (URR) (N = 840) underwent examination for trachoma and had blood collected for detection of antibodies against the Ct antigen Pgp3, by ELISA. Overall, 30 (1.6%) individuals had active trachoma; the prevalence in children aged 1–9 years was 3.4% (25/742) with no statistically significant difference in prevalence between the regions. There was a significant difference in overall seroprevalence by region: 26.2% in LRR and 17.1% in URR (p < 0.0001). In children 1–9 years old, seroprevalence was 4.4% in LRR and 3.9% in URR. Reversible catalytic models using information on age-specific seroprevalence demonstrated a decrease in the transmission of Ct infection in both regions, possibly reflecting the impact of improved access to water, health and sanitation as well as mass drug administration campaigns. Serological testing for antibodies to Ct antigens is potentially useful for trachoma programmes, but consideration should be given to the co-endemicity of sexually transmitted Ct infections.

Schistosomiasis mansoni incidence data in Rwanda can improve prevalence assessments, by providing high-resolution hotspot and risk factors identification

BackgroundSchistosomiasis mansoni constitutes a significant public health problem in Rwanda. The nationwide prevalence mapping conducted in 2007–2008 revealed that prevalence per district ranges from 0 to 69.5% among school children. In response, mass drug administration campaigns were initiated. However, a few years later some additional small-scale studies revealed the existence of areas of high transmission in districts formerly classified as low endemic suggesting the need for a more accurate methodology for identification of hotspots. This study investigated if confirmed cases of schistosomiasis recorded at health facility level can be used to, next to existing prevalence data, detect geographically more accurate hotspots of the disease and its associated risk factors.MethodsA GIS-based spatial and statistical analysis was carried out. Confirmed cases, recorded at primary health facilities level, were combined with demographic data to calculate incidence rates for each of 367 health facility service area. Empirical Bayesian smoothing was used to deal with rate instability. Incidence rates were compared with prevalence data to identify their level of agreement. Spatial autocorrelation of the incidence rates was analyzed using Moran’s Index, to check if spatial clustering occurs. Finally, the spatial relationship between schistosomiasis distribution and potential risk factors was assessed using multiple regression.ResultsIncidence rates for 2007–2008 were highly correlated with prevalence values (R2 = 0.79), indicating that in the case of Rwanda incidence data can be used as a proxy for prevalence data. We observed a focal distribution of schistosomiasis with a significant spatial autocorrelation (Moran’s I > 0: 0,05–0.20 and p ≤ 0,05), indicating the occurrence of hotspots. Regarding risk factors, it was identified that the spatial pattern of schistosomiasis is significantly associated with wetland conditions and rice cultivation.ConclusionIn Rwanda the high density of health facilities and the standardized microscopic laboratory diagnostic allow the derived data to be used to complement prevalence studies to identify hotspots of schistosomiasis and its associated risk factors. This type of information, in turn, can support disease control interventions and monitoring.

Schistosoma mansoni Infection and Its Related Morbidity among Adults Living in Selected Villages of Mara Region, North-Western Tanzania: A Cross-Sectional Exploratory Study

Schistosoma mansoni is highly endemic in Tanzania and affects all age groups at different degrees. However, its control approach does not include adult individuals who are equally at risk and infected. To justify the inclusion of adult individuals in MDA programs in Tanzania, the present study focused on determining the prevalence of S. mansoni infection and its related morbidities among adult individuals. This was a cross sectional study conducted among 412 adult individuals aged 18–89 years living in selected villages of Rorya and Butiama districts located along the shoreline of the Lake Victoria. A pretested questionnaire was used to collect socio-demographic and socio-economic information of participants. Ultrasonographic examinations were conducted for all study participants using the Niamey protocol. A single stool sample was obtained from all study participants and examined for S. mansoni using the Kato-Katz technique. The study revealed a high prevalence of S. mansoni (56.3%), and the majority of infected individuals had a light intensity of infection. Ultrasonographic findings revealed that 22.4% of adult individuals had periportal fibrosis (PPF) (grade C–F), with 18.4% having grade C and D and 4% having grade E and F. Males had the highest prevalence of PPF (31.7% vs 10.8%, P<0.001). Organomegaly was common with 28.5% and 29.6% having splenomegaly and hepatomegaly, respectively. S. mansoni infection and its related morbidities included PPF, hepatomegaly, and splenomegaly were common among adult individuals. To reduce the level of transmission of S. mansoni infection, planned mass drug administration campaigns should include adult individuals living in these villages.

Transmission of Opisthorchis viverrini, Schistosoma mekongi and soil-transmitted helminthes on the Mekong Islands, Southern Lao PDR

BackgroundPrevalence of Opisthorchis viverrini, Schistosoma mekongi and soil-transmitted helminths (STH) remains high in Lao People’s Democratic Republic (Lao PDR), despite control efforts including mass-drug administration, education and communication campaigns. New approaches are required to advance helminth control.MethodsAn ecohealth study was conducted on two Mekong islands in Southern Laos. Demographic and behavioural data were collected by questionnaire. Human and animal reservoir stools were examined. Bithynia spp. and Neotricula aperta snails were examined using shedding. Fresh water fish were examined using digestion technique. Multivariate random-effects analysis was used to find risk factors associated with helminth infections.ResultsHuman infection rates with O. viverrini, hookworm, S. mekongi, Trichuris trichiura, Ascaris lumbricoides and Taenia spp. were 60.7%, 44.1%, 22.2%, 4.1%, 0.6% and 0.1%, respectively. Heavy intensity infections were 4.2%, 3.6% and 1.8% for O. viverrini, S. mekongi and hookworm, respectively. O. viverrini and S. mekongi infection rates among dogs and cats were 25.0% and 14.7%, respectively. Of the cats tested, 53.1% were infected with O. viverrini. Prevalence of O. viverrini and S. mekongi in snails was 0.3% and 0.01%, respectively. Overall prevalence of O. viverrini infection in fresh water fish was 26.9%, with the highest infection rates occurring in Hampala dispa (87.1%), Cyclocheilichthys apogon (85.7%) and Puntius brevis (40.0%). Illiteracy and lower socioeconomic status increased the risk of O. viverrini infection, while those aged 10–16 years and possessing latrines at home were less likely to be infected. Household dogs and cats that consumed raw fish were significantly and positively associated with O. viverrini infection of the household members. For S. mekongi, children under 9 years old were exposed significantly to this infection, compared to older age groups.ConclusionsThere is a pressing need to design and implement an integrated helminth control intervention on the Mekong Islands in southern Lao PDR. Given the highly dynamic transmission of O. viverrini, S. mekongi, STH and extended multiparasitism, annual mass-drug administration is warranted along with environmental modifications, health education and improved access to clean water and adequate sanitation to consolidate morbidity control and move towards elimination.Trail registration numberOur findings presented here are from a cross-sectional study, therefore, it has not been registered.