Years Of Mass Drug Administration Research Articles

Onchocerciasis in the Cameroon–Chad border area after more than 20 years of annual mass ivermectin distribution

BackgroundThe main vectors of onchocerciasis in Africa are Simulium damnosum sensu lato, which transmit the causative agent Onchocerca volvulus. The force of transmission is driven by the vector density, hence influencing the disease prevalence and intensity. Onchocerciasis is currently targeted for elimination using mass drug administration (MDA) of ivermectin, a potent microfilaricide. MDA in Cameroon began in 1987 in the Vina Valley, an endemic cross-border area with Chad, known for high vector densities and precontrol endemicity. Evaluations in 2008–2010 in this area showed ongoing transmission, while border areas in Chad were close to interrupting transmission. This study aimed to evaluate transmission in this area after several rounds of MDA since the last evaluation surveys.MethodsBlack flies were collected by human landing catches at seven border sites in Cameroon, twice a week, from August 2021 to March 2022. A fraction of the flies was dissected for parity assessment and identification of Onchocerca larval stages. The transmission indices were estimated. Black fly larvae were also collected from the breeding sites at the fly catching sites and identified to species level by cytotaxonomy.ResultsA total of 14,303 female flies were collected, and 6918 were dissected. Of these, 4421 (64.0%) were parous. The total biting rates were high, reaching up to 16,407 bites/person/study period, and transmission potential (third-stage larvae (L3) from head/all L3) were 367/702, 146/506, 51/55, 20/32, 0/3, 0/0, and 0/0 infective larvae/person, respectively, for Mbere-Tchad, Babidan, Hajam/V5, Gor, Djeing, Touboro, and Koinderi. Infectivity rates (L3 from head) were 16.00, 12.75, 5.15, and 4.07 infective females (L3H)/1000 parous flies for Haijam, Mbere-Tchad, Babidan, and Gor, respectively. These values exceed the World Health Organization (WHO) thresholds of ≤ 20 annual transmission potential (ATP) or < 1 infective female/1000 parous females. The major vectors identified were Simulium damnosum sensu stricto, S. squamosum, and for the first time in the area, S. yahense.ConclusionsMore than 20 years of MDA has not eliminated onchocerciasis in the study area; hence, this area is a potential source of reintroduction of onchocerciasis in Chad and would require alternative treatment strategies. Many factors such as MDA efficiency, effectiveness of ivermectin, and cytospecies composition may be contributing to transmission persistence.Graphical

Prevalence of epilepsy in the onchocerciasis endemic middle belt of Ghana after 27 years of mass drug administration with ivermectin

BackgroundIn onchocerciasis-endemic areas with high ongoing Onchocerca volvulus transmission, a high prevalence of epilepsy has been reported. This study aimed to determine the prevalence and clinical characteristics of epilepsy in the Bono Region of Ghana following 27 years of implementation of ivermectin mass drug administration (MDA).MethodsBetween October 2020 and August 2021, cross-sectional surveys were conducted in nine communities in the Tain District and Wenchi Municipality of the Bono Region of Ghana. In the first stage, a random door-to-door approach was used to screen the population for epilepsy using a pre-tested questionnaire. Persons suspected of having epilepsy were invited for a second-stage neurological examination for case verification. Community O. volvulus microfilarial infection status and Ov16 seropositivity were also determined. Ninety-five confidence intervals (95% CI) for prevalence values were calculated using the Wilson Score Interval.ResultsOf the 971 participants, 500 (51.5%) were females, and the median age (interquartile range) was 26 (15‒43) years. Fourteen participants (1.4%, 95% CI: 1.0‒2.0) were diagnosed as having epilepsy with generalized seizures being the most frequent seizure type (85.7%, 12/14). The overall microfilarial prevalence of O. volvulus was 10.3% (November 2020) and 9.9% (August 2021); the Ov16 seroprevalence was 22.2% (June 2021). Only 63.2% took ivermectin in the last round of MDA distribution in March 2021.ConclusionsThe 1.4% prevalence of epilepsy in the Bono region is similar to the median epilepsy prevalence in sub-Saharan Africa. However, the persistent microfilarial prevalence and low ivermectin study coverage call for the Ghana Onchocerciasis Elimination Programme to step up its efforts to ensure that the gains achieved are consolidated and improved to achieve the elimination of onchocerciasis by 2030.Graphical

Protocol for a cluster randomised placebo-controlled trial of adjunctive ivermectin mass drug administration for malaria control on the Bijagós Archipelago of Guinea-Bissau: the MATAMAL trial

IntroductionAs malaria declines, innovative tools are required to further reduce transmission and achieve elimination. Mass drug administration (MDA) of artemisinin-based combination therapy (ACT) is capable of reducing malaria transmission where...

Understanding perceptions of schistosomiasis and its control among highly endemic lakeshore communities in Mayuge, Uganda.

Schistosomiasis is a neglected tropical disease and a serious global-health problem with over 230 million people requiring treatment, of which the majority live in Africa. In Uganda, over 4 million people are infected. Extensive parasitological data exist on infection prevalence, intensities and the impact of repeated praziquantel mass drug administration (MDA). However, how perceptions of schistosomiasis shape prevention and treatment practices and their implications for control measures are much less well understood. Rapid ethnographic appraisals were performed for six weeks in each of three Schistosoma mansoni high endemicity communities on the shores of Lake Victoria, Mayuge District, Uganda. Data were collected between September 2017 and April 2018. Data were collected through structured observations, transect walks, and participant observation, and sixty in-depth interviews and 19 focus group discussions with purposively recruited participants. Data were analyzed thematically using iterative categorization, looking at five key areas: perceptions of 1) the symptoms of schistosomiasis; 2) the treatment of schistosomiasis; 3) how schistosomiasis is contracted; 4) how schistosomiasis is transmitted onwards and responsibilities associated with this; and 5) how people can prevent infection and/or onward transmission. Observations revealed open defecation is a common practice in all communities, low latrine coverage compared to the population, and all communities largely depend on lake water and contact it on a daily basis. Perceptions that a swollen stomach was a sign/symptom of 'ekidada' (caused by witchcraft) resulted in some people rejecting free praziquantel in favour of herbal treatment from traditional healers at a fee. Others rejected praziquantel because of its perceived side effects. People who perceived that schistosomiasis is caught from drinking unboiled lake water did not seek to minimize skin contact with infected water sources. Community members had varied perceptions about how one can catch and transmit schistosomiasis and these perceptions affect prevention and treatment practices. Open defecation and urinating in the lake were considered the main route of transmission, all communities attributed blame for transmission to the fishermen which was acknowledged by some fishermen. And, lastly, schistosomiasis was considered hard to prevent due to lack of access to safe water. Despite over 15 years of MDA and associated education, common misconceptions surrounding schistosomiasis exist. Perceptions people have about schistosomiasis profoundly shape not only prevention but also treatment practices, greatly reducing intervention uptake. Therefore, we advocate for a contextualized health education programme, alongside MDA, implementation of improved access to safe-water and sanitation and continued research.

Assessment of the progress toward elimination of lymphatic filariasis in the Federal Capital Territory- Abuja, Nigeria

Lymphatic filariasis (LF) is a neglected tropical disease caused by threadlike worms (nematodes) that live in the lymphatic vessels of humans. Although three species of filarial parasites (Wuchereria bancrofti, Brugia malayi and Brugia timori) infect humans; 90% of infection is caused by Wuchereria Bancrofti and humans are its exclusive host. Nigeria is one of over 70 countries endemic for Lymphatic filariasis with an estimated 134 million people at the risk of infection. The Federal Capital Territory (FCT), which is endemic for LF, commenced mass drug administration (MDA) using ivermectin (IVM) and albendazole (ALB) in 2011. While MDA is continuing in two Area Councils, in 2020, we assessed the impact of MDA on LF prevalence in two area councils that had achieved five effective annual rounds of MDA. In 2010, a baseline mapping exercise was conducted in all six area councils of FCT-Abuja. The results revealed that four out of the six area councils were endemic for LF, with prevalence ranging from 1.0%-4.0%. The number of persons treated with ivermectin and albendazole in the four Area Councils was documented during annual MDA and population-based cluster surveys were conducted at least once in each area council during the five years of treatment, to verify the reported geographic and programme MDA coverage. This is the number treated divided by the total population eligible to receive treatment (usually &amp;lt;5years). The survey results confirmed that in two area councils (Abaji and Kuje) the coverage exceeded the target of 65% the while two other Councils did not reach the recommended coverage. A pre-transmission assessment survey (pre-TAS) was conducted in one sentinel site and at least one spot check site in Abaji and Kuje in 2019 and were found to have LF antigenemia (LF Ag) &amp;lt; 2% (range 0.0% to 1.99%). In 2020, transmission assessment surveys (TAS) were conducted in the two area councils that previously passed the Pre-transmission assessment survey. The results showed that the two Evaluation units had achieved the LF Ag threshold required to stop MDA. FCT has made significant progress towards LF elimination with two Area Councils qualifying to stop treatment. However, two other area councils still require a further two years of mass drug administration with effective MDA coverage before these area councils qualify for impact assessment.

Urogenital schistosomiasis among pre-school and school aged children in four districts of north western Tanzania after 15 years of mass drug administration: Geographical prevalence, risk factors and performance of haematuria reagent strips.

Urogenital schistosomiasis remains as a public health problem in Tanzania and for the past 15 years, mass drug administration (MDA) targeting primary school children has remained as the mainstay for its control. However, after multiple rounds of MDA in highly risk groups, there are no data on the current status of Schistosoma haematobium in known endemic areas. Furthermore, the performance of commonly used diagnostic test, the urine reagent strips is not known after the decline in prevalence and intensities of infection following repeated rounds of treatment. Thus, after 15 of national MDA, there is a need to review the strategy and infection diagnostic tools available to inform the next stage of schistosomiasis control in the country. A analytical cross-sectional study was conducted between October and November, 2019 among pre-school (3-5years old) and school aged children (6-17 years old) living in four (4) districts with low (<10%) and moderate (10%-<50%) endemicity for schistosomiasis as per WHO classification at the start of the national control programme in 2005/06, with mean prevalence of 20.7%. A total of 20,389 children from 88 randomly selected primary schools participated in the study. A questionnaire was used to record demographic information. A single urine sample was obtained from each participant and visually examined for macrohaematuria, tested with a dipstick for micro-haematuria, to determine blood in urine; a marker of schistosome related morbidity and a proxy of infection. Infection intensity was determined by parasitological examination of the urine sample for S. haematobium eggs. Overall, mean infection prevalence was 7.4% (95%CI: 7.0-7.7, 1514/20,389) and geometric mean infection intensity was 15.8eggs/10mls. Both infection prevalence (5.9% versus 9%, P<0.001) and intensity (t = -6.9256, P<0.001) were significantly higher in males compared to females respectively. Light and heavy infections were detected in 82.3% and 17.7% of the positive children respectively. The prevalence of macrohaematuria was 0.3% and that of microhaematuria was 9.3% (95%CI:8.9-9.7). The sensitivity and specificity of the urine reagent strip were 78% (95%CI: 76.1-79.9) and 99.8% (95%CI: 99.7-99.9). Having light (P<0.001) and heavy infection intensities (P<0.001) and living in the study districts increased the odd of having microhaematuria. Predictors of S. haematobium infection were being male (P<0.003), microhaematuria (P<0.001), and living in the three study districts (P<0.001) compared to living at Nzega district. The findings provide an updated geographical prevalence which gives an insight on the planning and implementation of MDA. Comparing with the earlier mapping survey at the start of the national wide mass drug administration, the prevalence of S. haematobium infection have significantly declined. This partly could be attributed to repeated rounds of mass drug administration. The urine reagent strips remain as a useful adjunct diagnostic test for rapid monitoring of urogenital schistosomiasis in areas with low and high prevalence. Based on prevalence levels and with some schools having no detectable infections, review of the current blanket mass drug administration is recommended.

Schistosomiasis solution is not as simple as mass drug administration: Lamberton Lab takes a holistic approach to break the cycle of infection

Schistosomiasis solution is not as simple as mass drug administration: Lamberton Lab takes a holistic approach to break the cycle of infection Schisto_Persist aims to understand why schistosomiasis is not reducing in some areas despite nearly 20 years of mass drug administration. Overarching questions: What is the best way to monitor schistosome infections and drug efficacy? Has praziquantel resistance been selected for and what is its potential for spread? What other factors drive maintained transmission? What other factors affect parasite clearance? All require improved diagnostics and interpretation to be answered. Here we discuss the advances the Lamberton Lab are making for Schistosoma diagnostics.

Occurrence of Lymphatic Filariasis infection after 15 years of mass drug administration in two hotspot districts in the Upper East Region of Ghana.

BackgroundLymphatic filariasis (LF) causes chronic morbidity, which usually manifests as lymphedema or hydrocele. Mass drug administration (MDA) began in Kassena Nankana East Municipal (KNEM) and Nabdam, two hotspot districts in the Upper East Region in Ghana, in 2000 and 2005, respectively. This cross-sectional study evaluated the impact of 15 years of MDA on the control of LF as determined by circulating filarial antigen (CFA) and microfilariae assessment in the KNEM and the Nabdam districts.Methodology/Principal findingsA total of 7,453 participants from eight sub-districts in the two hotspot districts (KNEM: N = 4604; Nabdam: N = 2849) were recruited into the study. The overall CFA prevalence as determined by the FTS was 19.6% and 12.8% in the KNEM and Nabdam districts, respectively. Manyoro, a sub-district on the border with Burkina Faso, recorded the highest CFA prevalence of 26% in the KNEM. Assessment of microfilariae and Og4C3 antigen was done from 1009 (KNEM: N = 799 (79.2%); Nabdam: N = 210 (20.8%)) randomly selected FTS-positive (N = 885) and FTS-negative (N = 124) individuals. The Og4C3 antigen was found in 22.6%/23.0% of the selected individuals (KNEM/Nabdam), whereas the night blood revealed microfilariae in only 0.7%/0.5%.Conclusions/SignificanceUsing the WHO endorsed FTS, CFA prevalence exceeded the long-standing <2% threshold—which may need revision and validation. Surprisingly, the Og4C3 ELISA showed positive results in only about one-fifth of the FTS positive samples. However, even this result would not have met the <2% CFA criteria for LF elimination. In contrast, projections from the microfilariae results revealed a halt in LF transmission. The global elimination target was due in 2020 but has been extended to 2030 since this could not be met. Focused MDA intervention intensification on seasonal migrants and non-compliers, and implementation of alternative treatment strategies may suffice for the elimination of the disease.

Mapping Spatial Variation and Impact of the National MDA Program on Lymphatic Filariasis Elimination in Ghana: An Initial Study

Lymphatic filariasis (LF) is a public health menace, especially in developing countries. A periodic review of mass drug administration (MDA) performance is critical to monitoring elimination progress. However, investigating the spatial pattern of LF with respect to MDA intervention is yet to be documented. This is essential to appreciating the transmission dynamics across LF-endemic communities and how it is spatially impacted by MDA programs. The aim of this study was to map and explore the spatial variation and hotspots of LF infection among endemic communities and evaluate the impact of the MDA intervention program on its spatial pattern in Ghana. Relative risks, clustering and clusters, prevalence odds ratios, and their confidence intervals were studied with community-level LF data prior to intervention and post intervention periods. The overall risk of LF infection was 0.12% and 0.02% before and after MDA, respectively, suggesting reduced transmission. Using empirical Bayesian smoothing to map the relative risk, a substantial variation in the spatial distribution of the relative risk of LF among endemic communities was observed. Most of the excess prevalence communities were unexpectedly visible even after years of MDA. The Empirical Bayesian Moran’s Index for global clustering showed a reduction in clustering of LF prevalence after MDA with IM = 0.455 and 0.119 for before and after MDA, respectively. Furthermore, examining risks associated with ecological zones, it was observed that the Guinea Savannah and the Transition Zone were the most vulnerable zones for LF infection with prevalence odds ratios 18.70- and 13.20-fold higher than in the reference Moist evergreen zone, respectively. We observed a drastic reduction in risk in the Wet evergreen zone after MDA, while the Guinea Savannah sustained high levels of risk even after MDA. These findings should prompt public health officials to adopt stratified cluster sampling in LF-endemic regions to monitor the rate and density of microfilaria.

How does onchocerciasis-related skin and eye disease in Africa depend on cumulative exposure to infection and mass treatment?

Onchocerciasis (river-blindness) in Africa is targeted for elimination through mass drug administration (MDA) with ivermectin. Onchocerciasis may cause various types of skin and eye disease. Predicting the impact of MDA on onchocercal morbidity is useful for future policy development. Here, we introduce a new disease module within the established ONCHOSIM model to predict trends over time in prevalence of onchocercal morbidity. We developed novel generic model concepts for development of symptoms due to cumulative exposure to dead microfilariae, accommodating both reversible (acute) and irreversible (chronic) symptoms. The model was calibrated to reproduce pre-control age patterns and associations between prevalences of infection, eye disease, and various types of skin disease as observed in a large set of population-based studies. We then used the new disease module to predict the impact of MDA on morbidity prevalence over a 30-year time frame for various scenarios. ONCHOSIM reproduced observed age-patterns in disease and community-level associations between infection and disease reasonably well. For highly endemic settings with 30 years of annual MDA at 60% coverage, the model predicted a 70% to 89% reduction in prevalence of chronic morbidity. This relative decline was similar with higher MDA coverage and only somewhat higher for settings with lower pre-control endemicity. The decline in prevalence was lowest for mild depigmentation and visual impairment. The prevalence of acute clinical manifestations (severe itch, reactive skin disease) declined by 95% to 100% after 30 years of annual MDA, regardless of pre-control endemicity. We present generic model concepts for predicting trends in acute and chronic symptoms due to history of exposure to parasitic worm infections, and apply this to onchocerciasis. Our predictions suggest that onchocercal morbidity, in particular chronic manifestations, will remain a public health concern in many epidemiological settings in Africa, even after 30 years of MDA.

Assessment of the Clinical, Serological and Parasitological Aspects of Onchocercal Skin Disease, 20 Years of Community Directed Treatment with Ivermectin (CDTI) in the Ruvuma, Southwestern Tanzania

Background: Onchocerciasis is a chronic disease caused by filarial worm, maintained in the communities through the black flies that breed in rapid fast flowing rivers. The disease triggers enormous sufferings and compromise community and individual socio-economic opportunities. Approximately 37 million people are afflicted by onchocerciasis and 46,000 new cases of blindness are reported each year in the hyper-mesoendemic communities. Study objective was assessing interruption of transmission after over 20 years of mass drug administration in the area.

Mapping Schistosoma haematobium for Novel Interventions against Female Genital Schistosomiasis and Associated HIV Risk in KwaZulu-Natal, South Africa.

.Women with female genital schistosomiasis (FGS) have been found to have genital symptoms and a three-fold higher risk of HIV infection. Despite WHO recommendations, regular antischistosomal mass drug administration (MDA) has not yet been implemented in South Africa possibly because of the lack of updated epidemiological data. To provide data for future prevention efforts against FGS and HIV, this study explored Schistosoma haematobium prevalence in girls and young women and the effects of antischistosomal MDA, respectively. Urinary schistosomiasis and genital symptoms were investigated in 70 randomly selected secondary schools in three districts within KwaZulu-Natal and 18 primary schools. All study participants were treated for schistosomiasis, and schools with the highest urinary prevalence were followed up after 1 and 4 years of MDA. At baseline, urine analysis data showed that most schools were within the moderate-risk prevalence category where biennial antischistosomal MDA is recommended, as per WHO guidelines. Young women had high prevalence of genital symptoms (36%) after correcting for sexually transmitted infections. These symptoms may be caused by infection with schistosomes. However, FGS cannot be diagnosed by urine analysis alone. In KwaZulu-Natal rural schools, this study suggests that antischistosomal MDA with praziquantel could prevent genital symptoms in more than 200,000 young women. Furthermore, it is feasible that more than 5,000 HIV infections could be prevented in adolescent girls and young women by treatment and prevention of FGS.

Individual Efficacy and Community Impact of Ivermectin, Diethylcarbamazine, and Albendazole Mass Drug Administration for Lymphatic Filariasis Control in Fiji: A Cluster Randomized Trial.

Bancroftian filariasis remains endemic in Fiji despite >10 years of mass drug administration (MDA) using diethylcarbamazine and albendazole (DA). The addition of ivermectin to this combination (IDA) has improved efficacy of microfilarial clearance at 12 months in individually randomized trials in nocturnal transmission settings, but impact in a setting of diurnally subperiodic filarial transmission has not been evaluated. This cluster randomized study compared the individual efficacy and community impact of IDA vs DA as MDA for lymphatic filariasis in 35 villages on 2 islands of Fiji. Participants were tested at enrollment for circulating filarial antigen and, if positive, for microfilariae. Weight-dosed treatment was offered according to village randomization. Communities were visited at 12 months and retested for lymphatic filariasis. Infected individuals from Rotuma were retested at 24 months. A total of 3816 participants were enrolled and 3616 were treated. At 12 months, microfilariae clearance was achieved in 72 of 111 participants detected with infection at baseline, with no difference in efficacy between treatment groups: DA, 69.2% (95% confidence interval [CI], 57.2%-79.1%) vs IDA, 62.5% (95% CI, 43.6%-78.2%); risk difference, 11.3 % (95% CI, -10% to 32.7%); P = .30. There was no difference between treatment groups in community prevalence of microfilariae at 12 months or individual clearance at 24 months. We found no difference between IDA and DA in individual clearance or community prevalence of lymphatic filariasis at 12 months, and no improved efficacy following a second annual round of IDA. Possible explanations for the apparent lack of benefit of IDA compared to DA include drug and parasite factors affecting clearance, and higher than expected reinfection rates. Clinical Trials Registration: NCT03177993 and Australian New Zealand Clinical Trial Registry: N12617000738325.

Impact of seven years of mass drug administration and recrudescence of Schistosoma haematobium infections after one year of treatment gap in Zanzibar: Repeated cross-sectional studies.

BackgroundConsiderable progress towards the elimination of urogenital schistosomiasis was made by the Zanzibar Elimination of Schistosomiasis Transmission project from 2012 till 2016, when biannual praziquantel mass drug administration (MDA) alone or with additional snail control or behaviour change interventions were implemented. Annual MDA was continued in 2017 and 2018, but not in 2019, imposing a 16-month treatment gap. We monitored the Schistosoma haematobium prevalence from 2012 till 2020 and assessed recrudescence patterns with focus on 2020.MethodologyRepeated cross-sectional surveys were conducted from 2011/12 till 2020 in 90 communities and 90 schools in Zanzibar. Annually, around 4,500 adults and up to 20,000 schoolchildren were surveyed. The S. haematobium prevalence was detected by urine filtration and reagent strips. In 2020, risk factors for infection were investigated using generalized estimated equation models.Principal findingsIn adults, the apparent S. haematobium prevalence was 3.9% in 2011 and 0.4% in 2020. In schoolchildren, the prevalence decreased from 6.6% in 2012 to 1.2% in 2019 with vicissitudes over the years. Prominent recrudescence of infection from 2.8% in 2019 to 9.1% (+225%) in 2020 was observed in 29 schools with historically moderate prevalences (≥10%). Compared with 2019, reinfection in 2020 was particularly striking in boys aged 9–16 years. Being male was a risk factor for infection in 2020 (adults: odds ratio (OR): 6.24, 95% confidence interval (95% CI): 1.96–19.60; schoolchildren: OR: 2.06, 95% CI: 1.52–2.78). Living near to a natural freshwater body significantly increased the odds of infection in adults (OR: 2.90, CI: 1.12–7.54).Conclusions/SignificanceAfter 11 rounds of MDA over 7 years and a 16-month treatment gap, the urogenital schistosomiasis prevalence considerably rebounded in hotspot areas. Future elimination efforts in Zanzibar should focus on re-intensifying MDA plus additional interventions in hotspot areas. In low-prevalence areas, the strategy might be adapted from MDA to targeted surveillance-response.

Soil-transmitted helminthiasis among school-aged children in Myanmar: the result of 14 years after the implementation of deworming

Background: Soil-transmitted helminth (STH) infections were the most common infections among school-aged children (SAC) in Myanmar. The routine school-based mass drug administration (MDA) with twice a year frequency has started in 2005.Methods: This cross-sectional study aimed to determine the prevalence and intensity of STH infection among SAC as the follow-up study after 14 years of MDA. In August 2019, 1000 school-aged children attending Grades 4 and 5 from four geographical regions across the country were enrolled using a multi-stage sample random sampling. The anthropometry and hemoglobin concentration was measured, and stool specimens were detected parasite eggs using the Kato Katz technique.Results: The intensity of infection was classified according to WHO criteria. Infection prevalence was 17% for any STH infections, 10.4% for A. lumbricoides, 17% for T. trichiura, and 2% for the hookworm. All STH infections were virtually not detected in the hilly region. The highest prevalence of A. lumbricoides and T. trichiura infection were seen in the coastal region. The hookworm was seen only in the plain region. The underweight prevalence was 9% and anemia prevalence was 38% while there were huge differences across regions. The finding showed that STH infections continued to be endemic among SAC throughout the country except for the hilly region after 14 years of MDA.Conclusions: The regular deworming program should be reduced to once a year frequency in Myanmar. Triple-dose regimens should be considered to eliminate the whipworms. The burden of anemia among SAC should also be addressed in cooperation with MDA.

Genetic epidemiology of lymphatic filariasis in American Samoa after mass drug administration

Over 892 million people in 48 countries are at risk of infection by nematodes that cause lymphatic filariasis. As part of the Global Programme to Eliminate Lymphatic Filariasis, mass drug administration is distributed to communities until surveillance indicates infection rates are below target prevalence thresholds. In some countries, including American Samoa, lymphatic filariasis transmission persists despite years of mass drug administration and/or has resurged after cessation. Nothing is known about the population genetics of Wuchereria bancrofti worms in Polynesia, or whether local transmission is persisting and/or increasing due to inadequate mass drug administration coverage, expansion from residual hotspots, reintroduction from elsewhere, or a combination. We extracted DNA from microfilariae on blood slides collected during prevalence surveys in 2014 and 2016, comprising 31 pools of five microfilariae from 22 persons living in eight villages. We sequenced 1104 bp across three mitochondrial markers (ND4, COI, CYTB). We quantified parasite genetic differentiation using variant calls and estimated haplotypes using principal components analysis, F-statistics, and haplotype networks. Of the variants called, all but eight were shared across the main island of Tutuila, and three of those were from a previously described hotspot village, Fagali’i. Genotypic data did not support population genetic structure among regions or villages in 2016, although differences were observed between worms collected in Fagali’i in 2014 and those from 2016. Because estimated haplotype frequency varied between villages, these statistics suggested genetic differentiation, but were not consistent among villages. Finally, haplotype networks demonstrated American Samoan sequence clusters were related to previously published sequences from Papua New Guinea. These are, to our knowledge, the first reports of W. bancrofti genetic variation in Polynesia. The resurgent parasites circulating on the main island of American Samoa represent a single population. This study is the first step towards investigating how parasite population structure might inform strategies to manage resurgence and elimination of lymphatic filariasis.

Positive impact of preventative chemotherapy during a national helminth control program: Perception and KAP

Helminth control at the national level is currently based on mass drug administration (MDA) programs. Perception of the MDA programs for helminth control by the affected populations influences compliance and future designs of the programs. We determined the perception of Zimbabwe’s National Helminth Control Program (2012–2017) with a specific focus on schistosomiasis in the school children treated with praziquantel, schoolteachers and village health workers (VHW). The study enrolled 409 children from Grades 6 and 7 who had the full benefit of the 6 years of MDA from 2012 to 2017. Thirty-six schoolteachers and 22 VHW serving the schools were also recruited. A structured questionnaire developed in English, translated into the local language Shona, and validated prior to the study was administered to the children and the adults. The questions focused on the perceived impact on health, school attendance and performance and Knowledge Attitudes and Practice (KAP) among the school children. Data were captured electronically on android platforms using the Open Data Kit. Overall, 84% of the children responded that their awareness of schistosomiasis (transmission, disease, treatment and infection avoidance) had improved because of participating in the MDAs. Of the 151 children self-diagnosed with schistosomiasis, 74% reported that their health had improved following treatment with praziquantel. This included resolution of haematuria, painful urination, sore stomach, tiredness and falling asleep during class lessons. The children and teachers reported improvements in both pupil school attendance and performance at school while the VHW and teachers reported an increase in health-seeking behaviour amongst the school children for schistosomiasis treatment in-between MDAs. The majority of VHW (96%) reported improvement in handwashing behaviour, schistosomiasis awareness (96%) and treatment uptake (91%) within the communities where the school children belonged. However, only 59% of the VHW reported improvement in toilet use while only 50% of the VHW reported improvement in clean water use within their communities. This study indicated that the surveyed children perceived the MDA program had improved their health, school attendance, school performance and awareness of schistosomiasis. The VHW also perceived that the MDA program had improved the community KAP.

Evaluation of morbidity in Schistosoma mansoni-positive primary and secondary school children after four years of mass drug administration of praziquantel in western Kenya

BackgroundWorld Health Organization guidelines recommend preventive chemotherapy with praziquantel to control morbidity due to schistosomiasis. The primary aim of this cross-sectional study was to determine if 4 years of annual mass drug administration (MDA) in primary and secondary schools lowered potential markers of morbidity in infected children 1 year after the final MDA compared to infected children prior to initial MDA intervention.MethodsBetween 2012 and 2016 all students in two primary and three secondary schools within three kilometers of Lake Victoria in western Kenya received annual mass praziquantel administration. To evaluate potential changes in morbidity we measured height, weight, mid-upper arm circumference, hemoglobin levels, abdominal ultrasound, and quality of life in children in these schools. This study compared two cross-sectional samples of Schistosoma mansoni egg-positive children: one at baseline and one at year five, 1 year after the fourth annual MDA. Data were analyzed for all ages (6–18 years old) and stratified by primary (6–12 years old) and secondary (12–18 years old) school groups.ResultsThe prevalence of multiple potential morbidity markers did not differ significantly between the egg-positive participants at baseline and those at 5 years by Mann Whitney nonparametric analysis and Fisher’s exact test for continuous and categorical data, respectively. There was a small but significantly higher score in school-related quality of life assessment by year five compared to baseline by Mann Whitney analysis (P = 0.048) in 13–18 year olds where malaria-negative. However, anemia was not positively impacted by four annual rounds of MDA, but registered a significant negative outcome.ConclusionsWe did not detect differences in morbidity markers measured in a population of those infected or re-infected after multiple MDA. This could have been due to their relative insensitivity or a failure of MDA to prevent morbidity among those who remain infected. High malaria transmission in this area and/or a lack of suitable methods to measure the more subtle functional morbidities caused by schistosomiasis could be a factor. Further research is needed to identify and develop well-defined, easily quantifiable S. mansoni morbidity markers for this age group.

Review of MDA registers for Lymphatic Filariasis: Findings, and potential uses in addressing the endgame elimination challenges.

BackgroundLymphatic filariasis (LF) is endemic in Ghana, and the country has implemented the GPELF strategy since 2000 with significant progress made in the control of the disease. However, after several years of mass drug administration (MDA) implementation, there is persistent transmission in 17 of the 98 endemic districts in the country. Current approaches to surveillance are clearly unable to target untreated individuals and new strategies are required to address the endgame challenges to enhance LF elimination as a public health problem in endemic countries. Community registers are used during MDAs to enumerate community members, their age, gender, house numbers, and records of their participation in MDAs. These MDA registers represent an untapped opportunity to identify and characterize non-compliance and inform appropriate programmatic actions. In this study, we analyzed the data presented in the registers to assess the coverage and individuals’ compliance in MDA.MethodsThe information in the MDA registers were assessed to verify the reported coverages obtained from the district. The community registers were obtained from the district health offices and the data from each individual record was entered into a database. A simple questionnaire was used to cross-check the participation of study participants in the 2017 MDA. The questionnaire solicited data on: participation in the 2017 MDA, reasons for not taking part in the MDA, adverse events experienced, what was done for the adverse events, and willingness to participate in subsequent MDAs.ResultsWe found that 40.1% of the population in the registers missed at least one MDA in 3 years (2016–2018) and the majority of them were between 10–30 years of age. The results of the questionnaire assessment indicated that 13.8% of the respondents did not receive treatment in 2017 for various reasons, the most prominent among them being “absence/travel” (37.1%). Data in the registers were used to verify the treatment coverage for the years 2017 and 2018, and reviewed against the reported coverage obtained from the district. Significant differences between the reported and verified coverages were only observed in four communities. However, the assessment also revealed that the reported coverage was only accurate in 33.3% of cases.ConclusionsThe MDA registers allow for the identification of eligible individuals who were not reached during any MDA round. Thus, the MDA registers could be utilized at the community and programme levels to identify missing and untreated individuals, appropriately address their non-compliance to MDA, and thereby improve MDA coverage in each implementation unit and monitor the progress towards elimination of LF. The challenges observed through the review of the registers also offer opportunities to improve the training given to the community drug distributors.

Discovering, Defining, and Summarizing Persistent Hotspots in SCORE Studies.

.The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) conducted large field studies on schistosomiasis control and elimination in Africa. All of these studies, carried out in low-, moderate-, and high-prevalence areas, resulted in a reduction in prevalence and intensity of Schistosoma infection after repeated mass drug administration (MDA). However, in all studies, there were locations that experienced minimal or no decline or even increased in prevalence and/or intensity. These areas are termed persistent hotspots (PHS). In SCORE studies in medium- to high-prevalence areas, at least 30% of study villages were PHS. There was no consistent relationship between PHS and the type or frequency of intervention, adequacy of reported MDA coverage, and prevalence or intensity of infection at baseline. In a series of small studies, factors that differed between PHS and villages that responded to repeated MDA as expected included sources of water for personal use, sanitation, and hygiene. SCORE studies comparing PHS with villages that responded to MDA suggest the potential for PHS to be identified after a few years of MDA. However, additional studies in different social-ecological settings are needed to develop generalizable approaches that program managers can use to identify and address PHS. This is essential if goals for schistosomiasis control and elimination are to be achieved.