Annual Mass Drug Administration Research Articles

Current status of schistosomiasis in school-aged children in Mwanga district, Tanzania: impact of two decades of annual Mass Drug Administration programme.

Schistosomiasis is a neglected tropical disease with significant health implications, particularly among children. A cross-sectional study was conducted among school-aged children (SAC) in Mwanga district, Tanzania, a region known to be co-endemic for S. haematobium and S. mansoni infection and where annual mass drug administration (MDA) has been conducted for 20 years. In total, 576 SAC from 5 schools provided a urine sample for the detection of Schistosoma circulating anodic antigen using the upconverting particle-based lateral flow (UCP-LF CAA) test. Additionally, the potential of the point-of-care circulating cathodic antigen (POC-CCA) and microhaematuria dipstick test as field-applicable diagnostic alternatives for schistosomiasis were assessed and the prevalence outcome compared to UCP-LF CAA. Risk factors associated with schistosomiasis was assessed based on UCP-LF CAA. The UCP-LF CAA test revealed an overall schistosomiasis prevalence of 20.3%, compared to 65.3% based on a combination of POC-CCA and microhaematuria dipstick. No agreement was observed between the combined POC tests and UCP-LF CAA. Factors associated with schistosomiasis included age (5–10 years), involvement in fishing, farming, swimming activities and attending 2 of the 5 primary schools. Our findings suggest a significant progress in infection control in Mwanga district due to annual MDA, although not enough to interrupt transmission. Accurate diagnostics play a crucial role in monitoring intervention measures to effectively combat schistosomiasis.

Compliance with tetracycline eye ointment during annual mass drug administration for trachoma control in the Amhara region, Ethiopia.

A 6-week course of tetracycline eye ointment is an alternative to single -dose oral azithromycin in annual mass drug administration for trachoma control. Compliance with the recommended tetracycline eye ointment regimen has not been well characterised when administered as part of a trachoma control program. A routine mass drug administration for trachoma was carried out in 40 communities in the Amhara region of Ethiopia. Two tubes of tetracycline eye ointment, to be administered twice daily for 6 weeks, was offered to all children under 6 months of age, to pregnant women who declined to take azithromycin, and to all individuals with a macrolide allergy. Seven weeks following the mass drug administration, a treatment compliance survey was performed for all community members documented to have received tetracycline eye ointment during the mass drug administration. Of the 491 individuals documented as having received tetracycline eye ointment from the treatment records, 367 completed the survey, of which 214 recalled being offered tetracycline eye ointment. A total of 105 (49%) respondents reported taking ≥1 daily dose of tetracycline eye ointment on most days of the week for at least the first week. Only 20 (9%) respondents reported taking at least 1 tetracycline eye ointment dose per week for 6 weeks. The most common reasons for low compliance included 'saving it for a future infection' and 'stopped because I (or my child) seemed healthy'. The odds of low compliance were greater for those who reported not having adequate counselling (e.g., odds ratio [OR] 5.3, 95% CI 2.5-28.9 when low compliance was defined as not taking a tetracycline eye ointment dose for most days of at least the first week). Compliance with tetracycline eye ointment was low when administered by a trachoma program during a routine mass drug administration, especially for those reporting inadequate counselling. Further research with a larger sample size and varied settings is warranted to better understand and improve compliance.

Ongoing transmission of onchocerciasis in the Pru District of Ghana after two decades of mass drug administration with ivermectin and comparative identification of members of the Simulium damnosum complex using cytological and morphological techniques

Background Human onchocerciasis remains a public health problem in Ghana. Mass drug administration (MDA) with ivermectin (IVM) has reduced disease morbidity and prevalence, but the transmission of onchocerciasis remains ongoing in several endemic foci. We investigated parasite transmission in some endemic communities in Ghana that had received > 18 rounds of annual MDA with IVM and determined the species composition of black fly (Simulium damnosum) vectors in these areas.MethodsAdult female black flies were collected using human landing catches and identified as either forest or savanna species using morpho-taxonomic keys. The adult flies underwent dissection to determine their parity and detect any O. volvulus larvae, followed by the calculation of entomological indices. Simulium damnosum s.l. larvae were collected and preserved in freshly prepared Carnoy’s fixative and were later used for cytotaxonomic studies.ResultsA total of 9,983 adult flies were caught: 6,569 and 3,414 in the rainy and dry seasons respectively. Black fly biting activities over the study period showed bimodal or trimodal patterns. The highest monthly biting rate (MBR) of 10,578.75 bites/person/month was recorded in July in Beposo, while the highest monthly transmission potential of 100.69 infective bites/person/month was recorded in Asubende in August. Morphological analysis of 2,032 flies showed that 99.8% (2,028) of the flies were savanna species, with only 4 (0.2%) adult flies being of the forest species. Cytogenetic studies on 114 black fly larvae revealed three cytospecies (Simulium damnosum s.s., S. sirbanum and S. sanctipauli) in the study area.ConclusionsThe present studies confirmed an ongoing transmission of onchocerciasis in the study communities except Abua-1. It also provides further information on biting behaviors and onchocerciasis transmission indices in the study communities. Further, our data confirmed the savanna species (S. damnosum s.s. and S. sirbanum) of the S.damnosum s.l. to be the major vectors of onchocerciasis in the study areas, with only an occasional influx of forest cytotypes.Graphical

The Interruption of Transmission of Onchocerciasis in Abia, Anambra, Enugu, and Imo States, Nigeria: The Largest Global Onchocerciasis Stop-Treatment Decision to Date.

Onchocerciasis causes severe morbidity in sub-Saharan Africa. Abia, Anambra, Enugu, and Imo states of Nigeria were historically classified meso- or hyperendemic and eligible for ivermectin mass drug administration (MDA). After ≥25 years of annual and biannual MDA, serological and entomological assessments were conducted to determine if Onchocerca volvulus transmission was interrupted. Dried blood spots collected in October 2020 from ≥3167 children 5-9 years old in each state were screened for O. volvulus-specific Ov16 antibody by enzyme-linked immunosorbent assay. Additionally, 52,187 Simulium damnosum heads (≥8845 per state) collected over 12 months between 2021 and 2022 were tested by pooled polymerase chain reaction (PCR) for O-150 DNA. Among seven seropositive children, four were found for follow-up skin snip PCR to confirm active infection. Three were negative and the fourth was excluded as he was visiting from an endemic state. The final seroprevalence estimates of each state had 95% upper confidence limits (UCL) < 0.1%. All fly pools were negative by O-150 PCR, giving a 95% UCL infective fly prevalence < 0.05% in each state. Each state therefore met the World Health Organization epidemiological and entomological criteria for stopping MDA effective January 2023. With 18.9 million residents eligible for MDA, this marked the largest global onchocerciasis stop-treatment decision to date.

Modelling onchocerciasis-associated epilepsy and the impact of ivermectin treatment on its prevalence and incidence

Retrospective cohort studies in Cameroon found an association between Onchocerca volvulus microfilarial load in childhood (measured in 1991–1993) and risk of developing epilepsy later in life (measured in 2017). We parameterised and integrated this relationship (across children aged 3–15 years) into the previously published, stochastic transmission model, EPIONCHO-IBM, for Simulium damnosum sensu lato-transmitted onchocerciasis. We simulated 19 years (1998–2017) of annual ivermectin mass drug administration (MDA) reflecting coverage in the study area, and modelled epilepsy prevalence and incidence. Scenario-based simulations of 25 years of (annual and biannual) MDA in hyper- and holoendemic settings, with 65% and 80% therapeutic coverage, were also conducted. EPIONCHO-IBM predicted 7.6% epilepsy prevalence (compared to 8.2% in the Cameroon study) and incidence of 317 cases/100,000 person-years (compared to 350). In hyperendemic areas, 25 years of biannual MDA (80% coverage) eliminated onchocerciasis-associated epilepsy (OAE) and protected untreated under-fives from its development. Strengthening onchocerciasis programmes, implementing alternative strategies, and evaluating treatment for under-fives and school-age children are crucial to prevent OAE in highly-endemic settings.

Feasibility and acceptability of integrating mass distribution of azithromycin to children 1-11 months into a trachoma mass drug administration campaign to reduce child mortality in Côte d'Ivoire.

Evidence suggests that bi-annual mass drug administration (MDA) of single-dose azithromycin to 1-11 month-old children reduces child mortality in high child-mortality settings. Several countries conduct annual MDAs to distribute azithromycin to individuals ages 6 months and older to prevent trachoma infection. This study examined the feasibility and acceptability of reaching 1-11 months-old children during a trachoma MDA in Côte d'Ivoire by extending azithromycin distribution to infants 1-5 months old during the campaign. In November 2020, the study piloted single-dose azithromycin for 1-5 month-olds during a trachoma MDA in one health district. Monitoring data included the number of children reached and occurrences of adverse drug reactions. Feasibility, the extent to which the target population received the intervention (coverage), was assessed through a population-based, household survey with parents/caregivers of eligible children conducted after the MDA. Acceptability was explored through in-depth interviews (IDIs) with parents/caregivers of eligible children, focus group discussions (FGDs) with community drug distributors (CDDs), and IDIs with their supervisors. CDD FGDs and supervisor IDIs also documented implementation challenges and recommendations for scale-up. 1,735 1-5 month-olds received azithromycin during the pilot activity (estimated population coverage of 90.2%). Adverse drug reactions were reported for 1% (n = 18) infants; all were mild and self-limited. The post-MDA coverage survey interviewed 267 parents/caregivers; survey-based intervention coverage was 95.4% of 1-5 month-olds. Qualitative data revealed high intervention acceptability among parents, CDDs, and supervisors. Implementation challenges included the need to weigh babies to calculate dosage for 1-5 month-olds and the need to obtain written informed consent from parents to provide the drug to 1-5 month-olds. CDDs also indicated the need for more information on azithromycin and possible side effects during training. Delivering azithromycin to younger infants appears acceptable to parents and implementers; >90% coverage indicates feasibility to integrate into a trachoma MDA. (Clinicaltrials.gov ID number: NCT04617626).

Factors associated with hookworm and Schistosoma mansoni infections among school-aged children in Mayuge district, Uganda

BackgroundHookworm infection and schistosomiasis are two of sub-Saharan Africa's most common neglected tropical diseases. An annual mass drug administration (MDA) program against schistosomiasis and soil-transmitted helminths (STHs), including hookworm, has been implemented in Mayuge district, Uganda, since 2003 to date. However, hookworm and schistosomiasis remain prevalent in Mayuge district. Understanding the factors that predispose children to these infections in the context of MDA could inform interventions to reduce prevalence in Uganda and similar settings.MethodThis cross-sectional study took place in 33 randomly selected primary schools in the Mayuge district from January to February 2022. Children in primary classes 4 or 5, in the selected schools provided single stool samples and completed questionnaires. Stool specimens were examined using the Kato-Katz method to determine the prevalence of hookworm and schistosomiasis. We performed univariable and multivariable logistic regression to assess the associations of each infection with potential risk factors.ResultA total of 1,617 students (mean age 12.1 years, 50.1% male) were enrolled. The prevalence of hookworm infection and schistosomiasis was 21.8% (95% confidence interval (CI): 19.8–23.9%) and 18.7% (95% CI: 16.8–20.7%), respectively. In multivariable analysis, longer water fetching time (over 30 min versus less than 30 min) and working daily in the soil were associated with increased odds of hookworm infection (adjusted odds ratio (AOR): 1.49, 95% CI: 1.13–1.96 and 1.37, 95% CI: 1.03–1.82, respectively). Higher odds of schistosomiasis were linked to proximity to water bodies within a one-hour walking distance (AOR: 1.84, 95% CI: 1.35–2.50), and not always washing hands before eating (AOR: 2.00, 95% CI: 1.50–2.67). Swimming, bathing, or washing in water bodies twice a week, compared to never, also increased schistosomiasis odds (AOR: 2.91, 95% CI: 1.66–5.13).ConclusionConsistent with the mechanisms of acquisition, hookworm infection increased with exposure to soil, and schistosomiasis increased with exposure to unclean water. Our findings highlight the importance of Water, Sanitation, and Hygiene programs and strategies aimed at reducing exposure within the framework of Neglected Tropical Disease elimination programs.

Schistosomiasis transmission in Zimbabwe: Modelling based on machine learning

Zimbabwe, located in Southern Africa, faces a significant public health challenge due to schistosomiasis. We investigated this issue with emphasis on risk prediction of schistosomiasis for the entire population. To this end, we reviewed available data on schistosomiasis in Zimbabwe from a literature search covering the 1980-2022 period considering the potential impact of 26 environmental and socioeconomic variables obtained from public sources. We studied the population requiring praziquantel with regard to whether or not mass drug administration (MDA) had been regularly applied. Three machine-learning algorithms were tested for their ability to predict the prevalence of schistosomiasis in Zimbabwe based on the mean absolute error (MAE), the root mean squared error (RMSE) and the coefficient of determination (R2). The findings revealed different roles of the 26 factors with respect to transmission and there were particular variations between Schistosoma haematobium and S. mansoni infections. We found that the top-five correlation factors, such as the past (rather than current) time, unsettled MDA implementation, constrained economy, high rainfall during the warmest season, and high annual precipitation were closely associated with higher S. haematobium prevalence, while lower elevation, high rainfall during the warmest season, steeper slope, past (rather than current) time, and higher minimum temperature in the coldest month were rather related to higher S. mansoni prevalence. The random forest (RF) algorithm was considered as the formal best model construction method, with MAE = 0.108; RMSE = 0.143; and R2 = 0.517 for S. haematobium, and with the corresponding figures for S. mansoni being 0.053; 0.082; and 0.458. Based on this optimal model, the current total schistosomiasis prevalence in Zimbabwe under MDA implementation was 19.8%, with that of S. haematobium at 13.8% and that of S. mansoni at 7.1%, requiring annual MDA based on a population of 3,003,928. Without MDA, the current total schistosomiasis prevalence would be 23.2%, that of S. haematobium 17.1% and that of S. mansoni prevalence at 7.4%, requiring annual MDA based on a population of 3,521,466. The study reveals that MDA alone is insufficient for schistosomiasis elimination, especially that due to S. mansoni. This study predicts a moderate prevalence of schistosomiasis in Zimbabwe, with its elimination requiring comprehensive control measures beyond the currently used strategies, including health education, snail control, population surveillance and environmental management.

Community Feedback on Mass Medicines Administration for Neglected Tropical Diseases in Federal Capital Territory, Abuja, Nigeria.

The World Health Organization (WHO) recommends the use of annual mass drug administration (MDA) as the strategy for controlling and eliminating the five preventive chemotherapy neglected tropical diseases (PC-NTDs). The success of MDAs hinges on community acceptance, active participation, and compliance. This study aimed to explore the experiences and perceptions of community members, to obtain a more thorough understanding of their openness and willingness to participate in MDA and other NTD elimination activities. A mixed-methods approach was employed, utilizing qualitative and quantitative methods for comprehensive data collection. Eighteen key informant interviews (KIIs) and sixteen focus group discussions (FGDs) were conducted to explore community engagement, participation, medication utilization, and programme perception. Triangulation of findings from interviews and discussions with household survey results was performed to gain a deeper understanding of emerging themes. The household survey involved interviewing 1220 individuals (Abaji: 687; Bwari: 533). Audio tapes recorded KIIs and FGDs, with interview transcripts coded using Nvivo 12.0 software based on predefined themes. Descriptive analysis using SPSS version 21 was applied to quantitative data. Results indicated high awareness of mass drug administration (MDA) campaigns in both area councils (Abaji: 84.9%; Bwari: 82.9%), with a small percentage claiming ignorance (15.1%), attributed to lack of information or absence during health campaigns. Respondents primarily participated by taking medication (82.5%), with minimal involvement in other MDA campaigns. Perception of medicines was generally positive, with a significant association between participation level and performance rating (p < 0.05). The study recommends leveraging high awareness and community responsiveness to enhance engagement in various MDA activities, ensuring sustainability and ownership of the programme.

Factors associated with never treatment and acceptability of mass drug administration for the elimination of lymphatic filariasis in Guyana, 2021.

Guyana remains one of four countries in the Americas endemic for lymphatic filariasis (LF). Elimination of LF requires repeated annual mass drug administration (MDA) with sufficient levels of coverage for success. This study assesses the acceptability and never treatment of LF MDA using data from a routine assessment survey in 2021. A subset of individuals, over 20 years of age (n = 2498), were selected to receive an expanded questionnaire to examine factors associated with acceptability and never treatment. Assessed factors include respondent demographics, knowledge, risk perceptions of LF, and opinions on the MDA programme. The majority (73%) of those with scores above the acceptability threshold (score ≥22.5) reported participating in MDA two or more times. Factors strongly and positively associated with scoring above the acceptability threshold include beliefs in importance of participation in MDA for their community (aOR = 2.8, 95%CI (1.1-7.2)), perception of importance of LF treatment (6.9 (3.2-14.7)), receiving treatment in 2021 (2.9 (1.5-5.4)), and the number of self-reported times taking treatment for LF (2.2 (1.1-4.4)). Ten percent of respondents participated in the MDA for the first time in 2021, while 15% reported never treatment during any round of LF MDA. Three factors were statistically associated with participation in MDA across the two levels of the models (level 1: took LF treatment once versus never, and level 2: took LF treatment twice versus never) included: 1) scoring above the acceptability threshold (aOR = 6.2, 95%CI(3.8-10.0)), 2) self-reported importance of participation in MDA for their community (7.1 (2.9-17.8)), and 3) personal beliefs that they should take LF treatment even if they are not sick (2.6 (1.7-3.9)). As Guyana moves closer to LF elimination, these results provide further insight and understanding into programmatic results and could inform further action following MDA activities-particularly if an approach is needed to address never treatment during MDA.

How Does the Proportion of Never Treatment Influence the Success of Mass Drug Administration Programs for the Elimination of Lymphatic Filariasis?

Mass drug administration (MDA) is the cornerstone for the elimination of lymphatic filariasis (LF). The proportion of the population that is never treated (NT) is a crucial determinant of whether this goal is achieved within reasonable time frames. Using 2 individual-based stochastic LF transmission models, we assess the maximum permissible level of NT for which the 1% microfilaremia (mf) prevalence threshold can be achieved (with 90% probability) within 10 years under different scenarios of annual MDA coverage, drug combination and transmission setting. For Anopheles-transmission settings, we find that treating 80% of the eligible population annually with ivermectin + albendazole (IA) can achieve the 1% mf prevalence threshold within 10 years of annual treatment when baseline mf prevalence is 10%, as long as NT <10%. Higher proportions of NT are acceptable when more efficacious treatment regimens are used. For Culex-transmission settings with a low (5%) baseline mf prevalence and diethylcarbamazine + albendazole (DA) or ivermectin + diethylcarbamazine + albendazole (IDA) treatment, elimination can be reached if treatment coverage among eligibles is 80% or higher. For 10% baseline mf prevalence, the target can be achieved when the annual coverage is 80% and NT ≤15%. Higher infection prevalence or levels of NT would make achieving the target more difficult. The proportion of people never treated in MDA programmes for LF can strongly influence the achievement of elimination and the impact of NT is greater in high transmission areas. This study provides a starting point for further development of criteria for the evaluation of NT.

Repurposed Drugs That Activate Autophagy in Filarial Worms Act as Effective Macrofilaricides.

Onchocerciasis and lymphatic filariasis are two neglected tropical diseases caused by filarial nematodes that utilize insect vectors for transmission to their human hosts. Current control strategies are based on annual or biannual mass drug administration (MDA) of the drugs Ivermectin or Ivermectin plus Albendazole, respectively. These drug regimens kill the first-stage larvae of filarial worms (i.e., microfilariae) and interrupt the transmission of infections. MDA programs for these microfilaricidal drugs must be given over the lifetime of the filarial adult worms, which can reach 15 years in the case of Onchocerca volvulus. This is problematic because of suboptimal responses to ivermectin in various endemic regions and inefficient reduction of transmission even after decades of MDA. There is an urgent need for the development of novel alternative treatments to support the 2030 elimination goals of onchocerciasis and lymphatic filariasis. One successful approach has been to target Wolbachia, obligatory endosymbiotic bacteria on which filarial worms are dependent for their survival and reproduction within the human host. A 4-6-week antibiotic therapy with doxycycline, for example, resulted in the loss of Wolbachia that subsequently led to extensive apoptosis of somatic cells, germline, embryos, and microfilariae, as well as inhibition of fourth-stage larval development. However, this long-course regimen has limited use in MDA programs. As an alternative approach to the use of bacteriostatic antibiotics, in this study, we focused on autophagy-inducing compounds, which we hypothesized could disturb various pathways involved in the interdependency between Wolbachia and filarial worms. We demonstrated that several such compounds, including Niclosamide, an FDA-approved drug, Niclosamide ethanolamine (NEN), and Rottlerin, a natural product derived from Kamala trees, significantly reduced the levels of Wolbachia in vitro. Moreover, when these compounds were used in vivo to treat Brugia pahangi-infected gerbils, Niclosamide and NEN significantly decreased adult worm survival, reduced the release of microfilariae, and decreased embryonic development depending on the regimen and dose used. All three drugs given orally significantly reduced Wolbachia loads and induced an increase in levels of lysosome-associated membrane protein in worms from treated animals, suggesting that Niclosamide, NEN, and Rottlerin were effective in causing drug-induced autophagy in these filarial worms. These repurposed drugs provide a new avenue for the clearance of adult worms in filarial infections.

Assessment of microfilaremia in 'hotspots' of four lymphatic filariasis endemic districts of Nepal during post-MDA surveillance.

The lymphatic filariasis (LF) elimination program in all sixty-three endemic districts of Nepal was based on annual mass drug administration (MDA) using a combination of diethylcarbamazine (DEC) and albendazole for at least 5 years. The MDA program was started in the Parsa district of the Terai region and at least six rounds of MDA were completed between 2003 and 2017 in all filariasis endemic districts of Central Nepal. Transmission Assessment Survey (TAS) report indicated that circulating filarial antigen (CFA) prevalence was below the critical value i.e., ≤ 2% in selected LF endemic districts of Central Nepal. Based on the TAS report, antigen-positive cases were found clustered in the foci of those districts which were considered as "hotspots". Hence the present study was designed to assess microfilaremia in hotspots of four endemic districts of Central Nepal after the MDA program. The present study assessed microfilaremia in hotspots of four endemic districts i.e. Lalitpur and Dhading from the hilly region and Bara and Mahottari from the Terai region of Central Nepal. Night blood samples (n = 1722) were collected by finger prick method from the eligible sample population irrespective of age and sex. Community people's participation in the MDA program was ensured using a structured questionnaire and chronic clinical manifestation of LF was assessed using standard case definition. Two districts one each from the hilly region (Lalitpur district) and Terai region (Bara district) showed improved microfilaria (MF) prevalence i.e. below the critical level (<1%) while the other two districts are still over the critical level. There was a significantly high prevalence of MF in male (p = <0.05) and ≥41 years of age group (p = <0.05) community people in the hotspots of four endemic districts. People who participated in the previous rounds of the MDA program have significantly low MF prevalence. The upper confidence limit of MF prevalence in all hotspots of four districts was above the critical level (>1%). Chronic clinical manifestation of LF showed significant association with the older age group (≥41 years) but not with sex. The study revealed LF transmission improved in hotspots of two districts while continued in others but the risk of LF resurgence cannot be ignored since the upper confidence level of MF prevalence is over 1% in all the hotspots studied districts. High MF prevalence is well correlated with the number of MDA rounds but not with the MDA coverage. Community people involved in MDA drug uptake in any previous and last rounds have significantly less MF infection. Hence it is recommended that before deciding to stop the MDA rounds it is essential to conduct the MF survey at the hotspots of the sentinel sites.

Entomological assessment in ‘hotspots’ of four lymphatic filariasis endemic districts, Central Nepal during post-MDA surveillance

Background &amp; objectives: Annual mass drug administration (MDA) is the main strategy to interrupt the transmission of lymphatic filariasis (LF) in the community. The main aim of monitoring the MDA program, for its effectiveness and interruption of LF is the post-MDA surveillance using antigen survey in children born after MDA. The latest technique of new research suggests that xenomonitoring is an effective tool for monitoring LF intervention. The objective of this study was to assess the W. bancrofti infection/or infectivity in vector mosquitoes by xenomonitoring during post-MDA surveillance. Methods: A descriptive cross-sectional study was conducted in the hotspots of selected four districts of Central Nepal. A gravid trap technique was used for sampling mosquitoes. Infection/or infectivity was determined via the dissection of vector mosquitoes. Anopheles, Aedes, Armigerus and Culex species were collected from hotspots of four endemic districts, two from the hilly region (Lalitpur and Dhading) and two from Terai region (Bara and Mahottari) of Central Nepal. Results: A total of 4450 mosquitoes belonging to four genera, Anopheles, Culex, Armigeres, and Aedes were collected from four hotspots. The distribution of Culex quinquefasciatus was found to be the highest, 88.9% (n=3955/4450) followed by Cx. vishnui (4.5%), Armigeres sp (5.8%), An. culicifascies (0.2%), Aedes spp (0.8%). The proportion of female mosquitoes trapped is significantly higher. A total of 3344 parous Cx. quinquefasciatus mosquitoes were dissected for any larval stage of W. bancrofti. We could not find any filarial infection in dissected mosquito samples. Interpretation &amp; conclusion: We conclude that the gravid trap is an efficient tool for the collection of gravid Cx. quinquefasciatus mosquitoes for xenomonitoring studies of filariasis endemic regions. Vector composition indicated a maximum number of vector mosquitoes of lymphatic filariasis were trapped compared with the other three species. Distribution and density of Cx. quinquefasciatus was found highest in four hotspots of endemic districts. None of the Cx. quinquefasciatus dissected were found to be infected by larval forms of filaria. Since the low levels of infection persistence in the human population in these hot spots, vector infection and infectivity can’t be ignored. Microscopic xenomonitoring at a low level of infection persistent is less likely to be efficient so molecular xenomonitoring along with a large sample should be required in each of the hot spots of the districts. Additionally, area is receptive so further vector control intervention should be required to reduce the risk of resurgence of infection.

Household Survey to Evaluate the Coverage of Mass Drug Administration for the Lymphatic Filariasis in District Umaria, Madhya Pradesh, India in Year 2023

Background: In 2023, the Umaria district in Madhya Pradesh, India, was identified as an endemic district for Lymphatic Filariasis (LF). The National Programme for Elimination of Lymphatic Filariasis conducted annual mass drug administration (MDA) campaigns in February to eliminate LF by 2027. Objective: This study aimed to estimate the coverage and compliance rate of MDA in the Umaria district of Madhya Pradesh, India, in 2023. Methodology: A cluster sampling method was used for evaluation. The district was divided into three implementation units, corresponding to its three administrative blocks. Four clusters were selected within each unit, consisting of one urban and three rural clusters. Thirty households were randomly selected as respondents from each cluster. Data was collected in May 2023 using a standardized coverage evaluation form designed by the World Health Organization. Result: Among the 360 households surveyed, information on 1606 beneficiaries was obtained. MDA was offered to 94% of the total population, with a coverage and compliance rate of 98.5% among the eligible population. The most common reasons for not consuming the drugs were "not present at house during the campaign" and "fear of drugs." Less than one percent of beneficiaries reported any side effects following the consumption of MDA. Conclusion &amp; Implication: The coverage and compliance of MDA in the district appear to be optimal. The National Programme for Elimination of Lymphatic Filariasis should now consider conducting Transmission Assessment Surveys to determine the endemicity of districts that have reached the critical threshold of LF infection. Additionally, establishing adequate sentinel sites, organizing night blood examination camps in endemic areas, and improving Information Education Communication activities may aid in achieving LF elimination by 2027.

Understanding gender and its intersection with social stratifiers on prevention and care seeking behavior of lymphatic filariasis in Nepal

BackgroundLymphatic filariasis (LF) is a debilitating and painful neglected tropical disease and is one of the leading causes of permanent disability. In many countries, the intersection of gender with various social stratifiers has influenced exposure to LF and ultimately impacting the disease burden and its elimination. This study aimed to explore the influence of gender and its intersection with other social stratifiers for the prevention and care seeking behavior of LF in Nepal.MethodsThis study employed qualitative research methods: in-depth interviews (IDIs) and focus group discussions (FGDs) for data collection in Bardiya, Nepal. A total of 22 IDIs (11 male, 11 female) and 2 FGDs (1 male and 1 female) were conducted with the community people between January and March 2020. The participants were purposively selected to represent different social stratifiers including age, sex, ethnicity, occupation. The data collected were analyzed using a thematic framework approach with use of intersectional gender analysis matrix.ResultsThe study findings revealed that men spend more time outside their household compared to women while fulfilling their roles and responsibilities, largely determined by societal expectations and gender norms. This resulted in limited access to preventive health services for men, as they often missed annual mass drug administration programme in their community and limited access to preventive methods. Further traditional occupation, specific to particular ethnicity, influenced the vulnerability to LF for certain ethnic groups. The ability to prevent exposure varied among individuals. Although women made decisions regarding the use of protective methods, it was influenced by patriarchal and gender norms. They often felt a responsibility to take care and priorities males and other family members when resources are limited. The intersectionality of gender with other social stratifiers such as marital status, ethnicity, and geographical areas influenced individual’s ability to access information related to LF and care seeking.ConclusionsOverall, the findings emphasized how access to resources, division of work, norms and values and decision-making power alone and its interaction with various social stratifiers shaped peoples’ vulnerability to disease, ability to prevent exposure and response to illness.Graphical

Can mass drug administration of moxidectin accelerate onchocerciasis elimination in Africa?

Epidemiological and modelling studies suggest that elimination of Onchocerca volvulus transmission (EoT) throughout Africa may not be achievable with annual mass drug administration (MDA) of ivermectin alone, particularly in areas of high endemicity and vector density. Single-dose Phase II and III clinical trials demonstrated moxidectin's superiority over ivermectin for prolonged clearance of O. volvulus microfilariae. We used the stochastic, individual-based EPIONCHO-IBM model to compare the probabilities of reaching EoT between ivermectin and moxidectin MDA for a range of endemicity levels (30 to 70% baseline microfilarial prevalence), treatment frequencies (annual and biannual) and therapeutic coverage/adherence values (65 and 80% of total population, with, respectively, 5 and 1% of systematic non-adherence). EPIONCHO-IBM's projections indicate that biannual (six-monthly) moxidectin MDA can reduce by half the number of years necessary to achieve EoT in mesoendemic areas and might be the only strategy that can achieve EoT in hyperendemic areas. Data needed to improve modelling projections include (i) the effect of repeated annual and biannual moxidectin treatment; (ii) inter- and intra-individual variation in response to successive treatments with moxidectin or ivermectin; (iii) the effect of moxidectin and ivermectin treatment on L3 development into adult worms; and (iv) patterns of adherence to moxidectin and ivermectin MDA. This article is part of the theme issue 'Challenges in the fight against neglected tropical diseases: a decade from the London Declaration on NTDs'.

Low Prevalence of Soil-Transmitted Helminth Infections among Children in the States of Chhattisgarh and Himachal Pradesh, India, 2018.

Large-scale impact assessments of soil-transmitted helminth (STH) programs are essential for determining the frequency of mass drug administration (MDA). In baseline surveys, the prevalence of STHs in the Indian States of Chhattisgarh and Himachal Pradesh was 80.2% in 2015 and 29.0% in 2016, respectively. In 2018, we estimated the prevalence and intensity of STHs after six rounds of biannual MDA in Chhattisgarh and annual MDA in Himachal Pradesh. We conducted multistage cluster sampling surveys in preschool-age children (PSAC), school-age children (SAC), and adolescent cohorts. Stool samples from 3,033 respondents (PSAC, n = 625; SAC, n = 1,363; adolescents, n = 1,045) in Chhattisgarh and 942 respondents (PSAC, n = 192; SAC, n = 388; adolescents, n = 362) in Himachal Pradesh were examined for presence of STH infection using the Kato-Katz method. The overall cluster-adjusted prevalence in Chhattisgarh was 11.6% among all age groups (95% CI, 5.6-22.4)-an 85.5% reduction in the prevalence since 2015. Prevalence was not significantly different across cohorts (PSAC, 11.0% [95% CI, 5.0-22.6]; SAC, 10.9% [95% CI, 5.2-21.6]; adolescents, 12.8% [95% CI, 6.2-24.5]). Ascaris lumbricoides was the most common helminth, with most infections of light intensity. In Himachal Pradesh, only three STH infections were detected in 2018, resulting in a cluster-adjusted prevalence of 0.3% (95% CI, 0.1-1.7)-a 99.0% reduction in prevalence since 2016. All infections were of light intensity. Both states showed substantial improvements in socioeconomic and water, sanitation, and hygiene (WASH) indicators since the baseline surveys. Extensive reductions in prevalence and intensity are linked to sustained, high deworming coverage, as well as socioeconomic WASH indicators.

Onchocerciasis-associated epilepsy in Maridi, South Sudan: Modelling and exploring the impact of control measures against river blindness.

Onchocerciasis, also known as "river blindness", is caused by the bite of infected female blackflies (genus Simuliidae) that transmit the parasite Onchocerca volvulus. A high onchocerciasis microfarial load increases the risk to develop epilepsy in children between the ages of 3 and 18 years. In resource-limited settings in Africa where onchocerciasis has been poorly controlled, high numbers of onchocerciasis-associated epilepsy (OAE) are reported. We use mathematical modeling to predict the impact of onchocerciasis control strategies on the incidence and prevalence of OAE. We developed an OAE model within the well-established mathematical modelling framework ONCHOSIM. Using Latin-Hypercube Sampling (LHS), and grid search technique, we quantified transmission and disease parameters using OAE data from Maridi County, an onchocerciasis endemic area, in southern Republic of South Sudan. Using ONCHOSIM, we predicted the impact of ivermectin mass drug administration (MDA) and vector control on the epidemiology of OAE in Maridi. The model estimated an OAE prevalence of 4.1% in Maridi County, close to the 3.7% OAE prevalence reported in field studies. The OAE incidence is expected to rapidly decrease by >50% within the first five years of implementing annual MDA with good coverage (≥70%). With vector control at a high efficacy level (around 80% reduction of blackfly biting rates) as the sole strategy, the reduction is slower, requiring about 10 years to halve the OAE incidence. Increasing the efficacy levels of vector control, and implementing vector control simultaneously with MDA, yielded better results in preventing new cases of OAE. Our modeling study demonstrates that intensifying onchocerciasis eradication efforts could substantially reduce OAE incidence and prevalence in endemic foci. Our model may be useful for optimizing OAE control strategies.

Lymphatic Filariasis Elimination in Kerala: A Success Story

National Filaria Control Programme has been running in the country since the year 1955 with the strategy of parasite detection, treatment and vector control mainly in urban areas. In the year 1997, the fiftieth World Health Assembly Resolution listed Lymphatic Filariasis (LF) for elimination by 2020 which now has been aligned with Sustainable Development Goal to be achieved by 2030. India also started its campaign to eliminate LF in 2004. The main strategy of the elimination programme is the Annual Mass Drug Administration (MDA) to progressively reduce and ultimately interrupt LF transmission. The other pillar of the strategy is morbidity management and disability prevention. Kerala state also started its LF elimination campaign in 11 endemic districts out of a total of 14 districts. The average population coverage during MDA in Kerala was reported to be more than 90% from 2004 to 2013, however, drug compliance during independent assessment was reported to be 40%-60% which improved in subsequent years due to a multipronged approach. The main reason of low consumption was the fear of side effects and the same was resolved through massive IEC activities highlighting its benefits compared to side effects, which are mostly self-limiting. The innovative strategic approach of extending the MDA period from 3 days to 3 weeks was undertaken to ensure that all the target population was covered. The results have been encouraging as compliance improved to above 65% and many districts have been validated for having achieved the elimination threshold through successfully clearing transmission assessment survey (TAS).