Assessment of spillover of antimicrobial resistance to untreated children 7 to 12 years old after mass drug administration of azithromycin for child survival in Niger: a secondary analysis of the MORDOR cluster-randomized trial

BACKGROUND

The risk of antibiotic resistance is complicated by the potential for spillover effects from one treated population to another. Azithromycin mass drug administration programs report higher rates of antibiotic resistance among treatment arms in targeted groups. This study aims to understand the risk of spillover of antibiotic resistance to non-target groups in these programs.

METHODS

Data was used from a cluster-randomized trial comparing the effect of biannual azithromycin and placebo distribution to children 1-59 months on child mortality. Nasopharyngeal samples from untreated children 7-12 years old were tested for genetic determinants of macrolide resistance (primary outcome) and resistance to other antibiotic classes (secondary outcomes). Linear regression was used to compare the community-level mean difference in prevalence by arm at the 24-month timepoint adjusting for baseline prevalence.

RESULTS

1,103 children 7-12 years old in 30 communities were included in the analysis (15 azithromycin, 15 placebo). Adjusted mean differences in prevalence of resistance determinants for macrolides, beta-lactams and tetracyclines were 3.4% (95% CI -4.1% to 10.8%, P-value 0.37), -1.2% (95% CI -7.9% to 5.5%, P-value 0.72), and -3.3% (95% CI -9.5% to 2.8%, P-value 0.61), respectively.

CONCLUSIONS

We were unable to demonstrate a statistically significant increase in macrolide resistance determinants in untreated groups in an azithromycin mass drug administration program. While the result might be consistent with a small spillover effect, this study was not powered to detect such a small difference. Larger studies are warranted to better understand the potential for spillover effects within these programs.

Patterns of individual compliance with anthelmintic treatment for soil-transmitted helminth infections in southern Ethiopia over six rounds of community-wide mass drug administration

BACKGROUND

The mainstay of soil-transmitted helminth (STH) control is repeated mass drug administration (MDA) of anthelmintics to endemic populations. Individual longitudinal compliance treatment patterns are important for identifying pockets of infected individuals who remain untreated and serve as infection reservoirs.

METHODS

The Geshiyaro Project censused the study population in Wolaita, Ethiopia at baseline in 2018. Individual longitudinal compliance was recorded for six rounds of community-wide MDA (cMDA). The probability distribution of treatment frequency was analysed by age and gender stratifications. Probabilities of transmission interruption for different compliance patterns were calculated using an individual-based stochastic model of Ascaris lumbricoides transmission.

RESULTS

The never-treated (0.42%) population was smaller than expected from a random positive binomial distribution. The observed compliance frequency was well described by the beta-binomial distribution. Preschool-age children (odds ratio [OR] 10.1 [95% confidence interval {CI} 6.63 to 15.4]) had the highest never-treated proportion of the age groups. Conversely, school-age children (SAC) and adults (OR 1.03 [95% CI 0.98 to 1.09]) had the highest always-treated proportion of the age groups.

CONCLUSIONS

The study reports the largest dataset of individual longitudinal compliance to cMDA for STH control. Clear pattens are shown in the age-dependent distribution of individual compliance behaviour. The impact of compliance on the probability of elimination is significant, highlighting the importance of recording the full frequency distribution, not just the never-treated proportion.

Is the neglected tropical disease mass drug administration campaign approach an effective strategy to deliver universal health coverage? A case study of the Liberia neglected tropical disease programme

BACKGROUND

Access to affordable, quality healthcare is the key element of universal health coverage (UHC). This study examines the effectiveness of the neglected tropical disease (NTD) mass drug administration (MDA) campaign approach as a means to deliver UHC, using the example of the Liberia national programme.

METHODS

We first mapped the location of 3195 communities from the 2019 national MDA treatment data reporting record of Liberia. The association between coverage for onchocerciasis and lymphatic filariasis treatment achieved in these communities was then explored using a binomial geo-additive model. This model employed three key determinants for community 'remoteness': population density and the modelled travel time of communities to their supporting health facility and to their nearest major settlement.

RESULTS

Maps produced highlight a small number of clusters of low treatment coverage in Liberia. Statistical analysis suggests there is a complex relationship between treatment coverage and geographic location.

CONCLUSIONS

We accept the MDA campaign approach is a valid mechanism to reach geographically marginal communities and, as such, has the potential to deliver UHC. We recognise there are specific limitations requiring further study.

How Does Treatment Coverage and Proportion Never Treated Influence the Success of Schistosoma mansoni Elimination as a Public Health Problem by 2030?

BACKGROUND

The 2030 target for schistosomiasis is elimination as a public health problem (EPHP), achieved when the prevalence of heavy-intensity infection among school-aged children (SAC) reduces to <1%. To achieve this, the new World Health Organization guidelines recommend a broader target of population to include pre-SAC and adults. However, the probability of achieving EPHP should be expected to depend on patterns in repeated uptake of mass drug administration by individuals.

METHODS

We employed 2 individual-based stochastic models to evaluate the impact of school-based and community-wide treatment and calculated the number of rounds required to achieve EPHP for Schistosoma mansoni by considering various levels of the population never treated (NT). We also considered 2 age-intensity profiles, corresponding to a low and high burden of infection in adults.

RESULTS

The number of rounds needed to achieve this target depends on the baseline prevalence and the coverage used. For low- and moderate-transmission areas, EPHP can be achieved within 7 years if NT ≤10% and NT <5%, respectively. In high-transmission areas, community-wide treatment with NT <1% is required to achieve EPHP.

CONCLUSIONS

The higher the intensity of transmission, and the lower the treatment coverage, the lower the acceptable value of NT becomes. Using more efficacious treatment regimens would permit NT values to be marginally higher. A balance between target treatment coverage and NT values may be an adequate treatment strategy depending on the epidemiological setting, but striving to increase coverage and/or minimize NT can shorten program duration.

Unraveling Lymphatic Filariasis in an Old Man: A Case Report

Lymphatic filariasis, caused by filarial worms such as Wuchereria bancrofti, Brugia malayi, and Brugia timori, represents a significant public health burden in endemic regions. The disease primarily affects the lymphatic system, leading to lymphatic dysfunction and chronic morbidity. This abstract provides a comprehensive overview of lymphatic filariasis, including its transmission dynamics, pathogenesis, clinical manifestations, diagnostic approaches, and treatment options. Special attention is given to the socioeconomic impact of the disease and the challenges associated with its control and elimination. The patient in this particular case is a 58-year-old man who had lower limb swelling and pain, characteristic of chronic lymphatic obstruction. Additionally, the swelling tends to worsen during the evening hours often resulting in difficulty in walking and discomfort. Lymphatic filariasis was diagnosed based on clinical presentation.

Factors influencing implementation of mass drug administration for lymphatic filariasis elimination: a mixed-method study in Odisha, India

Background: Lymphatic filariasis (LF) persists as a public health problem in India. Despite more than ten rounds of mass drug administration (MDA), LF continues to be endemic in the Dhenkanal district of Odisha. Hence, we assessed the coverage and compliance of the MDA program and explored the factors affecting it in the Dhenkanal district. Methods: An explanatory mixed-method study was conducted, wherein for the quantitative survey, 552 participants aged 2 years and above were recruited following a multistage cluster random sampling during February 2022. In-depth interviews were conducted among purposively selected key stakeholders and program implementers. Descriptive statistics were used to report coverage and compliance, along with a 95% confidence interval. Qualitative data were analyzed using a thematic approach. Results: We observed coverage of 99.28% and compliance of 85.87% for MDA drugs. Supervised drug administration proved to be a major pillar in increasing compliance. There was difficulty in administering drugs in urban areas due to gated societies, the absence of individuals during the day, and the perspective toward healthcare providers. Participants reported a lack of confidence in drug distributors and a fear of side effects as major causes for non-compliance. Conclusion: There is a need to strengthen MDA, especially in urban areas. An urban-specific strategy, along with surveillance, behavioral change communication, and the involvement of multi-disciplinary teams, is required.

No secondary impact of ivermectin mass drug administration for onchocerciasis elimination on the prevalence of scabies in northwestern Ethiopia

BACKGROUND

Mass drug administration (MDA) is among the five major strategies that are currently in use to control, eliminate or eradicate Neglected Tropical Diseases (NTDs). Optimising MDA to control multiple NTDs maximises impact. The objective of this study is to estimate the secondary impact of ivermectin MDA for onchocerciasis on the prevalence of scabies.

METHODS

This quasi-experimental study was conducted in Ayu Guagusa district, northwestern Ethiopia. Scabies prevalence was estimated in surveys before the MDA, at 6 and 12 months afterwards. The sample size was 1437 people from a panel of 381 randomly selected study households. Multistage sampling was employed in randomly selecting six kebeles (the lowest administrative unit) with respective gotes (small villages) and households. All members of the selected households were invited to participate in the study and participants who were available in all three surveys formed a cohort.

RESULTS

Scabies prevalence was similar prior to the MDA (13.4%, 95% CI 11.7 to 15.2%) and 6 months after (11.7%, 95% CI 10.1 to 13.2%) but was substantially greater at 12 months (22.1%, 95% CI 20.1 to 24.1%). The 6-month incidence and disappearance rates were 10.8% (95% CI 8.8 to 13.2%) and 82.6% (95% CI 75.0 to 88.6%), respectively.

CONCLUSIONS

Ivermectin MDA for onchocerciasis was not observed to have a secondary impact on the prevalence of scabies over the follow-up period of 12 months.

Progress towards the implementation of control programmes for strongyloidiasis in endemic areas: estimation of number of adults in need of ivermectin for strongyloidiasis

The World Health Organization has started a process to issue guidelines for the control of strongyloidiasis. The guidelines might recommend to implement preventive chemotherapy (PC) at community level (i.e. to all individuals above 5 years of age), over a defined prevalence threshold. We previously estimated the number of school-age children (SAC) who would need PC. Here we estimate the number of people above 15 years of age who might be included in PC for strongyloidiasis. Based on previous Strongyloides prevalence estimates and on countries' age distribution, we retrieved the number of adults in need of PC. We then subtracted the number of people already involved in ivermectin mass distribution for the elimination of onchocerciasis and lymphatic filariasis and people living in countries where Loa loa is endemic. The number of adults to be involved in PC was estimated at 905.4 (95% confidence interval (CI): 520.6-1177.2), 660.2 (95% CI: 512.7-1214.9), and 512.1 (95% CI: 276-719.4) million people, when the strongyloidiasis prevalence threshold for implementing PC was set to 10%, 15% and 20%, respectively. Estimates at country level are also provided.These estimates might help endemic countries wishing to implement PC for strongyloidiasis to allocate resources to include adults in addition to SAC in control programmes. This article is part of the Theo Murphy meeting issue 'Strongyloides: omics to worm-free populations'.

Treatment coverage of mass administration of azithromycin among children aged 1-11 months in 21 districts of Kebbi state, Nigeria

BACKGROUND

The WHO recommends mass drug administration (MDA) as a strategy to deliver safe and cost-effective medicines to prevent and treat diseases. The antibiotic, azithromycin, has been used during MDA for the treatment and prevention of trachoma in Nigeria. Azithromycin has recently been shown to reduce infant mortality in communities receiving it for trachoma-elimination purposes in sub-Saharan Africa. This article reports on the implementation strategies for the safety and antimicrobial resistance of mass administration of azithromycin to children aged 1-11 mo using the trachoma programme platform in Kebbi state.

METHODS

The mass administration of azithromycin among 1-11-mo-olds in Kebbi was implemented in three phases: (i) the preimplementation phase, during which specific activities were conducted to achieve government and community buy-in, ownership and capacity building; (ii) the implementation phase, which included the mass administration of azithromycin carried out by community volunteers (also known as community-directed distributors [CDDs]), monitoring (by health workers and independent monitors) and reporting of the distribution by all personnel; and (iii) the postimplementation phase, which included the validation of community data, where each item of community summary data is verified and checked for completeness and accuracy before uploading to the District Health Information System platform, where data are visualised, analysed and stored.

RESULTS

In total, 97% of the target population received treatment; the remaining 3% were not treated due to signs of ill health, history of allergy to antibiotics, parental refusal or absence at the time of MDA. Children aged 1-11 mo accounted for 17% of the under-5 population, with females constituting 56% of the target population. In communities that were monitored, reports showed that only 5% lacked distribution materials (scales, slings or registers), >80% correctly entered data into community registers and 5% of children were not treated due to inadequate azithromycin provided to the CDDs for distribution.

CONCLUSION

The implementation of azithromycin MDA for children aged 1-11 mo in Kebbi, utilising the trachoma platform, exhibited commendable coverage due to existing programme platform, healthcare and community structures, intensive advocacy and social mobilisation, real-time monitoring and progress-tracking strategies. It also demonstrated that the trachoma platform is suitable for implementing public health interventions, even after the elimination of trachoma in previously endemic districts.

High prevalence of soil-transmitted helminths and schistosomiasis among primary schoolchildren in Southwest Ethiopia: the need for health strategies alongside mass drug administration

BACKGROUND

Soil-transmitted helminths (STH) and schistosomiasis remain widely prevalent in Ethiopia. The aim of this study was to evaluate the prevalence of STH and schistosomiasis among schoolchildren in Gidi Bench district (Southern Nations, Nationalities, and People's Republic, Southwest Ethiopia) and the association with knowledge and health-related behaviors.

METHODS

A cross-sectional study was conducted. Stool samples, analyzed by the Kato-Katz technique and a knowledge, attitudes and practices questionnaire, were collected.

RESULTS

Out of 611 participants (mean age 12.8±3.1 y), 129 (21.1%) were infected with schistosomiasis and 382 (62.5%) had STH. More than 30% (n=195, 31.9%) were infected with a single intestinal parasite, while 138 (22.6%) and 47 (7.7%) were infected with two or three parasitic infections, respectively. Boys and those who did not participate in school clubs had higher infection rates (p=0.05). Lower parasitic infection was associated with using a latrine when available, washing hands and vegetables and wearing shoes regularly. Higher rates of infection were found among those who reported swimming and washing cloths and utensils in the river regularly.

CONCLUSIONS

Schistosomiasis and STH were highly prevalent among schoolchildren in Gidi Bench district. Infection rates were associated with gender, lack of knowledge on parasitic infections and unhealthy behaviors. Findings from this study may assist in decision making regarding disease prevalence and methods of control alongside mass drug administration.

Persons 'never treated' in mass drug administration for lymphatic filariasis: identifying programmatic and research needs from a series of research review meetings 2020-2021

As neglected tropical disease programs rely on participation in rounds of mass drug administration (MDA), there is concern that individuals who have never been treated could contribute to ongoing transmission, posing a barrier to elimination. Previous research has suggested that the size and characteristics of the never-treated population may be important but have not been sufficiently explored. To address this critical knowledge gap, four meetings were held from December 2020 to May 2021 to compile expert knowledge on never treatment in lymphatic filariasis (LF) MDA programs. The meetings explored four questions: the number and proportion of people never treated, their sociodemographic characteristics, their infection status and the reasons why they were not treated. Meeting discussions noted key issues requiring further exploration, including how to standardize measurement of the never treated, adapt and use existing tools to capture never-treated data and ensure representation of never-treated people in data collection. Recognizing that patterns of never treatment are situation specific, participants noted measurement should be quick, inexpensive and focused on local solutions. Furthermore, programs should use existing data to generate mathematical models to understand what levels of never treatment may compromise LF elimination goals or trigger programmatic action.

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'.

Efficacy of Single-Dose Praziquantel for the Treatment of Schistosoma mansoni Infections among School Children in Rwanda

Preventive chemotherapy with single-dose praziquantel is the WHO-recommended intervention strategy to eliminate schistosomiasis as a public health problem in endemic countries. Surveillance of drugs used in mass drug administration (MDA) programs is recommended to evaluate its effectiveness in reducing transmissions. After a decade-long implementation of a school-based MDA program in Rwanda, we conducted efficacy surveillance of single-dose praziquantel MDA against S. mansoni infection. Two weeks before MDA, stool examinations were performed to screen MDA-eligible school children (n = 4998) for S. mansoni infection using the Kato-Katz technique, and 265 (6.5%) children tested positive for the infection. All children received praziquantel and albendazole as preventive chemotherapy through the MDA campaign. Infected children were enrolled and followed for efficacy monitoring, and stool examination was repeated after three weeks post-MDA (n = 188). Before treatment, 173 (92%) had a light infection, and 15 (8%) had a moderate infection intensity. The primary and secondary outcomes were parasitological cure and egg reduction rates at three weeks post-treatment. The overall cure and egg reduction rates for S. mansoni infection were 97.9% (95% CI = 94.6-99.4) and 97.02%, respectively. Among the 173 children with light infection intensity, 170 (98.3%, 95% CI = 95.0-99.6) were cured, and among the 15 children who had moderate infection intensity, 14 (93.3%) were cured. No significant association between cure rate and pre-treatment infection intensity was observed. We conclude that single-dose praziquantel is efficacious against light-to-moderate S. mansoni infection. Preventive chemotherapy with praziquantel effectively reduces schistosome reservoirs and transmission among school-age children.

Modelling mass drug administration strategies for reducing scabies burden in Monrovia, Liberia

Scabies is a parasitic infestation with high global burden. Mass drug administrations (MDAs) are recommended for communities with a scabies prevalence of >10%. Quantitative analyses are needed to demonstrate the likely effectiveness of MDA recommendations. In this study, we developed an agent-based model of scabies transmission calibrated to demographic and epidemiological data from Monrovia. We used this model to compare the effectiveness of MDA scenarios for achieving scabies elimination and reducing scabies burden, as measured by time until recrudescence following delivery of an MDA and disability-adjusted-life-years (DALYs) averted. Our model showed that three rounds of MDA delivered at six-month intervals and reaching 80% of the population could reduce prevalence below 2% for three years following the final round, before recrudescence. When MDAs were followed by increased treatment uptake, prevalence was maintained below 2% indefinitely. Increasing the number of and coverage of MDA rounds increased the probability of achieving elimination and the number of DALYs averted. Our results suggest that acute reduction of scabies prevalence by MDA can support a transition to improved treatment access. This study demonstrates how modelling can be used to estimate the expected impact of MDAs by projecting future epidemiological dynamics and health gains under alternative scenarios.

Targeted Mass Azithromycin Distribution for Trachoma: A Community-Randomized Trial (TANA II)

BACKGROUND

Current guidelines recommend annual community-wide mass administration of azithromycin for trachoma. Targeting treatments to those most likely to be infected could reduce the amount of unnecessary antibiotics distributed.

METHODS

In a cluster-randomized trial conducted from 1 November 2010 through 8 November 2013, 48 Ethiopian communities previously treated with annual mass azithromycin distributions for trachoma were randomized in equal numbers to (1) annual azithromycin distributions targeted to children aged 0-5 years, (2) annual azithromycin distributions targeted to households with a child aged 0-5 years found to have clinically active trachoma, (3) continued annual mass azithromycin distributions to the entire community, or (4) cessation of treatment. The primary outcome was the community prevalence of ocular chlamydia infection among children aged 0-9 years at month 36. Laboratory personnel were masked to treatment allocation.

RESULTS

The prevalence of ocular chlamydia infection among children aged 0-9 years increased from 4.3% (95% confidence interval [CI], .9%-8.6%) at baseline to 8.7% (95% CI, 4.2%-13.9%) at month 36 in the age-targeted arm, and from 2.8% (95% CI, .8%-5.3%) at baseline to 6.3% (95% CI, 2.9%-10.6%) at month 36 in the household-targeted arm. After adjusting for baseline chlamydia prevalence, the 36-month prevalence of ocular chlamydia was 2.4 percentage points greater in the age-targeted group (95% CI, -4.8% to 9.6%; P = .50; prespecified primary analysis). No adverse events were reported.

CONCLUSIONS

Targeting azithromycin treatment to preschool children was no different than targeting azithromycin to households with a child with clinically active trachoma. Neither approach reduced ocular chlamydia over the 3-year study.

CLINICAL TRIALS REGISTRATION

NCT01202331.

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

INTRODUCTION

As 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 coverage of control interventions is already high, though the impact is short-lived. Combining ACT with ivermectin, an oral endectocide shown to reduce vector survival, may increase its impact, while also treating ivermectin-sensitive co-endemic diseases and minimising the potential impact of ACT resistance in this context.

METHODS AND ANALYSIS

MATAMAL is a cluster-randomised placebo-controlled trial. The trial is being conducted in 24 clusters on the Bijagós Archipelago, Guinea-Bissau, where the peak prevalence of Plasmodium falciparum (Pf) parasitaemia is approximately 15%. Clusters have been randomly allocated to receive MDA with dihydroartemisinin-piperaquine and either ivermectin or placebo. The primary objective is to determine whether the addition of ivermectin MDA is more effective than dihydroartemisinin-piperaquine MDA alone in reducing the prevalence of P. falciparum parasitaemia, measured during peak transmission season after 2 years of seasonal MDA. Secondary objectives include assessing prevalence after 1 year of MDA; malaria incidence monitored through active and passive surveillance; age-adjusted prevalence of serological markers indicating exposure to P. falciparum and anopheline mosquitoes; vector parous rates, species composition, population density and sporozoite rates; prevalence of vector pyrethroid resistance; prevalence of artemisinin resistance in P. falciparum using genomic markers; ivermectin's impact on co-endemic diseases; coverage estimates; and the safety of combined MDA.

ETHICS AND DISSEMINATION

The trial has been approved by the London School of Hygiene and Tropical Medicine's Ethics Committee (UK) (19156) and the Comite Nacional de Eticas de Saude (Guinea-Bissau) (084/CNES/INASA/2020). Results will be disseminated in peer-reviewed publications and in discussion with the Bissau-Guinean Ministry of Public Health and participating communities.

TRIAL REGISTRATION NUMBER

NCT04844905.

Effectiveness of population-wide screening and mass drug administration for leprosy control in Kiribati: the COMBINE protocol

INTRODUCTION

Progress towards leprosy elimination is threatened by increasing incidence in 'hot-spot' areas where more effective control strategies are urgently required. In these areas, active case finding and leprosy prevention limited to known contacts is insufficient for control. Population-wide active case-finding together with universal prevention through mass drug administration (MDA) has been shown to be effective in 'hot-spot' areas, but is logistically challenging and expensive. Combining leprosy screening and MDA with other population-wide screening activities such as for tuberculosis may increase programme efficiency. There has been limited evaluation of the feasibility and effectiveness of combined screening and MDA interventions. The COMBINE study aims to bridge this knowledge gap.

METHODS AND ANALYSIS

This implementation study will assess the feasibility and effectiveness of active leprosy case-finding and treatment, combined with MDA using either single-dose rifampicin or rifamycin-containing tuberculosis preventive or curative treatment, for reducing leprosy incidence in Kiribati. The leprosy programme will run over 2022-2025 in concert with population-wide tuberculosis screening-and-treatment in South Tarawa. The primary research question is to what extent the intervention reduces the annual leprosy new case detection rate (NCDR) in adults and children compared with routine screening and postexposure prophylaxis (PEP) among close contacts (baseline leprosy control activities). Comparisons will be made with (1) the preintervention NCDR separably among adults and children in South Tarawa (before-after study) and (2) the corresponding NCDRs in the rest of the country. Additionally, the postintervention prevalence of leprosy obtained from a survey of a 'hot-spot' sub-population will be compared with prevalence documented during the intervention. The intervention will be implemented in collaboration with the Kiribati National Leprosy Programme.

ETHICS AND DISSEMINATION

Approval has been obtained from the Kiribati Ministry of Health and Medical Services (MHMS), the University of Otago (H22/111) and the University of Sydney (2021/127) Human Research Ethics Committees. Findings will be shared with the MHMS, local communities and internationally through publication.

Prevalence and Determinants of Schistosoma mansoni Infection among Pre-School Age Children in Southern Ethiopia

School-based deworming program is implemented to control and eliminate Schistosoma mansoni infection in many endemic countries, including Ethiopia. However, pre-school-age children (pre-SAC) are not targeted to receive preventive chemotherapy against S. mansoni infection, partly due to a lack of information on the disease burden. We assessed the prevalence and correlates of S. mansoni infection among pre-SAC in Southern Ethiopia. A total of 1683 pre-SAC aged 4 to 7 years were screened for S. mansoni infection. A multilevel binary logistic regression was fitted to detect the significant determinants of S. mansoni infection. Adjusted odds ratios (AORs) with a 95% confidence interval (CI) were used to identify determinants of S. mansoni infection. The overall prevalence of S. mansoni infection was 14.3% (95% CI: 12.6, 16.0%). S. mansoni infection was significantly higher among 6-year-old (AOR = 2.58, 95% CI: 1.55, 4.27) and 7-year-old children (AOR = 4.63, 95% CI: 2.82, 7.62). Accompanying others to water sources sometimes (AOR = 2.60, 95% CI: 1.12, 6.01) and all the time (AOR = 5.91, 95% CI: 2.51, 13.90), and residing in less than one kilometer from the infested water source (AOR = 3.17, 95% CI: 1.47, 6.83) increased the odds of S. mansoni infection. In conclusion, the prevalence of S. mansoni infection among pre-SAC in the study area was moderate. The study highlights the urgent need to include pre-SAC aged 4 to 7 years in annual preventive chemotherapy campaigns to reduce the risk of possible sources of infection and enhance the achievement of the elimination target.

Reduced Type 2 Innate Lymphocyte Cell Frequencies in Patent Wuchereria bancrofti-Infected Individuals

Approximately 51 million individuals suffer from lymphatic filariasis (LF) caused mainly by the filarial worm Wuchereria bancrofti. Mass drug administration (MDA) programs led to a significant reduction in the number of infected individuals, but the consequences of the treatment and clearance of infection in regard to host immunity remain uncertain. Thus, this study investigates the composition of myeloid-derived suppressor cells (MDSCs), macrophage subsets and innate lymphoid cells (ILCs), in patent (circulating filarial antigen (CFA)+ microfilariae (MF)+) and latent (CFA+MF-) W. bancrofti-infected individuals, previously W. bancrofti-infected (PI) individuals cured of the infection due to MDA, uninfected controls (endemic normal (EN)) and individuals who suffer from lymphoedema (LE) from the Western Region of Ghana. Frequencies of ILC2 were significantly reduced in W. bancrofti-infected individuals, while the frequencies of MDSCs, M2 macrophages, ILC1 and ILC3 were comparable between the cohorts. Importantly, clearance of infection due to MDA restored the ILC2 frequencies, suggesting that ILC2 subsets might migrate to the site of infection within the lymphatic tissue. In general, the immune cell composition in individuals who cured the infection were comparable to the uninfected individuals, showing that filarial-driven changes of the immune responses require an active infection and are not maintained upon the clearance of the infection.

Coverage and predictors of the uptake of the mass drug administration of praziquantel chemotherapy for schistosomiasis in a selected urban setting in Zambia

The burden of schistosomiasis in Zambia has remained high over the years. The World Health Assembly recommended adequate mass drug administration coverage for schistosomiasis using Praziquantel chemotherapy for school-aged children and all at-risks adults. We aimed at investigating the coverage and the factors associated to the uptake for MDA for schistosomiasis in Ng'ombe township of Lusaka, Zambia. A cross-sectional survey was conducted in May and June 2021 via phone calls to the residents of Ng'ombe township. Commcare software was used in the conduct of the survey. Pearson's Chi-square test and multiple logistic regression were conducted using the STATA version 15.0. 769 study participants were randomly selected using systematic sampling, of which 76.3% were younger than 40 years, 64.9% were female, 64.4% were married, 56.3% had reached the secondary educational level and 51.9% were employed. Coverage for MDA for schistosomiasis in Ng'ombe township in 2018 was found to be 49.8% (95% CI: 46.2%-53.4%). Positive predictors of the MDA were prior knowledge of the occurrence of the MDA in 2018 (aOR: 2.892, p < 0.001) and believing that the provision of incentives like snacks was important during the MDA with PZQ in Ng'ombe township (aOR: 1.926, p = 0.001), whereas age (aOR:0.979, p = 0.009), marital status (aOR:0.620, p = 0.006), employment status (aOR:0.587, p = 0.001) were negative predictors of the MDA. Elimination of the burden of schistosomiasis in endemic settings needs the attainment of an optimum coverage and uptake during MDA with PZQ. Therefore, prior knowledge about an impending intervention and the provision of incentives like snacks during the intervention should be prioritized by MDA implementers, while background characteristics such as age, marital status, and employment status need to be taken into consideration when planning and promoting uptake in future MDAs.

Promoting equity through inclusive learning, planning and implementing: lessons from Nigeria's mass drug administration programme for neglected tropical diseases

BACKGROUND

An inclusive, localised approach to planning and implementing equitable mass drug administration was developed through participatory action research (PAR). This new approach aligns with principles of learning health systems (LHS). Tools were co-developed to support scaling up the new approach across two Nigerian states. Lessons are distilled here to enable learning for other programmes.

METHODS

Observations and reports by researchers (2019-2021) from 23 meetings and workshops, 8 in-depth interviews and 8 focus group discussions (FGDs) were used.

RESULTS

Nine key steps of best practice were identified to promote inclusive LHS for participatory planning and implementing: utilise participatory research methodologies to facilitate community engagement and tailor interventions; develop tools and governance structures to support learning, teamwork and sustainability; strengthen capacity for participation and collaboration with space for dialogue and shared learning; undertake participatory planning to develop action plans; advocate for implementation; monitor action plans; review and act on successes and challenges; apply community evaluation to understand challenges and enablers and disseminate policy and programme changes.

CONCLUSIONS

PAR in disease programmes can support health systems to embed cyclical and iterative learning to sustainably address localised equity challenges. However, it takes time, resources and political commitment.

Job satisfaction among community drug distributors in the Mass Drug Administration programme in Nigeria: a cross-sectional study

BACKGROUND

Despite having one of the largest human resources for health in Africa, the delivery of neglected tropical disease (NTD) health interventions in Nigeria has been hampered by health worker shortages. This study assessed factors associated with job satisfaction among community drug distributors (CDDs) supporting the Nigerian NTD programme, with the goal of identifying opportunities to improve job satisfaction in support of NTD control and elimination efforts in Nigeria.

METHODS

A health facility-based cross-sectional survey was conducted in 2019 among CDDs in two states with sharply contrasting NTD programme support, Kaduna and Ogun. A multivariate logistic regression model was used to determine the association between respondent characteristics, programme delivery modalities and job satisfaction.

RESULTS

Overall, 75.3% and 74.0% of CDDs were categorised as being satisfied with their job in Kaduna and Ogun states, respectively. The component with the highest reported satisfaction was motivation, where 98.9% and 98.6% of CDDs were satisfied, in Kaduna and Ogun, respectively. Participants were least satisfied with remuneration, communication, supplies and materials, as well as workload. Location (rural/urban) and state, years of experience, who delivers training and reimbursement of transport fare during medicine distribution were significantly associated with job satisfaction.

CONCLUSIONS

Including multiple health staff and NTD programme cadres in CDD training and providing remuneration to cover transport fares spent during MDA delivery may improve CDDs' job satisfaction both in Ogun and Kaduna states. Given these two states are at opposite ends of the programme support spectrum, such adaptative measures might help improve CDD job satisfaction in the wider Nigerian NTD programme context.

When the Neighboring Village is Not Treated: Role of Geographic Proximity to Communities Not Receiving Mass Antibiotics for Trachoma

BACKGROUND

Mass administration of azithromycin is an established strategy for decreasing the prevalence of trachoma in endemic areas. However, nearby untreated communities could serve as a reservoir that may increase the chances of chlamydia reinfection in treated communities.

METHODS

As part of a cluster-randomized trial in Ethiopia, 60 communities were randomized to receive mass azithromycin distributions and 12 communities were randomized to no treatments until after the first year. Ocular chlamydia was assessed from a random sample of children per community at baseline and month 12. Distances between treated and untreated communities were assessed from global positioning system coordinates collected for the study.

RESULTS

The pretreatment prevalence of ocular chlamydia among 0 to 9 year olds was 43% (95% confidence interval [CI], 39%-47%), which decreased to 11% (95% CI, 9%-14%) at the 12-month visit. The posttreatment prevalence of chlamydia was significantly higher in communities that were closer to an untreated community after adjusting for baseline prevalence and the number of mass treatments during the year (odds ratio, 1.12 [95% CI, 1.03-1.22] for each 1 km closer to an untreated community).

CONCLUSIONS

Mass azithromycin distributions to wide, contiguous geographic areas may reduce the likelihood of continued ocular chlamydia infection in the setting of mass antibiotic treatments.

Repeat Ivermectin Mass Drug Administrations for Malaria Control II: Protocol for a Double-blind, Cluster-Randomized, Placebo-Controlled Trial for the Integrated Control of Malaria

BACKGROUND

The gains made against malaria have stagnated since 2015, threatened further by increasing resistance to insecticides and antimalarials. Improvement in malaria control necessitates a multipronged strategy, which includes the development of novel tools. One such tool is mass drug administration (MDA) with endectocides, primarily ivermectin, which has shown promise in reducing malaria transmission through lethal and sublethal impacts on the mosquito vector.

OBJECTIVE

The primary objective of the study is to assess the impact of repeated ivermectin MDA on malaria incidence in children aged ≤10 years.

METHODS

Repeat Ivermectin MDA for Malaria Control II is a double-blind, placebo-controlled, cluster-randomized, and parallel-group trial conducted in a setting with intense seasonal malaria transmission in Southwest Burkina Faso. The study included 14 discrete villages: 7 (50%) randomized to receive standard measures (seasonal malaria chemoprevention [SMC] and bed net use for children aged 3 to 59 months) and placebo, and 7 (50%) randomized to receive standard measures and monthly ivermectin MDA at 300 μg/kg for 3 consecutive days, provided under supervision to all eligible village inhabitants, over 2 successive rainy seasons. Nonpregnant individuals >90 cm in height were eligible for ivermectin MDA, and cotreatment with ivermectin and SMC was not permitted. The primary outcome is malaria incidence in children aged ≤10 years, as assessed by active case surveillance. The secondary safety outcome of repeated ivermectin MDA was assessed through active and passive adverse event monitoring.

RESULTS

The trial intervention was conducted from July to November in 2019 and 2020, with additional sampling of humans and mosquitoes occurring through February 2022 to assess postintervention changes in transmission patterns. Additional human and entomological assessments were performed over the 2 years in a subset of households from 6 cross-sectional villages. A subset of individuals underwent additional sampling in 2020 to characterize ivermectin pharmacokinetics and pharmacodynamics. Analysis and unblinding will commence once the database has been completed, cleaned, and locked.

CONCLUSIONS

Our trial represents the first study to directly assess the impact of a novel approach for malaria control, ivermectin MDA as a mosquitocidal agent, layered into existing standard-of-care interventions. The study was designed to leverage the current SMC deployment infrastructure and will provide evidence regarding the additional benefit of ivermectin MDA in reducing malaria incidence in children.

TRIAL REGISTRATIONS

ClinicalTrials.gov NCT03967054; https://clinicaltrials.gov/ct2/show/NCT03967054 and Pan African Clinical Trials Registry PACT201907479787308; https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=8219.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/41197.

Predisposition to soil-transmitted helminth reinfection after four rounds of mass drug administration: results from a longitudinal cohort in the Geshiyaro project, a transmission elimination feasibility study in the Wolaita zone of southern Ethiopia

BACKGROUND

Current WHO strategies for reaching soil-transmitted helminths (STH) elimination as a public health problem excludes treating certain adult populations in endemic areas, creating infection reservoirs that drive 'bounce back' of STH infection to pretreatment levels post-mass drug administration (MDA). Predisposition is a widespread, but poorly understood phenomena among helminth infections where individuals are predisposed to reinfection after repeated treatments.

METHODS

This analysis uses Geshiyaro project data, an STH control programme exploring transmission interruption by community-wide MDA and enhanced water, sanitation and hygiene during 2019-2023. Parasitological survey data from longitudinal cohorts are analysed using Kendall's Tau-b rank correlation to assess the evidence for predisposition to light or heavy infection between four consecutive rounds of MDA.

RESULTS

Correlation analyses revealed the strongest evidence for predisposition to heavy or light Ascaris lumbricoides infection was between survey 1 and 2 (Tau-b 0.29; p<0.001). Overall patterns were not observed for Trichuris trichiura or hookworm infections, however, some significant and notable correlations were recorded for some stratifications and time points.

CONCLUSIONS

Evidence for predisposition in endemic settings in southern Ethiopia with low STH prevalence suggests that more targeted approaches to MDA in those predisposed to infection may be a sensible control strategy if cheap, point of care diagnostics are available.

A Post-Lockdown Assessment of Albendazole Treatment Coverage in Mass Drug Administration Campaigns Implemented Before and During COVID-19 Pandemic in Ekiti, Southwest Nigeria

Objective: This study assessed the coverage of albendazole (ALB) in mass drug administration (MDA) programs implemented before (2019) and during the (2020 and 2021) COVID-19 pandemic in Ekiti State, Nigeria. Methods: Standardized questionnaires were administered to 1,127 children across three peri-urban communities to ascertain if they received and swallowed ALB across the years. Reasons, why ALB was not received, were documented and analyzed in SPSS. 20.0. Results: In 2019, the medicine reach was between 42.2%-57.8%, however, during the pandemic, the reach significantly reduced to 12.3%-18.6%, and increased to 28.5%-35.2% in 2021 (p < 0.000). About 19.6%-27.2% of the participants have missed 1 MDA, while 26.9%-37.8% and 22.4%-32.8% have missed 2 and 3 MDAs, respectively. The majority who did not receive ALB (60.8%-75%) claimed drug distributors never came, while about 14.9%-20.3% mentioned they did not hear about MDA. However, individual compliance towards swallowing was above 94% across the study years (p < 0.00). Conclusion: These results highlight the need to explore the perceptions of those who have consistently missed MDAs, and also understand the health-system-related issues including those imposed by the pandemic affecting MDA.

Research priorities to support the development of integrated national strategies to control skin-neglected tropical diseases

BACKGROUND

Skin-presenting neglected tropical diseases (skin-NTDs) impose large burdens on affected people, families and communities. The NTD Roadmap 2021-2030 presents a strategic plan to guide collaborative, multisectoral action to overcome these burdens, defining targets to control, eliminate and/or eradicate skin-NTDs by 2030. One of its targets is for 40 countries to adopt integrated skin-NTD strategies. Despite this high-level support for integration, only four countries were implementing integrated skin-NTD strategies in 2020.

METHODS

We hosted workshops at the 2021 annual meeting of the Coalition for Operational Research on NTDs, to discuss the operationalisation of Roadmap goals into national strategies and interventions for skin-NTD control. Speakers included NTD Programme Managers from NTD-endemic countries, technical experts and researchers of different aspects of skin-NTDs.

RESULTS

Challenges include community perceptions of interventions, demonstrating the cost-effectiveness of integrated care, availability and accessibility of community-based and primary healthcare services, the quality of data on skin-NTD morbidity and changes to operational structures required for integration. Research priorities included the identification of optimal case detection platforms, evaluation of integrated care, understanding the impacts of integration on community members and community health staff and development of point-of-care diagnostics.

CONCLUSIONS

The operational research priorities are intended to support the scale-up of integrated skin-NTDs programmes.

A literature review of schistosomiasis in Ghana: a reference for bridging the research and control gap

Schistosomiasis is endemic in most sub-Saharan African countries, including Ghana, where the need for effective control involving preventive chemotherapy was indicated by the WHO. Mass drug administration commenced in 2008 and has continued since then in Ghana, but the country remains highly endemic. Here, we review the literature on schistosomiasis to identify research and knowledge gaps potentially affecting disease control. A total of 100 Ghana-related schistosomiasis literature sources were reviewed, showing that most studies were conducted on epidemiology, control of transmission and diagnosis. By contrast, many aspects of this disease remain neglected, including livestock schistosomiasis and its zoonotic potential, recent distribution of disease vectors or widely overlooked genital schistosomiasis. Stratified by region, the highest number of studies focus on Greater Accra, while studies are limited or absent for several other regions. Although this review shows apparent progress in terms of schistosomiasis research and control, a considerable amount of work remains to achieve at least a reduction in the prevalence of the disease, which affects a significant proportion of the population. National epidemiological data based on a nationwide survey, integrated control and improved monitoring and evaluation must be ensured.

Efficacy of Single-Dose Albendazole for the Treatment of Soil-Transmitted Helminthic Infections among School Children in Rwanda-A Prospective Cohort Study

Mass drug administration (MDA) of single-dose albendazole to all at-risk populations as preventive chemotherapy (deworming) is recommended by WHO to halt transmission of soil-transmitted helminth (STH) in endemic countries. We assessed the effectiveness of single-dose albendazole against STH infection in the western province of Rwanda, where STH prevalence remains high despite the implementation of preventive chemotherapy for over a decade. Two weeks before the scheduled MDA, 4998 school children (5-15 years old) were screened for STH infections (Ascaris lumbricoides, Trichuris trichiura, and hookworm), and 1526 children who tested positive for at least one type of STH parasite were enrolled and received single-dose albendazole (400 mg) through MDA. A follow-up stool exam was performed at three weeks post-treatment using Kato-Katz. Efficacy was assessed by cure rate (CR), defined as the proportion of children who became egg-free, and egg reduction rates (ERRs) at three weeks post-treatment. The CR and ERR for hookworms (CR = 96.7%, ERR = 97.4%) was above, and for Ascaris lumbricoides (CR = 95.1%, ERR = 94.6%) was borderline compared with the WHO efficacy threshold (CR and ERR ≥ 95%). However, the CR and ERR for T. trichiura (CR = 17.6% ERR = 40.3%) were below the WHO threshold for efficacy (CR and ERR ≥ 50%). Having moderate-to-heavy infection intensity and coinfection with another type of STH parasites were independent risk factors for lower CR and ERR against Trichirus trichiura (p < 0.001). Single-dose albendazole used in the MDA program is efficacious for the treatment and control for hookworms and Ascaris lumbricoides infections but not effective for Trichirus trichiura. An alternative treatment regimen is urgently needed to prevent, control, and eliminate STH as a public health problem.

The Impact of Targeted Treatment and Mass Drug Administration Delivery Strategies on the Prevalence and Intensity of Schistosomiasis in School Aged Children in Africa: A Systematic Review

Schistosomiasis is a public health problem in more than 78 countries in the world. The disease is most prevalent among children than adults due to their high exposure to infectious water sources. Various interventions such as mass drug administration (MDA), snail control, safe water provision and health education have been implemented independently or jointly to control, reduce and ultimately eliminate Schistosomiasis. This scoping review focused on studies reporting the impact of different delivery strategies of targeted treatment and MDA on the prevalence and intensity of schistosomiasis infection in school aged children in Africa. The review focused on Schistosoma haematobium and Schistosoma mansoni species. A systematic search for eligible literature from peer-reviewed articles was done from Google Scholar, Medline, PubMed and EBSCO host databases. The search yielded twenty-seven peer-reviewed articles. All articles found reported a decrease in the prevalence of schistosomiasis infection. Five studies (18.5%) reported a prevalence change below 40%, eighteen studies (66.7%) reported a change between 40% and 80%, and four studies (14.8%) reported a change above 80%. The infection intensity post-treatment was varied: twenty-four studies reported a decrease, while two studies reported an increase. The review showed that the impact of targeted treatment on the prevalence and intensity of schistosomiasis depended on the frequency at which it was offered, complementary interventions, and its uptake by the target population. Targeted treatment can significantly control the infection burden, but cannot eliminate the disease. Constant MDA programs coupled with preventative and health promotional programs are required to reach the elimination stage.

Knowledge and participation in mass drug administration against lymphatic filariasis and soil-transmitted helminth infections among the community members in Dar es Salaam, Tanzania

BACKGROUND

Although the WHO has made an effort to ensure optimal participation of the community in mass drug administration (MDA) against lymphatic filariasis (LF) and soil-transmitted helminth infections (STHIs), studies are still reporting suboptimal coverage. This study assessed the knowledge and participation of the community in MDA against LF and SHTIs in Tanzania to provide updates on its acceptability.

METHODS

A cross-sectional study was conducted in Dar es Salaam from December 2021 to February 2022 among market vendors. The information regarding demographic characteristics, knowledge and participation in MDA was collected using a questionnaire. Statistical Package for Social science version 26 was used for data analysis.

RESULTS

More than half of the participants demonstrated an adequate level of knowledge of LF and STHI, 212 (50.8%) and 267 (64%), respectively. Only 286 (68.5%) reported having heard about MDA against LF and STHIs, out of which 119 (42%) had taken the medication. Of those who disagreed to participate in MDA, 20 (50%) claimed to fear the side effects of the medication.

CONCLUSIONS

This study found that the community has average knowledge and poor participation in MDA against LF and STHIs. Community sensitization is recommended to increase the participation of the community.

Urogenital schistosomiasis outbreak in a basic school, Volta Region, Ghana: a case-control study

Introduction

schistosomiasis is a neglected parasitic infection caused by nematode worms. It affects approximately 200 million people globally. Prevalence in Ghana is 23.3%, mostly affecting school children. On November 28th 2018, the Disease Surveillance Department received reports of increase in occurrence of bloody urine among students of a basic school in the Volta Region. We investigated to identify the agent and source, to determine the magnitude, risk factors and to implement control measures.

Methods

we conducted a case-control study. A suspected case was any student of the school, who has bloody urine with or without: dysuria, itching of the skin, frequent urination or lower abdominal pain from September 2018 to November 2018. A confirmed case was one with laboratory-isolation of Schistosoma ova in appropriate urine sample. We identified cases from the school and hospital records. We collected socio-demographic, clinical and exposure data from cases and controls. Descriptive and inferential analysis were performed to estimate odds ratios at 95% confidence intervals (CI) to determine associations.

Results

of 880 students, 112 suspected cases were identified (attack rate = 12.7%). Mean age of suspected cases was 14-years (standard deviation = ±3.5). Confirmed cases were 76.8%(86/112). Males had twice odds of becoming cases (cOR = 2.3, 95% CI = 1.35-3.96). Fishing (cOR = 7.29, 95% CI = 4.08-13.04) and swimming (aOR = 44.63, 95% CI = 4.73-420.86) were factors significantly associated with infection. Students with previous history of bloody urine had greater odds of being cases (aOR = 47.9, 95% CI = 4.19-546.55).

Conclusion

Schistosoma haematobium was isolated in this outbreak. Fishing and swimming were risky water-related activities. WASH education and mass drug administration with Praziquantel were control measures.

Asymptomatic and low-density Plasmodium infections in India: an unexplored link

Presently in India, high endemic zones of malaria are shifting towards low endemic zones and in this changing scenario, tackling the asymptomatic and low-density infections (LDI) would be an important factor. Role of the asymptomatic and LDI in transmitting parasites successfully to mosquito vectors needs to be systematically investigated. We here highlight the limited work done on the burden of asymptomatic Plasmodium infections in India with an emphasis on its infectiousness, and infrastructure available for the detection of LDI. Studies reporting the threshold of gametocytes required for transmission of parasites are lacking for Indian malaria vectors. In the wake of malaria elimination target by 2030, specific point of care test is required to be developed for the detection of low density infections and/or asymptomatic patients. Also, mapping of asymptomatic malaria burden pan India and the role of LDI in vector infectivity would guide the way forward in achieving malaria elimination goal in India.

Doing 'reciprocity work': The role of fieldworkers in a mass drug administration trial in the Gambia

In their roles as nurses, data collectors, or other, fieldworkers undertake myriad tasks working intimately with and on the bodies of others - a type of work called 'body work'. This work further includes the micro-political relations shaping these interactions, and studies have shown the importance of these relationships in the success of clinical trials, particularly in the Gambia. This study seeks to expand the concept of body work to understand the roles and interactions of fieldworkers within the trial community, and the effect on a mass drug administration (MDA) clinical trial. We conducted a mixed-methods social science study alongside the MDA in 2018-2019, including in-depth interviews, focus group discussions, and semi-structured observations with the population involved (and not) in the MDA, as well as the MRC fieldworkers. We found that fieldworkers participated in what we call 'reciprocity work'. Through their regular tasks and interactions, they necessarily showed respect and established trust in a way that formed and contributed to reciprocal relationships, the results of which impacted the trial and individuals' autonomy in the decision-making process. Understanding the role of fieldworkers and their reciprocity work is a vital component in comprehending how research ethics are made and conducted in global health research.

The filarial and the antibiotics: Single or combination therapy using antibiotics for filariasis

Filarial infections caused by nematodes are one of the major neglected tropical diseases with public health concern. Although there is significant decrease in microfilariae (mf) prevalence following mass drug administration (IVM/DEC/ALB administration), this is transient, in that there is reported microfilaria repopulation 6-12 months after treatment. Wolbachia bacteria have been recommended as a novel target presenting antibiotic-based treatment for filarial disease. Potency of antibiotics against filarial diseases is undoubtful, however, the duration for treatment remains a hurdle yet to be overcome in filarial disease treatment.

The conjunctival microbiome before and after azithromycin mass drug administration for trachoma control in a cohort of Tanzanian children

Background

Trachoma, caused by ocular infection with Chlamydia trachomatis, is a neglected tropical disease that can lead to blinding pathology. Current trachoma control programmes have successfully used mass drug administration (MDA) with azithromycin to clear C. trachomatis infection and reduce transmission, alongside promoting facial cleanliness for better personal hygiene and environmental improvement. In areas of low-trachoma endemicity, the relationship between C. trachomatis infection and trachomatous disease weakens, and non-chlamydial bacteria have been associated with disease signs.

Methods

We enrolled a cohort of children aged 6-10 years from three adjacent trachoma endemic villages in Kilimanjaro and Arusha regions, Northern Tanzania. Children were divided into four clinical groups based on the presence or absence of ocular C. trachomatis infection and clinical signs of trachomatous papillary inflammation (TP). To determine the impact of treatment on the ocular microbiome in these clinical groups, we performed V4-16S rRNA sequencing of conjunctival DNA from children 3-9 months pre-MDA (n = 269) and 3 months post-MDA (n = 79).

Results

Chlamydia trachomatis PCR-negative, no TP children had the highest pre-MDA ocular microbiome alpha diversity, which was reduced in C. trachomatis infected children and further decreased in those with TP. Pre-MDA, Haemophilus and Staphylococcus were associated with C. trachomatis infection with and without concurrent TP, while Helicobacter was increased in those with TP in the absence of current C. trachomatis infection. Post-MDA, none of the studied children had ocular C. trachomatis infection or TP. MDA increased ocular microbiome diversity in all clinical groups, the change was of greater magnitude in children with pre-MDA TP. MDA effectively reduced the prevalence of disease causing pathogenic non-chlamydial bacteria, and promoted restoration of a normal, healthy conjunctival microbiome.

Conclusion

We identified Helicobacter as a non-chlamydial bacterium associated with the clinical signs of TP. Further investigation to determine its relevance in other low-endemicity communities is required. MDA was shown to be effective at clearing C. trachomatis infection and other non-chlamydial ocular pathogens, without any detrimental longitudinal effects on the ocular microbiome. These findings suggest that azithromycin MDA may be valuable in trachoma control even in populations where the relationship between clinical signs of trachoma and the prevalence of current ocular C. trachomatis infection has become dissociated.

Factors Associated with the Acceptability of Mass Drug Administration for Filariasis: A Systematic Review

Mass drug administration (MDA) has been implemented as a tool to eliminate lymphatic filariasis. Acceptability among susceptible populations is crucial to achieving MDA effective coverage. This systematic review aims to present and systematically determine the factors associated with the acceptability of MDA. Articles related to factors associated with acceptability were collected electronically from three different databases (Scopus, Web of Science, and PubMed). Four pairs of independent reviewers screened the titles and abstracts of the collected data, stored in EndnoteX7, against the inclusion criteria. Afterwards, the included articles have been critically appraised to assess the quality of the studies using the Mixed Method Appraisal Tool (MMAT). Of the 68 articles identified, 11 were included in the final review. Knowledge, awareness, attitude and perceptions, communications, delivery and accessibility of MDA, gender, and age are the factors associated with MDA acceptability. Community acceptance remains a challenge in the implementation of MDA. To expand MDA coverage in all endemic countries, there is a strong need to address the factors influencing community acceptance of MDA.

Prevalence and factors associated with persistent transmission of Schistosoma haematobium among primary school children after five rounds of mass drug administration using praziquantel: A cross sectional study in Mkuranga district, Tanzania

Despite a human schistosomiasis control programme through praziquantel mass drug administration (MDA) between 2011 and 2015,there was still persistent transmission among primary schoolchildren (PSC) in Mkuranga district, Tanzania. Our cross-sectional study was conducted among 396 PSC who provided urine for diagnosis of Schistosoma haematobium infection. Observations were conducted to determine PSC water contact activities. Logistic regression was used to test association between dependent and independent variables. We found MDA uptake among PSC as 72.5%, and the prevalence of Schistosoma haematobium infection 5.8%. The risk of infection increased among PSC engaged in fetching water and adjusted odds ratio (AOR) for swimming, bathing, fishing, crossing ponds and paddy fields were 0.123, 0.166, 0.232, 0.202 and 0.093 respectively. Thus we conclude that multiple water contact activities and low participation in MDA is responsible for persistent Schistosoma transmission.

Coverage and compliance of mass drug administration in lymphatic filariasis amidst the COVID-19 pandemic: A community based epidemiological study

Background

Despite the target of elimination of lymphatic filariasis by 2015, a few districts of West Bengal including Bankura district failed to achieve it. Under-coverage and unsupervised consumption of medicines during mass drug administration (MDA) campaign were implicated for the failure. Thereby, directly observed therapy (DOT) and mop up by repeated home visits for MDA were adopted.

Objective

The objective of this study is to assess the coverage of anti-filarial medicines distribution and rate of consumption as well as to find out the causes of nonconsumption.

Materials and Methods

A cross-sectional survey was conducted in three sub-centers each of three blocks and three wards of Bankura municipality of Bankura district, WB, India, selected through the stratified random sampling method. Information was collected interviewing inhabitants of the house hold selected through the systematic random sampling technique.

Results

Overall, appropriate medicine distribution was 82.9% with 95.3% of correct consumption of both medicines under supervision. 91.87% of the respondents were aware about Lymphatic filariasis (LF) of which 89.95% reported swelling of leg/foot/hand, 9.57% as pain, 6.22% fever, and 1.44% reported swelling of testis as symptoms of LF. Altogether 10.6% individual, who consumed any medicine (527), reported AEs, out of that 66.1%, 19.6%, and 14.3% complained of dizziness/headache, nausea/vomiting, and drowsiness, respectively, and 28.6% of them sought consultation with health workers.

Conclusion

Substantial supervised consumption in the form DOT in this round too leads to the fact that the effective coverage of MDA has reached the target. It seemed that some segment of the beneficiary is remaining as persistent noncomplaints. Mass mobilization for motivating this persistent defaulter section is the need of the hour.

Mass drug administration for lymphatic filariasis elimination amidst COVID-19 pandemic in Odisha, India: A step towards achieving SDG-3

Sustainable Development Goal-3 (SDG) aims to eliminate lymphatic filariasis by 2030 through >65% coverage and compliance of mass drug administration (MDA), the preventive chemotherapy strategy of delivering anthelminthic drugs. However, the ongoing COVID-19 pandemic has disrupted such programmes, yet MDA was administered during February 2021 in Odisha, India. We aimed to assess the coverage and compliance of the present round of MDA amidst the pandemic and explore factors for non-compliance in Cuttack district of Odisha, a filariasis endemic area. Community-based participants enrolled through multistage stratified sampling were administered a semi-structured questionnaire following COVID-19 protocols. The coverage of MDA was 93.2% whereas consumption was 73.7%. Participants reported that healthcare workers were motivated and satisfactorily explained the benefits of MDA but still fear of side-effects was the major cause of non-compliance. Nonetheless, this recent round of MDA was effective, despite challenges posed by the ongoing pandemic.

Safety and Tolerability of Ivermectin and Albendazole Mass Drug Administration in Lymphatic Filariasis Endemic Communities of Tanzania: A Cohort Event Monitoring Study

Ivermectin and albendazole (IA) combination preventive chemotherapy to all at-risk populations is deployed to eliminate lymphatic filariasis. Although safety monitoring is imperative, data from Sub-Saharan Africa is scarce. We conducted a large-scale active safety surveillance of adverse events (AEs) following IA mass drug administration (MDA) to identify the type, incidence, and associated risk factors in Tanzania. After recording sociodemographic, clinical, and medical histories, 9640 eligible residents received single-dose IA combination preventive chemotherapy. Treatment-associated AEs were actively monitored through house-to-house visits on day 1, day 2, and day 7 of MDA. Events reported before and after MDA were cross-checked and verified to identify MDA-associated AEs. 9288 participants (96.3%) completed the seven-day safety follow-up, of whom 442 reported 719 MDA-associated AEs. The incidence of experiencing one or more type of MDA-associated AE was 4.8% (95% CI = 4.3−5.2%); this being significantly higher among those with Pre-MDA clinical events than those without (8.5% versus 4.1%, p < 0.001). AEs were mild (83.8%), moderate (15.9%), and severe (0.3%), and most resolved within 72 h. The incidence of experiencing one, two, ≥ three types of AEs were 2.8%, 1.3%, and 0.6%, respectively. The most common AEs were headache (1.23%), drowsiness (1.15%), fever (1.12%), and dizziness (1.06%). A chronic illness, or clinical manifestation of lymphatic filariasis, or being female or pre-existing clinical symptoms were independent significant predictors of AEs. IA combination preventive chemotherapy is safe and tolerable, and associated AEs are mild-to-moderate and transient, with few severe AEs. Safety monitoring during MDA campaigns in individuals with underlying clinical conditions is recommended for timely detection and management of AEs.

Safety of mass drug coadministration with ivermectin, diethylcarbamazine, albendazole, and azithromycin for the integrated treatment of neglected tropical diseases: a cluster randomized community trial

Introduction

Neglected tropical diseases control programmes run separately. For settings with more than one endemic disease, combined mass drug administration (MDA) has potential practical advantages compared with separate programmes but needs confirmation of safety. We assessed the safety of combined MDA for multiple neglected tropical diseases using ivermectin, diethylcarbamazine, albendazole (IDA) and azithromycin (AZI).

Methods

We conducted an open-label, cluster-randomized trial involving individuals living in 34 wards (smaller administrative division) in two study sites, Namatanai District and Lihir Island, Papua New Guinea. We randomly assigned wards to the combined treatment arm (which received a single dose of the triple combination IDA and a single dose of AZI at the same visit) or the control arm (which received IDA separately followed by AZI separately one week after). All participants underwent safety assessments one day after drug administration. Methodology for collecting the adverse events (AEs) was a general question (in Namatanai) and individual questions about specific AEs (in Lihir). The primary endpoint was the prevalence of AEs. Safety of combined treatment was taken to be non-inferior to that of IDA if the upper limit of the two-sided CI for the difference in rates was equal or lower than 5%.

Findings

The study enrolled 15,656 participants. Of those enrolled, 7,281 (46.3%) received the combined regimen and 8,375 (53.3%) received standard treatment with IDA for lymphatic filariasis between Nov 1, 2018, and Apr 15, 2019. Of the individuals in the control group, 4,228 (50.5%) attended a second visit one week apart to receive AZI for yaws. In Namatanai, the proportion of AEs was similar in the combined group (0.8%) compared to the IDA group (1.3%, difference 0.5% [95CI -2.5% to 1.4%]) or the AZI group (3.6%, d -2.8% [95CI -8.6% to 2.8%]). In Lihir, the proportion of AEs was higher in the combined group (23.0%) compared to the IDA group (12.2%, d 10.8% [95% CI 1.5% to 20.2%]) or the AZI group (11.1%, d 11.9% [95% CI 2.7% to 21.1%]).We observed 21 (0.3%) grade-2 AEs in the combined treatment group, 33 (0.4%) in the IDA separately group, and 18 (0.2%) in the AZI separately group. No participants required treatment for any AE. We observed no deaths, serious AEs, or AEs of special interest.

Interpretation

In the largest trial so far involving coadministration of regimens based on IDA and AZI, the combination was safe and feasible in a population of more than 15,000 people. Combined MDA based on these two regimens opens up new potential for the control of neglected tropical diseases in the Western Pacific region.

Incorporating qualitative research methods into the monitoring and evaluation of neglected tropical disease programmes: a scoping literature review

This publication addresses the limited use of qualitative methods in neglected tropical disease (NTD) programmes. It describes a scoping literature review conducted to inform the development of a guide to inform the use of rapid qualitative assessments to strengthen NTD mass drug administration (MDA) programmes. The review assessed how qualitative methods are currently used by NTD programmes and identified qualitative approaches from other health and development programmes with the potential to strengthen the design of MDA interventions. Systematic review articles were reviewed and searched using key terms conducted on Google Scholar and PubMed. Results show that methods used by NTD programmes rely heavily on focus group discussions and in-depth interviews, often with time-consuming analysis and limited information on how results are applied. Results from other fields offered insight into a wider range of methods, including participatory approaches, and on how to increase programmatic uptake of findings. Recommendations on how to apply these findings to NTD control are made. The topic of human resources for qualitative investigations is explored and a guide to improve MDAs using qualitative methods is introduced. This guide has direct applicability across the spectrum of NTDs as well as other public health programmes.

Transmission Dynamics of Schistosoma haematobium among School-Aged Children: A Cohort Study on Prevalence, Reinfection and Incidence after Mass Drug Administration in the White Nile State of Sudan

The reinfection rate of schistosomiasis after mass drug administration (MDA) has not been documented in Sudan. We aimed to explore the transmission dynamics of urogenital schistosomiasis after MDA, targeting school-aged children in the White Nile State of Sudan, assessing the prevalence, reinfection rate, and incidence. A single dose of praziquantel (40 mg/kg) was administered to 1951 students in five primary schools from January to February 2018 immediately after a baseline survey, and follow-up surveys were performed at 2 weeks and 6 months after treatment. We examined Schistosoma haematobium eggs by centrifugation methods. The overall reinfection rate at 6 months after treatment was 9.8% (95% confidence interval: 0.5-17.4%). By school, the reinfection rate was highest in the Al Hidaib school, whose prevalence was highest at baseline. The reinfection rate was significantly higher in high-infection areas than low-infection areas (p = 0.02). Of the prevalence at 6 months in high-infection areas, 41% of cases were due to reinfection. MDA interventions are decided upon and undertaken at the district level. A more targeted treatment strategy should be developed with a particular focus on tracking high-risk groups, even within a school or a community.

Soil-transmitted helminth infections after mass drug administration for lymphatic filariasis in rural southern India

OBJECTIVES

Targeted deworming is the current strategy for control of morbidity associated with soil-transmitted helminths (STH) among at-risk populations: preschool-aged children, school-aged children and women of childbearing age. We report the prevalence and intensity of STH in a district after lymphatic filariasis (LF) mass drug administration (MDA) in southern India where albendazole was co-administered from 2001.

METHODS

Children aged 2 to 15 years and adults (defined as ≥15 years) in a rural administrative block of Tamil Nadu were recruited using a probability proportional to size method. Stool samples were screened and eggs per gram (EPG) determined by Kato-Katz method. Multilevel logistic regression (MLR) and multilevel negative binomial regression (MNBR) analyses were used to identify factors associated with infection and intensity, respectively.

RESULTS

Of 862 participants who provided samples, 60 (7.0%; 95% confidence interval (CI): 5.3-8.7) were positive for STH with a predominance of hookworm infections (n = 57, 6.6%; 95% CI: 5.0-8.3). Increasing age (odds ratio (OR): 1.09; 95% CI: 1.04-1.15) and regular usage of the toilet (OR: 0.32; 95% CI: 0.12-0.88) were independently associated with hookworm infection and age was significantly associated with increasing intensity of hookworm infection (infection intensity ratio (IIR): 1.28; 95% CI: 1.19-1.37). A brief review of STH prevalence in endemic settings before and after the stoppage of LF MDA indicated that, in most settings, a substantial reduction in STH prevalence is seen.

CONCLUSION

Community-wide MDA in all age groups in these post-LF MDA districts with low prevalence and light intensity infections could result in transmission interruption of STH.

Effectiveness of azithromycin mass drug administration on trachoma: a systematic review

BACKGROUNDS

Azithromycin mass drug administration (MDA) is a key part of the strategy for controlling trachoma. This systematic review aimed to comprehensively summarize the present studies of azithromycin MDA on trachoma; provide an overview of the impact of azithromycin MDA on trachoma in different districts; and explore the possible methods to enhance the effectiveness of azithromycin MDA in hyperendemic districts.

METHODS

PubMed, Embase, the Cochrane Central Register of Controlled Trials, Web of Science, and ClinicalTrials.gov were searched up to February 2021 with no language restriction. Studies reporting the effect of azithromycin MDA on trachoma were included. Mathematical modeling studies, animal studies, case reports, and reviews were excluded. The trachomatous inflammation-follicular (TF) <5.0% was used to judge the effect of azithromycin MDA on eliminating trachoma as a public health problem. Two researchers independently conducted the selection process and risk of bias assessment.

RESULTS

A total of 1543 studies were screened, of which 67 studies including 13 cluster-randomized controlled trials and 54 non-randomized studies were included. The effect of azithromycin MDA on trachoma was closely related to the baseline prevalence in districts. For the districts with baseline prevalence between 5.0% and 9.9%, a single round of MDA achieved a TF <5.0%. For the districts with baseline between 10.0% and 29.9%, annual MDA for 3 to 5 years reduced TF <5.0%. However, for the districts with high level of baseline prevalence (TF >30.0%), especially with baseline TF >50.0%, annual MDA was unable to achieve the TF <5.0% even after 5 to 7 years of treatment. Quarterly MDA is more effective in controlling trachoma in these hyperendemic districts.

CONCLUSIONS

Azithromycin MDA for controlling trachoma depends on the baseline prevalence. The recommendation by the World Health Organization that annual MDA for 3 to 5 years in the districts with TF baseline >10.0% is not appropriate for all eligible districts.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Targeted Antibiotics for Trachoma: A Cluster-Randomized Trial

BACKGROUND

Current guidelines recommend community-wide mass azithromycin for trachoma, but a targeted treatment strategy could reduce the volume of antibiotics required.

METHODS

In total, 48 Ethiopian communities were randomized to mass, targeted, or delayed azithromycin distributions. In the targeted arm, only children aged 6 months to 5 years with evidence of ocular chlamydia received azithromycin, distributed thrice over the following year. The primary outcome was ocular chlamydia at months 12 and 24, comparing the targeted and delayed arms (0-5 year-olds, superiority analysis) and the targeted and mass azithromycin arms (8-12 year-olds, noninferiority analysis, 10% noninferiority margin).

RESULTS

At baseline, the mean prevalence of ocular chlamydia in the 3 arms ranged from 7% to 9% among 0-5 year-olds and from 3% to 9% among 8-12 year-olds. Averaged across months 12-24, the mean prevalence of ocular chlamydia among 0-5 year-olds was 16.7% (95% confidence interval [CI]: 9.0%-24.4%) in the targeted arm and 22.3% (95% CI: 11.1%-33.6%) in the delayed arm (P = .61). The final mean prevalence of ocular chlamydia among 8-12 year-olds was 13.5% (95% CI: 7.9%-19.1%) in the targeted arm and 5.5% (95% CI: 0.3%-10.7%) in the mass treatment arm (adjusted risk difference 8.5 percentage points [pp] higher in the targeted arm, 95% CI: 0.9 pp-16.1 pp higher).

CONCLUSIONS

Antibiotic treatments targeted to infected preschool children did not result in significantly less ocular chlamydia infections compared with untreated communities and did not meet noninferiority criteria relative to mass azithromycin distributions. Targeted approaches may require treatment of a broader segment of the population in areas with hyperendemic trachoma.

Dihydroartemisinin-piperaquine chemoprevention and malaria incidence after severe flooding: evaluation of a pragmatic intervention in rural Uganda

BACKGROUND

Malaria epidemics are a well-described phenomenon after extreme precipitation and flooding, which account for nearly half of global disasters over the past two decades. Yet few studies have examined mitigation measures to prevent post-flood malaria epidemics.

METHODS

We conducted an evaluation of a malaria chemoprevention program implemented in response to severe flooding in western Uganda. Children ≤12 years of age from one village were eligible to receive 3 monthly rounds of dihydroartemisinin-piperaquine (DP). Two neighboring villages served as controls. Malaria cases were defined as individuals with a positive rapid diagnostic test result as recorded in health center registers. We performed a difference-in-differences analysis to estimate changes in the incidence and test positivity of malaria between intervention and control villages.

RESULTS

A total of 554 children received at least one round of chemoprevention with 75% participating in at least two rounds. Compared to control villages, we estimated a 53.4% reduction (aRR 0.47, 95% CI 0.34 - 0.62, p<.01) in malaria incidence and a 30% decrease in the test positivity rate (aRR=0.70, CI 0.50 - 0.97, p=0.03) in the intervention village in the six months post-intervention. The impact was greatest among children receiving the intervention, but decreased incidence was also observed in older children and adults (aRR=0.57, CI 0.38-0.84, p<.01).

CONCLUSIONS

Three rounds of chemoprevention with DP delivered under pragmatic conditions reduced the incidence of malaria after severe flooding in western Uganda. These findings provide a proof-of-concept for the use of malaria chemoprevention to reduce excess disease burden associated with severe flooding.

Strongyloides stercoralis seropositivity is not associated with increased symptoms in a remote Aboriginal community

BACKGROUND

Strongyloides stercoralis is a soil-transmitted helminth, endemic in remote Aboriginal and Torres Strait Islander communities in northern Australia with estimates of prevalences up to 60%. Hyperinfection in the setting of immunosuppression is a rare, but well recognised cause of significant morbidity and mortality. However, the morbidity associated with chronic uncomplicated infection is less well characterised.

AIMS

To measure the prevalence of symptoms potentially attributable to S. stercoralis infection and their association with seropositivity.

METHODS

This retrospective matched case-control study reviewed records of primary healthcare presentations for symptoms in the 12 months before and after an ivermectin mass drug administration (MDA) in a remote Aboriginal community.

RESULTS

One hundred and seventy-five S. stercoralis seropositive cases were matched with 175 seronegative controls. The most frequently reported symptom overall in the 12 months prior to the MDA was cough followed by abdominal pain, weight loss/malnutrition, diarrhoea and pruritis. Seropositive cases were not more likely than matched controls to have symptoms typically attributed to strongyloidiasis. In the seropositive cohort, we found no difference in symptoms in the 12 months before and after an ivermectin MDA despite a reduction in seroprevalence.

CONCLUSION

We found no evidence to suggest that S. stercoralis seropositivity was associated with increased symptoms when compared to matched seronegative controls. Treatment with ivermectin did not reduce symptoms in seropositive cases. Without evidence to support that population-based screening or treatment programmes reduce symptoms, the emphasis must remain on identifying and managing those few individuals with immunosuppression that predisposes them to potentially life-threatening hyperinfection.