scholarly journals Individual adherence to mass drug administration in neglected tropical disease control: A probability model conditional on past behaviour

2021 ◽  
Vol 15 (1) ◽  
pp. e0009112
Author(s):  
Robert J. Hardwick ◽  
James E. Truscott ◽  
William E. Oswald ◽  
Marleen Werkman ◽  
Katherine E. Halliday ◽  
...  
Keyword(s):  
Drug Administration ◽  
Mass Drug Administration ◽  
Neglected Tropical Diseases ◽  
Probability Model ◽  
Randomised Trial ◽  
Age Groups ◽  
Substantial Reduction ◽  
Probability Models ◽  
Considerable Impact ◽  
The Impact

We present a general framework which describes the systematic (binary) scenario of individuals either taking treatment or not for any reason, over the course of mass drug administration (MDA)—which we refer to as ‘adherence’ and ‘non-adherence’. The probability models developed can be informed by observed adherence behaviour as well as employed to explore how different patterns influence the impact of MDA programmes, by the use of mathematical models of transmission and control. We demonstrate the interpretative value of the developed probability model employing a dataset collected in the TUMIKIA project, a randomised trial of deworming strategies to control soil-transmitted helminths (STH) by MDA conducted in coastal Kenya. We stratify our analysis by age and sex, although the framework which we introduce here may be readily adapted to accommodate other stratifications. Our findings include the detection of specific patterns of non-adherence in all age groups to varying extents. This is particularly apparent in men of ages 30+. We then demonstrate the use of the probability model in stochastic individual-based simulations by running two example forecasts for the elimination of STH transmission employing MDA within the TUMIKIA trial setting with different adherence patterns. This suggested a substantial reduction in the probability of elimination (between 23-43%) when comparing observed adherence patterns with an assumption of independence, with important implications for programmes. The results here demonstrate the considerable impact and utility of considering non-adherence on the success of MDA programmes to control neglected tropical diseases (NTDs).

scholarly journals Dynamics of individual adherence to mass drug administration in a conditional probability model

2020 ◽  
Author(s):  
Robert J. Hardwick ◽  
James E. Truscott ◽  
William E. Oswald ◽  
Marleen Werkman ◽  
Katherine E. Halliday ◽  
...  
Keyword(s):  
Drug Administration ◽  
Mass Drug Administration ◽  
Real World ◽  
Disease Transmission ◽  
Neglected Tropical Diseases ◽  
Probability Model ◽  
Control Measures ◽  
Real World Data ◽  
Adherence Behaviour ◽  
The Impact

AbstractWe present a comprehensive framework which describes the systematic (binary) choice of individuals to either take treatment, or not for any reason, over the course of multiple rounds of mass drug administration (MDA) — which we here here refer to as ‘adherence’ and ‘non-adherence’. This methodology can be fitted to (or informed by) program data as well as manipulated to reproduce the same adherence behaviours of past analyses, and can go beyond past analyses to describe new behaviours that have yet to be considered in the literature. Our model also has a straightforward interpretation and implementation in simulations of mass drug trials for disease transmission studies and forecasts for control through MDA. We demonstrate how our analysis may be implemented to statistically infer adherence behaviour from a dataset by applying our approach to the recent adherence data from the TUMIKIA project, a recent trial of deworming strategies in Kenya. We stratify our analysis according to age and sex, though the framework which we introduce here may be readily adapted to accomodate other categories. Our findings include the detection of past behaviour dependent non-adherence in all age groups to varying degrees of severity and particularly strong non-adherent behaviour of men of ages 30+. We then demonstrate the use of our model in stochastic individual-based simulations by running two example forecasts for elimination in TUMIKIA with the learned adherence behaviour implemented. Our results demonstrate the impact and utility of including non-adherence from real world datasets in simulations.Author summaryMass drug administration (MDA) is an important tool in prevention of morbidity from various neglected tropical diseases (NTDs). Due to a variety of social and medical reasons, many people will either not be offered or refuse such treatment, and if this behaviour is recurring then control measures may face a challenge to achieving their stated goals. Learning the patterns of individual adherence or non-adherence to MDA control measures for NTDs from real world data followed by their implementation in simulated scenarios is a relatively recent development in the study of NTDs. Past analyses assessing individual adherence have informed the approach we take in this work. However, we have sought to provide a framework which encapsulates as many types of adherence behaviour as possible so that their implementation in modern simulations is streamlined effectively. Our example application to the TUMIKIA data highlights the importance of such a general framework as we find past behaviour dependence that may have been missed by other methods.

scholarly journals Mass Drug Administration Interruption by COVID-19 reportedly increases lymphatic filarial attacks, pains, and perceived increased lymphatic filarial infection transmission in rural Ghana

2021 ◽  
Author(s):  
Alexander Kwarteng ◽  
Yarhands Dissou Arthur ◽  
Samuel Opoku Asiedu ◽  
John Kanyiri Yamba ◽  
Emmanuel Kobla Amewu ◽  
...  
Keyword(s):  
Drug Administration ◽  
Mass Drug Administration ◽  
Neglected Tropical Diseases ◽  
Cross Sectional Study ◽  
P Value ◽  
Chi Square ◽  
Statistical Tool ◽  
Cross Sectional ◽  
Rural Ghana ◽  
The Impact

Abstract BackgroundLike all other diseases, the advent of the COVID-19 pandemic has been implicated to impact the elimination schedule and control of neglected tropical diseases such as human lymphatic filarial (LF) infections in endemic countries. However, it is unclear the extent to which delays in mass drug administration has affected people living with chronic lymphatic filarial pathology in rural Ghana as a result of the COVID-19 pandemic, and thus remain to be investigated. MethodTo address this, a cross-sectional study where 133 LF participants from 8 LF-endemic communities in the Ahanta West District of Ghana were recruited to assess the impact of MDA interruptions as a result of COVID-19 among individuals presenting with the filarial pathology. Here, the chi-square test of independence was used as a statistical tool to assess the dependency: 1) between MDA interruption and filarial attacks 2) between MDA interruption and filarial-related pains 3) between MDA interruption and a perceived increase in LF transmission.ResultsStudy participants were asked whether the MDA interruption has affected them in any way. Here, 81% of the patients indicated yes, it had. In addition, we sought to investigate whether MDA interruption has resulted in increased filarial attacks and pains. At this, 68% of the study respondents reported an increase in filarial attacks. Similarly, 65% reported an increase in filarial-related pains. The study further reported that filarial attacks (B=14.997, df=1, p-value <0.001) and pains (a=11.773, df=1, p-value <0.001) are dependent on MDA interruption. Next, we further report that the perceived increase in LF transmission is dependent on MDA interruption (c=9.415, df=1, p-value=0.002). ConclusionIn this study, MDA interruption is reported to increase filarial attacks, filarial-related pains, and a perceived LF transmission increase in the study communities. This study's findings are important and urgent, suggesting that sustained MDA interruption in LF-endemic communities could further worsen LF patients' plight as filarial attacks, pains, and transmission could increase. Therefore, the need to immediately identify alternative modes of MDA distribution in LF-endemic areas where mass treatment has been halted in the wake of COVID-19 to prevent an unwarranted surge in LF attacks, pains, and transmission.

scholarly journals Modelling the ability of mass drug administration to interrupt soil-transmitted helminth transmission: Community-based deworming in Kenya as a case study

2021 ◽  
Vol 15 (8) ◽  
pp. e0009625
Author(s):  
Nyuk Sian Chong ◽  
Stacey R. Smith? ◽  
Marleen Werkman ◽  
Roy M. Anderson
Keyword(s):  
Drug Administration ◽  
Mass Drug Administration ◽  
Neglected Tropical Diseases ◽  
Initial Conditions ◽  
Drug Efficacy ◽  
World Health ◽  
High Prevalence ◽  
Lower Drug ◽  
Health Organization ◽  
The Impact

The World Health Organization has recommended the application of mass drug administration (MDA) in treating high prevalence neglected tropical diseases such as soil-transmitted helminths (STHs), schistosomiasis, lymphatic filariasis, onchocerciasis and trachoma. MDA—which is safe, effective and inexpensive—has been widely applied to eliminate or interrupt the transmission of STHs in particular and has been offered to people in endemic regions without requiring individual diagnosis. We propose two mathematical models to investigate the impact of MDA on the mean number of worms in both treated and untreated human subpopulations. By varying the efficay of drugs, initial conditions of the models, coverage and frequency of MDA (both annual and biannual), we examine the dynamic behaviour of both models and the possibility of interruption of transmission. Both models predict that the interruption of transmission is possible if the drug efficacy is sufficiently high, but STH infection remains endemic if the drug efficacy is sufficiently low. In between these two critical values, the two models produce different predictions. By applying an additional round of biannual and annual MDA, we find that interruption of transmission is likely to happen in both cases with lower drug efficacy. In order to interrupt the transmission of STH or eliminate the infection efficiently and effectively, it is crucial to identify the appropriate efficacy of drug, coverage, frequency, timing and number of rounds of MDA.

scholarly journals Does mass drug administration affect Schistosoma mansoni infection trends in West Dembia district, Northwest Ethiopia?

2020 ◽  
Vol 14 (06.1) ◽  
pp. 72S-77S
Author(s):  
Ayalew Jejaw Zeleke ◽  
Ayenew Addisu ◽  
Abebe Genetu Bayih ◽  
Hannock Tweya ◽  
Collins Timire ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Drug Administration ◽  
Mass Drug Administration ◽  
Neglected Tropical Diseases ◽  
Intestinal Parasites ◽  
Age Groups ◽  
Northwest Ethiopia ◽  
District Health ◽  
Chi Square ◽  
School Aged Children

Introduction: Schistosomiasis is one of the Neglected Tropical Diseases in Ethiopia. Since 2015, yearly school-based mass drug administration (MDA) using praziquantel has become the major control strategy. This study aimed to assess trends of Schistosoma mansoni infection in a high-endemic area in Northwest Ethiopia. Methodology: Data were extracted from routine laboratory logbooks at two health centers in West Dembia district, Amhara region, for the period 2013-2018. Wet-mount direct microscopy was used to diagnose intestinal parasites. Chi-square test was used to compare proportions of S. mansoni-positive results before and after the start of MDA with praziquantel, across sex, age groups, and seasons. Results: Data of 8002 stool tests was extracted. The proportion of S. mansoni progressively decreased from 9.6% in 2013 to 4.1% in 2018 in the overall patient population and from 20.3% in 2013 to 8.8% in 2018 in school-aged children. However, a declining trend of S. mansoni was observed before the launch of MDA and remained constant after the start of the MDA. The positivity rate was significantly higher in males and in the 5-14 years age group. S .mansoni infection in school aged children showed significant seasonal variation. Conclusions: The declined trend of S. mansoni positivity rate is encouraging and may be related to the existence of intervention packages. Although the timing of MDA was related with low positivity rate of S. mansoni infection, it has not resulted in the expected beneficial effect. Therefore, the district health office should work on both MDA and other interventions.

scholarly journals Longitudinal changes in the prevalence and intensity of soil-transmitted helminth infection following expanded community-wide mass drug administration in the delta region of Myanmar

2018 ◽  
Author(s):  
Julia C Dunn ◽  
Alison A Bettis ◽  
Nay Yee Wyine ◽  
Aye Moe Moe Lwin ◽  
Aung Tun ◽  
...  
Keyword(s):  
Drug Administration ◽  
Mass Drug Administration ◽  
Neglected Tropical Diseases ◽  
Age Groups ◽  
World Health ◽  
Delta Region ◽  
Social Settings ◽  
Before And After ◽  
Target Disease ◽  
Health Organization

AbstractMass drug administration (MDA), targeted at school-aged children is the method recommended by the World Health Organization for the control of morbidity induced by soil-transmitted helminth (STH) infection in endemic countries. However, MDA does not prevent reinfection between treatment rounds. In countries with endemic infection, such as Myanmar, the MDA coverage, who is targeted, and rates of reinfection in given environmental and social settings will determine how effective mass drug treatment is in suppressing transmission in the long-term. In this paper, data from an epidemiology study on STH, conducted between June 2015 and June 2016 in the delta region of Myanmar, are analysed to determine the risks of STH infection in the whole community over a year which included two MDA rounds. Risk ratios (RRs) for the four-month reinfection period were below one, whereas RRs for the six-month reinfection period were above one, indicating that more people were infected after six months of exposure post-MDA. Evidence of predisposition, as measured by the Kendall Tau-b statistic, was found for all STH species and across all age groups. This study demonstrates that a six-month gap between MDA in these communities is enough time for STH infection to return to pre-MDA levels and that the same individuals are being consistently infected between MDA rounds.Author summaryMass drug administration (MDA), treating either whole communities or targeted groups without a prior diagnosis, is used as a control strategy for many neglected tropical diseases, including soil-transmitted helminth (STH) infection. MDA takes place at set intervals, aiming to reduce morbidity caused by the target disease and potentially interrupt transmission. In this study we measure STH infection in two villages in the delta region of Myanmar over the course of a year, both before and after MDA rounds, to quantify the effect of treatment on infection and to identify groups with persistent infections. We found that whilst overall prevalence of STH infection decreased over the year, intensity of infection, measured by eggs per gram of faeces, did not significantly decrease. We also found evidence to suggest that particular people are predisposed to STH infection. This is possibly due to non-compliance to MDA, or behavioural and social factors. The findings presented here will provide evidence to support continuing Myanmar’s MDA programme for STH control and using accurate diagnostics to identify and target “predisposed” people for sustained treatment.

scholarly journals Feasibility of onchocerciasis elimination using a “test-and-not-treat” strategy in Loa loa co-endemic areas

2020 ◽  
Author(s):  
David J Blok ◽  
Joseph Kamgno ◽  
Sebastien D Pion ◽  
Hugues C Nana-Djeunga ◽  
Yannick Niamsi-Emalio ◽  
...  
Keyword(s):  
Adverse Events ◽  
Drug Administration ◽  
Mass Drug Administration ◽  
Treatment Duration ◽  
Loa Loa ◽  
Serious Adverse Events ◽  
Endemic Areas ◽  
The Individual ◽  
The Impact ◽  
Main Strategy

Abstract Background Mass drug administration (MDA) with ivermectin is the main strategy for onchocerciasis elimination. Ivermectin is generally safe but associated with serious adverse events in individuals with high Loa loa microfilarial densities (MFD). Therefore, ivermectin MDA is not recommended in areas where onchocerciasis is hypo-endemic and L. loa is co-endemic. To eliminate onchocerciasis in those areas, a test-and-not-treat (TaNT) strategy has been proposed. We investigated whether onchocerciasis elimination can be achieved using TaNT and the required duration. Methods We used the individual-based model ONCHOSIM to predict the impact of TaNT on onchocerciasis microfilarial (mf) prevalence. We simulated pre-control mf prevalence levels from 2-40%. The impact of TaNT was simulated under varying levels of participation, systematic non-participation and exclusion from ivermectin due to high L. loa MFD. For each scenario, we assessed the time to elimination, defined as bringing onchocerciasis mf prevalence below 1.4%. Results In areas with 30-40% pre-control mf prevalence, the model predicted that it would take between 14 and 16 years to bring the mf prevalence below 1.4% using conventional MDA, assuming 65% participation. TaNT would increase the time to elimination by up to 1.5 years, depending on the level of systematic non-participation and the exclusion rate. At lower exclusion rates (≤2.5%), the delay would be less than six months. Conclusions Our model predicts that onchocerciasis can be eliminated using TaNT in L. loa co-endemic areas. The required treatment duration using TaNT would be only slightly longer than in areas with conventional MDA, provided that participation is good.

scholarly journals Costs of Integrated Mass Drug Administration for Neglected Tropical Diseases in Haiti

2011 ◽  
Vol 85 (5) ◽  
pp. 826-833 ◽  
Author(s):  
Ann S. Goldman ◽  
Molly A. Brady ◽  
Luccene Desir ◽  
Abdel Direny ◽  
Roland Oscard ◽  
...  
Keyword(s):  
Drug Administration ◽  
Mass Drug Administration ◽  
Neglected Tropical Diseases ◽  
Tropical Diseases

scholarly journals Eliminating Neglected Tropical Diseases in Urban Areas: A Review of Challenges, Strategies and Research Directions for Successful Mass Drug Administration

2018 ◽  
Vol 3 (4) ◽  
pp. 122 ◽  
Author(s):  
Alayne Adams ◽  
Myriam Vuckovic ◽  
Eleanor Birch ◽  
Tara Brant ◽  
Stephanie Bialek ◽  
...  
Keyword(s):  
Drug Administration ◽  
Mass Drug Administration ◽  
Rural Areas ◽  
Urban Areas ◽  
Neglected Tropical Diseases ◽  
Monitoring And Evaluation ◽  
Population Heterogeneity ◽  
Tropical Diseases ◽  
Urban Settings ◽  
Context Specific

Since 1950, the global urban population grew from 746 million to almost 4 billion and is expected to reach 6.4 billion by mid-century. Almost 90% of this increase will take place in Asia and Africa and disproportionately in urban slums. In this context, concerns about the amplification of several neglected tropical diseases (NTDs) are warranted and efforts towards achieving effective mass drug administration (MDA) coverage become even more important. This narrative review considers the published literature on MDA implementation for specific NTDs and in-country experiences under the ENVISION and END in Africa projects to surface features of urban settings that challenge delivery strategies known to work in rural areas. Discussed under the thematics of governance, population heterogeneity, mobility and community trust in MDA, these features include weak public health infrastructure and programs, challenges related to engaging diverse and dynamic populations and the limited accessibility of certain urban settings such as slums. Although the core components of MDA programs for NTDs in urban settings are similar to those in rural areas, their delivery may need adjustment. Effective coverage of MDA in diverse urban populations can be supported by tailored approaches informed by mapping studies, research that identifies context-specific methods to increase MDA coverage and rigorous monitoring and evaluation.

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