The staff and partners of IMA World Health are excited to join colleagues at the American Society of Tropical Medicine and Hygiene 2020 Annual Meeting (#TropMed20). We join colleagues from ministries of health in Tanzania and Haiti, academic researchers from Brigham Young University and others to present our shared work, moving us ever closer to ending debilitating diseases.
Poster Session Presentations
1:30 P.M. - 3 P.M., November 16, 2020
Strategies toward meeting the Lymphatic Filariasis (LF) elimination goal in Tanzania
Read the abstract here.
Denis Kailembo, Gerald Robi, Veronica Kabona, Kerry Dobies, Mary Linehan, Abdel Direny
Lymphatic Filariasis (LF) is endemic across 120 districts in Tanzania. Tanzania’s Neglected Tropical Diseases Control Program (TZNTDCP) is using the drug-package of Ivermectin+Albendazole (IVM+ALB) during mass drug administration (MDA) as the primary strategy for achieving LF elimination. Among the 120 LF endemic districts, 105 districts have passed transmission assessment survey (TAS), reaching the criteria to stop MDA. While the TZNTDCP continues surveillance in districts which passed TAS, the focus is now on the remaining 15 districts with persistent LF transmission. TZNTDCP added extra clusters that were positive in TAS1 and TAS2 during TAS2 and TAS3 conducted in 2019. No positive cases were reported in the extra clusters. Of the 15 districts still requiring MDA, 14 were scheduled for re-pre-TAS in 2020 (to determine eligibility for conducting TAS) after successfully achieving sufficient coverage in the last two rounds of MDA. During this re-pre-TAS, three to five sites within each district were selected. The sites included both sentinel and spot check sites from previous assessments with a history of failure (Ag >2%), as well as new sites selected from those with reported cases of LF and a history of low MDA coverage. About 300 individuals aged 5 years and older were tested per site with Filarial Test Kits (FTS). Preliminary results showed that 8 of the 14 districts did not pass re-pre-TAS, highlighting ongoing transmission. TZNTDCP will develop and implement new strategies to strengthen MDA and to reach all populations (including migrant populations) before the next disease specific assessment (DSA). The strategies include allocation of community drug distributors (CDDs) according to level of effort (applying the CDD ratio), implement micro-plans at the sub-district level, and enhance supportive supervision. Moreover, DSA failure investigation will be conducted to critically analyze and provide recommendations to address why the districts did not pass the assessment. These strategies will help TZNTDCP move towards LF elimination in line with the WHO proposed target of eliminating LF as a public health problem by 2030.
Integrating community health workers in Mass Drug Administration (MDA) supervision to improve MDA implementation
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Eurica Denis, Alain Javel, Carl Renand Fayette, Paul-Emile Dalexis, Ellen Knowles, Mary Linehan, Abdel Direny
To achieve global goals to eliminate lymphatic filariasis (LF), the Haiti NTD Control Program (HNTDCP) follows WHO’s recommendations to implement rounds of annual mass drug administration (MDA) of diethylcarbamazine and albendazole for at least five consecutive years among at risk populations to halt LF transmission. In Haiti, MDA has always been supervised by the Ministry of Health (MOH) staff and its partners. The MDA strategy employs school- and community-based distribution posts to distribute the drugs to the targeted population. Due to a lack of resources and accessibility, some distribution posts have not been adequately supervised during MDA, resulting in poor reporting and low epidemiological coverage (<65%) by community drug distributors (CDDs). In 2019, the Haiti Neglected Tropical Disease Control Program (HNTDCP) developed a multi-level supervision plan to improve MDA supervision. The first level included a platform of 157 community health workers (CHWs) in 12 communes to ensure each distribution post is visited daily. The second level of supervision was comprised of MOH representatives and implementing partners, providing technical and logistical support to the first level supervisors, or directly to the distribution posts. With this new strategy, each distribution post is supervised every day using an electronic supervision checklist. The electronic forms are completed by each CHW using Open Data Kit through mobile phone, in which data is sent to an online server. A total of 1400 out of 1501 distribution posts (93%) are now supervised daily and geo-localized. Geo-localization is important to avoid uncovered areas during MDA. In addition, partial MDA results from every distribution post is collected daily and other information such as cleanliness of the distribution post and directly observed treatment strategy were also reported. With the information collected, HNTDCP was able to evaluate coverage daily and provide necessary assistance where needed, as well as inform program adaption in real-time to ensure effective coverage was reached. MDA supervision and reporting quality have improved while maintaining low costs.
11:45 A.M. - 1:15 P.M., November 18, 2020
What to do differently to enhance elimination of trachoma in Tanzania: lessons learned from districts with persistent TF prevalence of more than 5%
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Gerald Robi, Denis Kailembo, Veronica Kabona, Kerry Dobies, Mary Linehan, Abdel Direny
Tanzania has reduced the number of districts requiring mass drug administration (MDA) for Trachoma by over 90% (71 to 6). These districts have successfully passed the trachoma impact survey indicating continuing transmission cannot be sustained. Despite this progress, the Tanzania neglected tropical diseases (NTD) program must still address districts where Trachoma transmission persists. Four districts failed TIS in 2014, 2016, and 2019 while two districts failed Trachoma surveillance survey in 2019, two years after stopping MDA. After failures in 2019, the NTD program conducted key informant interviews and reviewed MDA coverage history, health-facility MDA coverage, and coverage evaluation surveys (CES) to identify possible reasons for failures and to explore appropriate actions to improve program effectiveness. The program further conducted a desk review to identify key reasons and factors that have contributed to failure. The MDA historical data from 2004 revealed that all districts have trachoma follicular (TF) baseline prevalence >20% in children of 1-9 years of age, and had at least 8 rounds of MDA though all districts reported MDA coverage ≥80% at least in two rounds (ranging 2-5). In addition, the data showed low access to water (6-28%) and sanitation (4-29%) in these areas. The four main reasons for low MDA coverage are absenteeism, wrong perception of MDA, lack of information on MDA, and lack of drug inventory. The data allows to identify some challenges during MDA implementation such as insufficient number of community drug distributors (CDDs) and MDA supervisors, and tetracycline not used in MDA for those ineligible for Zithromax. Based on desk review results, recommendations have been made to Tanzania NTD programs to promote increased access and advocate with WASH partners to improve access to facial cleanliness and environmental improvement (F&E) component of the SAFE strategy to decrease trachoma infection in these four districts. Also, the program will implement MDA, coverage supervisor tool (CST) and mop-up if needed at proper times, and will consider introducing tetracycline in MDA for those ineligible for Zithromax.
Onchocerciasis vectors and transmission status of Onchocerca Volvulus after 17 years of mass drug administration with ivermectin in Muheza district, Tanga focus in Tanzania
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Andreas Nshala, Denis Kailembo
After over 17 years of annual mass drug administration (MDA) with average therapeutic coverage around 80% through community directed treatment with ivermectin (CDTI), it was envisaged that transmission would be interrupted to allow progress toward elimination of onchocerciasis in Tanzania. A cross-sectional study was conducted in six villages distributed in six wards each in Muheza district in Tanga focus to evaluate the entomological status to understand the impact of CDTI on elimination of Onchocerca volvulus infection in the vectors. Black flies were captured using a standard method of human landing collection from June 2017 through August 2017, a peak period for biting activity and transmission of the parasite. Biting rate was calculated by dividing total flies collected by number of capture days. Collected flies were morphologically identified macroscopically, confirmed microscopically and preserved in absolute ethanol in pools of 100 flies by catching point. Polymerase chain reaction (PCR) using O-150 pool-screening method was performed in 2019 to detect O. volvulus infection in black flies. A total of 5,119 adult female black flies were collected at six catching points for 24 days. Simulium woodi were the main vector collected in the study area with daily biting rate of 213 flies/day. A total of 54 pools of heads and bodies of black flies were analyzed and 3 (5.6%) pools tested positive for O. volvulus which is over 0.1%, the current threshold for stopping MDA. Each positive pool came from a separate catching point in the study area, hence 3 of 6 (50%) sites had a positive signal. These findings suggest that despite long term MDA with ivermectin in Muheza district, transmission of O. volvulus is ongoing in vectors and humans.