Search

Background: Lymphatic filariasis (LF) has been targeted for global elimination as a public health problem since 1997. The primary strategy to interrupt transmission is annual mass drug administration (MDA) for ≥5 years. The transmission assessment survey (TAS) was developed as a decision-making tool to measure LF antigenemia in children to determine when MDA in a region can be stopped. The objective of this study was to investigate potential sampling strategies for follow-up of LF-positive children identified in TAS to detect evidence of ongoing transmission. Methodology/Principle findings: Nippes Department in Haiti passed TAS 1 with 2 positive cases and stopped MDA in 2015; however, 8 positive children were found during TAS 2 in 2017, which prompted a more thorough assessment of ongoing transmission. Purposive sampling was used to select the closest 50 households to each index case household, and systematic random sampling was used to select 20 households from each index case census enumeration area. All consenting household members aged ≥2 years were surveyed and tested for circulating filarial antigen (CFA) using the rapid filarial test strip and for Wb123-specific antibodies using the Filaria Detect IgG4 ELISA. Among 1,927 participants, 1.5% were CFA-positive and 4.5% were seropositive. CFA-positive individuals were identified for 6 of 8 index cases. Positivity ranged from 0.4–2.4%, with highest positivity in the urban commune Miragoane. Purposive sampling found the highest number of CFA-positives (17 vs. 9), and random sampling found a higher percent positive (2.4% vs. 1.4%). Conclusions/Significance: Overall, both purposive and random sampling methods were reasonable and achievable methods of TAS follow-up in resource-limited settings. Both methods identified additional CFA-positives in close geographic proximity to LF-positive children found by TAS, and both identified strong signs of ongoing transmission in the large urban commune of Miragoane. These findings will help inform standardized guidelines for post-TAS surveillance. Author summary: Lymphatic filariasis (LF) is a debilitating parasitic disease that has been targeted for global elimination. The transmission assessment survey (TAS) is a tool used to determine if LF transmission has reached low enough levels that prevention activities can be stopped. This study aimed to identify methods to investigate positive LF cases found during TAS. The investigation was conducted in Nippes Department, Haiti, where 8 positive cases were found in TAS in 2017. Participants were recruited through two methods: purposive selection of the closest 50 households to the positive case, and random selection of 20 households in the census enumeration area of the case. Participants completed a survey and were tested for LF antigen, indicative of current infection, and parasite-specific antibody, indicative of current or past infection. A total of 1,927 people participated in the study; 1.5% of these were antigen-positive, and 4.5% were antibody-positive. Purposive sampling found a higher number of antigen-positive individuals, and random sampling found a higher percent positive. Both sampling methods were feasible to use in this setting, and both methods identified signs of ongoing transmission in a large urban area. Additional research is needed to help standardize guidance for post-TAS surveillance to best identify ongoing transmission. [ABSTRACT FROM AUTHOR]

In Haiti, 22 communes still require mass drug administration (MDA) to eliminate lymphatic filariasis (LF) as a public health problem. Several clinical trials have shown that a single oral dose of ivermectin (IVM), diethylcarbamazine (DEC) and albendazole (ALB) (IDA) is more effective than DEC plus ALB (DA) for clearing Wuchereria bancrofti microfilariae (Mf). We performed a cluster-randomized community study to compare the safety and efficacy of IDA and DA in an LF-endemic area in northern Haiti. Ten localities were randomized to receive either DA or IDA. Participants were monitored for adverse events (AE), parasite antigenemia, and microfilaremia. Antigen-positive participants were retested one year after MDA to assess treatment efficacy. Fewer participants (11.0%, 321/2917) experienced at least one AE after IDA compared to DA (17.3%, 491/2844, P<0.001). Most AEs were mild, and the three most common AEs reported were headaches, dizziness and abdominal pain. Serious AEs developed in three participants who received DA. Baseline prevalence for filarial antigenemia was 8.0% (239/3004) in IDA localities and 11.5% (344/2994) in DA localities (<0.001). Of those with positive antigenemia, 17.6% (42/239) in IDA localities and 20.9% (72/344, P = 0.25) in DA localities were microfilaremic. One year after treatment, 84% percent of persons with positive filarial antigen tests at baseline could be retested. Clearance rates for filarial antigenemia were 20.5% (41/200) after IDA versus 25.4% (74/289) after DA (P = 0.3). However, 94.4% (34/36) of IDA recipients and 75.9% (44/58) of DA recipients with baseline microfilaremia were Mf negative at the time of retest (P = 0.02). Thus, MDA with IDA was at least as well tolerated and significantly more effective for clearing Mf compared to the standard DA regimen in this study. Effective MDA coverage with IDA could accelerate the elimination of LF as a public health problem in the 22 communes that still require MDA in Haiti. Author summary: Lymphatic filariasis (LF) also known as "elephantiasis" is caused by infection with filarial worms that are transmitted by mosquitoes. The Global Programme to Eliminate LF (GPELF) aims to interrupt disease transmission through annual rounds of mass drug administration (MDA). Several studies have shown that a single dose of a triple-drug therapy (ivermectin, diethylcarbamazine and albendazole or IDA) was superior to a single dose of the standard double-drug therapy (diethylcarbamazine and albendazole or DA) and might accelerate LF elimination. In Northern Haiti, we performed a large community treatment study to compare the safety and efficacy of three-drug and two-drug therapies. Almost 6,000 participants were treated with IDA or DA and tested for LF. Each participant was assessed for adverse events (AE) and participants who tested positive for LF at enrollment were retested one year after treatment. Less participants who received IDA (11.0%) experienced AEs compared to participants who received DA (17.3%). IDA was also more effective to eliminate microfilariae (adult worm offspring) from the blood compare to DA. Results from this study showed that IDA was well tolerated in Haiti and has the potential to accelerate LF elimination in countries that currently use DA if high MDA coverage can be achieved. [ABSTRACT FROM AUTHOR]

The article offers information on the prevention of Cholera and control in refugee settings. Topics discussed Cholera is considered as a serious threat for refugee populations; mentions the humanitarian community developed the sphere standards for the living conditions and availability of health services in refugee camps; and highlights several historic outbreaks in refugee camps.

The early period of the COVID-19 pandemic limited access to HIV services for children and adolescents living with HIV (C/ALHIV). To determine progress in providing care and treatment services, we describe viral load coverage (VLC) and suppression (VLS) (<1000 copies/ mL) rates during the COVID-19 pandemic in 12 United States President's Emergency Plan for AIDS Relief (PEPFAR)-supported countries. Data for children (0-9 years) and adolescents (10-19 years) on VLC and VLS were analyzed for 12 sub-Saharan African (SSA) countries between 2019 (pre-COVID-19) and 2020 (during COVID-19). We report the number of viral load (VL) tests, and percent change in VLC and VLS for patients on ART. For 12 countries, 181,192 children had a VL test during the pre-COVID-19 period compared with 177,683 December 2020 during COVID-19. VLC decreased from 68.8% to 68.3% overall. However, 9 countries experienced an increase ranging from a 0.7%-point increase for Tanzania and Zimbabwe to a 15.3%-point increase for Nigeria. VLS increased for all countries from 71.2% to 77.7%. For adolescents the number with a VL test increased from 377,342 to 402,792. VLC decreased from 77.4% to 77.1%. However, 7 countries experienced an increase ranging from 1.8% for Mozambique to 13.8% for Cameroon. VLS increased for all countries from 76.8% to 83.8%. This analysis shows variation in HIV VLC across 12 SSA countries. VLS consistently improved across all countries demonstrating resilience of countries during 2020. Countries should continue to improve clinical outcomes from C/ALHIV despite service disruptions that may occur during pandemic response., Competing Interests: The authors have declared that no competing interests exist., (Copyright: This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.)