Individual responses to a single oral dose of albendazole indicate reduced efficacy against soil-transmitted helminths in an area with high drug pressure

Background Albendazole (ALB) is administered annually to millions of children through global deworming programs targeting soil-transmitted helminths (STHs: Ascaris lumbricoides, Trichuris trichiura and hookworms, Necator americanus and Ancylostoma duodenale). However, due to the lack of large individual patient datasets collected using standardized protocols and the application of population-based statistical methods, little is known about factors that may affect individual responses to treatment. Methodology/Principal findings We re-analyzed 645 individual patient data from three standardized clinical trials designed to assess the efficacy of a single 400 mg oral dose of ALB against STHs in schoolchildren from different study sites, each with varying history of drug pressure based on duration of mass drug administration programs: Ethiopia, low; Lao People’s Democratic Republic (PDR), moderate; Pemba Island (Tanzania), high. Using a Bayesian statistical modelling approach to estimate individual responses (individual egg reduction rates, ERRi), we found that efficacy was lower in Pemba Island, particularly for T. trichiura. For this STH, the proportion of participants with a satisfactory response (ERRi ≥50%), was 65% in Ethiopia, 61% in Lao PDR but only 29% in Pemba Island. There was a significant correlation between ERRi and infection intensity prior to drug administration (ERRi decreasing as a function of increasing infection intensity). Individual age and sex also affected the drug response, but these were of negligible clinical significance and not consistent across STHs and study sites. Conclusions/Significance We found decreased efficacy of ALB against all the STHs analyzed in Pemba Island (Tanzania), an area with high drug pressure. This does not indicate causality, as this association may also be partially explained by differences in infection intensity prior to drug administration. Notwithstanding, our results indicate that without alternative treatment regimens, program targets will not be achievable on Pemba Island because of inadequate efficacy of ALB. Trial registration The study was registered on Clinicaltrials.gov (ID: NCT03465488) on March 7, 2018.

Moving Seaweed Farms from Shallow to Deep Seawater to Cope with Warming and Diseases in Zanzibar. Current Socio-Economic and Cultural Barriers

This study aimed at identifying the climate and non-climate stressors affecting the seaweed farming practices. It also examines the deep water seaweed farming as a viable adaptation measure to these stressors and barriers that could constrained female seaweed farmers who are the majority. The study was carried out in six selected groups, two groups were from South District, Unguja Main Island (Furahiya Wanawake-Paje and Flower Group-Muungoni). And four groups were selected from Pemba Island (Tuwe Imara and Umoja Kazi- East Msuka and Ipo sababu and Umoja ni Nguvu – East Tumbe) from Micheweni District. These groups were selected because they participated in previous project implemented by Milele Zanzibar Foundation (MZF) and The Panje Project (TPP). Questionnaire interview collected various information related to the study from 111 seaweed farmers who are members of these groups. Information such as baseline seaweed production, climate change and diseases that affect seaweed production, farmer’s awareness on moving seaweed farms to deep water to cope with increasing warming and diseases and their capacity to swim as prerequisite for the adoption of this coping strategy. The focal group discussions were conducted in all six groups to collect various information to triangulate the findings collected from the questionnaire interview. The data obtained from three methods analyzed using descriptive statistics. The findings show that seaweed farming production has declined at least over the last seven years. Climate change and its variability, diseases, over utilization of shallow water space for farming seaweed, COVID 19 and price has contributed a lot in the observed decline. Deep water (0.5 meter during low tide and 3-5 meters during high tide) seaweed farming seen as viable option to cope and adapt to increasing warming and diseases but its adoption especially amongst female seaweed farmers constrained by their limited capacity to swim and their limited ownership of the vessels. The study also identified other barriers such as age, gender and cultural factors that could constrained female seaweed farmers from participation in swimming and sea safety training. To facilitate adoption of the deep-water seaweed farming method amongst the seaweed farmers, concerted effort should be made to overcome the barriers that are likely to limit the massive adoption of this method.

Long-term outcomes of ivermectin-albendazole versus albendazole alone against soil-transmitted helminths: Results from randomized controlled trials in Lao PDR and Pemba Island, Tanzania

Background Preventive chemotherapy is the cornerstone of soil-transmitted helminth (STH) control. Long-term outcomes and adequate treatment frequency of the recently recommended albendazole-ivermectin have not been studied to date. Methodology/principal findings Double-blind randomized controlled trials were conducted in Lao PDR, Pemba Island, Tanzania and Côte d’Ivoire between 2018 and 2020 to evaluate the efficacy and safety of ivermectin-albendazole versus albendazole-placebo in Trichuris trichiura-infected individuals aged 6 to 60. In the framework of this study, in Lao PDR 466 and 413 participants and on Pemba Island, 558 and 515 participants were followed-up six and 12 months post-treatment, respectively. From each participant at least one stool sample was processed for Kato-Katz diagnosis and cure rates (CRs), egg reduction rates (ERRs) and apparent reinfection rates were calculated. If found helminth-positive at 6-months, participants were re-treated according to their allocated treatment. Long-term outcomes against T. trichiura based on CRs and ERRs of ivermectin-albendazole compared to albendazole were significantly higher at six months in Lao PDR (CR, 65.8% vs 13.4%, difference; 52.4; 95% CI 45.0–60.0; ERRs: 99.0% vs 79.6, difference 19.4; 95% CI 14.4–24.4) and Pemba Island (CR: 17.8 vs 1.4%, difference; 16.4%; 95% CI 11.6–21.0; ERRs: 84.9 vs 21.2, difference 63.8; 95% CI 50.6–76.9) and also at 12 months in Lao PDR (CR, 74.0 vs 23.4%, difference; 50.6; 95% CI 42.6–61.0; ERRs: 99.6 vs 91.3, difference 8.3; 95% CI 5.7–10.8) and Pemba Island (CR, 19.5 vs 3.4%, difference; 16.1; 95% CI 10.7–21.5; ERRs: 92.9 vs 53.6, difference 39.3; 95% CI 31.2–47.4) respectively. Apparent reinfection rates with T. trichiura were considerably higher on Pemba Island (100.0%, 95% CI, 29.2–100.0) than in Lao PDR (10.0%, 95% CI, 0.2–44.5) at 12 months post-treatment for participants treated with albendazole alone. Conclusions/significance The long-term outcomes against T. trichiura of ivermectin-albendazole are superior to albendazole in terms of CRs and ERRs and in reducing infection intensities. Our results will help to guide decisions on how to best use ivermectin-albendazole in the context of large-scale PC programs tailored to the local context to sustainably control STH infections. Trial registration ClinicalTrials.gov registered with clinicaltrials.gov, reference: NCT03527732, date assigned: 17 May 2018.

The Natural Course of Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and Mycoplasma genitalium in Pregnant and Post-Delivery Women in Pemba Island, Tanzania

This study aimed to determine the persistence of Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Trichomonas vaginalis (TV) and Mycoplasma genitalium (MG) infections during pregnancy and after delivery in vaginal swabs of women from Pemba Island, Tanzania. In the context of an earlier biobanking effort, vaginal swabs were collected at two timepoints during pregnancy and once post-delivery. Detection of CT, NG, TV, and MG was performed by PCR using validated detection kits in samples from 441 pregnant women aged 16–48 years old. Among those, 202 samples were matched during pregnancy and 38 at the second timepoint of the pregnancy and post-delivery CT infection persistence during pregnancy was 100% (n = 11) after an average of eight weeks, that of TV infection 82% (n = 11) after ten weeks, and that of MG infection 75% (n = 4) after ten weeks. Post-delivery (after approximately 22 weeks) infection persistence was 100% for CT (n = 1) and 20% for TV (n = 5). NG was only detected at the last collection timepoint, its persistence rate could not be determined. These results show persistence and clearance of curable infections during and after pregnancy. Analysis of biobanked samples is a valuable approach in the investigation of the natural history of curable pathogens.

Dissection of the gut microbiota in mothers and children with chronic Trichuris trichiura infection in Pemba Island, Tanzania

Background Soil-transmitted helminthiases are important neglected tropical diseases that result in a notably high number of disability-adjusted life years worldwide. Characterizing the interactions between the human intestinal microbiome and helminths is of interest in the development of alternative treatments that do not rely on chemotherapeutics and do not lead to drug resistance. Methods We recruited and obtained fecal samples from 32 pairs of mothers and children on Pemba Island and monitored their intestinal microbiota using 16S rRNA gene sequencing. Results We observed that microbial changes occur in the gut microbiota of infected mothers and children. Some short-chain fatty acid (SCFA)-producing bacteria and carbohydrate-degrading bacteria exhibited lower abundance in the infected individuals. Potentially pathogenic Campylobacter and proinflammatory Methanobrevibacter in infected mothers and opportunistic Enterococcus in infected children exhibited greater abundance. Conclusions Our findings could reveal the microbiota profiling in T. trichiura-infected individuals, indicate the potential roles of key microbiota in the host and aid to the development of novel strategies to control T. trichiura infection. Graphic abstract

Predictors for Uptake of Tetanus Toxoid Vaccination During Pregnancy Among Women of Reproductive Age in Tanzania; An Analysis of Data from the 2015-16 Tanzania Demographic and Health Survey and Malaria Indicators Survey

Background: Tetanus is a vaccine preventable disease. Tanzania through its Ministry of Health, Community Development, Gender, Elderly and Children (MoHCDGEC) recommend all women should receive at least five TT doses in their reproductive life. Little is known on predictors of TT uptake during pregnancy among women of reproductive age in TanzaniaMethod: The study used data from the 2015-16 Tanzania Demographic and Health Survey and Malaria Indicators Survey (2015-16 TDHS-MIS). A total of 6924women of active reproductive age from 15 to 49 were included in the analysis. Both univariate and multiple regression analyses were used to determine the predictors of TT uptake during pregnancy among women of reproductive age in Tanzania.Results: More than half, 3480 (50.3%) of the study population had either no or one tetanus injection. A total of 3444 (49.7%) had two or more tetanus injection during pregnancy. After adjusted for confounders, predictors of uptake of tetanus vaccination were early antenatal booking (AOR=1.174 at 95% CI=1.033-1.335, p=0.014), age group of women [ 20 to 34 years (AOR=1.433 at 95% CI= 1.155-1.778, p=0.001), more than 34 years (AOR=1.379 at 95% CI=1.065-1.786, p=0.015)], wealth index [ rich (AOR=1.261 at 95% CI= 1.083-1.468, p = 0.003)], parity [para 2-4 (AOR=0.401 at 95% CI=0.343-0.468, p<0.001), para 5 and above (AOR=0.217 at 95% CI=0.178-0.265, p<0.001)], level of education [ primary level, (AOR=0.864 at 95% CI=0.754-0.99, p=0.035)] zones [Unguja Zanzibar Island (AOR=0.434 at 95% CI=0.309-0.609, p<0.001), Pemba (Pemba Island) (AOR=0.34 at 95% CI=0.226-0.512, p<0.001)] and adequate ANC visits (AOR=0.649 at 95% CI=0.582-0.723, p<0.001)Conclusion: Antenatal care service utilization, including both timeliness and the number of ANC visits attended were found important predictors for TT vaccine uptake. Therefore, the responsible ministry of health in the country should strengthen the strategies in place to increase maternal awareness on importance of ANC service utilization.