The latest medical research on Tropical Medicine

Insecticide-treated nets (ITNs) are the most commonly deployed tools for controlling malaria transmission in sub-Saharan Africa. However, some reports associate multiple alternative uses of nets with poor disposal practices, prompting this study to assess existing alternative uses and disposal practices of old ITNs in Burkina Faso after four universal distribution campaigns.

A quantitative survey combined with qualitative data collection was used to describe existing alternative uses and disposal practices for old ITNs in households from selected study sites in the three climatic zones of Burkina Faso. A survey questionnaire was distributed to 3,780 participants, and 12 focus groups were held to elucidate responses regarding existing disposal practices and alternative uses of ITNs.

Of the 3780 households surveyed, 87.4% (3,330) reported having disposed of their ITNs when they were no longer usable due to age or wear. The most commonly cited disposal methods included alternative uses (67.4%), disposal with other garbage (61.4%), and burying (9%). In addition, the most common alternative uses included fencing for crops and seedlings (51.8%); ropes for tying items (40.4%); animal protection fencing (17.8%); house fencing (16.8%); bed covers (13.3%) and curtains for doors or windows (12.6%). Furthermore, trends in ITNs disposal mechanisms and alternative uses differed between study sites in each climate zone. All these ITNs disposal mechanisms and the different types of alternative use of old ITNs were confirmed in the focus group discussions.

The findings underscore the need for comprehensive strategies to manage the disposal and repurposing of old ITNs in Burkina Faso. Addressing gaps in disposal guidelines, promoting safe and beneficial reuse practices, and actively involving communities in the decision-making process can help mitigate health risks associated with the improper disposal and repurposing of old insecticide-treated nets and improve the overall effectiveness of malaria control programmes. Through these efforts, both public health and environmental concerns can be addressed in a sustainable and collaborative manner.

Despite the progress in scaling vector control interventions in Ethiopia, malaria is still a major health problem in the country. Monitoring of the local vector populations and the effectiveness of vector control strategies is necessary to guide programme decisions to optimize malaria prevention efforts. This study investigated the feeding preference, the biting behaviour and resting behaviours of Anopheles mosquitoes in selected localities of Dembiya District.

Adult Anopheles mosquitoes were sampled indoors and outdoors from June 2018 to May 2019 using CDC light traps, pyrethrum spray catches, artificial pit shelters, and mouth aspirators at both Guramba Bata and Arebiya study sites. Anopheles mosquitoes were identified to the species level. Their blood meal source and Plasmodium sporozoite infections were determined using an enzyme-linked immunosorbent assay.

Anopheles mosquitoes belonging to 11 species were identified from 2,055 collected mosquito specimens. Anopheles pharoensis was the predominant species at both the Guramba Bata (46.5%) and Arebiya (46.2%) study sites. The CDC light traps caught the highest number of Anopheles mosquitoes in both study sites. In Guramba Bata the density of outdoor host-seeking and resting Anopheles mosquitoes were higher than indoors (P ≤ 0.05). The human blood indexes (HBI) of indoor and outdoor host-seeking Anopheles arabiensis were 17.4% and 15.3%, respectively. The entomological inoculation rate (EIR) of outdoor host-seeking An. arabiensis was 4.7 infective bites/person/year. Additionally, the outdoor EIR of host-seeking Anopheles coustani was 25.7ib/p/year.

Anopheles mosquitoes in Dembiya district were more likely to seek a host and rest outdoors than indoors. A reevaluation of vector control strategies is needed to ensure Ethiopia remains on the path to malaria elimination. The detection of Plasmodium circumsporozoite protein in potential secondary vectors, such as An. coustani requires further investigation to substantiate their role in malaria transmission.

We tested whether providing BCG vaccine to healthcare workers (HCWs) could reduce non-planned absenteeism and thereby reduce the potential impact of the COVID-19 pandemic on healthcare systems in Africa.

We conducted a multicenter, single-blinded, placebo-controlled randomized trial in Guinea-Bissau and Mozambique between December 2020 and June 2022. Participants were randomized 1:1 to BCG vaccine or placebo (saline) and followed by biweekly telephone calls for 6 mo. The incidence of unplanned absenteeism due to illness was analyzed using Bayesian negative binomial regression yielding relative RRs. Secondary outcomes included infectious disease episodes, COVID-19 infection and all-cause hospitalizations.

We enrolled 668 HCWs (Guinea-Bissau, n=503; Mozambique, n=165). The RR for absenteeism of BCG vs placebo was 1.29 (0.81 to 1.94) with comparable effects by country. No protection against infectious disease episodes (HR=1.18 [0.97 to 1.45]) or COVID-19 infection (HR=1.19 [0.80 to 1.75]) was observed. Two trial deaths (1 BCG, 1 control) were registered and nine admissions (3 BCG, 6 control), the all-cause admission HR being 0.51 (0.13 to 2.03).

With 64% of the planned sample size and unplanned absenteeism rates lower than expected, BCG did not reduce self-reported absenteeism due to illness. Rather, BCG tended to increase the risk of self-reported absenteeism, infectious disease episodes and COVID-19 infections.

This was a randomized control trial assessing non-specific effects of BCG vaccination in healthcare workers. There was no beneficial effect on self-reported absenteeism due to illness within 6 mo of follow-up during the COVID-19 pandemic, but a trend towards fewer all-cause hospital admissions.

The mechanisms that determine the progression to cardiac or digestive forms of chronic Chagas disease (CD) are still unclear. We assessed the association between blood group antigens ABO, Rh, Kell, Kidd, Duffy and MNS, and chronic CD clinical forms.

Patients were included consecutively between March 2013 and April 2016. Clinical and epidemiological data were obtained from electronic medical records and interviews. Classification of CD clinical forms followed the Brazilian Consensus on CD. The ID-Gel Card technology from Bio-Rad (Diamed/Bio-Rad Latin America, MG, Brazil) was used to analyze the blood group antigens.

A total of 619 adult patients (56.9% women, mean age 60±12 y) were included. Patients' clinical forms of CD were classified as follows: indeterminate 29.1%, cardiac 55.4%, digestive 5.5% and mixed 10.0%. Logistic regression analysis adjusted for age, comorbidities and time away from an endemic area revealed that the S+s- allele of the MNS blood type was associated with a lower odds of cardiac disease and that the B blood group type was associated with a higher odds of digestive disease. All other blood types did not have an association with CD clinical form.

Blood group systems ABO and MNS were associated with chronic CD clinical forms.