Health systems impacts of the COVID-19 pandemic on malaria control program implementation and malaria burden in Benin: A mixed-method qualitative and mathematical modelling and study.

The COVID-19 pandemic has sent ripple effects across health systems and impacted the burden of many other diseases, such as malaria in sub-Saharan Africa. This study takes a mixed method approach to assess the impact of COVID-19 on malaria control programs in three rural communes in Benin. We conducted individual semi-structured interviews with key informants who play important roles in malaria control in Benin at three levels of the health system-national, health zone, and commune. Using a purposive sampling technique, informants were interviewed regarding their roles in malaria control, the impact of the pandemic on their activities, and the mitigation strategies adopted. Relevant themes were identified by content analysis. We then formulated an agent-based model of malaria epidemiology to assess the impacts of treatment disruption on malaria burden. The key informant interviews revealed that essential aspects of malaria control were upheld in Benin due to the close collaboration of public health practitioners and health care providers at all levels of the health system. There were some disruptions to case management services for malaria at the start of the pandemic due to the public avoiding health centers and a brief shortage of malaria treatment that may not be entirely attributable to the pandemic. Results from the agent-based model suggest that duration, severity, and timing of treatment disruption can impact malaria burden in a synergistic manner, though the effects are small given the relatively mild disruptions observed. This study highlights the importance of top-down leadership in health emergencies, as well as the critical role of community health workers in preventing negative health outcomes for their communities. We also showcased the integration of qualitative research and mathematical models-an underappreciated form of mixed methods research that offer immense value in the continued evaluation of rapidly evolving health emergencies.

Risk factors for Lyme disease resulting from residential exposure amidst emerging Ixodes scapularis populations: A neighbourhood-level analysis of Ottawa, Ontario.

Lyme disease is an emerging health threat in Canada due to the continued northward expansion of the main tick vector, Ixodes scapularis. It is of particular concern to populations living in expanding peri-urban areas where residential development and municipal climate change response impact neighbourhood structure and composition. The objective of this study was to estimate associations of socio-ecological characteristics with residential Lyme disease risk at the neighbourhood scale. We used Lyme disease case data for 2017-2020 reported for Ottawa, Ontario to determine where patients' residential property, or elsewhere within their neighbourhood, was the suspected site of tick exposure. Cases meeting this exposure definition (n = 118) were aggregated and linked to neighbourhood boundaries. We calculated landscape characteristics from composited and classified August 2018 PlanetScope satellite imagery. Negative binomial generalized linear models guided by a priori hypothesized relationships explored the association between hypothesized interactions of landscape structure and the outcome. Increases in median household income, the number of forest patches, the proportion of forested area, forest edge density, and mean forest patch size were associated with higher residential Lyme disease incidence at the neighbourhood scale, while increases in forest shape complexity and average distance to forest edge were associated with reduced incidence (P<0.001). Among Ottawa neighbourhoods, the combined effect of forest shape complexity and average forest patch size was associated with higher residential Lyme disease incidence (P<0.001). These findings suggest that Lyme disease risk in residential settings is associated with urban design elements. This is particularly relevant in urban centres where local ecological changes may impact the presence of emerging tick populations and how residents interact with tick habitat. Further research into the mechanistic underpinnings of these associations would be an asset to both urban development planning and public health management.

Postpartum amenorrhea duration by sex of the newborn in two natural fertility populations.

OBJECTIVES: Postpartum amenorrhea (PA) affects the length of interbirth intervals and thus is intimately related to human life history strategies. PA duration appears to be influenced by maternal energetic status. In humans, as in other mammals, sons are costlier than daughters. Thus, we hypothesize that, in energetically constrained environments, a newborn's sex should be associated with PA duration. METHODS: We analyzed data from two natural fertility populations in which mothers have differing energy budgets: Qom women (n = 121) from a periurban village in Argentina, who have a comparatively calorically dense diet and are sedentary (prepregnancy mean BMI = 24.8 ± 4.5 kg/m2 in 1997), and agropastoral Kaqchikel Maya women (n = 88), who have a comparatively calorically restricted diet and high physical activity levels (mean BMI = 21.8 ± 3.7 kg/m2 ). We predict that (a) mothers of sons exhibit longer PA duration than mothers of daughters and (b) this association between offspring sex and PA duration is stronger in the Maya, who have smaller energy budgets. RESULTS: Maya mothers with sons exhibited estimated mean and median PA durations that were 1.34 times the estimated mean and median PA duration of mothers with daughters (p = 0.02). Among the Qom, mean, and median PA duration did not differ significantly in relation to offspring sex (p = 0.94). CONCLUSIONS: Maya mothers with sons exhibited longer PA duration than those with daughters. This phenomenon was not observed in the well-nourished Qom, possibly due to "buffering" effects from larger energy budgets. Offspring sex may influence birth spacing and maternal life history strategies in energetically constrained environments.

Deconstructing the Impact of Malaria Vector Diversity on Disease Risk.

AbstractRecent years have seen significant progress in understanding the impact of host community assemblage on disease risk, yet diversity in disease vectors has rarely been investigated. Using published malaria and mosquito surveys from Kenya, we analyzed the relationship between malaria prevalence and multiple axes of mosquito diversity: abundance, species richness, and composition. We found a net amplification of malaria prevalence by vector species richness, a result of a strong direct positive association between richness and prevalence alongside a weak indirect negative association between the two, mediated through mosquito community composition. One plausible explanation of these patterns is species niche complementarity, whereby less competent vector species contribute to disease transmission by filling spatial or temporal gaps in transmission left by dominant vectors. A greater understanding of vector community assemblage and function, as well as any interactions between host and vector biodiversity, could offer insights to both fundamental and applied ecology.