Enhancing engagement in HIV care among adolescents and young adults: A focus on phone-based navigation and relationship building to address barriers in HIV care.

Structural, psychological, and clinical barriers to HIV care engagement among adolescents and young adults living with HIV (AYAH) persist globally despite gains in HIV epidemic control. Phone-based peer navigation may provide critical peer support, increase delivery flexibility, and require fewer resources. Prior studies show that phone-based navigation and automated text messaging interventions improve HIV care engagement, adherence, and retention among AYAH.

Evidence of multiple bacterial, viral, and parasitic infectious disease agents in rodents in riverine areas in selected parts of Zambia.

Background: Infectious disease agents pose significant threats to humans, wildlife, and livestock, with rodents carrying a third of these agents, many linked to human diseases. However, the range of pathogens in rodents and the hotspots for disease remain poorly understood.

Aim: This study evaluated the prevalence of viral, bacterial, and parasitic pathogens in rodents in riverine and non-riverine areas in selected districts in Zambia.

Occupational exposure to respirable crystalline silica at an underground copper mine in Zambia.

Introduction: Overexposure to respirable crystalline silica (RCS) can lead to the development of silicosis and other respiratory diseases. The mine under study was reported to have the highest number of certified cases of pneumoconiosis in Zambia in 2015, and in 2008, a study revealed that 56% of the RCS samples exceeded 0.05 mg/m3.

Determining Targets for Antiretroviral Drug Concentrations: A Causal Framework Illustrated With Pediatric Efavirenz Data From the CHAPAS-3 Trial.

Background: Determining a therapeutic window for maintaining antiretroviral drug concentrations within an appropriate range is required for identifying effective dosing regimens. The limits of this window are typically calculated using predictive models. We propose that target concentrations should instead be calculated based on counterfactual probabilities of relevant outcomes and describe a counterfactual framework for this.

World Health Organization African Region national heads of units of diagnostics and laboratory services meetings proceedings.

Background: In the World Health Organization (WHO) African Region, many cases of serious and preventable diseases remain unmanaged because appropriate and good quality diagnostic support is not available at all levels within countries' health systems. Diagnostic and laboratory services influence the efficiency and effectiveness of both clinical and public health functions, including diagnosis, treatment, health promotion, disease prevention, surveillance and response, and research. Essential to global health security, these services are vital to decision-making processes by clinicians, epidemiologists, public health specialists, and health policymakers.

African lineage 1a West Nile virus isolated from crocodiles exhibits low neuroinvasiveness in mice.

West Nile virus (WNV) is a mosquito-borne flavivirus that causes encephalitis in humans and infects crocodiles, resulting in rashes and neurological signs. In Zambia, two distinct lineages of WNV have been detected in neighbouring areas: lineage 2 in mosquitoes and lineage 1a in farmed crocodiles. Considering the risk of direct or vector-mediated WNV transmission from crocodiles to mammals, it is necessary to elucidate the pathogenicity of WNV strains derived from crocodiles.

Health technology assessment to support health benefits package design: a systematic review of economic evaluation evidence in Zambia.

Background: Health technology assessment uses explicit economic evaluation evidence to support health benefits package design. However, the limited availability of technical expertise, data, and methods has restricted the production of economic evaluation evidence in low- and middle-income countries. Zambia has initiated a roadmap to support its policy of reviewing and implementing its national benefits package.

Efficacy of attractive targeted sugar bait stations against malaria in Western Province Zambia: epidemiological findings from a two-arm cluster randomized phase III trial.

Background: Attractive targeted sugar bait (ATSB) stations containing bait (to attract) and ingestion toxicant (to kill) sugar-foraging mosquitoes are hypothesized to reduce malaria transmission by shortening the lifespan of Anopheles vectors.

Methods: A two-arm cluster-randomized controlled trial (cRCT) was conducted in Western Province Zambia. Seventy clusters of 250-350 households were assigned (1:1) by restricted randomization to an intervention arm (ATSB) or control arm (no ATSB) in the context of standard of care vector control (insecticide-treated nets and/or indoor residual spraying).

Mpox in East Africa: Learning from COVID-19 and Ebola to Strengthen Public Health Responses.

The Africa Centers for Disease Control and Prevention declared mpox a Public Health Emergency of Continental Security (PHECS) in Africa. African public health systems have moved to mobilize a response against a backdrop of inherent significant challenges. With this commentary, we discuss how lessons from past public health emergencies, particularly COVID-19 and Ebola outbreaks, have prepared the region for improved disease surveillance, rapid response strategies, and effective public health communication and how these lessons can be applied to the mpox response, emphasizing the importance of strong healthcare infrastructure, effective data sharing, community engagement, targeted interventions, and robust contact tracing.

Causal Inference for Continuous Multiple Time Point Interventions.

There are limited options to estimate the treatment effects of variables which are continuous and measured at multiple time points, particularly if the true dose-response curve should be estimated as closely as possible. However, these situations may be of relevance: in pharmacology, one may be interested in how outcomes of people living with-and treated for-HIV, such as viral failure, would vary for time-varying interventions such as different drug concentration trajectories. A challenge for doing causal inference with continuous interventions is that the positivity assumption is typically violated.

Why does malaria transmission continue at high levels despite universal vector control? Quantifying persistent malaria transmission by Anopheles funestus in Western Province, Zambia.

Background: Some settings continue to experience a high malaria burden despite scale-up of malaria vector control to high levels of coverage. Characterisation of persistent malaria transmission in the presence of standard control measures, also termed residual malaria transmission, to understand where and when individuals are exposed to vector biting is critical to inform refinement of prevention and control strategies.

Methods: Secondary analysis was performed using data collected during a phase III cluster randomized trial of attractive targeted sugar bait stations in Western Province, Zambia.

Trust in government moderates the association between fear of COVID-19 as well as empathic concern and preventive behaviour.

With the COVID-19 pandemic, behavioural scientists aimed to illuminate reasons why people comply with (or not) large-scale cooperative activities. Here we investigated the motives that underlie support for COVID-19 preventive behaviours in a sample of 12,758 individuals from 34 countries. We hypothesized that the associations of empathic prosocial concern and fear of disease with support towards preventive COVID-19 behaviours would be moderated by trust in the government.

Breaking the threshold: Developing multivariable models using computer-aided chest X-ray analysis for tuberculosis triage.

Objectives: Computer-aided detection (CAD) software packages quantify tuberculosis (TB)-compatible chest X-ray (CXR) abnormality as continuous scores. In practice, a threshold value is selected for binary CXR classification. We assessed the diagnostic accuracy of an alternative approach to applying CAD for TB triage: incorporating CAD scores in multivariable modeling.

Evaluating trends in damage to attractive targeted sugar baits (ATSBs) deployed during the second year of a two-year Phase III trial in Western Zambia.

Background: Attractive Targeted Sugar Baits (ATSBs) are a proposed new vector control tool for malaria that contain sugar and an ingestion toxicant, and are designed to attract and kill sugar-feeding mosquitoes. During a two-arm cluster randomized Phase III trial conducted in Zambia to test the efficacy of ATSB stations on malaria incidence, ATSB stations deployed on eligible household structures within intervention clusters were routinely monitored to ensure their good physical condition and high coverage. This study investigates trends in prevalence and rate of damage to ATSB stations during year 2 of the two-year trial.

Characterization of Neonicotinoid Metabolites by Cytochrome P450-Mediated Metabolism in Poultry.

Neonicotinoids, a neuro-effective class of insecticides, are heavily applied in agricultural activities worldwide. Poultry can be exposed to neonicotinoids by several routes, but the knowledge of neonicotinoid's metabolism in poultry and its associated interspecies differences is highly limited. Hence, this study aims to investigate the species differences in metabolite formations, as well as cytochrome P450 (CYP)-dependent metabolism of four major neonicotinoid compounds, acetamiprid, imidacloprid, clothianidin, and thiamethoxam, in poultry.

Community acceptance of a novel malaria intervention, Attractive Targeted Sugar Baits, in the Zambia phase III trial.

Background: Community acceptance is an important criterion to assess in community trials, particularly for new tools that require high coverage and use by a target population. Installed on exterior walls of household structures, the attractive targeted sugar bait (ATSB) is a new vector control tool designed to attract and kill mosquitoes. ATSBs were evaluated in Western Zambia during a two-year cluster randomized controlled trial to assess the efficacy of ATSBs in reducing malaria transmission.

The prioritisation of curable sexually transmitted infections among pregnant women in Zambia and Papua New Guinea: Qualitative insights.

Curable sexually transmitted infections (STIs) are neglected in public health policy, services and society at large. Effective interventions are available for some STI but seem not to be prioritised at global, regional or local levels. Zambia and Papua New Guinea (PNG) have a high burden of STIs among pregnant women but little is known about the prioritisation of STI treatment and care among this group.

Entomological effects of attractive targeted sugar bait station deployment in Western Zambia: vector surveillance findings from a two-arm cluster randomized phase III trial.

Background: Attractive targeted sugar bait (ATSB) stations are a novel tool with potential to complement current approaches to malaria vector control. To assess the public health value of ATSB station deployment in areas of high coverage with standard vector control, a two-arm cluster-randomized controlled trial (cRCT) of Sarabi ATSB® stations (Westham Ltd., Hod-Hasharon, Israel) was conducted in Western Province, Zambia, a high-burden location were Anopheles funestus is the dominant vector.

Programme science in action: lessons from an observational study of HIV prevention programming for key populations in Lusaka, Zambia.

Introduction: Optimizing uptake of pre-exposure prophylaxis (PrEP) for individuals at risk of HIV acquisition has been challenging despite clear scientific evidence and normative guidelines, particularly for key populations (KPs) such as men who have sex with men (MSM), female sex workers (FSWs), transgender (TG) people and persons who inject drugs (PWID). Applying an iterative Programme Science cycle, building on the effective programme coverage framework, we describe the approach used by the Centre for Infectious Disease Research in Zambia (CIDRZ) to scale up PrEP delivery and address inequities in PrEP access for KP in Lusaka, Zambia.

Methods: In 2019, CIDRZ partnered with 10 local KP civil society organizations (CSOs) and the Ministry of Health (MOH) to offer HIV services within KP-designated community safe spaces.