BACKGROUND: Indoor residual spraying (IRS) has been implemented to prevent malaria in Zambia for several decades, but its effectiveness has not been evaluated long term and in Vubwi District yet. This study aimed to assess the association between IRS and the malaria burden in Zambia and Vubwi District and to explore the factors associated with refusing IRS.
METHODS: A retrospective study was used to analyze the association between IRS and malaria incidence in Zambia in 2001-2020 and in Vubwi District in 2014-2020 by Spearman correlation analysis. A case-control study was used to explore the factors associated with IRS refusals by households in Vubwi District in 2021. A logistic regression model was performed to identify factors associated with IRS refusals.
RESULTS: The malaria incidence reached its peak (391/1000) in 2001 and dropped to the lowest (154/1000) in 2019. The annual percentage change in 2001-2003, 2003-2008, 2008-2014, 2014-2018 and 2018-2020 was - 6.54%, - 13.24%, 5.04%, - 10.28% and 18.61%, respectively. A significantly negative correlation between the percentage of population protected by the IRS against the total population in Zambia (coverage) and the average malaria incidence in the whole population was observed in 2005-2020 (r = - 0.685, P = 0.003) and 2005-2019 (r = - 0.818, P < 0.001). Among 264 participants (59 in the refuser group and 205 in the acceptor group), participants with specific occupations (self-employed: OR 0.089, 95% CI 0.022-0.364; gold panning: OR 0.113, 95% CI 0.022-0.574; housewives: OR 0.129, 95% CI 0.026-0.628 and farmers: OR 0.135, 95% CI 0.030-0.608 compared to employees) and no malaria case among household members (OR 0.167; 95% CI 0.071-0.394) had a lower risk of refusing IRS implementation, while those with a secondary education level (OR 3.690, 95% CI 1.245-10.989) had a higher risk of refusing IRS implementation compared to those who had never been to school.
CONCLUSIONS: Increasing coverage with IRS was associated with decreasing incidence of malaria in Zambia, though this was not observed in Vubwi District, possibly because of the special geographical location of Vubwi District. Interpersonal communication and targeted health education should be implemented at full scale to ensure household awareness and gain community trust.

BACKGROUND: There have been few empirical studies for diagnostic test accuracy of syphilis using a sequence of rapid tests in populations with low prevalence of syphilis such as pregnant women. This analysis describes syphilis test positivity frequency among pregnant women at an antenatal clinic in Zambia using a reverse-sequence testing algorithm for antenatal syphilis screening.
METHODS: Between August 2019 and May 2023, we recruited 1510 pregnant women from a peri-urban hospital in Lusaka, Zambia. HIV positive and HIV negative women were enrolled in a 1:1 ratio. Blood collected at recruitment from the pregnant mothers was tested on-site for syphilis using a rapid treponemal test. Samples that tested positive were further tested at a different laboratory, with rapid plasma reagin using archived plasma.
RESULTS: Of the total 1,421 sera samples which were screened with a rapid treponemal test, 127 (8.9%) were positive and 1,294 (91.1%) were negative. Sufficient additional samples were available to perform RPR testing on 114 of the 127 (89.8%) RDT positive specimens. Thirty-one (27.2%) of these 114 were reactive by RPR and 83 (72.8%) were negative, resulting in a syphilis overtreatment rate of 3 fold (i.e, 84/114). Insufficient sample or test kit availability prevented any testing for the remaining 89 (5.9%) participants.
CONCLUSIONS: Use of only treponemal tests in low prevalence populations, like pregnant women, subjects individuals with non-active syphilis to the costs and possible risks of overtreatment. The use of the dual treponemal and non-treponemal tests would minimize this risk at some additional cost.

We report the case of a traveler who returned from Zambia and was diagnosed with Mediterranean spotted fever (MSF), an infectious disease caused by Rickettsia conorii conorii. The patient presented to Sapporo City General Hospital with symptoms of fever, malaise, headache, and rash. The pathogen was identified by Polymerase Chain Reaction assays and subsequent analyses. The patient improved with 10-day treatment of oral doxycycline. Although some cases of MSF have been reported in sub-Saharan Africa, none have been reported in Zambia. Rhipicephalus sanguineus sensu lato, the vector of the Rickettsia conorii conorii, has been found in various areas of Zambia. Our case report highlights the potential threat of Mediterranean spotted fever in urban areas of Zambia.

Two case studies of parenting programs for parents of children 0 to 36 months of age, developed and implemented by Save the Children/Ministry of Health/Khesar Gyalpo University in Bhutan and UNICEF Zambia, were conducted by an independent research group. The focus was on how program delivery and scale-up were revised on the basis of feedback from implementation research. Feedback on workforce delivery quality was based on observations of deliveries using a monitoring form, as well as survey and interview data collected from the workforce. In-depth interviews with the resource team during the fourth year of implementation revealed how the feedback was used to address horizontal and vertical scaling. Delivery quality was improved in some cases by revising the delivery manual, offering refresher courses, and instituting regular monitoring. Scaling challenges in Zambia included slow progress with regard to reaching families in the two districts, which they addressed by trialing group sessions, and stemming workforce attrition. The challenges in Bhutan were low attendance and reducing the workload of providers. Vertical scaling challenges for both countries concerned maintaining demand through continuous advocacy at community and government levels to sustain financing and to show effectiveness in outcomes.

Organophosphate poisoning is a common, under-reported cause of attempted and completed suicide worldwide. Following the resolution of the acute cholinergic syndrome, patients may develop respiratory muscle and proximal limb weakness, known as intermediate syndrome. A young man was brought to our rural hospital unconscious, in extremis, due to organophosphate pesticide poisoning. He developed atypical intermediate syndrome with global paralysis, persistent fasciculations and prolonged cholinergic symptoms, differing from the recognised presentation. He was intubated for fifteen days in our newly developed intensive care unit. Limited treatment options and the absence of blood gases, electrolyte testing, ECGs, invasive monitoring and imaging, in conjunction with regular disruptions to electricity and oxygen, and complications including seizures and pneumonia, all made this prolonged intubation an ambitious and challenging endeavour. We offer learning points for the acute physician and rural intensivist, and a summary of our reflections and hints for best care when adapting to a resource-limited setting.

We document the development and institutionalization in Zambia of a health innovation for diarrhea treatment aimed at children aged younger than 5 years: a unique oral rehydration salts and zinc (ORSZ) co-pack. Seven recommendations from the World Health Organization/ExpandNet are used retrospectively to analyze and describe the successful scale-up of this innovation from its concept stage, including in-country expansion and policy, institutional, and regulatory changes. The 7 recommendations comprise using a participatory process, tailoring to the country context, designing research to test the innovation, testing the innovation, identifying success factors, and scaling up. The scale-up of co-packaged ORSZ in Zambia is shown to be sustainable. Five years after donor funding ended in 2018, an independent, local manufacturer continues to supply the private and public sectors on a commercially viable basis. Furthermore, national coverage of ORSZ increased from less than 1% in 2012 to 34% in 2018. A key success factor was the continuous facilitation over 8 years (spanning planning, trial, evaluation, and scale-up) by a learning and steering group chaired by the Ministry of Health, open to all and focused on learning transfer and ongoing alignment with other initiatives. Other success factors included a long lead-in of inclusive initial consultation, ideation, and planning with all key stakeholders to build on and mobilize existing resources, knowledge, structures, and systems; alignment with government policy; thorough testing and radical review of the product and its value chain before scale-up, including manufacture, distribution, policy, and regulatory matters; and adoption by the government of a co-packaging strategy to ensure cases of childhood diarrhea are treated with ORSZ. With appropriate local adaptations, this approach to scale-up could be replicated in other low- and middle-income countries as a strategy to increase coverage of ORSZ and potentially other health products.

The study aim was to evaluate vaccine effectiveness (VE) of COVID-19 vaccines in preventing symptomatic COVID-19 among healthcare workers (HCWs) in Zambia. We sought to answer the question, \'What is the vaccine effectiveness of a complete schedule of the SARS-CoV-2 vaccine in preventing symptomatic COVID-19 among HCWs in Zambia?\'
We conducted a test-negative case-control study among HCWs across different levels of health facilities in Zambia offering point of care testing for COVID-19 from May 2021 to March 2022.
1767 participants entered the study and completed it. Cases were HCWs with laboratory-confirmed SARS-CoV-2 and controls were HCWs who tested SARS-CoV-2 negative. Consented HCWs with documented history of vaccination for COVID-19 (vaccinated HCWs only) were included in the study. HCWs with unknown test results and unknown vaccination status, were excluded.
The primary outcome was VE among symptomatic HCWs. Secondary outcomes were VE by: SARS-CoV-2 variant strains based on the predominant variant circulating in Zambia (Delta during May 2021 to November 2021 and Omicron during December 2021 to March 2022), duration since vaccination and vaccine product.
We recruited 1145 symptomatic HCWs. The median age was 30 years (IQR: 26-38) and 789 (68.9%) were women. Two hundred and eighty-two (24.6%) were fully vaccinated. The median time to full vaccination was 102 days (IQR: 56-144). VE against symptomatic SARS-CoV-2 infection was 72.7% (95% CI: 61.9% to 80.7%) for fully vaccinated participants. VE was 79.4% (95% CI: 58.2% to 90.7%) during the Delta period and 37.5% (95% CI: -7.0% to 63.3%) during the Omicron period.
COVID-19 vaccines were effective in reducing symptomatic SARS-CoV-2 among Zambian HCWs when the Delta variant was circulating but not when Omicron was circulating. This could be related to immune evasive characteristics and/or waning immunity. These findings support accelerating COVID-19 booster dosing with bivalent vaccines as part of the vaccination programme to reduce COVID-19 in Zambia.

Seizures are relatively common among children with HIV in low- and middle-income countries and are associated with significant morbidity and mortality. Early treatment with antiretroviral therapy (ART) may reduce this risk by decreasing rates of central nervous system infections and HIV encephalopathy.
We conducted a prospective, unmatched case-control study. We enrolled children with new-onset seizure from University Teaching Hospital in Lusaka, Zambia and 2 regional hospitals in rural Zambia. Controls were children with HIV and no history of seizures. Recruitment took place from 2016 to 2019. Early treatment was defined as initiation of ART before 12 months of age, at a CD4 percentage >15% in children aged 12-60 months or a CD4 count >350 cells/mm 3 for children aged 60 months or older. Logistic regression models were used to evaluate the association between potential risk factors and seizures.
We identified 73 children with new-onset seizure and compared them with 254 control children with HIV but no seizures. Early treatment with ART was associated with a significant reduction in the odds of seizures [odds ratio (OR) 0.04, 95% confidence interval: 0.02 to 0.09; P < 0.001]. Having an undetectable viral load at the time of enrollment was strongly protective against seizures (OR 0.03, P < 0.001), whereas history of World Health Organization Stage 4 disease (OR 2.2, P = 0.05) or CD4 count <200 cells/mm 3 (OR 3.6, P < 0.001) increased risk of seizures.
Early initiation of ART and successful viral suppression would likely reduce much of the excess seizure burden in children with HIV.

Kaposi sarcoma (KS), a multifocal vascular neoplasm frequently observed in HIV-positive individuals, primarily affects the skin, mucous membranes, visceral organs, and lymph nodes. KS is associated primarily with Kaposi sarcoma-associated herpesvirus (KSHV) infection. In this case report, we present a rare occurrence of co-infection and co-localization of KSHV and Epstein-Barr virus (EBV) in KS arising from the conjunctiva, which, to our knowledge, has not been reported previously. Immunohistochemistry (IHC), DNA polymerase chain reaction (PCR), and EBV-encoded RNA in situ hybridization (EBER-ISH) were utilized to demonstrate the presence of KSHV and EBV infection in the ocular KS lesion. Nearly all KSHV-positive cells displayed co-infection with EBV. In addition, the KS lesion revealed co-localization of KSHV Latency-Associated Nuclear Antigen (LANA) and EBV Epstein Barr virus Nuclear Antigen-1 (EBNA1) by multi-colored immunofluorescence staining with different anti-EBNA1 antibodies, indicating the possibility of interactions between these two gamma herpesviruses within the same lesion. Additional study is needed to determine whether EBV co-infection in KS is a common or an opportunistic event that might contribute to KS development and progression.

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