Clinical Characteristics and Factors Associated with Long COVID in Zambia, August 2020 to January 2023 (preprint)

BackgroundSeveral seroprevalence studies in Africa documented the extent of spread of SARS-CoV-2, yet there is limited data on signs, symptoms and conditions that continue or develop after acute COVID-19 infection (long COVID). We sought to examine patient characteristics at post-acute COVID-19 (PAC-19) clinics in Zambia and assess factors associated with long COVID at first visit to a PAC-19 clinic and longitudinally among a cohort of patients. MethodsLong COVID was defined, initially in the Zambia PAC-19 clinical guidelines, as new, relapsing or persistent symptoms lasting >4 weeks after an initial SARS-CoV-2 infection. Severe illness was defined as COVID-19 episode that required supplemental oxygen therapy, intensive care unit stay or treatment with steroids/remdesivir. We fitted logistic regression models with cross-sectional and longitudinal data and considered statistical significance at p<0.05. ResultsIn total, 1,359 patients attended PAC-19 clinics and had data abstracted from Aug-2020 to Jan-2023; 548 (40.3%) patients with [≥]2 visits were included in the longitudinal analysis. Patients median age was 53 (interquartile range [IQR]: 41-63) years, 919 (67.6%) were hospitalized for acute COVID-19, and of whom 686 (74.6%) had severe illness. Patients with hospital length of stay [≥]15 days (adjusted odds ratio [aOR]: 5.50; 95% confidence interval [95% CI]: 3.06-10.3), severe illness (aOR: 3.23; 95% CI: 1.68-6.75), and comorbidities (aOR:1.51; 95% CI: 1.04-2.22) had significantly higher odds of long COVID. Longitudinally, long COVID prevalence significantly (p<0.001) declined from 75.4% at the first PAC-19 visit to 26.0% by the fifth visit. The median follow-up time was 7 (IQR: 4-12) weeks. ConclusionLong COVID symptoms were common among patient presenting for care in PAC-19 clinics in Zambia, but most recovered within [~]2 months. Despite potentially substantial morbidity due to long COVID, few patients overall with COVID-19 attended a PAC-19 clinic. Scaling up PAC-19 services and integrating into routine clinical care could improve access by patients.

Factors associated with SARS-CoV-2 among persons living with HIV in Zambia: Analysis of three concurrent SARS-CoV-2 prevalence surveys conducted in July 2020 in six districts of Zambia (preprint)

People living with HIV (PLHIV) are a unique population because of their altered immune systems and taking antiretroviral therapy (ART) that may modify risk of SARS-CoV-2. Evidence from sub-Saharan African countries suggests that, despite not having higher SARS-CoV-2 infection prevalence than HIV-negative persons, PLHIV suffer worse COVID-19 outcomes. We assessed the prevalence of SARS-COV-2 infection by HIV status in Zambia in July 2020. We analyzed data from three different concurrent SARS-CoV-2 prevalence surveys (household, outpatient-department, and health-worker) conducted in six districts of Zambia in July 2020. Information on demographics and medical history was collected. Nasopharyngeal swabs were used to screen for SARS-CoV-2 RNA using polymerase-chain-reaction (PCR) and blood specimens were screened for SARS-CoV-2 virus-specific antibodies using an enzyme-linked-immunosorbent-assay (ELISA). Test-specific SARS-CoV-2 prevalence was calculated. Multilevel logistic regression models were used to measure test-specific adjusted odd ratios (aORs) of SARS-CoV-2 positivity by HIV status, controlling for demographic and medical history. We analysed the outcomes of the two different tests separately. Among 7,092 participants, 4,717 (66.5%) consented to blood-draw and 4,642 (65.5%) consented to nasopharyngeal swab. Overall SARS-CoV-2 positivity was 9.4% by PCR and 3.8% by ELISA. SARS-CoV-2 prevalence detected by PCR was higher among PLHIV than HIV-negative respondents (12.4% vs 9.1%, respectively, OR: 1.4, 95% confidence intervals [CI]: 1.0-1.9) and lower by ELISA (1.9% vs 3.9%, respectively, OR: 0.5, 95%CI: 0.2-0.9). Among PLHIV, not being on ART was an independent predictor of SARS-CoV-2 PCR positivity (aOR: 5.24,95% CI: 1.19-22.22) but did not have a significant effect on ELISA results. During the first COVID-19 wave in Zambia, PLHIV were more likely to be acutely infected with SARS-CoV-2 but less likely to be seropositive than participants without HIV. Intervention programs could focus on early access to COVID-19 vaccinations, testing and ART might reduce COVID-19 morbidity among PLHIV.

COVID-19 vaccine effectiveness during a prison outbreak when the Omicron was the dominant circulating variant, Zambia, December 2021 (preprint)

Abstract: During a COVID-19 outbreak in a prison in Zambia from 14th to 19th December 2021, a case-control study was done to measure vaccine effectiveness (VE) against infection and symptomatic infection, when the Omicron variant was the dominant circulating variant. Among 382 participants, 74.1% were fully vaccinated and the median time since full vaccination was 54 days. There were no hospitalizations or deaths. COVID-19 VE against any SARS-CoV-2 infection was 62.8% and VE against symptomatic SARS-CoV-2 infection was 74.1%. COVID-19 vaccination helped protect incarcerated persons against SARS-CoV-2 infection during an outbreak while Omicron was the dominant variant in Zambia.

SARS-CoV-2 Mortality Surveillance among Community Deaths brought to University Teaching Hospital Mortuary in Lusaka, Zambia, 2020 (preprint)

Introduction During March-December 2020, Zambia recorded 20,725 confirmed COVID-19 cases, with the first wave peaking between July and August. Of the 388 COVID-19-related deaths occurring nationwide, most occurred in the community. We report findings from COVID-19 mortality surveillance among community deaths brought to the University Teaching Hospital (UTH) mortuary in Lusaka. Methods In Zambia, when a person dies in the community, and is brought into a health facility mortuary, they are recorded as ‘brought in dead’ (BID). The UTH mortuary accepts persons BID for Lusaka District, the most populated district in Zambia. We analyzed data for persons BID at UTH during 2020. We analyzed two data sources: weekly SARS-CoV-2 test results for persons BID and monthly all-cause mortality numbers among persons BID. For all-cause mortality among persons BID, monthly deaths during 2020 that were above the upper bound of the 95% confidence interval for the historic mean (2017-2019) were considered significant. Spearman’s rank test was used to correlate the overall percent positivity in Zambia with all-cause mortality and SARS-CoV-2 testing among persons BID at UTH mortuary. Results During 2020, 7,756 persons were BID at UTH (monthly range 556-810). SARS-CoV-2 testing began in April 2020, and through December 3,131 (51.9%) of 6,022 persons BID were tested. Of these, 212 (6.8%) were SARS-CoV-2 positive with weekly percent test positivity ranging from 0-32%, with the highest positivity occurring during July 2020. There were 1,139 excess persons BID from all causes at UTH mortuary in 2020 compared to the 2017-2019 mean. The monthly number of persons BID from all causes was above the upper bound of the 95% confidence interval during June-September and December. Conclusion Increases in all-cause mortality and SARS-CoV-2 test positivity among persons BID at UTH mortuary corresponded with the first peak of the COVID-19 epidemic in June and August 2020, indicating possible increased mortality related to the COVID-19 epidemic in Zambia. Combining all-cause mortality and SARS-CoV-2 testing for persons BID provides useful information about the severity of the epidemic in Lusaka and should be implemented throughout Zambia.

Two-Month Follow-up of Persons with SARS-CoV-2 Infection: Zambia, September 2020 (preprint)

BackgroundCOVID-19 is often characterized by an acute upper respiratory tract infection. However, information on longer-term clinical sequelae following acute COVID-19 is emerging. We followed a group of persons with COVID-19 in Zambia at two months to assess persistent symptoms. MethodsIn September 2020, we re-contacted participants from SARS-CoV-2 prevalence studies conducted in Zambia in July 2020 whose PCR tests were positive. Participants with valid contact information were interviewed using a structured questionnaire that captured demographics, pre-existing conditions, and types and duration of symptoms. We describe the frequency and duration of reported symptoms and used chi-square tests to explore variability of symptoms by age group, gender, and underlying conditions. ResultsOf 302 participants, 155 (51%) reported one or more acute COVID-19-related symptoms in July 2020. Cough (50%), rhinorrhoea (36%) and headache (34%) were the most frequently reported symptoms proximal to diagnosis. The median symptom duration was 7 days (IQR: 3-9 days). At a median follow up of 54 days (IQR: 46-59 day), 27 (17%) symptomatic participants had not yet returned to their pre-COVID-19 health status. These participants most commonly reported cough (37%), headache (26%) and chest pain (22%). Age, sex, and pre-existing health conditions were not associated with persistent symptoms. ConclusionA notable percentage of persons with SARS-CoV-2 infection in July still had symptoms nearly two months after their diagnosis. Zambia is implementing post-acute COVID-19 clinics to care for patients with prolonged symptoms of COVID-19, to address their needs and better understand how the disease will impact the population over time.