The prevalence and distribution of malaria in Mpumalanga Province before and during COVID-19 (2017 - 2022)

BACKGROUND

South Africa (SA) has committed to eliminating malaria by 2028. However, the initial target was set for 2023. Additionally, the ongoing COVID-19 pandemic and the emergence of drug and insecticide resistance have been identified as potential stumbling blocks in the achievement of this goal. The impact of COVID-19 on the prevalence and distribution of malaria in SA is unclear.

OBJECTIVE

To describe the trends and distribution of malaria before and during the pandemic and its associated lockdown strategies in one of the country's malaria-endemic provinces, Mpumalanga Province.

METHOD

A descriptive, retrospective and cross-sectional study was conducted using Mpumalanga provincial malaria case data extracted from the provincial District Health Information System 2. The impact of COVID-19 on the prevalence and distribution of malaria was assessed in Mpumalanga Province between 2017 and 2022 using descriptive trend analysis. Malaria cases before (2017 - 2019) and post- COVID-19 (2020 - 2022) were cross-tabulated using Stata version 17. We used χ2 tests to test for significant differences, set at p<0.05.

RESULTS

During the study period, 25 380 malaria cases were reported, with the majority men (61%) >26 years old, with reported international travel, primarily to Mozambique. Limpopo Province (93%) accounted for most of the locally imported cases. Headaches and fever were the most common symptoms before and post COVID-19, while asymptomatic malaria carriage was higher during and post COVID (p<0.05). Prior to the pandemic reporting of the preferred treatment for uncomplicated malaria, Coartem use was at 53%, declining to 21% thereafter. Although COVID-19-related restrictions on human movement greatly reduced the malaria burden in Mpumalanga Province, the high-risk group (young mobile men) remained unchanged over the study period. Of concern were the marked reduction in the reporting of Coartem doses administered and the increased prevalence of asymptomatic carriage since 2020. The importation of malaria poses one of the biggest challenges to malaria elimination in Mpumalanga Province.

CONCLUSION

This study highlighted the impact of COVID-19 and its related lockdown restrictions on the delivery of malaria health services in Mpumalanga Province. If malaria elimination is to be achieved, all aspects of the malaria programme must be strengthened urgently. Additionally, the health system and cross-border collaborations must also be strengthened.

SARS-CoV-2 Transmission Risk in the School Environment: a pilot case-ascertained prospective study to inform future school-based surveillance

BACKGROUND

There is no current active or passive disease surveillance programme focused on schools in South Africa. As such the country is missing an opportunity to rapidly and effectively flag and address pathogen outbreaks, for example SARS-CoV-2, in a key closed setting. Furthermore, the role of school transmission in the spread of the SARS-CoV-2 virus within communities is uncertain.  Objective. This pilot study, conducted during March 2022 in Cape Town, aimed to indicate the feasibility of conducting intense active contact-tracing in a school environment prior to a large national study to compare school versus community SARS-CoV-2 transmission risk.  Methods. We conducted a pilot school-level case-ascertained prospective study with a component of enhanced surveillance. Following study initiation, the first learner at a participating school who tested SARS-CoV-2 positive (via Polymerase Chain Reaction (PCR) or a Rapid Antigen Test (RAT)) was invited to join the study as the index case and all their school-based close contacts were followed up telephonically, monitored for symptoms for 14 days, and tested using a PCR if any symptoms were reported.  Results. On 8th March 2022, a student with RAT laboratory-confirmed COVID-19 was identified and they and their guardian consented to participate as the index case. Of the 11 eligible close contacts, six provided consent/assent and completed symptom monitoring calls until the end of the 14-day study period. The Secondary Attack Rate (SAR) was 2/11 (18.18%) of all close contacts who were at risk of infection, 2/4 (50.0%) of all those close contacts who developed symptoms, and 2/4 (50.0%) of all those close contacts who developed symptoms and were tested for SARS-CoV-2. During the same period, the school reported that nine of the 926 learner body tested COVID-19 positive (0.97%). Total hours spent conducting monitoring for 6 learners was 27 hours, with each learner requiring approximately 4.5 hours of contact time during the study period.  Conclusion. This is the first South African school-based COVID-19 transmission study, the results of which can inform national discussions regarding the role of schools and school-based active and passive surveillance in pathogen prevention and control.

Comparing adults with severe SARS-CoV-2 or influenza infection: South Africa, 2016-2021

Background

Comparisons of the characteristics of individuals hospitalised with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or seasonal influenza in low-to middle-income countries with high human immunodeficiency virus (HIV) prevalence are limited.

Objectives

Determine the epidemiological differences with those hospitalised with influenza or SARS-CoV-2 infection.

Method

We investigated hospitalised individuals ≥18 years of age testing positive for seasonal influenza (2016-2019) or SARS-CoV-2 (2020-2021). We used random effects multivariable logistic regression, controlling for clustering by site, to evaluate differences among adults hospitalised with influenza or SARS-CoV-2 infection.

Results

Compared to individuals with influenza, individuals with SARS-CoV-2 infection were more likely to be diabetic (adjusted odds ratio [aOR]: 1.70, 95% confidence interval [CI]: 1.11-2.61) or die in hospital (aOR: 2.57, 95% CI: 1.61-4.12). Additionally, those with SARS-CoV-2 infection were less likely to be living with HIV (not immunosuppressed) (aOR: 0.50, 95% CI: 0.34-0.73) or living with HIV (immunosuppressed) (aOR: 0.27, 95% CI: 0.18-0.39) compared to not living with HIV and less likely to be asthmatic (aOR: 0.21, 95% CI: 0.13-0.33) rather than those living with influenza.

Conclusion

Individuals hospitalised with SARS-CoV-2 had different characteristics to individuals hospitalised with influenza before the coronavirus disease 2019 (COVID-19) pandemic. Risk factors should be considered in health management especially as we move into an era of co-circulation of SARS-CoV-2 and influenza pathogens.

Contribution

Identifying groups at high risk of severe disease could help to better monitor, prevent and control SARS-CoV-2 or influenza severe disease.

Wastewater surveillance overcomes socio-economic limitations of laboratory-based surveillance when monitoring disease transmission: The South African experience during the COVID-19 pandemic

Wastewater and environmental surveillance has been promoted as a communicable disease surveillance tool because it overcomes inherent biases in laboratory-based communicable disease surveillance. Yet, little empirical evidence exists to support this notion, and it remains largely an intuitive, though highly plausible hypothesis. Our interdisciplinary study uses WES data to show evidence for underreporting of SARS-CoV-2 in the context of measurable and statistically significant associations between economic conditions and SARS-CoV-2 incidence and testing rates. We obtained geolocated, anonymised, laboratory-confirmed SARS-CoV-2 cases, wastewater SARS-CoV-2 viral load data and socio-demographic data for Gauteng Province, South Africa. We spatially located all data to create a single dataset for sewershed catchments served by two large wastewater treatment plants. We conducted epidemiological, persons infected and principal component analysis to explore the relationships between variables. Overall, we demonstrate the co-contributory influences of socio-economic indicators on access to SARS-CoV-2 testing and cumulative incidence, thus reflecting that apparent incidence rates mirror access to testing and socioeconomic considerations rather than true disease epidemiology. These analyses demonstrate how WES provides valuable information to contextualise and interpret laboratory-based epidemiological data. Whilst it is useful to have these associations established for SARS-CoV-2, the implications beyond SARS-CoV-2 are legion for two reasons, namely that biases inherent in clinical surveillance are broadly applicable across pathogens and all pathogens infecting humans will find their way into wastewater albeit in varying quantities. WES should be implemented to strengthen surveillance systems, especially where economic inequalities limit interpretability of conventional surveillance data.