Author Contributions: Drs Jakubowski and Egger had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.

BackgroundMany countries in sub-Saharan Africa have so far avoided large outbreaks of COVID-19, perhaps due to the strict lockdown measures that were imposed early in the pandemic. Yet the harsh socio-economic consequences of the lockdowns have led many governments to ease the restrictions in favor of less stringent mitigation strategies. In the absence of concrete plans for widespread vaccination, masks remain one of the few tools available to low-income populations to avoid the spread of SARS-CoV-2 for the foreseeable future.MethodsWe compare mask use data collected through self-reports from phone surveys and direct observations in public spaces from population-representative samples in Ugunja subcounty, a rural setting in Western Kenya. We examine mask use in different situations and compare mask use by gender, age, location, and the riskiness of the activityFindingsWe assess mask use data from 1,960 phone survey respondents and 9,549 direct observations. While only 12% of people admitted in phone interviews to not wearing a mask in public, 90% of people we observed did not have a mask visible (77.7% difference, 95% CI 0.742, 0.802). Self-reported mask use was significantly higher than observed mask use in all scenarios (i.e. in the village, in the market, on public transportation).InterpretationWe find limited compliance with the national government mask mandate in Kenya using directly observed data, but high rates of self-reported mask use. This vast gap suggests that people are aware that mask use is socially desirable, but in practice they do not adopt this behavior.Focusing public policy efforts on improving adoption of mask use via education and behavioral interventions may be needed to improve compliance.FundingWeiss Family Foundation, International Growth Centre

BackgroundMeasuring effectiveness of HIV prevention interventions is challenged by bias when using self-reported knowledge, attitude or behavior change. HIV incidence is an objective marker to measure effectiveness of HIV prevention interventions, however, because new infection rates are relatively low, prevention studies require large sample sizes. Herpes simplex virus type 2 (HSV-2) is similarly transmitted and more prevalent and could thus serve as a proxy marker for sexual risk behavior and therefore HIV infection.MethodsHSV-2 antibodies were assessed in a sub-study of 70,000 students participating in an education intervention in Western Province, Kenya. Feasibility of testing for HSV-2 antibodies was assessed comparing two methods using Fisher’s exact test. Three hundred and ninety four students (aged 18 to 22 years) were randomly chosen from the cohort and tested for HIV, Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis. Out of these, 139 students were tested for HSV-2 with ELISA and surveyed for sexual risk behavior and 89 students were additionally tested for HSV-2 with a point-of-contact (POC) test.ResultsPrevalence rates were 0.5%, 1.8%, 0.3% and 2.3% for HIV, Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis, respectively. Prevalence of HSV-2 antibodies was 3.4 % as measured by POC test (n=89) and 14.4 % by ELISA (n=139). Specificity of the POC test compared with ELISA was 100%, and the sensitivity only 23.1%. Associations between self-reported sexual behavior and HSV-2 serostatus could not be shown.ConclusionsAssociations between self-reported sexual risk behavior and HSV-2 serostatus could not be shown, probably due to social bias in interviews since its transmission is clearly linked. HSV-2 antibody testing is feasible in resource-poor settings and shows higher prevalence rates than other sexually transmitted diseases thus representing a potential biomarker for evaluation of HIV prevention interventions.

Background: COVID-19 continues to pose a major threat to countries around the world, and non-pharmaceutical interventions such as social distancing and face coverings remain important to reduce transmission, especially in settings with low vaccination rates. Despite a nationwide mask mandate in Kenya during the pandemic, proper masking remained low in Siaya County. We conducted a pilot study with the Siaya County Ministry of Health to improve mask adoption within Ugunja subcounty, and present initial findings on mask usage effects. Methods: The study took place across 72 villages in Ugunja subcounty, which were randomly assigned to receive: (i) free mask and education on mask usage; (ii) only education on mask usage; or (iii) no mask or education by community health workers. A role model intervention was also cross-randomized across half of the villages, along with SMS messages reinforcing a variety of messages around masking. The intervention was administered in January 2021. Data collection was done via phone survey and direct observation of mask usage. Findings: Preliminary analysis of the pilot study suggests providing free face masks may improve compliance, particularly in settings with higher COVID-19 risks. Two weeks to three months after the intervention, the free mask and education arm increased directly-observed correct mask usage by 3.1 percentage points (95% confidence interval 1.9, 6.0) on a control mean of 6.8 percent. Some treatment arms also improved COVID-19 knowledge and mask attitudes. Interpretation: Interventions designed to increase adoption of health measures can be successful, but behavioral change is challenging and may require frequent reinforcement.