Factors affecting tuberculosis health message recall 2 years after active case finding in Blantyre, Malawi.

SETTING: Urban slums, Blantyre, Malawi. OBJECTIVE: To explore tuberculosis (TB) community-wide active case finding (cwACF) recall and accompanying messaging 2 years after the intervention. DESIGN: This mixed-methods study used population-weighted random cluster sampling to select three cwACF-receiving and three non-cwACF-receiving neighbourhoods in Blantyre. Qualitative data were collected using 12 focus group discussions (community peer-group members) and five in-depth interviews (TB officers) with script guides based on the concepts of the Health Belief Model (HBM). Thematic analysis was used to explore transcripts employing deductive coding. Questionnaires completed by focus group participants were used to collect quantitative data, providing a 'knowledge score' evaluated through univariate/multivariate analysis, analysis of variance and multiple linear regression. RESULTS: Community peer-group participants (n = 118) retained high awareness and positive opinions of cwACF and recognised the relationship between early diagnosis and reduced transmission, considering cwACF to have prompted subsequent health-seeking behaviour. TB-affected individuals (personal/family: 47.5%) had significantly higher knowledge scores than unaffected individuals (P = 0.039), but only if resident in cwACF-receiving neighbourhoods (P = 0.005 vs. P = 0.582), implying effect modification between exposures, albeit statistically under-powered (P = 0.229). CONCLUSION: Consistent with epidemiological evidence and HBM theory, cwACF may have a permanent impact on knowledge and behaviour, particularly in communities with a high prevalence of TB-affected individuals. Behaviour change strategies should be explicitly included in cwACF planning and evaluation

Serological profile of first SARS-CoV-2 reinfection cases detected within the SIREN study.

OBJECTIVES: To describe the serological profile of first two SARS-CoV-2 confirmed reinfections in the national healthcare worker cohort study SARS-CoV-2 Immunity and Reinfection Evaluation (SIREN) and potentially identify correlates of protection against reinfection. METHODS: In addition to routine testing within the SIREN study, viral culture, sequencing and phylogenetic analysis were performed. Total antibody testing (Anti-SARS-CoV-2 nucleocapsid and Anti-SARS-CoV-2 spike) were complemented by receptor binding domain indirect ELISA and neutralising antibody assays. RESULTS: The first two SARS-CoV-2 confirmed reinfections had mild symptomatic illness episodes from which infectious virus was recovered at the time of reinfection. The recovered viruses and their sequences were closely related to viruses circulating locally during the time of reinfection and serology was consistent with reinfection. Prior to reinfection, both cases had ELISA and immunoblot detectable anti-N antibodies, but lacked live virus neutralising antibody. Within days following reinfection, neutralising antibodies became detectable and anti-N and anti-S binding antibodies were boosted. CONCLUSIONS: We hypothesise that titres of neutralising antibody can be used as a correlate of protection against reinfection. Further analysis using a case-control design is essential in order to confirm this hypothesis