Characterizing Transmission of SARS-CoV-2 in a Peri-urban Population in Mozambique Using Population-based Sero-Surveillance (AfriCoVER Project)
Aims to conduct population-based surveillance in a Demographic Health Surveillance System (HDSS) of 16,500 people in a peri-urban neighborhood of Maputo, Mozambique, by collecting clinical information and respiratory specimens from patients during biweekly household visits, complemented with data from local clinics.
The investigators will use the established HDSS to set up population-based COVID19 surveillance in a household cohort. From any individual in this population with any respiratory symptom or loss of smell or taste, with or without fever, investigators will collect a respiratory specimen and test these for SARS-CoV-2 virus by PCR, during 12 months. These cases will be identified through bi-weekly household visits, through an alert system involving community leaders and HDSS interviewers, or when presenting with symptoms at healthcare centres or the referral hospital. Demographic, epidemiological and clinical data (comorbidities, medication, obesity, HIV, TB, smoking) of possible cases and of the source population will be recorded at baseline; recent illness, potential risk exposure of each household member (including duration and type) to SARS-CoV-2 positive individuals, uptake of measures to reduce exposure/transmission, and barriers to the uptake of such measures, will be recorded/updated during every household visit.
An age-stratified serial sero-survey will be conducted at baseline in a subset of the population in the population-based COVID19 surveillance, and at 3, 6 and 12 months, after confirmation of community transmission.
The Polana Caniço-HDSS (Health- and Demographic Surveillance System) has been established since 2017. In total, 2108 households (defined as residents of the same building, sharing a cooking area) have been enrolled in the HDSS. All members residing in the household for at least 3 months (infants, children, adults, elderly) are enrolled in the HDSS.
All households in the HDSS (2108 during the last round, in 2019) consenting to participate in the study will be visited biweekly by a trained HDSS interviewer, following the same procedures as in routine HDSS rounds, specified in the HDSS protocol (Instituto Nacional de Saude, 2016). We assume the same number of households will consent to participate as in other HDSS rounds.
Biospecimen Retention: Samples With DNA
Nasal swabs (for all possible Covid-19cases)
Dried Blood Spots (only in a subset of the population, 2400 individuals)
- Any individual enrolled in the Polana Caniço-HDSS: All members residing in the household for at least 3 months (infants, children, adults, elderly), regardless of age, underlying conditions, medical history, infection or disease status or history
- Able and willing to provide written informed consent: by the household head for the surveillance; by each selected participant for the sero-survey.
No Exclusion Criteria
Primary Outcome Measures :
- COVID-19 disease incidence rate (symptomatic infections per month) [ Time Frame: 12 months ]
- Estimate the COVID-19 incidence rate over a 12 month period in peri-urban Maputo
- COVID-19 related hospitalization rate due to SARS-CoV-2 [ Time Frame: 12 months ]
- Estimate the hospitalization rate related to SARS-CoV-2 over a 12 month period in peri-urban Maputo
- Case (disease) fatality risk (percent) due to SARS-CoV-2 [ Time Frame: 12 months ]
- Estimate the COVID-19 case fatality of cases detected during a 12 month period in peri-urban Maputo
- Proportion asymptomatic infections, by age group [ Time Frame: 12 months ]
- Estimate the proportion of infections that are asymptomatic, by age group
- SARS-CoV-2 infection annual attack rate (percent) [ Time Frame: 12 months ]
- Estimate the attack rate of SARS-CoV-2 infection during 12 months in peri-urban Maputo
- SARS-CoV-2 infection fatality risk [ Time Frame: 12 months ]
- Estimate the SARS-CoV-2 infection fatality of infections detected during a 12 month period in peri-urban Maputo
- Infection fatality of SARS-CoV-2 infection. [ Time Frame: 12 months ]
- Estimate the infection fatality of SARS-CoV-2 infection in peri-urban Maputo.
- Serial interval number of SARS-CoV-2 infection [ Time Frame: 12 months]
- Estimate the serial interval number of SARS-CoV-2 infection in peri-urban Maputo.
- Reproduction number of SARS-CoV-2 infection [ Time Frame: 12 months]
- Estimate the reproduction number of SARS-CoV-2 infection in peri-urban Maputo.
Secondary Outcome Measures:
- Correlation between anti-coronavirus (endemic coronavirus or SARS-CoV-2) antibody titers and reinfection [ Time Frame: 12 months ]
- Analyze the correlation between anti-coronavirus (endemic coronavirus or SARS-CoV-2) antibody titers and reinfection
- Antibody titers against SARS-CoV-2 over time [ Time Frame: 12 months ]
- Measure antibody titers against SARS-CoV-2 over time