Transmission Dynamics of COVID-19 in a Rural Setting of the Democratic Republic of the Congo
Condition: Covid19
MeSH terms: COVID-19
Study type: Observational

Summary: 
      A fixed cohort of adults in rural Kimpese will be followed up every two months since they are
      assumed to be at above average risk of contracting COVID-19. Every two months these
      individuals will be interviewed with a focus on COVID-19 related symptoms and possible
      exposure to the disease and have their temperature recorded.

      A social mixing survey will also be carried out to assess human contact behaviour. The data
      generated will help inform mathematical modelling that can predict which proportion of the
      population per age group is likely to get infected once COVID-19 is introduced in this rural
      population, and the epidemic size if no intervention, as well as when targeted interventions
      are introduced. During the outbreak, physical distancing measures could be implemented. The
      monitoring of social contacts, again using a social-mixing survey, will contribute to the
      understanding of the impact of such measures in a rural context on transmission of
      SARS-CoV-2. The results from the seroprevalence over time, will be used to refine and
      validate the predictions from the modelling results, (re)calibrate the model where needed,
      and test hypotheses on transmission-dynamics of COVID-19.

      In case of an established epidemic of Severe acute respiratory syndrome coronavirus 2
      (SARS-CoV-2) in the Health Zone of Kimpese, the sero-surveillance will be extended from an
      assumed high risk cohort to a representative sample of the overall population. Moreover,
      support to the COVID-19 control measures will be provided by the study team. The national
      guidelines recommend household transmission investigation for the first 100 confirmed
      laboratory cases. During the household visit, information on symptoms and one serum sample
      will be requested of all household members of the index case. If household members are
      present with symptoms and fever, the COVID-19 outbreak team of Kimpese will provide
      diagnostic testing and medical care.
    

Detailed description: 
      The sero-surveillance will start in a cohort of 800 adults (18-50y). In case of an
      established outbreak, this sample will be extended to 800 pre-school children (0-5y), 800
      schoolchildren (6-17y) and elderly (50+y). Human interactions will be quantified for the
      rural context of Kimpese in four age categories, pre-school children (0-5y), schoolchildren
      (6-17y), adults (18-50y) and elderly (50+). A sample of 300 persons in each age group will be
      selected.

      The study site will be the Health Demographic Surveillance System (HDSS) in the health
      district of Kimpese, Kongo-Central province, DRC, managed Centre de Recherche en Santé de
      Kimpese (CRSK). Each village, household and household member is listed in the HDSS database,
      each household has been geo-referenced. The HDSS has enrolled a cohort of 60 000 inhabitants
      in 11 rural health areas of the district. CRSK is the partner involved in the study and from
      the core database the cohort population for the study will be selected using two stage
      sampling. In stage one 20 villages will be randomly selected from the HDSS database using
      population size as sampling weight. In stage two a random sample of 40 eligible individuals
      will be drawn in each of the selected villages.

      In the cohort, a blood sample will be collected for serology (sero-surveillance). When an
      individual presents seroconversion, the household attack rate will be explored. Information
      on symptoms and one serum sample of each household member, irrespective of age, will be
      requested during the next follow-up visit. Any study subject reporting symptoms or presenting
      with a fever, will be referred to the Institut Médical Evangélique (IME) hospital for
      appropriate medical care.

      A social mixing survey will be carried out to assess human contact behaviour, in an extended
      cohort involving four age groups (0-5 years; 6-17 years; 18-50 years; >50 years old), sampled
      from the overall population in rural Kimpese.
    

Intervention name(s): serological surveillance
Intervention type(s): Biological
Intervention description(s): serological surveillance, detection of antibodies (Total Ig and IgM) developed against SARS-CoV-2 in a population living in a rural area (Kimpese, DRC)
Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        The study site will be the Health Demographic Surveillance System (HDSS) in the health
        district of Kimpese, Kongo-Central province, DRC, managed by Centre de Recherche en Santé
        de Kimpese (CRSK). Each village, household and household member is listed in the HDSS
        database, each household has been geo-referenced. The HDSS has enrolled a cohort of 60 000
        inhabitants in 11 rural health areas of the district. Up to now, this area has not declared
        any COVID-19 cases. The IME hospital of Kimpese has been designated for the hospitalisation
        and medical care of COVID-19 suspect and confirmed cases and the outbreak response team has
        been established
      
Biospecimen description: 
      Whole blood samples
    
Keywords: serological test