• #Transmission of #SARS-COV-2 Infections in Households — Tennessee and Wisconsin, April–September 2020 | MMWR

    Étude prospective (et en cours) sur la transmission du virus dans les foyers familiaux,

    – proportion de contacts contaminés : étonnamment élevée

    Among these 191 contacts, 102 had SARS-CoV-2 detected in either nasal or saliva specimens during follow-up, for a secondary infection rate of 53% (95% confidence interval [CI] = 46%–60%).

    #contagiosité en fonction de l’âge : les #enfants ne sont pas en reste et pas seulement les adolescents,

    Among fourteen households in which the index patient was aged <18 years, the secondary infection rate from index patients aged <12 years was 53% (95% CI = 31%–74%) and from index patients aged 12–17 years was 38% (95% CI = 23%–56%).

    – délai de positivité du PCR chez les personnes contaminées : court

    Approximately 75% of secondary infections were identified within 5 days of the index patient’s illness onset, and substantial transmission occurred whether the index patient was an adult or a child.

    – proportion de personnes #asymptomatiques au moment de la positivité du PCR (60%) et combien le restent (33%- sur un suivi de 7 jours) :

    Forty percent (41 of 102) of infected household members reported symptoms at the time SARS-CoV-2 was first detected by RT-PCR. During 7 days of follow-up, 67% (68 of 102) of infected household members reported symptoms, which began a median of 4 days (IQR = 3–5) after the index patient’s illness onset.

    Proportion de personnes PCR positifs asymptomatiques pour l’ensemble des contacts : 18%

    The rates of symptomatic and asymptomatic laboratory-confirmed SARS-CoV-2 infection among household members was 36% (95% CI = 29%–43%) and 18% (95% CI = 13%–24%), respectively.

    Enseignements :

    These findings suggest that transmission of SARS-CoV-2 within households is high, occurs quickly, and can originate from both children and adults.

    An important finding of this study is that fewer than one half of household members with confirmed SARS-CoV-2 infections reported symptoms at the time infection was first detected, and many reported no symptoms throughout 7 days of follow-up, underscoring the potential for transmission from asymptomatic secondary contacts and the importance of quarantine. Persons aware of recent close contact with an infected person, such as a household member, should quarantine in their homes and get tested for SARS-CoV-2