“SARS-CoV-2 testing and contact-tracing data from the Indian states of Tamil Nadu and Andhra Pradesh reveal stark contrasts from epidemics affecting high-income countries, with 92.1% of cases and 59.7% of deaths occurring among individuals <65yo.” medrxiv.org/content/10.110…
“The per-contact risk of infection is 9.0% (95% confidence interval: 7.5-10.5%) in the household and 2.6% (1.6-3.9%) in the community.”
“Superspreading plays a prominent role in transmission, with 5.4% of cases accounting for 80% of infected contacts.”
“The case-fatality ratio is 1.3% (1.0-1.6%), and median time-to-death is 5 days from testing.”
CFR is lower. TIme to death is lower.
CFR is lower. TIme to death is lower.
Up to 951 contacts were traced for each index case and tested within 5-14 days of exposure according to contact tracing protocols;
11 cases were linked to ≥200 contacts, whereas 50% of cases for whom contact tracing data were available had 7 or fewer contacts traced.
11 cases were linked to ≥200 contacts, whereas 50% of cases for whom contact tracing data were available had 7 or fewer contacts traced.
“Fitting a negative binomial distribution to the number of infected contacts linked to each index case, we estimated a dispersion parameter [k] of 0.072 (0.065-0.079). This estimate falls within the range estimated for SARS-CoV-2 outbreaks in other settings”
“Secondary attack rate estimates ranged from 1.0% (0.0-5.4%) in healthcare settings to 2.6% (1.6-3.9%) in the community and 9.0% (7.5-10.5%) in the household; in total, 48.3% of all positive contacts were traced to an index case in their household”
Very little nosocomial xsmn.
Very little nosocomial xsmn.
“Individuals who traveled in close (<1m) proximity to an index case in a shared conveyance were at the greatest risk of infection: this exposure was associated with 30.61 (23.03-40.75) fold higher risk than community exposure.”
Three Cs: close contact, confined spaces, crowds
Three Cs: close contact, confined spaces, crowds
“While contacts of index cases who were children appeared more likely to be infected than contacts of adult index cases, this pattern did not persist after adjusting for the fact that contact with children more often occurred in household settings”
But no association with age!
But no association with age!
“within the sub-cohort, no deaths occurred at ages 0-17 years, and case fatality ratios were 0.13% (0.04-0.28%) at ages 18-39 years, 2.3% (1.8-2.9%) at ages 40-64 years, and 6.5% (4.4-8.9%) at ages ≥65 years. Within each age group, men had greater risk of mortality than women”
“We estimated reproduction numbers in the range of ~2-3 in these settings as of late March, 2020, and identified reductions in Rt associated with the implementation of India’s country-wide lockdown and social distancing interventions at state and local levels.”
“we identify no difference in infection risk among contacts of infected children and adults.”
“our observation of equivalent transmission risk across ages suggests a prominent role of children and young adults in sustaining epidemics, where 33% of cases were <30 years old.”
“our observation of equivalent transmission risk across ages suggests a prominent role of children and young adults in sustaining epidemics, where 33% of cases were <30 years old.”
They only managed to trace 12% of contacts overall.
“This limitation likely contributes to an underestimate of the true community secondary attack rate, and an overestimate of the proportion of exposures occurring in household settings.”
“This limitation likely contributes to an underestimate of the true community secondary attack rate, and an overestimate of the proportion of exposures occurring in household settings.”
