A common view of the Facilities for Illness Management and Prevention (CDC) headquarters in Atlanta.
Tami Chappell | Reuters
A brand new CDC research discovered that some aged individuals who apparently recovered from the coronavirus later got here down with a second, even worse case — indicating that asymptomatic or gentle instances might not present plenty of safety towards changing into reinfected with Covid-19.
The research, revealed Thursday within the Facilities for Illness Management and Prevention’s Morbidity and Mortality Weekly Report, studied two separate outbreaks that occurred three months aside at a talented nursing facility in Kentucky. Between mid-July and mid-August, 20 residents and 5 health-care personnel examined optimistic for the virus, in line with the research.
The second outbreak, between late October and the start of December, was worse — 85 residents and 43 health-care personnel examined optimistic for the virus. Among the many residents who examined optimistic throughout the first outbreak and had been nonetheless dwelling within the facility, 5 of them examined optimistic a second time greater than 90 days after their first optimistic check.
Although Covid-19 reinfections do occur, they’re usually uncommon.
By means of frequent surveillance after the primary outbreak, all 5 residents had a minimum of 4 unfavorable checks between outbreaks, suggesting they had been doubtlessly reinfected with the virus afterward, the research discovered. Reinfection signifies that an individual who had Covid-19 recovered after which bought it once more, in line with the CDC.
“The publicity historical past, together with the timing of roommates’ infections and the brand new onset of signs throughout the second outbreak, counsel that the second optimistic RT-PCR outcomes represented new infections after the sufferers apparently cleared the primary an infection,” wrote Alyson Cavanaugh, one of many researchers who led the research.
Whereas solely two of the 5 residents skilled slight signs throughout the first outbreak, all 5 doubtlessly reinfected residents confirmed indicators of sickness the second time. The 2 residents who reported signs throughout the first outbreak “skilled extra extreme signs throughout the second infectious episode,” in line with the research. One resident was hospitalized and subsequently died.
In accordance with the research’s researchers, this was “noteworthy” as a result of it suggests the likelihood that individuals who present gentle to no signs throughout their first infections “don’t produce a sufficiently sturdy immune response to stop reinfection.” The outcomes “counsel the likelihood that illness might be extra extreme throughout a second an infection.”
“The findings of this research spotlight the significance of sustaining public well being mitigation and safety methods that scale back transmission danger, even amongst individuals with a historical past of COVID-19 an infection,” Cavanaugh wrote.
The research famous some limitations. As a result of specimens weren’t saved, researchers could not conduct genomic sequencing, a laboratory approach that breaks down the virus’s genetic code, to verify reinfection, researchers stated. Additionally, “no further check outcomes exist to assist the preliminary check consequence as a real optimistic” throughout the first outbreak, they stated.
It is thought that the chance of reinfection for the final inhabitants remains to be low, however nursing dwelling residents could also be significantly in danger given their congregate dwelling and excessive variety of exposures, in line with the research.
“Expert nursing services ought to use methods to cut back the chance for SARS-CoV-2 transmission amongst all residents, together with amongst those that have beforehand had a COVID-19 prognosis, Cavanaugh wrote.