The novel coronavirus can remain active for longer than expected even in patients with mild symptoms. People who may still be shedding active viruses 14 days after testing positive may contribute to community transmission.
A new study, published in the journal Frontiers in Medicine, has revealed that the novel coronavirus, which causes COVID-19, can continue to be present in some human bodies upto 232 days, i.e more than 7 months. The study was conducted by a team of international researchers including scientists from France's Pasteur Institute, the University of Sao Paulo (USP) and Oswaldo Cruz Foundation (Fiocruz) in Brazil.
The study included 38 Brazilian patients who were followed until they tested negative twice or three times consecutively by RT-PCR. In three cases, two men and a woman,SARS-CoV-2was continuously detected in their organism for more than 70 days, the researchers said.
Based on this finding, they suggested about 8 per cent of people infected by SARS-CoV-2 may be able to transmit the virus for more than two months, without necessarily manifesting any symptoms during the final stage of the infection.
Surprisingly, in a 38-year-old man who showedmild symptomsof Covid-19 for 20 days, the virus continued to be detected in his organism and to undergo mutations for 232 days, the researchers said.
If he had not received continuous medical care, followed Covid guidelines like social distancing and wearing a mask, he could have spread the virus throughout these seven months, they added.
Paola Minoprio, principal investigator for the study, cautioned that people who may still be shedding active viruses 14 days after testing positive could likely infect others and contribute to community transmission.
So, it's crucial to keep track of infected people to find out more about mutations, novel variants, and the transmissibility of the virus, the expert noted.
SARS-CoV-2 can remain active for longer than expected
Minoprio said that it can take a month for a Covid patient to test negative, and in some cases the patients remained positive for 71 to 232 days, as seen in their study.
Previous studies have also shown that COVID-19 virus can remain active for longer than expected even in patients with mild symptoms.
A recent study led by theUniversity of Exeterhad concluded that one in 10 Covid-affected people could remain infectious for over 10 days. The study, which was published in the international Journal of Infectious Diseases, found that 13 per cent of the participants (it included 176 people who had tested positive on standard PCR tests) still exhibited clinically relevant levels of virus after 10 days. Some of them continued to retain these levels for up to 68 days.
In a study published in June 2021, researchers at the University of Sao Paulo's Medical School (FM-USP) had also described a case of infection that lasted at least 218 days. The patient, who was about 40 years old, had undergone aggressivetreatment for cancerbefore contracting COVID-19.
In early December 2020, the New England Journal of Medicine also published a study that reported the case of a 45-year-old man with an autoimmune blood disorder in whom the virus continued to be detected for 143 days. In a female leukemia patient, SARS-CoV-2 continued to replicate for at least 70 days, although exhibited no symptoms of Covid-19. This case study was reported in Cell in late December.
With inputs from agencies