Wednesday, April 15, 2020

Covid-19: Why some recovered patients may test positive again

Helpful. A member of the medical staff helps a
Helpful. A member of the medical staff helps a patient as he leaves a hospital after recovering from the Covid-19 disease caused by the novel coronavirus in the city of Sale, north of the Moroccan capital Rabat, on April 12. PHOTO BY AFP 
By TONNY ABET
Some people who had won the fight and recovered from the deadly Covid-19 disease are increasingly
testing positive for the virus again, a short while after being released from hospital.
In February, doctors in Wuhan, China, the apparent source of the coronavirus pandemic said, up to 10 per cent of recovered coronavirus patients they had worked on and recovered from the virus had tested positive again after they were discharged from the hospital.
On April 6, at least 91 people in South Korea tested positive again, weeks after being released from hospital.
On Monday, Yonhap, a government-funded news agency in South Korea, reported that one of the patients who had tested positive for the second time died.
Another study in China estimated the number of people testing positive after being released from quarantine at around 10 per cent.
Prof Pontiano Kaleebu, a clinical immunologist and director of Uganda Virus Research Institute (UVRI), says re-infection could have occurred in the 91 patients.
“With our experience of influenza, if the virus mutates a bit, immune response you had may not work well and re-infection may occur,” he said.
The virus research scientist said the other reason why those people tested positive again could be because their immunity went low.
“The other way could be that the immune response has just come down,” the scientist said.
The professor, however, said it is not a common occurrence and that research is being done to find the exact cause.
Dr Misaki Wayengera, a researcher who is part of the technical advisory committee on Covid-19 at Ministry of Health, said the treatment being given to victims could be explanatory to re-infection.
In regards to this, he said the virus could have simply re-activated itself and manifested.
“The main question should be that is this a re-infection or a virus that has re-occurred?” he said.
“The treatment being used are not very specific as against viral infections. Drugs being used such as hydroxychloroquine has some antiviral property but it is not sufficient. Some of these viruses need combination of drugs like how it is done for HIV,” explained the expert.
Dr Wayengera who is also leading the team developing testing kits in Uganda, said several trials on drugs against viruses that have been conducted are not showing excellent results.
“Several trials of drugs related to anti-retroviral (ARV) have been done but the outcome were not very good. The benefits were not demonstrated very well,” he added.
The researcher said Covid-19 needs specific drug to treat it properly.
“You cannot use antiviral and expect it to work everywhere. The mechanism with which the covid-19 infects is quite different from HIV,” Dr Wayengera added.
Dr Ekwaro Obuku, the former president of Uganda Medical Association, said re-infection with Covid-19 is possible.
“It is called “super-infection”. This phenomenon as well happens with HIV-1, where a person living with HIV can be re-infected with another strain altogether,” he said.
“And if this strain is the resistant type then the HIV medicines the person is taking will not work as well as before,” Dr Obuku added.
editorial@ug.nationmedia.com

No comments :

Post a Comment