Covid-19 prevalence in Valley might have been underestimated, study suggestsOver 45 percent of hospital workers had developed antibodies by December, offering clues as to why new cases declined.
Over 45 percent of workers serving at various hospitals facilities across Kathmandu Valley had developed Covid-19 antibodies until December, according to a sero-epidemiology study carried out by the Nepal Health Research Council.
The study, ‘Sero-epidemiology of Covid-19 in Kathmandu Valley’, carried out among 800 health workers serving at 20 big hospitals of the Valley, showed that
36 percent of the nurses, 18 percent of the doctors, 22 percent of administrative staffers, 7 percent lab and pharmacy staffers, and 17 percent supporting staffers surveyed had developed such antibodies.
The presence of coronavirus antibodies in people suggests that they have been exposed to the virus, first detected in Wuhan, China in December 2019.
“The study was carried out to gauge the extent of infection among healthcare workers, and supporting staffers deployed on the Covid-19 frontlines,” Dr Kiran Pandey, principal investigator of the study, told the Post.
Samples were collected from health workers serving at Annapurna Neurological Institute and Allied Sciences, Bir Hospital, Nepal Eye Hospital, Paropakar Maternity and Women’s Hospital, Hams Hospital, Civil Hospital, Venus Hospital, Nepal Mediciti Hospital, Alka Hospital, Nepal Korea Friendship Municipality Hospital, KIST Medical College Teaching Hospital, Nepal Cancer Hospital, Star Hospital, Tribhuvan University Teaching Hospital, Grande International Hospital, Kanti Children’s Hospital, Nepal Medical College Teaching Hospital, Om Hospital, Nepal APF Hospital and Model Hospital Kirtipur.
Doctors say that the figures the study uncovered may reflect the prevalence of the disease among the general population—more people might have been infected with Covid-19 than reported. This could be the reason why the number of new reported cases has been declining in the country.
Covid-19 cases in Nepal, as well as in Kathmandu Valley, have seen a steady decline over the past months. Data from the Ministry of Health and Population shows that 53 people tested positive for the disease in three districts of Kathmandu Valley on Tuesday. The number had reached up to 3,107 on October 21.
“Results of the study also indicate that infection spread at the community level,” Dr Megnath Dhimal, chief researcher at the council, told the Post. “Actual infection in the community could be different from what is shown in the study. This means we need further studies to ascertain the actual extent of infection in society.”
The main objective of the study was to support authorities to formulate policies and decide to prioritise the vaccination of frontline workers, said Dhimal.
The study also showed that results of PCR tests didn’t determine the presence of antibodies among the participants. Only 76. 2 percent of the people who tested positive for Covid-19 (using PCR tests) were found to have developed antibodies. Similarly, 25.3 percent participants, who tested negative in the polymerase chain reaction test, had developed antibodies, and 37.4 percent of the participants who had developed antibodies had not undergone a PCR test.
“The study shows that all those who test positive do not necessarily develop antibodies for coronavirus,” Pandey, added. “Reasons may be anything. Either we have more false positives in PCR tests or antibodies did not develop or last long due to some conditions. It is a matter of further study.”
Those who tested negative in PCR tests but developed antibodies of the virus may have been infected sometime before or after the test. And those who did not undergo tests but developed may have been asymptomatic, according to doctors.
“Asymptomatic people can spread the infection unknowingly and the government’s policy of not performing free tests for asymptomatic cases is wrong. That is what we have been telling the government for a long time,” said Pandey.
Until September, around 13 percent of the country’s population was found to have been infected with coronavirus, according to an earlier seroprevalence survey carried out by the Ministry of Health and Population.
The nationwide study, which was conducted with technical as well as financial support from the World Health Organisation, found the highest prevalence in Province 2, followed by Bagmati Province, Province 1, Lumbini Province, Gandaki Province, Sudurpaschim Province and Karnali Province.
The Ministry of Health and Population has not yet made the report public and decided to carry out another study, which is yet to be started.
Doctors say that if the 45 percent health workers were infected in December, more might have contracted the infection later.
Experts say that in the community too a large percentage of people may already have been infected.
“As the infection of highly contagious virus like Covid-19 spreads exponentially, the majority of the people might have already been infected,” Dr Sher Bahadur Pun, chief of the Clinical Research Unit at the Sukraraj Tropical and Infectious Disease Hospital, told the Post. “If the majority of people have already got infected, it is natural to decline in new cases.”
It may take several months for one percent of the population to get infected, but when the infection rate reaches five percent, then it gets out of hand, doctor says.
Pandey said that the report was presented to the Ministry of Health and Population last week.
“Authorities may think that they can give up preventive measures, considering that many people have already got infected,” Pandey added. “But doing so will be catastrophic, as new variants of the virus have been spreading throughout the globe and even in neighbouring India.”
After a consistent decline in new cases in India, numbers have picked up in at least four states of India again due to new variants of the virus. According to Times of India, the number of coronavirus cases in India is surging, particularly in Punjab, Maharashtra, Kerala and in Madhya Pradesh.
The rise in the number of cases was reported amidst the discovery of several new variants of Covid-19, which is said to be more transmissible than the prevailing variants.
Antibodies developed against coronavirus spread in Nepal may not work for a new variant of the virus, according to doctors.
“Earlier we used to take examples of Europe and America but now we have examples at our doorstep(India),” Pun of Sukraraj Hospital, who is also a virologist added. “They are considering another lockdown due to a surge in new infections, and we cannot rule out such a scenario here in Nepal.”