PETALING JAYA: Although there are Covid-19 cases where the sources of infection are unknown and patients only detected incidentally, the local situation is under control, say experts.
Universiti Putra Malaysia medical epidemiologist Assoc Prof Dr Malina Osman said when it involved infectious diseases, there would be a certain number of cases where the source of infection could not be traced.
“However, as long as the prevention and control measures are
followed, usually the disease is well contained,” she said yesterday.
Dr Malina said the latest data in the media showed over 6,000 or almost 70% of the overall number of cases were associated with clusters while the rest were unknown.
In cases where the sources of transmission were unknown, she said this could be because the virus or agent was already present in the community, but unnoticed.
“This is because even though the number of those infected is very low, transmission still occurs,” she said.
Malaysia has also reported cases of Covid-19 being incidentally detected in patients who only knew they had the virus after undergoing screening for work purposes or before a surgery.
Asked if more of the asymptomatic should get tested, Dr Malina said ideally, ongoing screening was the best option for those who were susceptible but cost would be a restrictive factor.
“Those who have the opportunity to volunteer are encouraged to screen themselves but it is recommended to be done selectively according to health or medical risk assessment,” she added.
On how long the virus could last in asymptomatic persons who did not know they were infected, she said the viral count was usually highest in an individual within two and five days of being infected.
“It will decline and research shows that in mild cases, the infection is no longer contagious or infectious after 14 days,” she said.
Dr Malina said a prolonged stay of the virus, for more than 14 days, was associated with certain factors which included severe infection, old age, hypertension, delayed admission to hospital, invasive mechanical ventilation and corticosteroid treatment.
On the newly-detected Covid-19 virus mutation known as D614G, she said the strain was found to be less aggressive but in terms of spread, it has higher transmissibility. “It can potentially affect a larger group of individuals if they ignore the suggested prevention methods.
“The public should continue to practise strict SOP and preventive methods,” she added.
Universiti Malaya professor of epidemiology and public health Dr Sanjay Rampal said from the daily statistics, Malaysia still had a very low level of community transmission.
“We should not be alarmed when we hear of such cases as it has been happening sporadically over the past few months.
“The term community transmission is specifically used to describe cases that cannot be traced back to a previous cluster or international travel,” he said.
Dr Rampal said community transmission occurred when there were undiagnosed cases in the community.
Reasons for this included cases that were asymptomatic, or symptomatic but did not fulfil the criteria for screening, or patients not offering to be screened.
On the D614G mutation in the country, he said this had been detected in many countries with early evidence pointing to it being associated with higher infectivity.
However, the basic pillars of prevention and control of Covid-19 remained the same, he added.
“It includes border control, movement restriction, hand and respiratory hygiene, physical distancing and appropriate usage of personal protection equipment,” he said.
In South Korea, three mutated strains of Covid-19 were recently detected among three imported cases involving two people from Pakistan and one from Uzbekistan.
Possible mutations were detected in the virus’ “spike protein”, which was known to help the Covid-19 virus penetrate into a living human cell.