KOLKATA: Even as the Covid surge wanes, thousands across the city are being struck by successive bouts of fever and cold within a week sending them scurrying to doctors with renewed fear. Most are testing negative for Covid during the first bout of fever with the symptoms receding in three-four days only to recur in a couple of days, leaving the patients very weak.
Doctors believe this is the result of usual change-of-season spurt in viruses that have spread faster and affected many more this time, possibly due to post-Covid drop in immunity. A non-Covid viral attack, too, can reduce immunity making an individual susceptible to a repeat viral attack which has been happening, they say and warn a second bout could be severe if it turns out to be influenza A, rhinovirus or H1N1, which are now in circulation.
A 48-year-old Covid survivor from south Kolkata had successive bouts of mild fever and cold within a week. While he tested negative for Covid, the twin attack left him weak. A 65-year-old woman, who had an upper respiratory tract infection last week, also tested negative for Covid but a couple of days after her fever receded she suddenly had a recurrence of temperature and cough. Both disappeared within a couple of days and the woman has now recovered.
"Non-Covid respiratory viruses, which include influenza or influenza-like illnesses like para-influenza and orthomixo virus that are rarely tested, can trigger a bout of fever and cold. Since these, too, affect the upper respiratory tract, symptoms are similar to Covid. Viruses other than Covid remain largely undetected because tests to detect these are expensive," said RN Tagore intensivist Sauren Panja.
'People with lower immunity at risk'
When a Covid wave or a surge reaches its peak, the majority of viral infections are likely to be Covid, pointed out Institute of Post-Graduate Medical Education & Research (IPGMER) professor Diptendra Sarkar. "As we pass the peak and the wave declines, the percentage of Covid infections drop and other viral infections take over. This is exactly what is happening now. Since many have already had a mild Covid recently, they have turned susceptible to other viral attacks leading to repeat attacks," he added.
A repeat attack could also be the result of a Covid infection "not clearing out" sufficiently, said CMRI Hospital pulmonology director Raja Dhar. "It is more likely that most are secondary infections like influenza A, rhinovirus or H1N1 which are striking now, especially in those with lower immunity," said Dhar.
According to RTIICS intensivist Sauren Panja, some could also be suffering from a secondary bacterial infection. "Especially the elderly with comorbidities turn susceptible to bacterial infections after a bout of viral attack, whether Covid or non-Covid. In some cases, these could turn severe and even fatal," he warned.
Any viral attack reduces immunity for a while, making one vulnerable to a quick repeat infection, said Panja.
"We have had Covid patients suffering a non-Covid infection within a week of recovery. There have been others who had successive non-Covid viral attacks, including many who went back to work within days of suffering the first attack. Chances of re-infection rise with exposure to gatherings," added Panja.
