THIRUVANANTHAPURAM: Amid its battle against Covid-19, the Health Department has received some worrying news. The department has stumbled upon a report that warns of the difficulty in distinguishing between dengue fever and novel coronavirus, as symptoms like fever, headache, diarrhoea, sore throat, and seizures are common to both. What has the department worried is the arrival of pre-monsoon showers and the likelihood of clustering of dengue fever cases in various pockets of the state as a result.
Citing some cases in Singapore and Indonesia where doctors couldn’t differentiate between Covid-19 and dengue fever, public health experts said it was high time the state medical board and the state expert committee for Covid-19 discussed the matter in detail and came out with advice.
“The dengue outbreak in Kerala has become an annual affair now and the arrival of pre-monsoon showers will only escalate the problem. If dengue and Covid-19 are difficult to distinguish because of their shared clinical and laboratory features, the state has a serious problem at hand,” said a Health Department official.
In the report – published by international medical journal The Lancet, Singapore-based doctors mention two patients in Singapore with false-positive results from rapid serological testing for dengue. The duo was later confirmed to have the SARS-CoV-2 infection.“In one of the case studies, a patient with three days of fever and cough consulted a regional hospital. He was discharged after a negative rapid test for dengue. When the fever persisted, he went to a primary healthcare clinic. His worsening cough and dyspnoea (difficulty in breathing) led to the testing for SARS-CoV-2 by RT-PCR which returned positive,” said the officer. The study report concludes with the warning that failing to consider Covid-19 because of a positive dengue rapid test result has serious implications for the patient and for public health.
“The key takeaway of the report is the importance of recognising false-positive dengue serology results in patients with Covid-19. A strategy to address this is the need of the hour as it can put health workers at huge risks,” said the officer.
‘Different viruses’
An infectious disease specialist of government medical colleges said dengue fever and Covid-19 were caused by different viruses. “The first is caused by the flavivirus, while the other by coronavirus. Though initial symptoms are similar, the distinction can be made as the disease progresses,” said the expert, who did not wish to be named.
Dr Anup R Warrier said, “Not really. It’s because in dengue there is a decrease in the number of leukocytes (found in the blood and body’s primary defence against infection) with the higher-than-normal amount of lymphocytes (a subtype of white blood cells (WBC)) and with low blood platelet count. In the case of Covid19, one will have normal WBC count and normal platelet count.” B Ekbal, chairman of the Covid-19 expert group, remained unavailable for comment despite repeated attempts.
Total dengue fever cases reported till April 30 93
2019
4,651 persons contracted dengue fever Deaths14