Source :NEWS18 NEWS
Last Updated:May 25, 2025, 07:37 IST
The challenge to differentiate between COVID-19, Influenza, Dengue, may lead to misdiagnosis in the acute stage of the disease, which may lead to incorrect treatment
COVID-19 and Influenza are contagious respiratory illnesses that spread through respiratory droplets. Whereas dengue is a viral illness transmitted by the Aedes aegypti mosquito and is not contagious from human to human directly.
Clinically differentiating COVID-19, Influenza, Dengue, and other infections can be challenging in tropical regions due to the similarity of symptoms in these infections. These challenges may lead to misdiagnosis or delayed diagnosis in the acute stage of the disease, which may lead to incorrect treatment and undesirable clinical outcomes. Dr. LakshmiPriya R, Senior Consultant Microbiologist and Molecular Biologist, Metropolis Healthcare Limited (Chennai) shares the difference:
COVID-19 and Influenza are contagious respiratory illnesses that spread through respiratory droplets. Whereas dengue is a viral illness transmitted by the Aedes aegypti mosquito and is not contagious from human to human directly.
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The incubation period for COVID and Influenza virus is within 1-4 days after exposure, after which the fever may last for 3-7 days. It is not possible to differentiate between COVID and influenza infection with symptoms alone, since most of the symptoms are similar to both infections.
The incubation period for dengue infection is between 4-10 days after the mosquito bite, and the fever may last for 2-7 days. Dengue fever may vary from mild to severe. Only the mild dengue infection mimics flu infection, whereas severe forms may have hemorrhagic fever or dengue shock syndrome.
Most common symptoms of COVID 19 and Influenza infection are moderate to high grade fever (from 100°F to 102°F) and is continuous for 3- 4 days, chills, sore throat, cough, runny nose, shortness of breath, fatigue, body ache may be mild to moderate, headache, sometimes COVID infection can cause new loss of smell or taste.
Dengue infection presents with symptoms like high-grade fever up to 104°F/105°F, severe headache, severe joint pain (break-bone fever), severe body pain, rashes may appear after 2-5 days of onset of fever, nausea and vomiting, especially in children, and pain behind the eyes. If the patient develops dengue hemorrhagic fever or dengue shock syndrome, they may present with severe abdominal pain, rapid breathing, bleeding nose and gums, persistent vomiting, blood in stool, and hemoptysis.
The petechial rash in dengue usually begins in the chest and then spreads to other parts of the body.
Dengue usually presents in 3 phases. In the febrile phase, the patient presents with high-grade fever that lasts for 2-7 days along with other symptoms. During the critical phase, the fever may drop for a period of 3-5 days. But this is a risky stage, where there may be a drop in platelets. Followed by a recovery phase, where the body reabsorbs the excess fluid, and the patient gradually starts to feel better.
Complete blood count (CBC) is the most important test that helps in the initial differentiation of dengue and COVID infection. The blood-based parameters help in the differential diagnosis of the various febrile illnesses. Like Dengue patients have leucopenia, followed by a rapid drop in platelet count with a rise in haematocrit value, COVID patients may present with leucocytosis/leucopenia with eosinopenia and lymphopenia. The most common predictor for COVID is lymphopenia. There is potential cross-reactivity in the serological test of COVID-19-positive patients tested for Dengue and vice versa. This is because there is a similarity in the epitope of the HR2 domain of SARS-CoV-2 and the dengue envelope protein. In such patients, the dengue virus infection is ruled out by no evidence of seroconversion or persistence of a positive serological test. Also, confirmation can be done by performing Dengue RT-PCR.
- First Published:
May 25, 2025, 07:37 IST
SOURCE : NEWS 18
