It's the season of respiratory diseases in India and after around 451 cases of H3N2 cases and couple of deaths due to the influenza virus, mild cases of Covid-19 too have been detected in the country which calls for stronger measures around prevention and need for vaccination for both the dreaded diseases. Both Covid and H3N2 are respiratory viral diseases and share many symptoms, but is it possible to get infected by both? If yes, how will it change the symptoms? Experts say that it is very much possible for the two viruses to co-exist and if that happens, the symptoms could be more severe in vulnerable groups. People with dual infections, however, are not advised to take antibiotics or antivirals and symptomatic treatment is sufficient. It is best to get tested as soon as you get symptoms like fever, cough, body ache, sore throat, loose stools, weakness among others. (Also read: Should we worry about spike in Covid cases amid H3N2 scare? Experts take)
"Both Covid and H3N2 are respiratory viral diseases. Just like bacteria, viral diseases can co-exist. However, the symptoms are similar in both the cases, all viral diseases have myalgia, moderate to high grade fever, loose stools, and extreme weakness. We can send nasopharyngeal swab to confirm the diagnosis after clinical screening. The management of any viral disease is conservative, you just need to treat symptoms. Antibiotics are not required, and adequate hydration and rest are important in recuperating from viral prodrome. Around 1% of cases can have severe headache and breathlessness leading to respiratory failure and eventually hospitalization. Depending on further evaluation the treatment is decided in the hospital," says Dr. Arun Chowdary Kotaru, Consultant, Respiratory/ Pulmonology & Sleep Medicine at Artemis Hospitals, Gurgaon.
"SARS CoV-2 and H3N2 influenza are respiratory viruses that share their mode of transmission i.e., droplet or aerosols; route of infection i.e., inhalational route; clinical manifestations and risk factors for severe illness. It is very much possible for any person to get both infections at the same time (i.e., co-infection), either from one patient with both infections, or from two different patients," says Dr. Rohit Kumar Garg, Consultant with the Department of Infectious Diseases at Amrita Hospital, Faridabad.
"There's plenty of evidence of people testing positive for, say, COVID and the flu or flu and RSV simultaneously. In India, influenza virus circulation usually peaks during the monsoon season (June-September) with secondary peaks during the winter (November-February). India is currently seeing a surge in influenza viral infections due to H3N2 and H1N1," says Dr. Sunita Kapoor, Director and Consultant Pathologist at City X-ray & Scan Clinic.
"Although the probability of getting COVID and H3N2 at the same time is very low, the infection is rarely acquired. People who have poor immunity and are on steroids or immunosuppressive drugs are at a higher risk. At the same time, the risk is higher in patients who have comorbidities like liver, kidney, or heart diseases, those who are cancer patients, or have received an organ transplant," says Dr Ashok K. Rajput, Consultant - Pulmonology & Sleep Medicine, CK Birla Hospital, Delhi.
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Does Covid-19 and H3N2 co-infection affect symptoms?
Dr Garg says while the usual symptoms like high fever, cough, shortness of breath, sore throat, body aches, headache, fatigue, vomiting, diarrhoea etc remain the same, as per available data, patients with both infections, simultaneously, tend to have more severe symptoms.
"The severity of illness also depends on factors such as immunity, comorbidities, vaccination status etc. It means, patients vaccinated with both influenza and Covid vaccines, and/or without risk factors are unlikely to develop severe illness despite co-infection," says Dr Garg.
"The symptoms include fever, a runny nose, cough, a cold, and a sore throat which are similar to the symptoms of H3N2 or COVID. However, the test rate for these symptoms has declined (less than 5%), hence it is difficult to establish the exact number of H3N2 or COVID patients. People should get vaccinated for the influenza virus, and it is important to understand that even after vaccination, there is still a possibility of getting infected. If a patient is suffering from symptomatic trends like fever, cough, and cold, it is recommended not to take antibiotics," says Dr Rajput.
"Apart from this stuffiness of nose, sneezing, sore throat, loss of smell is seen in both the viral infections. Earache, nausea, diarrhoea are again common symptoms of both Covid and H3N2 influenza," says Dr Sunita.
How to find out if you have both Covid and H3N2 influenza
The infections with SARS CoV-2 and H3N2 viruses can be diagnosed with help of RT-PCR tests (available individually and in combination), done on nasopharyngeal swab samples.
"Most patients, with dual infections, do not require any antivirals, and only symptomatic treatment is sufficient. Only a small proportion of patients, particularly those who are not vaccinated, have comorbidities, low immunity etc. require treatment with specific antivirals for both H3N2 influenza and SARS CoV-2 virus. Lastly, it is very important to consult a doctor for early diagnosis, assessment of clinical condition, triaging for hospitalization as well as treatment, to prevent ourselves from getting very sick. Also, early diagnosis and preventive measures (face masks, cough etiquettes, hand hygiene) will help to prevent the near and dear ones from getting such infections," he says.
"For treating these symptomatic signs, either antipyretics are given for fever or inflammatory drugs like antitussives for cough and cold. However, if the patient is diagnosed with the flu or is already suffering from a lower respiratory tract infection like COPD or bronchiectasis, antibiotics can be given as per the requirement," says Dr Rajput.