India is on bird flu, H5N1 alert. Cases have been reported in Chennai. More than 1,500 crows have tested positive for the virus and this has stepped up surveillance in several areas of Tamil Nadu including Adyar, Velachery, Thiruvanmiyur and Old Mahabalipuram Road (OMR).This is a big health concern because H5N1 is classified as highly pathogenic. “H5N1, like several other influenza viruses, is part of the broader family of flu viruses that circulate seasonally. While human cases of H5N1 remain uncommon, the concern lies in its potential severity when infection does occur. From a clinical perspective, we see that influenza viruses tend to cause more significant illness in vulnerable populations rather than in otherwise healthy individuals,” Dr Kaushik N, Consultant Pulmonologist Aster RV Hospital, Bangalore told TOI Health. The World Health Organisation (WHO) has reported over 250 human infections from 2003 to 2024. Most of the reported cases have been severe. In India, no human cases have surfaced, said Dr Ram Gopalakrishnan, infectious diseases specialist at Apollo Hospitals told TOI. In 1996, the HPAI H5N1 virus was identified in geese in China. In 1997, first human infections were reported from Hong Kong, China. Since 2003, this virus has spread in bird populations across Asia, Europe, Africa, and the Americas. It is now endemic in poultry populations in many countries. Outbreaks have resulted in millions of poultry infections, several hundred human cases, and many human deaths.“People at higher risk include elderly patients, those with diabetes, chronic lung diseases such as asthma or COPD, kidney disease, cancer patients, individuals on immunosuppressive therapy, and patients undergoing dialysis. In these groups, viral infections can worsen underlying conditions and sometimes progress to complications like viral pneumonia. We often see acute exacerbations of pre-existing respiratory illnesses during flu seasons, particularly between November and March,” Dr Kaushik N said.The expert added, in most healthy individuals, flu-like viral infections typically settle within 3–5 days. However, in recent months, clinicians have observed that symptoms can last longer, sometimes extending beyond a week. Recovery from influenza infections usually takes about 7–10 days, though in some cases it may take up to two weeks. By this time, the body develops antibodies, and routine retesting is generally not required.“The most important preventive measures remain early detection, avoiding close contact with infected birds or animals, and following basic infection-control practices. Wearing a mask in crowded or poorly ventilated environments, maintaining hand hygiene, and avoiding close contact with sick individuals are effective steps. Early medical consultation is crucial, especially for high-risk individuals experiencing persistent fever, breathlessness, or worsening symptoms,” the doctor has urged.Medical experts consulted This article includes expert inputs shared with TOI Health by: Dr Kaushik N, Consultant Pulmonologist Aster RV Hospital, BangaloreInputs were used to explain the outbreak of H5N1 in Chennai and the symptoms and preventive tips one should be aware of.
