Blood sample with H1N1virus.
Credit: iStock Photo
Bengaluru: Karnataka’s reported H1N1 cases till July this year are nearly seven times more than those reported the whole of last year, shows data from the health department.
Till July 31 this year, 855 cases have been reported across the state, with the highest coming from BBMP limits in Bengaluru. Last year, this statewide total was 118.
Two people — a 15-year-old boy in Mysuru and a 48-year-old woman in Doddaballapur — died due to H1N1 this year, while three others who tested positive for the virus died due to comorbidities and advanced age, noted a senior official from the department.
Dr Ansar Ahmed, Project Director, Integrated Disease Surveillance Programme, said that while the health department does not conduct active surveillance for H1N1, greater public awareness and increased lab testing have aided in better reporting of cases occurring due to seasonal changes. “We are closely monitoring the cases and improving our recording efforts,” he said.
Doctors in Bengaluru have observed more than double the usual number of H1N1 cases with greater severity over the past couple of weeks. They call this surge in cases “atypical”, as outpatient department visits for flu across hospitals have gone up from single digits per week to double digits daily.
Dr Majeed Pasha, Consultant-Pulmonology at a private hospital in Nagarabhavi, Bengaluru, provided an example. “If I see about 30 patients in one shift, at least 20 of them are coming in with flu symptoms. Over the past month, of about 70 patients who tested positive for H1N1, more than 25 required oxygen support, and seven to 10 were put on ventilators,” he said.
Diagnosed using the RT-PCR test, the viral respiratory infection presents with high fever, cough, sore throat, body ache, fatigue and headache. Some may also experience nausea, vomiting, diarrohea and pneumonia with severe breathlessness, especially in older people.
People aged 50 years and above often present with severe symptoms but cases are being reported across ages, especially among schoolchildren and people with a travel history, noted doctors.
“Usually, this is not the period where we see so many flu cases but many people, irrespective of age, are suddenly falling ill. In the past two weeks, six people who tested positive for H1N1 virus were admitted to critical care, one of whom passed away, three are still critical and the two got discharged. Most of them are in their mid-40s and not immunocompromised,” said Dr Carolin Elizabeth George, Head, Community Health and Research at a hospital in Hebbal.
Several factors could explain this surge in cases, noted Dr Manjunath P H, Consultant - Interventional Pulmonologist. This includes seasonal changes, increased transmission due to social interactions, and possibly reduced immunity in the population as the flu virus evolves. “Additionally, lower vaccination rates in some groups may also be playing a role,” he said.
This month, in particular, has seen sudden fluctuating temperatures, contributing to the spread of infection.
High-risk individuals, including children, people aged above 60 years and those with comorbidities such as heart disease, diabetes, chronic lung and kidney diseases, are recommended to take the influenza vaccine before the onset of flu season every year, said Dr Ravi K, head, Karnataka’s State Technical Advisory Committee for Communicable Diseases.
Highlights -
H1N1 cases in Karnataka2018: 1,733 cases, 87 deaths2019: 2,030 cases, 96 deaths2020: 458 cases, 3 deaths2021: 13 cases, 0 deaths2022: 517 cases, 14 deaths2023: 181 cases, 0 deaths