West Nile fever is spreading across the three districts of Kerala–Malappuram, Kozhikode and Thrissur and State Health Department has issued an alert, instructing the authorities to speed up pre-monsoon cleaning activities. So far, at least ten cases of the vector-borne disease have been found. West Nile virus is a mosquito-borne flavivirus that can cause flu-like symptoms. It is spread via bite of an infected mosquito, mostly culex mosquitoes that are considered the primary carriers of the disease. Human to human transmission is not known yet. Death of two people in the recent days are suspected to be because of the WNV virus, as per a Hindustan Times report though no official confirmation has been made so far.
What is West Nile virus?
West Nile virus is a mosquito-borne flavivirus that can cause flu-like symptoms in people and some birds. The virus is most commonly found in Africa, Europe, West Asia, and North America, but it has been increasingly detected in other parts of the world, including Kerala.
“The virus is spread to humans by the bite of an infected mosquito. Culex mosquitoes, which are common in Kerala, are the primary carriers of the West Nile virus in the state. Most people infected with West Nile virus will not develop any symptoms. However, those who do experience symptoms will typically feel flu-like illness within 2 to 14 days after being bitten by an infected mosquito,” says Dr Neha Rastogi, Consultant, Infectious Diseases, Fortis Memorial Research Institute, Gurugram.
“West Nile fever is a mosquito-borne viral disease that has become a significant public health concern, particularly during the warmer months when mosquito activity peaks. While the majority of infected individuals remain asymptomatic or experience only mild, flu-like symptoms, we must remain vigilant as this virus has the potential to cause severe and even life-threatening neurological complications, especially in vulnerable populations such as the elderly and those with weakened immune systems,” says Dr Rakesh Gupta , Senior Consultant , Internal Medicine , Indraprastha apollo hospitals.
Symptoms of West Nile fever
“Some common symptoms of West Nile virus are fever, headache, body aches, fatigue, nausea, vomiting, diarrhoea etc,” adds Dr Rastogi.
“In a small number of cases, West Nile virus infection can lead to severe neurological illness, such as meningitis (inflammation of the membranes that surround the brain and spinal cord) or encephalitis (inflammation of the brain),” adds the expert.
Preventive tips
“There is no vaccine or specific treatment for West Nile virus infection. However, one can use insect repellent that contains DEET, picaridin, oil of lemon eucalyptus, or IR3535. Wear long-sleeved shirts and pants when outdoors, especially at dawn and dusk when mosquitoes are most active. Eliminate mosquito breeding grounds around your home by getting rid of standing water in tires, buckets, flowerpots, and other containers,” suggests Dr Rastogi.
“Effective prevention measures, such as using insect repellents, wearing protective clothing, and eliminating standing water sources where mosquitoes breed is very important. Early recognition of the symptoms, including fever, headache, body aches, and rash, is vital for prompt diagnosis and appropriate medical intervention,” says Dr Gupta.
Dr Gupta says people with severe cases of West Nile fever may require hospitalization and supportive care, including intravenous fluids, respiratory support, and prevention of secondary infections.
“Close monitoring and management of neurological complications, such as encephalitis and meningitis, are critical to minimize long-term effects and improve patient outcomes. While there is currently no specific treatment or vaccine for West Nile fever, ongoing research efforts hold promise for future therapeutic and preventive measures. Until then, our focus remains on raising awareness, promoting prevention strategies, and providing timely and comprehensive care,” he adds.