Norovirus: It’s not your regular food poisoning
After the threat of tomato flu and West Nile virus, Kerala was once again affected by another viral disease. This time, it’s norovirus. According to several media sources, two lower primary students have recently been infected by this stomach bug in Thiruvananthapuram, after having mid-day meals at school. But this isn’t the first time norovirus has been affecting people in India. Earlier, in 2007, kids in Delhi had shown signs of it. In fact, last year, in the month of November, the Wayanad district of Kerala had also reported rising cases of norovirus. But this is perhaps the first time that this viral stomach disease has made its appearance during summer. Want to know more about it? Read on.
Norovirus at a glance
Just like your regular food poisoning, norovirus, too, is a highly contagious disease. This viral disease is often referred to by two alternative names: ‘stomach flu’ and ‘winter vomiting bug’ (considering it mostly occurs during winter, barring exceptions). However, the biggest difference between these two conditions is that food poisoning can be triggered by bacteria, viruses, or parasites while the culprits behind norovirus are a bunch of viruses only. It is part of a virus group called caliciviruses that is known to attack people’s stomach lining. This animal-borne disease usually infects people of all age groups. However, children, elderlies, pregnant women and others with comorbidities are often more susceptible to this condition, because of their weakened immunity. It mainly leads to intestinal inflammation commonly known as acute gastroenteritis.
Symptoms to watch out for
Those of you, who are guessing that the norovirus symptoms must be somewhat similar to food poisoning, you’re right. The primary symptoms include severe vomiting and diarrhoea, that are revealed one or two days after the virus exposure. In severe cases, patients may also suffer from abdominal pain, fever, headache, body aches and dehydration. Though the symptoms are similar, there’s a big difference between these two conditions while it comes to the time of manifestation. In case of food poisoning, symptoms develop within a few hours of eating, while the signs for stomach flu show up within a day or two after exposure to the virus.
How is norovirus transmitted?
Like most viral diseases, norovirus too is transmitted orally through contaminated food, water and surfaces, and at times even through faeces. Experts believe that it has the same nature as that of diarrhoea inducing rotavirus. However, reports suggest that this infectious disease has been detected within closed spaces such as nursing homes, dormitories and even aboard cruise ships. In fact, WHO has recently revealed that norovirus affects approximately 685 million people in the world annually, half of them being children aged below five.
Norovirus: The origin story
For those of you who are about to mistake norovirus as a 21st century viral outbreak, here’s a little bit of a fact check: It has been existing since 1936. During this time, a norovirus outbreak was first detected in Roskilde, Denmark and was then simply called ‘Roskilde illness.’ However, norovirus became a much-talked about condition much later, when it occurred among school children in Norwalk, Ohio in the United States in 1968.
Experts believe that the name norovirus was derived out of its place of origin. According to them, it was known as ‘Norwalk agent’ back then. But it wasn’t until 1972, after a series of laboratory experiments, that it was revealed that this acute gastroenteritis was the result of a virus, identified as ‘Norwalk virus.’ Later, in 2002, the International Committee on Taxonomy of Viruses (ICTV) approved the name ‘norovirus.’ Since then, several outbreaks have been reported across the world, including one on a cruise in the Caribbean as well as in the UK.