PyeongChang 2018, the ongoing XXIII Olympic Winter Games at the South Korean city of Pyeongchang, has been hit by an extraordinary outbreak of disease. A Norovirus infection is sweeping through the Games Village and surrounding areas, cutting down people with severe attacks of diarrhoea and vomiting, and spreading panic among athletes and residents. The number of cases since the lead-up to the Games opening on February 9 has reached 232, officials said on Thursday. The infection seems to be spreading spatially — the 33 new cases that officials confirmed Thursday have been identified in staff quarters in Pyeongchang and Gangneung, places that are away from the previous hub of the outbreak at a youth centre housing Games staff. Some 1,200 security staff have been quarantined and replaced by military personnel. 92 countries are taking part in PyeongChang 2018, which will continue until February 25; no athletes have, however, taken ill so far.
So, what is Norovirus?
It is a bug similar to the diarrhoea-inducing rotavirus for which India has recently included a vaccine in its universal immunisation programme. While rotavirus primarily affects children, Norovirus infects people across age groups. Disease outbreaks typically occur aboard cruise ships, in nursing homes, dormitories, and other closed spaces (such as the Games quarters). Symptoms — a sudden onset of vomiting and/or diarrhoea — usually show up one or two days after exposure to the virus. Infected persons also experience nausea and abdominal pain, and may have fever, headaches and bodyaches. In extreme cases, loss of fluids could lead to dehydration. The disease is self-limiting — the infection, even though it takes a lot out of the patient, normally lasts only two or three days, and most individuals who are not very young, very old, or malnourished can ride it out with sufficient rest and hydration.
How do you get the infection?
Norovirus is highly contagious, and can be transmitted through contaminated food, water, and surfaces. The primary route is oral-faecal. One may get infected multiple times as the virus has different strains. Norovirus is resistant to many disinfectants and heat up to 60°C. Therefore, merely steaming food or chlorinating water does not kill the virus. The virus can also survive many common hand sanitisers.
How common is Norovirus infection?
It is the most common pathogen implicated in outbreaks of gastrointestinal disease (inflammation of the stomach and intestines), according to the World Health Organisation. The US Centers for Disease Control and Prevention estimates that about one out of every five cases of acute gastroenteritis worldwide is caused by Norovirus. There are 685 million cases annually, of which 200 million are detected among children younger than five years. Nearly 50,000 children die every year due to diarrhoea caused by the virus.
How can the infection be prevented and treated?
The basic precaution is also the most obvious — repeatedly washing hands with soap after using the lavatory or changing diapers. It is important to wash hands scrupulously before eating or preparing food. During outbreaks, surfaces must disinfected with a solution of hypochlorite at 5,000 parts per million. Diagnosis is done by real-time reverse transcription polymerase chain reaction. No vaccines are available for the disease. It is important to maintain hydration in the acute phase. In extreme cases, patients have to be administered rehydration fluids intravenously.
How did PyeongChang 2018 become the theatre for an outbreak?
Confined spaces with many individuals are generally vulnerable, but the specific reasons in this case are unclear. According to a statement issued by the organising committee, the Korean ministries of food and drug safety, and environment tested the water system used for cooking food in the facility, but found no signs of the virus. While this outbreak seems to be of a particularly large scale, there have been reports of similar attacks at sporting events earlier, including a suspected Norovirus attack on one of the team hotels during the World Athletics Championships in London last year.