A common disease that proves hard to stomach
'Tis the season to be jolly, but also for gastroenteritis, a common disease that's also known as stomach, or gastric, flu. It's not positive news for the festive period, though it can be prevented easily by taking simple precautions.
Gastroenteritis is usually a mild disease and can be caused by a variety of pathogens (disease-causing agents).
The condition is frequently termed as 'flu' because its cause is usually viral. However, this loose terminology can be confusing, because flu viruses are not the culprits; rotavirus and norovirus are the main ones in Hong Kong that have been identified.
According to Dr Carmen Wong, medical officer of the Health Department's Central Health Education Unit, these viruses can infect people year-round, though they tend to do so during the cooler months of the year, peaking in late winter. The viruses inflame the mucus membranes of the gastrointestinal tract (stomach and small and large intestines), causing diarrhoea and vomiting. Other symptoms include headache, fever and abdominal cramps.
'In general, the symptoms begin one to two days after infection and, depending on the type of virus, may last for up to 10 days,' she says.
Most people do not get seriously ill, but complications and even death can occur if infected people are not given proper management and care.
According to a report published last year in Clinical and Experimental Gastroenterology, there are billions of incidences of gastroenteritis worldwide each year. In children under five, it accounts for 1.5 million to 2.5 million deaths - or 12 per cent.
Deaths tend to occur in developing countries where there's limited access to hydration, good nutrition and primary health care; many infant deaths are due to dehydration caused by gastroenteritis.
The viruses are typically contracted through the faecal-oral route, by consuming contaminated food or water, or contact with contaminated objects or the vomit or faeces of an infected person. Infection can also be spread by air particles, produced during violent vomiting.
Though usually a childhood disease, anyone can fall victim. 'It's particularly easy to occur and is spread in institutional settings such as residential care homes for the elderly or disabled, or schools,' says Wong.
From January 2007 to last month, about two-thirds of the 431 norovirus-associated outbreaks in Hong Kong occurred in homes for the elderly. About one-third of the 49 rotavirus outbreaks took place in child-care centres and kindergartens, and another third in homes for the elderly.
Infants, young children, the elderly, the disabled and those who have a compromised immune system should seek early medical advice.
In Hong Kong, Rotarix and RotaTeq are registered vaccines to prevent gastroenteritis caused by rotavirus. They are both given orally to children six weeks and older.
To prevent gastroenteritis, the Health Department advises:
Eat only thoroughly cooked food, particularly if it's seafood and shellfish.
Wash hands thoroughly before handling food and eating, and after using the toilet and changing diapers.
Wear gloves when cleaning up vomit, faeces and contaminated areas and objects. Clean and disinfect promptly and thoroughly with one-in-49 diluted household bleach and wash hands thoroughly afterwards.
Maintain good indoor ventilation.
Rest at home and refrain from school or work when sick.
Approach family doctors for information and advice if parents are considering getting their babies vaccinated against rotavirus infection.