Winter diarrhoea in children

NOW that we are in the depths of winter those who have young children will notice an increase in episodes of fever, diarrhoea or vomiting.

There are a few possible causes for this but the commonest would be rota-virus. Globally, virus called rota-virus is the most common cause of severe gastroenteritis (fever, diarrhoea and vomiting) in early childhood. Almost all children have been infected by the time they reach five years of age. However, with each infection, immunity develops, and subsequent infections are less severe; adults are rarely affected. In developing countries rota-virus is responsible for approximately half a million deaths per year.

Once a child is infected by the virus, there is an incubation period of about two days before symptoms appear. Symptoms often start with vomiting and a mild fever followed by four to eight days of profuse watery diarrhoea. The most severe symptoms tend to occur in children six months to two years of age, the elderly, and those with compromised or absent immune system function. In some cases, severe dehydration and death can occur. Some infants (especially under 3 months) with rota-virus infection may not show any symptoms at all.

Rota-virus infections are highly infectious and are spread by the vomit or faeces of an infected person (so called faeco-oral route). The faeces of an infected person can contain more than 10 trillion infectious particles per gram! Fewer than 100 of these are required to transmit infection by, for example, touching someone who has been sick and has the virus on their hands, contaminated objects and contaminated food or drink. The virus may also be spread by coughing and sneezing.

Small children who are not immune to rota-virus (from either past infection or vaccination) are at greater risk of the disease, although older people can sometimes be infected too. Most children have developed immunity to rota-virus by three years of age. Immunity to the rota-viral infection is partial. Subsequent infections are generally milder than the first infection.

Rota-virus can be prevented by thorough hand washing using soap and water and drying with a clean towel after going to the toilet, before preparing or handling food, before eating food and after caring for someone with diarrhoea (especially after changing nappies or soiled linen). Never change nappies on surfaces where food is prepared or eaten.

Surfaces, objects (including toys) and clothing that have been exposed to vomit or faeces must be thoroughly cleaned with hot water and detergent. Allow objects to dry after they have been cleaned. Children who have experienced diarrhoea should not return to crèche or school until 24 hours after symptoms have resolved. Anyone with diarrhoea should not swim, wade or paddle in pools for at least 2 weeks after complete recovery. A rota-virus vaccine is now part of Zimbabwe's immunisation schedule and this is given from six weeks of age. This is expected to reduce the number of cases of winter diarrhoea significantly.

Diagnosis of rota-virus infection is usually suspected based on the symptoms and can be confirmed by testing the child's stools in a laboratory. The aim of treatment is to prevent dehydration and death. The World Health Organisation recommends oral rehydration therapy (i.e. giving extra home fluids, continuing breastfeeding, giving sugar salt solution and continuing with feeds) and zinc supplementation as the mainstay of treatment of diarrhoea in children. You should start oral rehydration therapy as soon as possible after the onset of vomiting or diarrhoea. Avoid undiluted fruit juices and soft drinks as they may increase dehydration and diarrhoea. Medicines to prevent vomiting and diarrhoea should not be given, especially to children, except when prescribed by a doctor.

Medicine to relieve fever (eg.Paracetamol) can be used if needed. Antibiotics are usually not necessary and can even prolong the course of the illness. They are only useful in some situations which your doctor will know. When a child is not keeping any fluids down, it is usually necessary to admit them for intravenous fluids.

Sugar salt solution, by the way, is now made up of 6 level teaspoons of sugar and half level teaspoon of salt dissolved in 1 litre of clean water. Commercial preparations can also be acquired from pharmacies and clinics. You should get worried when a child with diarrhoea is vomiting everything, has blood in the diarrhoea, is lethargic or unconscious, unable to drink, has sunken eyes, has a sunken fontanel (nhova) or is restless and irritable.

If you see any of these, you need to rush to your doctor or the nearest health centre for urgent attention.