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Beware of that deadly bite in the night

Sri Lanka has the dubious record of having the most number of snake bite victims in the world according to the Guiness Book of Records. The most number of deaths from snake bite are reported from the North Central Province.

Of the many poisonous snakes in Sri Lanka, the common krait is said to be the most venomous. Many people stung by this snake do not survive. However, with more people seeking admission to hospital rather than taking native treatment, the death rate has reduced. Nevertheless the toxicity of this particularly innocuous looking snake is so high that many die and the need to be informed about the habits and traits of this snake is imperative.

Dr. S.A.M. Kularatne, a Consultant Physician and lecturer at the Medical Faculty, University of Peradeniya who was earlier attached to the General Hospital, Anuradhapura, conducted pioneering research on krait bite from 1996 to 1998 in the North Central Province. He studied 210 krait bite victims admitted to the Anuradhapura General Hospital during his period there as Consultant Physician and analyzed the findings. His original research paper was published in the May 2002 issue of the prestigious Postgraduate Journal of Medicine bringing honour to Sri Lanka.

Dr. Kularatne's research concentrated on the epidemiology of krait bite, the clinical features, acute complications that manifest as a result and the treatment of krait bite. This study defined the optimum intensive care management parameters that are required for krait bite victims in Sri Lanka. This article is based on the original article by Dr. Kularatne published in the Postgraduate Journal of Medicine.

The common krait is found in Sri Lanka, India, Bangladesh and Pakistan. It is coppery black in colour and is six inches to six feet in length. Similar to the rat snake, its distinguishing characteristic, however, is the white bands on the body, from neck downwards.

The common victims of this snake are farmers who live in open wattle-and-daub houses and sleep in watch huts in the fields. A significant number of patients die before reaching hospital. However in recent years many people have sought the life saving benefits of hospital treatment and the fatality rate has come down drastically.

The common krait is a nocturnally active, terrestrial snake, which lives close to human dwellings but is not vicious by nature. It creeps into houses over the ground or through the roof and exhibits arboreal tendencies. Occasional daytime bites and biting on tops of trees have also been reported. It has also been observed that bites occur at night while the victims are sleeping. Why the snake prefers to creep into dwellings and how man becomes a victim is yet to be documented.

The common krait prefers to feed on small snakes. However, it is attracted by mice, rats and geckos that are abundant in homes. This may draw it into houses and while humans are asleep, they may be bitten due to accidental handling or rolling over the snake. Exposed parts of the body may be misidentified as prey. These may be possible provocative factors for a common krait bite even though the snake remains naturally indolent.

Once a person is bitten by the common krait, several clinical manifestations occur. Abdominal pain is common. A patient may wake up in the night with colicky abdominal pain, unaware that he has been bitten. Thus the pain has often been misdiagnosed as something not worth taking notice of and here lies the problem. Internal bleeding from the organs could occur. Many patients who are bitten by the common krait need assisted breathing or 'ventilation'. Thus the transfer of the patient immediately to a hospital that has proper intensive care facilities is important. Unlike in the case of cobra bite that could kill a man in 30 minutes, the process of envenoming can be slow in the case of krait bite. Nevertheless early medical intervention is needed.

The other symptoms that are manifest after krait bite include a comatose state, memory loss, autonomic or neuromuscular paralysis and hypokalamia.

Specific anti-venom treatment for krait bite is not available. Thus victims are given poiyvalent Haffkine anti-venom in varying doses according to the severity and the complications are managed.

This study has identified factors such as poor resuscitation, delay in hospital admission and resultant complications following krait bite as the contributory causes for death. Improvement of intensive care facilities in Sri Lanka, awareness of the clinical course and anticipation and management of complications can overcome the morbidity. This means that a person who is bitten must immediately seek the attention of a qualified medical practitioner in a hospital and not a native healer.

Educating high risk populations about the biting pattern of the common krait and the preventive measures that they can take will no doubt reduce the incidence of krait related deaths in Sri Lanka. Houses and their environs should be kept clean and well swept and sleeping in unprotected open spaces at night should be avoided.

-Mahes Salgado

Children better fighters of SARS

The deadly virus SARS may have a less serious effect on young children compared with teenagers and adults, research suggests.

A team from the Chinese University of Hong Kong have come to the preliminary conclusion after studying the first 10 children with SARS who received treatment during the early phase of the epidemic in Hong Kong.

There have been no childhood deaths from SARS up to 25 April. The researchers found that teenage patients presented with symptoms similar to adult cases. All four teenagers examined by the researchers had respiratory symptoms that were so severe that they had to be given oxygen.

Other symptoms included muscle ache, shivers and a general feeling of being unwell. However, younger children had much more mild symptoms such as a cough and runny nose.

And unlike the older patients, none of the younger children had shivers or muscle pains. They also regained full health much more quickly. Lead researcher Professor Tai Fai Fok said: "Our preliminary observations suggest that younger children possibly develop a milder form of disease and tend to run a less aggressive clinical course."

The research is published on the website of The Lancet medical journal. (BBC News)

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