Cholera: control thru' co-operation

• Safety hints

By Hiranthi Fernando.

First the dreaded Den gue, now cholera. It seems there is no let-up. A total of 433 confirmed cases of cholera have been reported during the first six months of the year, with ten deaths.In the first two weeks of July, this figure has leaped alarmingly to 604, with 17 deaths.

The outbreak began in October last year after a long cholera free period since 1983. There were 430 confirmed cases and 12 deaths reported in 1997.

Health authorities are making a concerted effort to contain the spread of the disease. "Cholera is not fatal if proper treatment is sought early," says Dr. Ms. W. Jayakuru, Director of the Epidemiology Unit. She pointed out that the figures quoted are of cases reported as confirmed, but most of whom are now cured. The percentage of deaths has fortunately not been high.

"Cholera is a watery, profuse, generally painless diarrhoea caused by the bacterium Vibrio Cholera," Dr. Jayakuru said. "Cholera is found to be present in about a hundred countries in the world. In fact, globally it is estimated that 5% of diarrhoea all over the world is due to cholera." With increasing travel between countries, the introduction of the disease from one country to another cannot be prevented, she says It has also been introduced into developed countries such as Japan and the United States. However, wherever the standards of sanitation and personal hygiene are high the disease does not spread rapidly. Even in Sri Lanka, cholera does not spread in places where sanitary facilities are satisfactory.

Dr. Jayakuru explained that the incubation period for cholera is very short, from 48 hours to a few days. In Sri Lanka, it has been found to be mostly two days. Also, more than 90% of the cholera cases are very mild with no visible symptoms. This makes it more difficult to control at once, unlike an explosive outbreak. To contain the spread of the disease, long term measures have to be taken such as providing safe water and latrines, regular maintenance of good food, hygiene, as well as educating the public.

"The public has a major role to play in preventing the spread of cholera," says Dr. Ms. Latha Hapugoda, Director, Health Education Bureau. The H.E.B. co-ordinates with decentralised health units and conducts activities to educate the public. Awareness programmes are organized through the media, poster displays and leaflets. Medical health staff conduct programmes for educating school children, particularly in affected areas. They also chlorinate the wells in these areas.

According to Dr. Hapugoda, because cholera is a disease borne by food and water, personal hygiene and the environmental sanitation, in addition to food hygiene is very important. For instance, the collection of refuse in one's premises breeds flies and so even hygienically cooked food can get contaminated. "It is always better to prepare food at home and keep it warm. Also to ensure that it is kept covered, advises Dr. Hapugoda.

Dr. Hapugoda stressed that special care has to be taken in the case of school children. Parents must advise their children to avoid eating pickles, ice cream, and such food items as well as drinks sold on the streets outside the schools.

It is preferable to give the children a snack and boiled water from home. It is essential that drinking water should be boiled. One minute at boiling point is sufficient to kill the bacteria.

Proper disposal of faecal matter is very important since the disease can be transmitted by faecal matter left open, Dr. Hapugoda said. For every ten patients with clinical cholera, there are 90 carriers without symptoms, who continue to pass the bacteria with their stools. This bacteria can be transmitted through flies or through water which goes into water sources.

While it is the responsibility of the public to avoid spreading the disease through negligence, the local health authorities are responsible for ensuring hygienic food preparation by the inspection of eating houses particularly during an outbreak. Several eating houses in the city have been closed since the cholera outbreak as they did not conform to the required hygienic standards,' Dr. Tissa Seneviratne, Chief Medical Officer of Health of the Colombo Municipal Council said. According to him, although cholera surfaced in Sri Lanka in October 1997, there were no cases detected within the municipal limits of Colombo until the 25th May, 1998. The first case was a labourer from the railway yard at Dematagoda, who had returned from duties at Vavuniya.

Since then, six more cases had been found in Colombo, one opposite the Fort Railway Station, two at Jampettah Street, two in the Mahawatte area and one at Sea Street. Dr. Seneviratne said that all eating houses in these areas were inspected. Rectal swabs were taken from all the food handlers and samples of water were taken for testing. A food handler from one of the eating places was found to be a carrier and tested positive. Two other places were using water which was unhygienic, from a private well. Several such eating houses which did not conform to hygienic standards in food handling or water facilities were closed down until these were rectified. A mass health education programme has also been carried out.

"When cholera cases are detected, we have to identify the sources of infection very quickly," Dr. Seneviratne said. "This is not easy since we have only 27 Public Health Inspectors (PHI) for Colombo where we should have 48." However, he said the Minister also realised this and last week 80 PHI trainees from Kalutara were mobilised and all eating houses in the city were inspected in two days. Those found wanting in hygiene were given two weeks to take corrective action. Random checking of food samples from different areas is carried out by the food inspectors in the six MOH divisions of Colombo.

"The CMC is responsible for the city's water supply," Dr. Seneviratne said. "The water is tested daily at the inlet and outlet before it is sent out to the ratepayers. Ten road taps at random are tested daily. We have advised the Water Board engineers to increase the chlorine content in the water. Some public wells in the city have also been chlorinated. To overcome the shortage of PHIs, a crash training programme has been ordered by the Ministry."

The Medical Research Institute (MRI) is open day and night for testing cholera specimens says Dr. Maya Attapattu, who heads the Department of Bacteriology and Mycology at the MRI. She says that stools specimens sent for testing have to be processed immediately or the bacteria will die. When a specimen is received at night, a medical technician put it in to an enrichment medium right away. After six hours it is transferred to another medium and so kept alive until the cholera laboratory starts works in the morning. According to Dr. Attapattu there are two types of Cholera. The classical form of cholera which is severe and a milder form known as El Tor. El Tor is milder but there are more carriers since there are no symptoms. She said that through antibiotic sensitivity tests carried out on the bacteria, it has been found that it is 100% sensitive to Tetracyclin and Chloramphenacol. It is usually treated with Tetracyclin since Chloramphenacol can cause side effects. The infectious period is one to two weeks. When the patient starts on an antibiotic, within about three days of treatment, the infectious period passes and he will no longer spread the disease.

The MRI has now trained lab technicians from some hospitals in the provinces in the cholera testing procedure. The final tube of the positive cases is sent to the MRI for cross checking. Dr. Attapattu said that factory workers especially in food establishments, coconut mills and export enterprises are screened for cholera. Food samples from these factories are also tested. To control cholera in the country, authorities say the public must co-operate in addition to coordinated activities of the various health departments involved in the work. The authorities need to provide long term preventive measures such as safe water facilities, latrines and ensuring satisfactory food hygiene in sales outlets.

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