KARACHI: Medical experts have demanded for proper chlorination of water, as Karachi fears more cases of Naegleria fowleri due to lack of proper chlorination of potable water being supplied to the city by the Karachi Water and Sewerage Board (KWSB) .

As per a recent survey, 40 per cent water samples collected from different parts of Karachi were not properly chlorinated, increasing chances of fatal diseases caused by Naegleria floweri.

Naegleria is an amoeba (single-celled living organism) commonly found in warm freshwater (ponds, tanks, lakes, rivers, and hot springs) and soil. Only one species (type) of Naegleria infects people: Naegleria fowleri. Naegleria fowleri infects people when water containing the amoeba enters the body through the nose. This typically occurs when people go swimming or diving in warm freshwater places, like lakes and rivers.

The Naegleria fowleri amoeba then travels up the nose to the brain where it destroys the brain tissue.

However, one cannot be infected with Naegleria fowleri by drinking contaminated water. Naegleria fowleri does not survive in seawater and has not been detected in seawater.

In very rare instances, Naegleria infections may also occur when contaminated water from other sources (such as inadequately chlorinated swimming pool water or contaminated tap water) enters the nose, for example when people submerge their heads or cleanse their noses during religious practices (like ablution), and when people irrigate their sinuses (nose) using contaminated tap water.

Naegleria fowleri has not been shown to spread via water vapour or aerosol droplets (such as shower mist or vapour from a humidifier). According to focal person for Naegleria fowleri Dr Zafar Mehdi, 40 per cent of water samples collected from Gulberg, Gadap, Nazimabad, North Nazimabad, New Karachi, Shah Faisal Colony and Orangi lacked proper chlorination.

He said it was the responsibility of the KWSB to add proper chlorine in water before its supply to citizens.

Pakistan Medical Association (PMA) leader Dr Qaiser Sajjad said: “As Muslims we have to clean our noses while ablution (Ghusil and Wuzu) and it demands that water we use should be properly boiled or chlorinated.”

He said the KWSB should ensure proper chlorination of potable water at pumping station level however, the citizens could use water purification tablets and powders commonly available at medical stores.

He told the PPI that household bleach could also be used, but as most people did not know how to use it; therefore, water purification tablets and powders were best alternative to be used in water tanks of homes, offices, mosques, hospitals at individual and community levels.

Professor of Pathology at the Shaheed Benazir Bhutto Medical University Larkana, Prof Dr Akbar Ali Soomro said that there was a need for solid steps for chlorination of water.

He said although through boiling water properly it could be made safe from Naegleria fowleri, chlorination was cost effective method of water disinfection being used worldwide.

However, citizens should also take measures at their level to use clean water to minimise risk of this disease. Such steps may include using water that has been previously boiled for 1 minute and left to cool. At elevations above 6,500 feet, boil water for three minutes.

The people can use a filter designed to remove some water-borne germs. The label may read “NSF 53” or “NSF 58”. Filter labels that read “absolute pore size of 1 micron or smaller” are also effective.

Citizens can disinfect water using chlorine bleach, he said.

Sodium hypochlorite is the active ingredient in common household bleach. Sodium hypochlorite is the source of chlorine in bleach. Most off-the-shelf bleach products will contain in between four and six per cent available chlorine. It needs just two drops of bleach per one litre or quart of water to get it chlorinate. When using household bleach for disinfecting water, add two drops of bleach per quart or litre of water. Stir it well, he added. Let the mixture stand for a half hour before use. If the water is cloudy with suspended particles: First filter the water as best you can, and then double the amount of bleach you add to the water. However, calcium hypochlorite is widely used to chlorinate water.

A one-pound bag of calcium hypochlorite in granular form will treat up to 10,000 gallons of drinking water. Calcium hypochlorite is one of the best chemical disinfectants for water, better than household bleach by far. It destroys a variety of disease causing organisms, including bacteria, yeast, fungus, spores, and viruses.

However, Dr Merajul Huda Siddqui, who is also the chief of Jamaat-i-Islami Sindh chapter talking to PPI said that in Karachi not only the water being supplied to citizens was non-chlorinated, but it was also mixed with sewage due to leaking sewerage lines that run parallel to clean water lines in different localities.

He said he had visited many countries of the world where the governments supply clean potable water to citizens. He said however in Pakistan and especially in Karachi there was a thriving business of ‘mineral water’ earning billions of rupees because citizens were not provided with clean potable water.

He said if citizens were given clean potable water it would deal a blow to mineral water business. He said the higher authorities should look into the vested interests in this regard that do not want improvement of quality of potable water.

He said besides Naegleria fowleri, coliform bacteria were commonly found in water used for drinking for majority of citizens in Karachi which was a matter of grave concern.

He demanded that clean and chlorinated water was supplied to citizens, especially Karachiites to save them from diseases, including Naegleria fowleri.

Published in Dawn, July 21st, 2016