The rat population in the country, especially in the major cities, seems to have increased many fold gauging from the number of public complaints and news reports in the media.

Rats have practically taken over some parts of the country especially in the Klang and Kinta valleys. It is now common to see rats running around in our immediate environment in broad daylight.

It appears that the people in these rat infested environments have come to terms with the reality that these creatures are here to stay for good, since efforts to control their proliferation by the local councils have not been successful.

There are no reliable statistics on the rodent population in the country but everyone is in agreement that the rat population in the country has increased to an alarming level. According to a local rodent biologist, apparently there are seven rodents to one person in the country.

For a population of 27 million, this works out to be a whopping 189 million rodents and mind you, that’s just a conservative estimate.

A renowned rodent biologist from the UK, Dr Lye Hinds has been quoted as saying that there are about four million rats born daily in the developing countries. I suppose the Klang Valley must be one of those places in the developing countries with a high rat population that live in close proximity to humans. This is indeed worrying.

Rodents are known to spread worldwide more than 60 diseases (virus, bacteria, parasites, fungus) that can infect humans through bite wounds, consuming of food and water contaminated with rodent feces and urine. Diseases from rodents are also spread indirectly to humans by way of their ecto-parasites like ticks, mites and fleas.

Many of the domestic rodent species are also reservoirs of organisms that cause debilitating diseases in humans and livestock. Some of the diseases carried by rodents and their vectors can cause serious medical problems including brain damage, paralysis and death.

A study conducted two years ago using rats trapped in Kuala Lumpur and its surrounding areas indicated that more than 60 percent of the rats examined were infected with at least one or more types of zoonotic pathogens (pathogens that can be transmitted to man). The epidemiology (disease pattern) of many of the rodent-borne diseases in Malaysia is poorly understood.

For instance, little is known about which species of rodents are the major reservoirs of diseases and how long do the infective stages of these pathogens which originate from rodents persist in domestic and rural environments and how these agents are transmitted under natural conditions.

There is a rising concern among biologists that rodents, especially those that live in close proximity with humans, may pose serious health risks in time to come. Scientists predict that the rapid global weather changes that we are experiencing now will facilitate new rodent breeding grounds and increase the risk of rodent borne zoonotic diseases being transmitted to humans.

The fear of these rodents triggering of a major disease outbreak similar to the black (bubonic) plague cannot be ruled out. In view of the obvious health risks associated with the increasing rat population in the country, especially in the cities and other human-dwelling areas, the authorities need to quickly think of a long-term plan to keep the rodent population in check.

The killing of rats by poison baits and snaring may not be practical and is not effective. These methods are only temporary measures. The rats will continue to breed and the population will return to normal. Furthermore ,the rats are much ‘smarter’ as they can sense the danger and avoid the baits and the snares.

Killing rats with poison baits also does not seem ethical to many as the rats die a violent and painful death with their lungs bursting due to drugs’ effect. And often, these poisoned rats are found dead in inaccessible areas thus fouling up the surrounding air and creating new environmental and hygiene problems.

It is time we view the rat infestation in the country seriously and take appropriate control measures before it is too late. If need be, review the relevant legislative and administrative systems currently in place too.

Meantime, I suggest that the authorities look to alternative methods of controlling these rats. Perhaps the authorities should explore the use of ‘sterilant incorporated’ rat baits. There are number of non-toxic environmental-friendly herbal sterilants that can be used as rat baits.

These sterilants will primarily focus on retarding the growth of the ovary and sperm cells in the female rats with no other ill effects. Rats with deformed reproductive organs or cells can continue to copulate but they (the females) will not able to conceive.

Over a period of time, the rat population will automatically dwindle naturally provided no other external factors come into play. If this harmless rat birth control methods works, we could then consider extending this method to control the stray dog and cat problem in the country.

How society views such control measures is debatable. As long as the method is safe and humane, I suppose the public will welcome it unless, of course, there are other implications of using sterilant coated baits.

I appeal to the authorities concernd to view the increase of the rat population in the country seriously. We are sitting on a ‘biological time bomb’ which may explode anytime and we need to act fast.