Keeping leptospirosis at bay

In spite of what is known about leptospirosis, why is it that we are unable to prevent the spread of this zoonotic disease from reservoir hosts to man, asks DR. SARANYA NARAYAN.

IN The Hindu (June 9), I read with dismay and disbelief, an article that said that 40 per cent of Chennai's waterways are contaminated with leptospirae. Adding to the sense of urgency were the news items in The Hindu and the New Indian Express of July 31 which mention that 26 people died of an outbreak of leptospirosis in Maharashtra. Over the last few years, articles have appeared at regular intervals in the press, which have imparted information on various aspects of this most under- reported spirochetal infection. In 1886, Weil's syndrome became an established clinical entity, though it was only in 1907 that the association of leptospirae as the causative spirochete was recognised.

Leptospirosis is a zoonotic disease with the reservoir hosts being various domestic and wild animals like bandicoots, dogs, cattle and pigs. Man is only the incidental host and acquires the infection when these organisms are shed in the urine of the affected animal into the environment. These organisms then gain entry into humans through cracks in the skin or mucous membranes. Leptopirosis is asymptomatic and clears spontaneously without treatment in almost 90 per cent of infected individuals. In those who are symptomatic, about 10-15 per cent have the icteric forms with jaundice, with or without renal involvement. In the remaining 85 per cent of people who have symptoms, infection follows an anicteric course, without jaundice but with neurological, ocular, auditory, cardiac, pulmonary, pancreatic and even adrenal involvement. Recently published information tells us that long term sequel and even chronic persistent forms of this seemingly innocuous infection are now well established. The systems most affected are the nervous system and the visual pathways.

There are several diagnostic and monitoring tools available for different stages of infection. Laboratories, depending on the population they cater to and the kind of laboratory they are - i.e. diagnostic, research or referral - use these tools to arrive at a diagnosis or report an outbreak. A look at the outbreaks in the 20th Century and the most recently reported one at the start of the 21st Century tells us just how real the problem of leptospirosis is (see table).

Treatment of this infection is most effective if begun early in the course of illness. Several antibiotics are effective when used alone or in combination, the most effective being penicillin followed by doxycycline.

In the 21st Century, we are armed with sufficient knowledge and ammunition and the most recent information on the subject is accessible at the click of the mouse (strange that here too, one needs a mouse). We are now able to predict with a fair degree of certainty, when the disease peaks every year and often as one of my colleagues says the "ink filler" principle operates. Several infections hit the poor unsuspecting victim all at once and confuse the clinical picture completely. This too, we are now attuned to detect. What we do lack is the infrastructure for case notification, reporting of an outbreak and a surveillance system. But what is heartening is that public health laboratories in Tamil Nadu are gearing up to take on this challenge.

In spite of what is known about leptospirosis, why is it that we are unable to prevent the spread of this zoonotic disease from reservoir hosts to man? Isn't it time civic authorities did something about it? Every other day we have photographs of waterlogged roads, uncovered and overflowing drains, garbage bins also overflowing into all this, children either urinating or playing in these murky waters and, to top it all, our bovine, porcine, feline and canine counterparts wandering majestically and totally unaffected through it all. While this may seem amusing to some and revolting to others, the fact remains that one cannot help but wonder how many more people need to lose their lives unnecessarily before the powers that be sit up and take notice.

There are several control measures that can be easily implemented in rural and urban areas. In rural areas, leptospirosis is an occupational hazard and whether it is a rice farmer in Tamil Nadu or a worker on a pineapple plantation in Kerala, everyone is equally affected. The chief reasons for spread of infection in rural areas are:

* Expansion of agriculture along with increased rodent activity and wet soil being the chief contributory factors.

* A lack of mechanisation coupled with the use of crude farming techniques.

* Absence of protection against environmental contamination.

Control measures need to address each of these issues and increased rodent activity must be prevented before damage is done.

In urban areas, like our own "Singara Chennai" we have a different set of problems to contend with and possible control measures could include the following:

* Safe water that is adequately chlorinated right up to the most peripheral point in the distribution system.

* Better drainage facilities.

* Banning of cattle from roads (in addition to being health hazards, they form a major traffic hazard).

* Better garbage disposal measures throughout the city (not just overflowing bins sprinkled with bleaching powder).

* Improved recreational facilities for children so that they do not have to use the roadside pools to play in or dirty lakes to swim or bathe in.

* Providing toilets in every area, if not on every road. This could be in the form of pay toilets that are manned so as to prevent defaulters.

* Vaccination of all reservoir hosts.

Apart from all this we need to improve our own civic sensibilities. This will certainly help to prevent not only leptospirosis, but a host of other infections too, like malaria and tuberculosis to name a few. The simplest control measures that we can all adopt immediately are to wear protective footwear and drink only boiled water at all times.

Every year, one reads that the quantum of loans sanctioned by the World Health Organisation, the World Bank and other funding agencies have only increased. Isn't it time that we get our own home into order, start at the grassroots level if need be and prevent these infections from entering or re-entering our midst? If one could convert bed-time stories into reality, our problems would be infinitely easier to solve but the important thing is to make a beginning and tackle the issue before it gets out of hand.

The writer is Director, Lister Laboratory, Chennai - 600034.

Send this article to Friends by E-Mail

Section  : Features
Previous : Customers can be wrong
Next     : Freedom from hunger