Beware of the rat

The most vulnerable to leptospirosis are farmers, fresh-water fishermen, gem-miners and those cleaning canals and drains

By Kumudini Hettiarachchi

Fever, muscle aches and reddish eyes, along with a history of working outdoors – don’t delay, go to the nearest hospital. This is the advice of the Chief Epidemiologist Dr. Nihal Abeysinghe as rat fever (leptospirosis) commonly known as Mee Una spreads across the country, in most districts.

The death toll from rat fever up to now this year, is 41, when taking hospital statistics, The Sunday Times learns, with the number falling sick amounting to 1,177. For the whole of last year, hospital-reported deaths from rat fever were 34 and cases were 2,195.

He pointed out that rat fever may be spreading due to the fact that the country has been experiencing rainy weather for almost six months and many people are engaging in paddy cultivations not only making use of these conditions but also in view of the high price of rice.

Unlike in previous years, The Sunday Times understands that in addition to high-risk districts, more cases have also been reported from the districts of Ratnapura, Hambantota, Anuradhapura and Moneragala. The Epidemiology Unit had alerted health personnel on the need to manage outbreaks of leptospirosis as far back as November last year, the Weekly Report put out by the Unit indicates.

The most vulnerable to leptospirosis are farmers, fresh-water fishermen, gem-miners and those cleaning canals and drains, says Dr. Abeysinghe, explaining that most people are not resorting to the traditional methods of paddy cultivation such as clearing the fields of dirt and also leftover dried sheaves of paddy first.

Now, in most areas, labourers get into the fields, not only those worked round the year but also neglected lands, which maybe highly infested with rats, he says, advising that attempts should be made to get rid of the rats before cultivations begin.

What is leptospirosis?

It is an infectious disease caused by bacteria called leptospires which are found in the kidneys of certain animals such as rodents, livestock (cattle and buffalo), canines and also wild mammals. The bacteria are transmitted directly or indirectly from animals to humans. Although some of the animals are natural hosts, when they excrete the bacteria through their urine and humans are exposed to contaminated water, soil or food, humans may become “incidental” or “accidental” hosts.

The bacteria may enter humans through wounds or lesions in the skin or nasal, oral or eye mucous membranes, says Dr. Abeysinghe, adding that drinking contaminated water can also lead to infection. “The bacteria then enter the blood and invade practically all tissues and organs.”

The symptoms of leptospirosis appear within 5-14 days of exposure to the germ and may range from mild flu-like illness to serious and sometimes fatal disease. The symptoms include fever, chills, conjunctival suffusion (reddening of the eyes), headache, muscle tenderness (particularly calf and lumbar areas) and jaundice (yellowing of the skin and eyes). Leptospirosis could also mimic many other diseases such as dengue, influenza, meningitis and hepatitis.

“The case fatality rate ranges from less than 5% to 30% and the important causes of death are renal failure, heart failure and haemorrhage. Liver failure is rare despite jaundice. Re-infection from the same sub-strain of bacteria does not occur once a person is cured but it is not a safeguard against a different sub-strain,” says Dr. Abeysinghe, stressing that though leptospirosis is a potentially serious disease it is treatable.

He requests clinicians not to await laboratory test reports but to begin treatment with antibiotics, as serological tests do not become positive until about a week after the onset of illness. “Supportive care with strict attention to fluid and electrolyte balance is essential with dialysis if renal failure occurs.”

How to prevent leptospirosis

• Remove garbage and keep areas around human habitation clean to prevent infestation by rodents. Rid fields of rats.

• Keep animals away from gardens, playgrounds and places where children play.

• Where possible use protective clothing, knee-high boots, gloves and keep wounds covered with waterproof dressings.

• Use boiled water as virulent organisms can withstand chlorination and filtering.

• Don’t wade through flood waters.