Leptospirosis
Is Leptospirosis a global problem?
Even though
Leptospirosis infections are seen worldwide, it is more common in the tropics
and subtropics. Each year an average of
1.03 million persons are infected and 58,900 deaths occur due
to leptospirosis globally. Infections and deaths disproportionately occur
among economically active young adult males between the ages of 20-49 years.
Leptospirosis infection is categorized as a neglected tropical disease.
(Source: Paul R. Torgerson, José E. Hagan, Federico Costa, Juan Calcagno,
Michael Kane, Martha S. Martinez-Silveira, Marga GA Goris, Claudia Stein,
Albert I. Ko, and Bernadette Abela-Ridder (2015)
Is Leptospirosis a problem in Sri Lanka?
Infections are
reported throughout the year and outbreaks commonly occur following rainfall
due to the higher possibility of contamination of water by infected rodent
urine. Seasonal variability is clearly seen in disease occurrence,
as Leptospira infections peak following the two monsoons. A smaller
peak in disease incidence is observed during March-May and a much higher peak
is seen during October-December. These two peaks coincide with the two main
paddy cultivation and harvesting seasons (especially if it rains during
harvesting) of “Yala” and “Maha”. There are more leptospirosis infections
following floods.
Who is more at risk for contracting Leptospirosis?
Leptospirosis is a disease associated with agriculture-related occupations such as paddy cultivation, Cattle farming and piggeries as well as occupations like Gem mining, sewage and canal work. People involved in recreational activities in marshy lands and water bodies could potentially be at risk of contracting this disease as well.
Figure 3 – Paddy
workers and people displaced in flood at risk of Leptospirosis
What is Leptospirosis?
Leptospirosis is an infection in humans
caused by a bacteria known as leptospira. These microorganisms are found in the
natural environment in the kidneys of animals of reservoir hosts, such as
rodents, ruminants, canines and wild animals. Water and soil are contaminated
either by infected animal urine directly or by urine infected rain or flood
water indirectly. The Leptospira bacteria can survive up to a few weeks in
stagnant water or wet soil. Mixing of urine-contaminated soil and water into
large freshwater bodies or fields creates conducive environments for disease
transmission among humans.
How is man infected with leptospirosis?
Entry into the human body is an accidental event in the life cycle of this
pathogen. Water or soil contaminated by the urine of affected animals is the
most common exposure, which allows the bacteria to enter man. This is commonly
seen following rainfall or flooding. The site of entry into the human body is
through abraded/damaged skin or undamaged/damaged mucosa of the nasal and oral
cavity or the mucus membranes of the eyes.
What are the symptoms of leptospirosis?
The clinical
presentation of those infected varies widely. A majority of those who are
exposed to this bacterium do not show any symptoms. On average symptoms appear
within 5-14 days following the exposure (the range for the incubation period is
2-30 days). When symptomatic it commonly manifests as an undifferentiated
febrile illness. Around 5-10% of those infected can develop severe forms of
disease which may often lead to fatalities.
The diagnosis of
leptospirosis is a possibility in any person presenting with acute febrile
illness with chills and headache together with muscle pain/ tenderness,
jaundice, conjunctival suffusion, cough, shortness of breath and
gastro-intestinal symptoms. Some important causes of death in
leptospirosis include renal heart or respiratory failure, widespread haemorrhage,
or involvement of the central nervous system.
How is leptospirosis treated?
Leptospirosis is a
serious but treatable disease. Early diagnosis and initiation of effective
antibiotic medication at the earliest will prevent complications of disease and
fatalities.
How can leptospirosis be Prevented?
Preventive measures
are based on local epidemiological and behavioural practices of high-risk
groups. As this disease is mainly related to occupations such as agriculture ,
farming, gem-mining, sewage and canal cleaning, raising awareness on
precautions and availing the prophylactic medication under the guidance of
Healthcare workers when indicated is important.
General preventive
measures such as good hygiene and appropriate waste management practices
especially around fields and waterbodies and farms, keeping animals away from
children’s play areas such as gardens, playgrounds and sandboxes, avoiding
potentially contaminated water for rinsing the mouth and washing face should be
practiced. It is also advisable to avoid unnecessarily playing/wading in flood
waters as it could be potentially contaminated.
It is also
important to cover all wounds/abrasions on the skin with a waterproof covering
prior to contact with any potentially infected environmental sources. Whenever
appropriate protective clothing including knee-high boots, gloves should be
worn.
Currently, occupational groups at high-risk of leptospirosis as well as communities affected by floods and landslides are recommended for weekly antibiotic prophylaxis under the guidance of the area Medical Officer of Health (MOH) or Public Health Inspector (PHI). Intersectoral collaboration and networking between health, agriculture, and the veterinary sector are needed for the prevention of disease through vector control and environmental management.
Figure 5: Awareness
campaign on high-risk areas for contracting Leptospirosis