Date: Sat 27 Jul 2019
Source: Today Online [abridged, edited]
It was supposed to be a fun school camp. Instead, the outdoor adventure turned into a harrowing ordeal for a 14-year-old student in Singapore when he contracted an unusual infection, likely from camp activities.
Weeks following his contact with murky water, the boy showed up at KK Women's and Children's Hospital (KKH) with fever, stomach pain, nausea and jaundice. Tests also showed a swollen liver and spleen. On the 2nd day, his condition worsened and he was transferred to the intensive care unit. The infection causing his misery? Leptospirosis, a disease more commonly seen in rodents, livestock, dogs and cats but can also spread to humans.
As families spend time bonding on holidays overseas and adrenaline-seekers head outdoors and go on off-the-beaten tracks, health experts raised the possibility that they could expose themselves to less commonly seen infections such as leptospirosis.
In the last 2 years, 96 human cases of leptospirosis were notified in Singapore, based on data published by the Ministry of Health. It was added to the list of notifiable infectious diseases in September 2016.
The _Leptospira_ bacteria, which is commonly found in tropical countries, can enter the body [through] cuts on the skin, the eye, or mucous membranes that line body parts such as the mouth, nose and windpipe. Associate Professor Chong Chia Yin, senior consultant at KKH's infectious disease service, said that besides exposure to urine or bodily fluids from infected animals, people may also get the disease if they are exposed to contaminated water during recreational activities such as swimming, water sports and rafting in contaminated lakes and rivers.
Dr. Chan Si Min, head and consultant at the division of paediatric infectious diseases at National University Hospital, said that leptospirosis can range in severity, from mild or asymptomatic (no symptoms) to severe and life-threatening, resulting in jaundice, kidney failure and bleeding in the lungs. It can also affect other organs such as the liver and heart. Assoc. Prof. Chong said that about 5% to 15% of cases will have life-threatening consequences. Death rate is the highest among people above 60 years old.
Certain measures may help reduce the risk of contracting leptospirosis when travelling and engaging in outdoor recreational activities. Assoc. Prof. Chong advised researching travel destinations before getting there, to check if there are any floods, previous outbreaks of leptospirosis in the lakes, rivers, and so forth.
Dr. Chan advised those who are wading, swimming or boating in freshwater -- which may be contaminated by animals shedding the infection in urine -- should avoid being submerged in the water or swallowing it.
Wear protective footwear and clothing when taking part in outdoor activities, as leptospirosis can be transmitted via abrasions or cuts on the skin that come into contact with contaminated soil, mud or water. For instance, it is advisable to wear covered splash-proof shoes or boots instead of going barefoot or wearing slippers, and long pants instead of shorts when trekking, and to be aware of touching certain surfaces that could potentially lead to accidental cuts and abrasion, Dr. Leong Hoe Nam [an infectious diseases specialist] said.
Assoc. Prof. Chong advised: "Avoid participating in outdoor water activities if you have any cuts on your skin."
Some studies suggest that taking the antibiotic doxycycline shortly after exposure to leptospirosis can potentially reduce illness caused by the disease.
It is not standard procedure to prescribe doxycycline before travel to prevent leptospirosis. However, Dr. Leong said that he might consider giving the medication to certain groups of adult travellers heading to high-risk areas as a preventive measure.
Besides potentially reducing the risk of illness by leptospirosis, it also protects against malaria, which is another type of zoonotic disease (that can be passed from animals to humans) more commonly seen among travellers, he added. [Byline: Eveline Gan]
[Leptospirosis is a zoonotic spirochetal infection that is distributed widely throughout the world in warm climates. The microorganism can be found in fresh (not salty) water, wet soil, or vegetation that has been contaminated by urine from chronically infected animals.
Leptospirosis affects humans and a variety of animals that include dogs, cattle, pigs, and rodents. Different leptospiral serovars are prevalent in particular geographical regions. Leptospires enter the body through open sores or wounds in the skin, or through mucous membranes following exposure to contaminated water. Outbreaks frequently follow large rainfalls, flooding with fresh water, and increasing rodent numbers.
Leptospirosis is a risk during recreational activities, such as camping, fresh water swimming, canoeing, kayaking, rafting, golfing, and trail biking, that involve exposure to water in lakes, rivers, or ponds contaminated by urine from leptospire-infected animals (<https://www.cdc.gov/leptospirosis/exposure/index.html
Leptospirosis is also an occupational hazard for people who work outdoors or with animals; for example, workers in wet agricultural settings (such as rice field workers), ranchers, slaughterhouse workers, trappers, loggers, sewer workers, veterinarians, fishery workers, dairy farmers, or military personnel.
Because of the relatively nonspecific nature of the clinical presentation of leptospirosis, its diagnosis cannot be made confidently without laboratory confirmation. The _Leptospira_ Dip-S-Tick (DST) IgM dot-ELISA test kits (PanBio Integrated Diagnostics) can provide in-the-field testing of suspected patients (<http://www.ncbi.nlm.nih.gov/pmc/articles/PMC149700/
>). Confirmatory testing uses the microscopic agglutination test (MAT). Molecular assays such as DNA PCR can also be used, if available. - ProMED Mod.ML]