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 second 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 two 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 though 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 per cent to 15 per cent of cases will have life-threatening consequences.

Death rate is the highest among people above 60 years old.

INFECTION AMONG THE YOUNG  

While adults are generally more likely to get an infection, severe leptospirosis has also been reported in children — as seen in the 14-year-old boy’s case.

He was one of four children diagnosed and treated for severe leptospirosis at KKH’s infectious disease service from 2011.

The youngest patient was a three-year-old girl who resided in Indonesia.

All four cases were highlighted in a recent report in the journal Annals by the Academy of Medicine, Singapore — the first paediatric case series of severe leptospirosis in children here.

In three of the four children aged up to 15, leptospirosis led to inflammation of the heart and required intensive care in hospitals.

One of them, a 10-year-old girl, became so critically ill that she required life support. Before developing symptoms, she had travelled to Australia, Indonesia and Malaysia.

THREE IN FIVE CASES TRAVEL-RELATED

Infectious diseases specialist Leong Hoe Nam, from Rophi Clinic at Mount Elizabeth Novena Specialist Centre, estimated that about three in five cases diagnosed here are acquired overseas.

Assoc Prof Chong, one of the authors of the report on the four children’s cases, said that there is a higher incidence of leptospirosis in tropical countries during heavy rainfall and flooding, compared with temperate countries.

A main reason is that the bacteria survive longer in warm and humid conditions. There is also a higher chance for humans to be exposed to infected animals in the developing countries.

In the report she co-wrote, three of the four young patients had travelled to South-east Asian countries shortly before they got infected. All of them reported recreational activities in fresh water or had contact with rats.

For Dr Leong, a patient he encountered picked up the disease after venturing into the jungles of Indonesia as part of her post-graduate work.

“She ended up falling and tripping all over the hills. She came in with kidney failure (one of the severe complications of leptospirosis) and required dialysis,” he said.

Two of the locally acquired adult cases treated by Dr Leong could have been exposed to the bacteria after spending time at the Singapore Botanic Gardens and a fish market.

DIFFICULT TO DIAGNOSE

As with any disease, early detection and treatment offer better outcomes.

Yet, diagnosing leptospirosis can be challenging. This is usually done using serological tests (blood tests that look for antibodies in the blood) and can be carried out only in certain laboratories, Dr Leong said.

In Singapore, the serology is offered only at the Singapore General Hospital, he added. 

Dr Chan said that patients may experience fever, chills, rash, tummy pain, vomiting and have muscle aches in the calf or back. However, these non-specific symptoms can make leptospirosis difficult to differentiate from other travel-related infections.

For instance, it is not uncommon for the disease’ symptoms to be initially mistaken for dengue or hepatitis infection.

“The presence of symptoms like conjunctival suffusion (red eyes without discharge) may help with the diagnosis although there are other illnesses, like Kawasaki’s disease, that can cause this,” Dr Chan added.    

She said that leptospirosis can present itself in a blood test as early as five to seven days after the illness starts. However, this can be delayed or transient in some patients. 

Dr Leong said that it may take up to four weeks or more for the blood test to confirm the disease and it may not be worth the wait.

“For that reason, you can’t wait (for a positive test) but, empirically, try to treat the disease before it worsens. For suspected cases, we would treat with antibiotics,” he said.

EARLY TREATMENT IS IMPORTANT

In the report on the four children, the authors concluded that a diagnosis of leptospirosis must be considered in children with febrile illness (fever), especially in returned travellers and where there is a history of recreational activity in fresh water or contact with rats.

Emphasising the importance of early treatment, Dr Leong said that half of all cases can be fatal if left untreated, for adults and children.

Dr Chan said that people infected with leptospirosis are treated with antibiotics such as penicillin, doxycycline, to name a few.

“Severe infections require intravenous antibiotics. Leptospirosis can affect many organs. The severe cases require supportive care such as fluid and electrolyte replacement, intensive care and dialysis.”

Those with mild leptospirosis infection usually recover fully but the recovery of those who come down with severe infection depends on the degree of organ failure, Dr Chan added.

SAFETY MEASURES

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 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.