Ticking Menace

Study flags public health threat posed by blood-feeding ticks

- Ang Qing

Hidden in leaf litter near wildlife corridors, a poorly known threat to public health lies in wait for hikers, cyclists and dog owners frequenting Singapore's green spaces.

These spots are ideal for bead-size parasites called ticks, which can transmit diseases as they latch on to humans and feed on their blood.

While Singapore does not require doctors to report tick bites or tick-borne diseases, a recent study has learned that all 11 species of ticks found to have bitten humans in the island state between 2002 and 2023 are capable of carrying one or more harmful microbes.

"If Singapore is going to be a city in nature, it needs to manage the parasites that come with the wildlife," said Hokkaido University parasitologist Mackenzie Kwak, lead author of the study by researchers based in Japan, Singapore, Switzerland and Saudi Arabia.

The paper, published on Jan 17, found that the gilded boar tick (Dermacentor auratus), named for its propensity to feed on wild pigs, had caused more than half of the 51 reported tick-bite cases between 2002 and 2023, making it the most medically important of Singapore's native ticks.

The species adorned with an ornate white pattern is a potential carrier of 10 kinds of microbes, including one that causes Kyasanur forest disease, which often sparks viral fever outbreaks in southern India.

Dr Kwak, who has specialized in ticks for over a decade, said: "They have been found on the skin around the eyes, the ears and on the scalp."

In one such case in Singapore, he said, a tick was originally mistaken for a sunspot before it began to grow, and the patient had to get a doctor to remove it.

The abundance of gilded boar ticks stems from the expansion of Singapore's wild pig population since the 1990s, the researchers wrote.