Stuart Raetz was on holiday with his sisters in Siem Reap in 2011 when the red skin irritation that had surfaced on his foot a week before, took on a distinct thread-like form.  

“Initially I thought it was a skin irritation or fungal infection like tinea.  But after a couple of days the itchiness persisted and the red mark grew,” Raetz says.

As they were traveling on the go, the 31-year-old, who was based in Cambodia, didn’t have time to make an appointment with a doctor. By the time he was back in Phnom Penh however, the peculiar itch began to worm away at him.

“The shape became more clear and you could see a fine line along my foot. I had no idea what it was, I thought it might be a parasite or a worm - so I went to get it checked at SOS clinic back in Phnom Penh.”

His doctor diagnosed the creature lurking beneath the skin on his foot as Necator Americanus, a common hookworm caught by walking barefoot where faeces containing the eggs are present.

Raetz remembered he had been walking carefree and shoe-less through grass in Kampot a couple of weeks before.

After treating it with an anti-parasitic worm drug, Raetz’s worm soon fizzled away, but for many in Cambodia – most significantly, children – soil transmitted worms (called helminthes) present a nagging problem that can exist on and off for years. Not content to lie beneath the surface of the skin, hookworm and ascaris enter through the skin, find a home in the organs, and reproduce.

With a tapeworm, “the head embeds in the stomach or somewhere in the intestinal tract and then it grows very long, it grows these little segments and it can live inside you for years,” Dr Steve Bjorge, of the World Health Organisation (WHO) explains.

 “Parasites want to live with you,” agrees Dr Gavin Scott, who runs the Western-patronised Tropical and Travellers Medical Clinic, “so symptoms tend to be minor: tiredness, some abdominal pain.”

These opaque symptoms can be left untreated and misunderstood, but the toll of them on school age children and women who are child raising or lactating is great: stunted growth, fatigue, anemia.

In Cambodia the problem was endemic. Other fatal worm infections such as Schistosomiasis, a worm that lives in water snails and lymphatic filariasis, a painfully disfiguring infection brought on by helminthes, were the subject of a mass drug administration by the National Center for Parasitology, Entomology and Malaria Control.

Twelve years ago, the Ministry of Health adopted the WHO goal of a mass de-worming program to treat 75 per cent of all school aged children. It has now become a routine fixture: once a year, teachers give children a tablet of albendazole, a cheap anti-worm drug that kills the organisms and consequently, the eggs which live on in faeces. For rural households without toilets, eliminating worms from a child might stop eggs from passing to other family members, and limit their overall presence.

Dr Bjorge is enthusiastic about the impact of the Kingdom’s de-worming program and its expanding scope: “Cambodia has taken it a step further by going for preschool children and also children of child bearing age. They’re expanding it and doing, really, a wonderful job.”

After 32 years working in Africa, where the majority of the developing world’s billion intestinal worms sufferers are, Phnom Penh physician Dr Galina Nikola has more than a few stomach-churning worm stories. At the Naga clinic, where she works, she is surprisingly forgiving of the parasites, whose hosts come into her clinic every week or so complaining of nausea, fatigue, and diarrhea.

“The  problem is when you go to live out of your own environment, you have to be ready to face things which are strange and unfamiliar,” she says of Westerners. “We live in the jungle (climate), we come to it – (so) you should understand the most important thing is hygiene,” she emphasises. “You can’t get drunk and go swimming in the Mekong.”

Swimming in the Mekong could lead to an ingestion of eggs from, among other things, the Schistosoma mekongi, which is endemic in the Mekong River region and not to be courted.

Unlike Stuart Raetz’s skin-crawling helminth, most worms are not immediately visible in the stool or under skin.

“To check for worms, you need to have eggs,”  Dr Galina says. “Some people even bring worm in a jar, saying, ‘look what I have’. These are people who have lived here a long time (and know what to look out for).”

After some additional internet investigating, Raetz thought he too knew what to look out for. When he began to cough up what he worried might be the remaining eggs of his departed worm, he returned to the doctor to settle his stomach.

“I read on the internet that the eggs can cause mild respiratory problems. The doctor I got this time didn’t know what Necator Americanus was - in contrast to my previous doctor - and said, ‘how can it get in your lungs? It is so far from your feet.’”

The journey of the worm from the soil to his feet, to his lungs, might be an unfortunately common one, but the story never runs out of mileage, he says.

To contact the reporter on this story: Rosa Ellen at [email protected]

Follow Rosa on twitter at: @rosaellen