Around the world in 80 diseases

Irish people's travel abroad is being reflected in new illnesses brought home

Irish people's travel abroad is being reflected in new illnesses brought home. Conor Pope outlines the fallout from contracting a tropical disease - the one souvenir you don't want to bring home from your dream holiday.

As faraway destinations draw closer and overseas travel becomes commonplace, patients presenting themselves at GPs with all manner of tropical diseases are becoming more frequent.

Upset stomachs and skin rashes are the most common ailments but more worrying conditions such as malaria, dengue fever and West Nile virus are also increasingly being detected in the Republic.

The recent spread of the West Nile virus highlights the speed with which potentially fatal diseases can travel. It was introduced to the US in 1999, probably by an infected mosquito carried on a plane from Israel. Within three years, it had spread to all but four American states and the number of cases of the disease stood at 10,000 - of which 3,000 were considered serious. Up to 250 people died in 2002 of the illness.

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At the end of July, two Irish tourists became ill with the virus after a trip to the Algarve. Because it is a blood-borne illness, the Irish Blood Transfusion Service immediately issued a ban on people returning from holidays in the Portuguese resort donating blood for at least 28 days after their return.

While numbers diagnosed with serious tropical diseases here remain small - there were 20 cases of malaria reported in 2002 and only a handful of typhoid and cholera cases - the numbers are certain to grow. "When we look at the increase in travel, there can be no doubt that people will develop more diseases," says Dr Paul McKeown, a public health specialist with the National Disease Surveillance Centre (NDSC).

He says the certainty is that current figures are underestimated. "It is still very difficult to say by how much they are underestimated. There is a fair amount of intelligent guestimating that goes on." In an effort to get more accurate data, the NDSC next year will introduce a nationwide computerised system that will log prevalence of notifiable tropical illnesses.

Another reason tropical illnesses may not be effectively recorded is because they can be difficult to diagnose. Although diseases like dengue fever (also known as bone crushing disease) have symptoms which manifest themselves within days of infection, they can be confused with flu-like conditions and go unrecorded.

Detecting malaria is even more problematic because its incubation period can be weeks, even months. The length of time which elapses between contracting the illness and symptoms developing can pose a real problem, according to Dr Graham Fry, medical director of the Tropical Medical Bureau. "If you are sick and you go to see your GP they, understandably enough, are not thinking of tropical conditions," he says, stressing the need in such cases for a geographical history to be taken. It is, he says, incumbent on the patient to tell the doctor they have been away. "We only think of the conditions that we think of," he says.

There are, he says, ways to maximise your chances of staying healthy while overseas, the best defence being "common sense".

"People should make sure they have the correct vaccines and take appropriate health advice ahead of travelling. A lot of people say 'Oh, I'm on holidays - I want to try the local food'. However, their stomachs may not approve of their adventurous spirit.

"People are not indestructible," he says, and they need to be more careful. He practises what he preaches - while on a recent trip to South Africa, he took to ordering steak on the burnt side of well-done, something he wouldn't consider at home.

One Irish man told The Irish Times he was confident he'd taken the necessary precautions while on a round-the-world-trip, but was still unfortunate enough to develop malaria. He contracted the disease on a trip from Australia to the Papua New Guinea jungle but didn't get sick for six months.

"At first, it was just a strange feeling of being out of sorts. I was in Cape Town which is a food heaven and I was finding that I couldn't eat even though I wanted to."

The sluggishness continued for a week - after which he was concerned. He went for blood tests that were inconclusive.

"I started getting cyclical fevers and I was feeling very fluey. I was laid low in a backpackers' hostel, feeling rotten for a couple of days."

He started feeling better and thought the illness had passed. He was wrong. "I went out for dinner and was actually able to eat. But when I woke up the next morning, I felt like death. I had a high temperature, coupled with absolutely uncontrollable shivering, nausea and vomiting.

"I was hoping it would pass but a friend insisted on me going to the hospital. By the time I got to the A&E, I felt absolutely awful. My temperature was sky-high. I was losing sight and had an enormous pain in my side this_is_a_left_sq_bracketsomething later diagnosed as an enlarged spleen]."

Doctors performed tests and confirmed he had malaria. Oddly enough, the news came as something of a relief. "I asked 'just malaria?' because then I knew it was identified and treatable. I went straight on quinine and within a couple of days was feeling normal." He was in hospital for four days and, after that, was on medication for about four weeks.

Because the malaria he had was potentially recurring, he had to take a second round of medication before the liver phase of the disease was killed.

Then he continued on his way north through Africa.

Going home only crossed his mind, "literally for about two minutes at my weakest moment. But I'd met people with malaria elsewhere and I knew they got over it. And in South Africa, they're very matter-of-fact about malaria."

Despite the illness, he remains stoic and insists he would rather continue travelling and deal with the consequences than let fear affect his quality of life.

"I would hate to spend my life worrying and wondering."

The feeling that fear should not limit your horizons is echoed by Dr McKeown. "People should get out and see as much of the world as possible," he says.

"If you take all the sensible precautions, then all you will be coming home with is your duty free and a tan."

Top 50 Tropical Bugs:

Malaria: Carried by mosquitoes. Nearly 90 per cent of travellers who contract malaria don't become ill until after they return home. Initial symptoms include fever, shivers, sweating, backache, joint pains, headache, vomiting, diarrhoea and sometimes delirium. If you exhibit any of these symptoms within a year of returning home, even if you took anti-malarial drugs, contact your doctor.

Typhoid: Spread through food, water or contact with other sufferers. While it is not an exclusively tropical disease, it is common in areas with poor hygiene and sanitary conditions. Incubation period lasts between 10 and 20 days. Initial symptoms are a fever and headache, followed by a loss of appetite, joint pain, sore throat, sweating and a general feeling of being unwell. The person will often experience soreness in the stomach area, a bloated feeling and constipation. Occasionally, symptoms also include coughing, nosebleeds and painful urination.

Dengue fever: Another viral infection transmitted by mosquitoes, it affects 20 million people annually and is endemic in 100 countries. The mosquito that carries it bites during the day and there's no vaccine to guard against it, so be wary if you get bitten in daylight. Symptoms include headaches and fever and some people get rashes, aches and pains.

Amoebic dysentery: An intestinal infection usually spread through contaminated food where hygiene conditions are poor. Symptoms can take several weeks to appear and are often mild and vague, but there is persistent low-grade abdominal discomfort and nausea, mild diarrhoea with blood and mucus, and sometimes tenderness over the liver.

West Nile virus: Infection can be asymptomatic or, in about 20 per cent of cases, can lead to West Nile fever or severe West Nile disease. Symptoms include flu-like conditions, fever, headache, tiredness, body aches, occasionally with a skin rash and swollen lymph glands. While the illness can be as short as a few days, even healthy people have reported being sick for several weeks. If you develop high fever, confusion, muscle weakness or severe headache, see your doctor immediately.

The National Disease Surveillance Centre: www.ndsc.ie

The Medical Tropical Bureau: www.tmb.ie