In transit - Infectious Diseases

Filariasis: This is a mosquito-borne disease that is very common in the local population, yet very rare in travellers. Mosquito-avoidance measures are the best way to prevent this disease.
 


Dengue

This mosquito-borne disease is becoming increasingly problematic throughout Southeast Asia, especially in the cities. As there is no vaccine available it can only be prevented by avoiding mosquito bites. The mosquito that carries dengue bites day and night, so insect avoidance measures at all times. Symptoms include high fever, severe headache and body ache (dengue was previously known as 'breakbone fever'). Some people develop a rash and experience diarrhoea. There is no specific treatment, jusl rest and paracetamol - do not take aspirin as it increases tlic likelihood of haem-orrhaging. See a doctor to he diagnosed and monitored.

 

Hepatitis A

A problem throughout ihe region, this food-and-water-borne virus infects the liver, causing jaundice (yellow skin and eyes), nausea and lethargy. There is no specific treatment for hepatitis A, you just need to allow time for the liver to heal. All travellers to Southeast Asia should be vaccinated against hepatitis A.

 

Hepatitis B

The only sexually transmitted disease that can be prevented by vaccination, hepatitis B is spread by body fluids, including sexual contact. In some parts of Southeast Asia up to 20% of the population are carriers of hepatitis B, and usually are unaware of this. The long-term consequences can include liver cancer and cirrhosis.

 

Hepatitis E

Hepatitis E is transmitted through contaminated food and water and has similar symp toms to hepatitis A, but is far less common. It is a severe problem in pregnant women and can result in the death of both mother and baby. There is currently no vaccine, and prevention is by following safe eating and drinking guidelines.

 

HIV

The official figures on the number of people with HIV/AIDS in Vietnam are vague, but they arc on the rise. Health-education messages relating to HIV/AIDS can be seen all over the countryside, however the official line is that infection is largely limited to sex workers and drug users. Condoms are widely available throuphoul Vietnam.

 

Influenza

Present year-round in the tropics, influenza (flu) symptoms include high lever, muscle aches, runny nose, cough and sore throat. It can be very severe in people over the age of 65 or in those with underlying medical conditions such as heart disease or diabetes; vaccination is recommended lor these individuals. There is no specific treatment, just rest and paracetamol.

 

Japanese B Encephalitis

While a rare disease in travellers, at least 50,000 locals are infected with Japanese B Encephalitis each year in Southeast Asia. This viral disease is transmitted by mosquitoes. Most cases occur in rural areas and vaccination is recommended for travellers spending more than one month outside of cities. There is no treatment, and a third of infected people will die while another third will suffer permanent brain damage.

 

Malaria

For such a serious and potentially deadly disease, there is an enormous amount of misinformation concerning malaria. You must get expert advice as to whether your trip actually puts you at risk. Many parts of Vietnam, particularly city and resort areas, have minimal to no risk of malaria, and the risk of side effects from the tablets may outweigh the risk of getting the disease. For most rural areas, however, the risk of contracting the disease far outweighs the risk of any tablet side effects. Travellers to isolated areas in high-risk regions such as Ca Mau  and Bac Lieu provinces, and the rural south, may like to carry a treatment dose of medication for if symptoms occur. Remember thai malaria can be fatal. Before you travel, seek medical advice on the right medication and dosage for you.

 

Malaria is caused by a parasite transmitted by the bite of an infected mosquito. The most important symptom of malaria is fever, but general symptoms such as headache, diarrhoea, cough, or chills may also occur. Diagnosis can only be made by taking a blood sample.

 

Two strategies should be combined to prevent malaria - mosquito avoidance, and antimalarial medications. Most people who catch malaria are taking inadequate or no antimalarial medication.

 

Travellers are advised to prevent mosquito bites by taking these steps:

- Choose accommodation with screens and fans (if not air-conditioned).

- Impregnate clothing with Permethrin in high-risk areas.

- Sleep under a mosquito net impregnated with Permethrin.

 

Spray your room with insect repellent before going out for your evening meal. a DEET-containing insect repellent on exposed skin. Wash this off at night, as long as you are sleeping under a mosquito net. Natural repellents such as Citronella can be effective, but must be applied more frequently than products containing DEET. mosquito coils.

Wear long sleeves and trousers in light colours.

 

MALARIA MEDICATION

There are a variety of medications available. The effectiveness of the Chloroquine and Paludrine combination is now limited in most of Southeast Asia. Common side effects include nausea (40% of people) and mouth ulcers. It is generally not recommended.

 

Lariam (Mefloquine) has received much bad press, some of it justified, some not. This weekly tablet suits many people. Serious side effects are rare but include depression, anxiety, psychosis and seizures. Anyone with a history of depression, anxiety, other psychological disorder, or epilepsy should not take Lariam. It is considered safe in the second and third trimesters of pregnancy. It is around 90% effective in most parts of Southeast Asia, but there is significant resistance in parts of northern Thailand, Laos and Cambodia. Tablets must be taken for four weeks after leaving the risk area.

 

Doxycycline, taken as a daily tablet, is a broad-spectrum antibiotic that has the added benefit of helping to prevent a variety of tropical diseases, including leptospirosis, tick-borne disease, typhus and melioidosis. The potential side effects include photosensi-tivity (a tendency to sunburn), thrush in women, indigestion, heartburn, nausea and interference with the contraceptive pill. More serious side effects include ulceration of the oesophagus - you can help prevent this by taking your tablet with a meal and a large glass of water, and never lying down within half an hour of taking it. It must be taken for four weeks after leaving the risk area.

 

Malarone is a new drug combining Atovaquone and Proguanil. Side effects arc uncommon and mild, most commonly nausea and headaches. It is the best tablet for scuba divers and lor those on short trips to high-risk areas. It must be taken for one week after leaving the risk area.

 

Derivatives of Artesunate are not suitable as a preventive medication. They are useful treatments under medical supervision.

 

A final option is to take no preventive medication but to have a supply of emergency medication should you develop the symptoms of malaria. This is less than ideal, and you'll need to get to a good medical facility within 24 hours of developing a fever. If you choose this option the most effective and safest treatment is Malarone (four tablets once daily for three days). Other options iriclude Mefloquine and Quinine but the side effects of these drugs at treatment doses make them less desirable. Fansidar is no longer recommended.

 

Measles

Measles remains a problem in some parts of Vietnam. This highly contagious bacterial infection is spread via coughing and sneezing. Many people born before 1966 are immune as they had the disease in childhood. Measles starts with a high fever and rash and can be complicated by pneumonia and brain disease. There is no specific treatment.

 

Rabies

This uniformly fatal disease is spread by the bite or lick of an infected animal - most commonly a dog or monkey. You should seek medical advice immediately after any animal bite and commence post-exposure treatment. Having a pretravel vaccination means the postbite treatment is greatly simplified. If an animal bites you, gently wash the wound with soap and water, and apply iodine based antiseptic. If you are not vaccinated you will need to receive rabies im-munoglobulin as soon as possible.

 

Schistosomiasis

Schistosomiasis (also called bilharzia) is a tiny parasite that enters your skin after you've been swimming in contaminated water - travellers usually only get a light infection and hence have no symptoms. If you are concerned, you can be tested three months after exposure. On rare occasions, travellers may develop 'Katayama fever' -this occurs some weeks after exposure, as the parasite passes through the lungs and causes an allergic reaction - symptoms are coughing and fever. Schistosomiasis is easily treated with medications.

 

STDs

Sexually transmitted diseases include herpes, warts, syphilis, gonorrhoea and chlamydia. People carrying these diseases often have no signs of infection. Condoms will prevent gonorrhoea and chlamydia but not warts or herpes. If after a sexual encounter you develop any rash, lumps, discharge or pain when passing urine seek immediate medical attention. If you have been sexually active during your travels have an STD check on your return home.
                                   

While abstinence from sexual contact is the only 100% effective prevention, using condoms is also effective. Condoms are widely available throughout Vietnam; when purchasing, ensure the package hasn't been stored in the sun as the rubber could have deteriorated.

 

Tuberculosis

Tuberculosis (TB) is rare in short-term travellers. Medical and aid workers, and long-term travellers who have significant contact with the local population should take precautions, however. Vaccination is usually only given to children under the age of five, but adults at risk are recommended pre-and post-travel TB testing. The main symptoms are fever, cough, weight loss, night sweats and tiredness.

 

Typhoid

This serious bacterial infection is spread via food and water. It gives a high, slowly progressive fever and headache, and may be accompanied by a dry cough and stomach pain. It is diagnosed by blood tests and treated with antibiotics. Vaccination is recommended for all travellers spending more than a week in Southeast Asia, or travelling outside of the major cities. Be aware that vaccination is not 100% effective so you must still be careful with what you eat and drink.

 

Typhus

Murine tvphus is spread bv the bile of a flea whereas scrub typhus is spread via a mite. These diseases are rare in travellers. Symptoms include fever, muscle pains and a rash. You can avoid these diseases by following general insect-avoidance measures. Doxycycline will also prevent them.  

 

SARS

In March 2003 the world's attention was drawn to the outbreak of an apparently new and serious respiratory illness that became known as SARS (Severe Acute Respiratory Syndrome). At the time of writing SARS appears to have been brought under control. Since the outbreak commenced, 8500 cases were confirmed, resulting in 800 deaths. The peak of disease activity was in early May 2003, when over 200 new cases were being reported daily. The outbreak started in the Chinese province of Guangdong in November 2002. By mid-March numerous cases of an unusually virulent respiratoiy virus were being reported in Hong Kong, Vietnam, Singapore and Canada. The World Health Organization (WHO) soon issued a global alert to health authorities and the public. Although this helped to bring the disease under control, it also resulted in widespread panic, and the cost of SARS to countries in the Far East as a result of tost tourism and trade was estimated as at least US$30 billion.

The caof SARS was identified in April 2003 - a new virus unlike any other previously known in humans or animals. The symptoms of SARS are identical to many other respiratory infections, namely high fever and cough. The case definition of SARS is a person with fever and cough who has travelled to an infected area or had close contact with an infected individual within the previous 10 days. There is no specific quick lest for SARS but certain blood test and chest X-ray results offer support for the diagnosis. There is no specific treatment available and death from respiratory failure occurs in around 10% of patients. Fortunately it appears it is not as easy to catch SARS as was initially thought. Wearing masks has limited effectiveness and is not generally recommended.

The risk of contracting SARS is extremely low. However, there are stilkfundamental questions to be answered about SARS - where did it come from, will it come back and can we develop a rapid test or treatment for it? AT least another year will be needed to see whether SARS has become established in our ecosystem.

 

 

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