By: Sally Plomley, ISB Health Clinic
nurse@isb.ac.th
Mosquito bites can be annoying due to local itchiness and swelling. We also need to think about diseases that are spread to us through mosquito bites. In Thailand, there are several diseases that can be spread by mosquitoes.
Dengue Fever
- Spread by Aedes mosquito.
- 4 different types of virus cause it so you can get the disease more than once (and tends to be worse each time you get it).
- Symptoms include fevers, headache, muscle aches and pains, loss of appetite, vomiting and diarrhoea, rash, bleeding from gums and nose.
- Can develop Dengue Haemorrhagic Fever as you get better where you bleed excessively and this can be fatal.
- Can not be spread directly human to human. Spread by human to mosquito to human.
- Diagnosed by symptoms and can be detected on a blood test.
- Treatment is for symptom relief only. There are no antiviral medications that are effective.
- Dengue fever illness tends to be more severe each time you get exposed to a strain of the virus so if you have had it in the past you must take extra precautions to prevent getting it again.
- Prevention is by mosquito avoidance (see below). A vaccine is being developed but is not currently available in Thailand.
Zika
- Spread by the Aedes mosquito.
- Caused by a virus.
- Cases have occurred in Thailand since 2012. There has been a recent increase in the number of cases but this may be due to increased testing due to public awareness of the virus. There have been on average 20 new cases a week according to Thailand’s Ministry of Public Health.
- Spread through mosquitos and can also be sexually transmitted.
- Symptoms are usually mild and include low grade fever, rash, conjunctivitis, muscle aches, joint pains, fatigue and headaches.
- It has now been found to be associated with Guillain-Barre Syndrome (where the immune system attacks the nerves) and birth abnormalities in babies born to women who were infected whilst pregnant (microcephaly or small heads). None of these complications have been reported in Thailand, however, extra precautions to avoid being bitten by mosquitos should be taken by women (and their partners) who are pregnant or trying to conceive (see below). If a pregnant woman is concerned she has Zika she should contact her doctor for further advice.
- Treatment is for symptom relief only. There are no antiviral medications that are effective.
- Prevention is by mosquito avoidance (see below) and safe sexual practices following infection (for 6 months for a male and 8 weeks for a female). There is no vaccine available.
Chikungunya
- Spread by Aedes mosquito.
- Caused by a virus.
- Can not be spread directly human to human. Spread by human to mosquito to human.
- Symptoms include high fever, joint pain and swelling, muscle pain, rash, headache, fatigue and nausea.
- Treatment is for symptom relief only. There are no antiviral medications that are effective.
- Prevention is by mosquito avoidance (see below)
Japanese Encephalitis
- Spread by the Culex mosquito.
- Caused by a virus.
- Most people will have no symptoms or very mild symptoms which include fever and headaches. 1 in 250 will get severe disease with inflammation of the brain which may cause permanent brain damage and/or death.
- Treatment is for symptom relief only. There are no antiviral medications that are effective.
- Prevention is by mosquito avoidance (see below). Vaccination against Japanese Encephalitis is recommended for people living in an endemic area (which includes Thailand).
Malaria
- Spread by the Anopheles mosquito.
- Caused by a parasite called Plasmodium (5 different species).
- Symptoms include fevers (which may go up and down), profuse sweating, chills, malaise, muscle aches, headache, nausea, abdominal pain, diarrhoea and cough.
- Treatable infection if diagnosed early and treated with appropriate antimalarial medications.
- Prevention is by mosquito avoidance (see below) and by taking antimalarial prophylaxis if travelling to a high risk area. Bangkok is considered a low risk area for malaria and mosquito avoidance is the recommended preventative measure whilst living here.
Mosquito Avoidance
As outlined above there are many diseases that can be spread by mosquitoes and mosquito avoidance is one of the main preventative measures that should be employed. This avoidance should be all day and night not just in the dusk and dawn period as some of the species carrying disease are active during the day and others at night.
Mosquito avoidance measures include:
- Wearing loose light coloured clothing that covers as much skin as possible.
- Using mosquito nets to sleep under (including daytime naps)
- Prevent mosquitoes entering the house with screens on door and windows and keeping doors closed.
- Use of insect repellant which contains DEET, IR3535 or icaridin.
- Eliminate stagnant water in which mosquitoes can breed from around the house.
- Consider the use of mosquito coils/fans outside doors that are frequently opened.
- Discuss with landlord use of insecticide sprays in the compound you live in.
ISB is committed to your child’s overall development, both educationally and health related. Should you have any questions or concerns, please contact your healthcare provider or the ISB Health Clinic (nurse@isb.ac.th).