Introduction
Malaria is transmitted by the Anopheles mosquito.Transmission occurs only between dusk and dawn in tropical areas usually beneath 1500 m. Risk diminishes between 1500 and 2500 m, and disappears above 2500 m.Transmission is very rare in big cities, except for Africa.
Different types
There are 4 types of malaria: Plasmodium Falciparum is the most common and most dangerous. It can infect up to 20 % of the red blood cells.P. Vivax, P. Ovale and P. Malariae are less dangerous, they only infect up to 2% of red blood cells.
Prophylaxis
General measures against mosquito bites This is the cornerstone of prophylaxis.
It's very important to take measures against bites while asleep:
- If possible the windows of the room should be shut with mosquito nets. AC does not completely protect against bites.
- If this is not possible, a mosquito net covering the bed and the ends put underneath the mattress should be used. Impregnation with deltamethrine or permethrine increases the efficacy. Impregnation with permethrine 500 mg/m² works for 6 months (shorter if you wash in between).
- When going out at night, you should cover up as much as possible. Other skin areas should be covered with a DEET containing product. DEET concentration should be between 20 and 30%. BE CAREFUL: DEET only works for 4 to 6 hours, this is not enough to get you through the night (at least not for most of us).
- Insecticides in the room can be helpful.
Prophylaxis with pills
General guidelines of WHO3 different areasThe WHO has designated areas according to the risk of malaria and resistance patterns against known drugs. For more detailed info for every country, look underneath.
Roughly, these regions can be designated as follows:
- A: Central America, a small part of Brazil, some areas in the Middle East and China.
- B: Parts of Yemen and Oman, Afghanistan, Pakistan, India, Sri Lanka, the lower parts of Nepal, most parts of Indonesia, Malaysia and the Philippines.
- C: The jungle areas of Brazil, Peru, Ecuador, Colombia, Venezuela, Suriname and French Guyana.
Guidelines of the WHO according to the area:Area A There's no risk in the cities, only in rural areas.The risk is low and usually confined to rainy season.Plasmodium Vivax is the predominant strain here.
Guidelines:
- When staying in cities at night with trips to rural areas: general measures, no pills.
- When travelling adventurous with staying overnight in rural areas:
Either general measures + Chloroquine pills
Either general measures and Chloroquine in case of infection
Area B No risk in the big citiesVery low risk in the tourist areas of Java, Bali, India, Malaysia and Venezuela.
Guidelines Trip shorter then 14 days: Tourism or business: general measures
Adventure travel with nights in rural areas: general measures + Chloroquine + Proguanil
Trip longer then 14 days: Tourism or business: general measures + Chloroquine + Proguanil OR take treatment in case of infection with you
Adventure travel General measures + Chloroquine + Proguanil and take treatment in case of infection with you
In certain areas of Indonesia, Malaysia and the Philippines, Lariam is indicated if no contra-indications.
Area C Trip less then 12 weeks*: Lariam if no contra-indications
In case of contra-indication: Trip < 2 weeks: General measures Chloroquine + Proguanil
Trip > 2 weeks: General measures Chloroquine + Proguanil and take treatment in case of infection with you.
General remarks: Exceptions to these rules are touristic or business trips in malaria free area with side trips to high risk area: f.i. Thailand with side trip to Burmese borderf.i. Brazil with side trip to Manausf.i. South Africa with side trip to Krüger Park
AND on condition
that Overnight stay is in good hotelsAdequate measures against bites are taken
Good medical infrastructure is available
* In selected cases, the term of 3 months may be prolonged.
Detailed advice according to the country you visit:In order to know what to take in zone A, B or C, look above
Afghanistan North-West: WHO area A. Risk of malaria from may till November in areas lower then 2000 m.
South-East: WHO area B: Risk of malaria from may till November in areas lower then 2000 m, not in Kabul.
Angola WHO area C
Antilles No malaria
Argentina WHO area A
There's no risk of malaria in most areas of Argentina, so no prophylaxis needed.There's a small risk of malaria (P. Vivax) from October till may in the far North and this only in the rural areas beneath 1200 m, namely Near the Bolivian border in the province of Salta (Iruya, Oran, San Martin and Santa Victoria) and the province of Jujuy (Ledesma, San Pedro, Santa Barbara).
Near the border with Paraguay in the provinces Misiones and Corrientes.
Bangladesh Biggest part WHO area BNo malaria in big cities like Dakka and Chittagong
Eastern border areas WHO area CIn the border areas in the North and East along the border with Assam (India) and Burma, the risk of malaria is very high and there is resistance against Chloroquine.
Belize WHO area ANo risk in the citiesBenin WHO area C
Bhutan WHO area CNo risk in areas above 1700 m, nor in the capital Thimbu.
There's only risk in the Southern provinces of Chirang, Gaylegphug, Samchi, Samdrupjongkhar, Shemgang, more in particular in areas beneath 1700 m.
Bolivia Areas above 2500 m: no risk in the Oruro department, some provinces in the western part of the La Paz department (Ingavi, Los Andes, Omasuyos, Pacajes) and in Southern and Central Potosi department.
The Amazone: WHO area CThere is Chloroquine resistant malaria in the departments Pando and Beni, at the border of Brasil (borders with Acre and Rondonia), especially in Guayaramerin, Riberalta and Puerto Rico.
Areas beneath 2500 m: WHO area AThe risk of malaria is very low, and there's only P. Vivax. Only general measures against bites are necessary. Only in rural areas bordering Paraguay and Argentina, measures applying for area A are necessary.
Botswana WHO area B/CRisk from November till June, more particularly in Boteti, Chobe, Ngamiland, Okavango, Tutume.
Brasil - Amazone: WHO area CRisk of malaria in most forested areas beneath 900 m of the 9 states of Legal Amazon Region (Acre, Amapa, Amazonia, Maranhao (only the west), Mato Grosso (only the North, not in Mato Grosso do Sul), Para, Rondonia, Roraima and in Tocantins (North of Goias). No risk in Belem, but small risk around big cities like Porto Velho, Boa Vista, Macapa, Manaus, Santarem and Maraba. If you stay less then 4 days in Manaus and other big cities, only general measures are needed. The same goes for a visit to Foz de Iguacu.
- Minas Gerais No malaria
- Other provinces No malaria
Cambodia WHO area CVery low risk of malaria in Phnom Penh and around, more in particular downstream from the Mekong and the Tonle Bassac, upstream along Tonle Sap and around the lake Tonle Sap, as well as in most capitals of provinces (exceptions are Prey Vihar, Rattanakiri, Mondolkiri) and Siem Reap, however there is a risk around the temples. There's also a risk along the coast and on beaches like Sihanoukville and Kep. Along the border with Thailand, Doxycycline should be preferred above Lariam.
Colombia WHO area B/CNo risk for malaria in Bogota and around nor in other big cities. No risk above 1000 m in the Cordillera Occidental, Central and Oriental. No risk along the Caribbean coast (except Cordoba) and in the lowlands along the border with Venezuela.
Some areas beneath 800 m have a risk differing from place to place:
- Area C along the Pacific Coast (Narino, Cauca, Valle del Cauca, Chocoa), also in the Northern region of Uraba-Bajo Cauca (Choco, Antioquia, Cordoba) and in the tropical jungle (small risk in Amazonas and Vaupes).
PERSONAL NOTE: There was a trial in 1998 with Colombian soldiers being stationed in Uraba. In the placebo group, 24/54 got malaria during a 4 month stay. So this is definitely a high risk area.
- Area B for the rest between Andes and Venezuela (Arauca, Boyaca, Caqueta, Guiana, Guaviare, Meta, Norte de Santander, Putamayo, Vichada.
Costa Rica - WHO area A: No risk of malaria is the cities and areas above 500 m.
risk of malaria only in provinces of Alajnela, Guanacaste, Limon and
Puntarenas
Ecuador WHO area B/CNo risk of malaria in areas above 1500 m, in the big cities and the Galapagos.Low risk in rural areas in the Northern provinces (bordering Colombia like Esmeraldas and Sucumbios) and in a narrow border area with Peru.
Egypt WHO area AVery low risk from June till October in the Sennoris district.
El Salvador WHO area ARisk from may till October in areas beneath 600 m , not in big cities.
Ethiopia WHO area CNo risk in areas above 2000 m and in Addis Abeba.
Guatemala WHO area ANo risk in the capital or in areas above 1500 m.Only risk in rural areas beneath 1500 m, risk is highest in Alta Verapaz, Escuintla, Huehuetenango, Peten and Quiche. Intermediate risk in Baja Verapaz, Izabal, Jutipa, Retalhuleu, San Marcos, Suchitepequez and Zacapa.
Honduras WHO area ANo risk in big cities.Risk is highest in rural areas of Choluteca, Cortes, Colon, Valle and Yoro. Risk is lower in departments of Atlantida, El Paraiso, Gracias a Dios, Islas de la Bahia and Orlancho.Other departments have minimal risks.
India Biggest part of India WHO area BRisk of malaria all year long, but risk varies greatly depending on the area. Risk is usually very low in the center of big cities and in Southern India (South of the Madras-Bangalore-Mangalore line).
Himalaya No risk in areas above 2000 m in Kashmir, Jammu, Himachal Pradesh, Sikkim.
Assam WHO area CThere's a bigger risk of resistant malaria.
Indonesia Touristic trip No risk in big cities and low risk in Java and Bali. In case of a short trip (< 2 weeks) and stay in good hotels, only general measures are needed.
Adventure/backpackers trip WHO area B/CThe biggest part of Indonesia is in zone BC measures with Lariam prophylaxis are needed in Irian Jaya even for short tripsAdventurous trips longer then 2 weeks on Eastern islands like Borneo, Flores, Molucca, Sulawesi, Timor etc.
Personal note: There are few remaining areas of malaria in
Java, namely Ujong Kulong, Kokap and Purworejo.
There is some debate among travellers saying you should take Lariam in Lombok. I also tended to believe this, however there has been an article published in 1997 with data from 1994 where 14 villages in Lombok were screened for malaria. 6% of the inhabitants had malaria at that time. 49 patients were treated with Chloroquine. All but 4 of them responded well, the 4 who did not had low levels of Chloroquine in the blood, suggesting either they didn't take the medication properly, or they vomited is or had another problem. Still this paper suggests Chloroquine is still active in Lombok.
A report on Nias (Sumatra) with data from 1995 suggested 14% of plasmodium Vivax resistance against Chloroquine.
KenyaWHO area CNo risk in Nairobi and areas above 2500 m.
Laos WHO area CNo risk in Vientiane
Malaysia Touristic trip (coast, cities): no risk of malaria, only general measures to be taken
Adventure trip: WHO area B/CRisk of malaria in areas outside the touristic circuit, with overnight stay in primitive circumstances in the jungle of the inner land of Sabah (area C), Sarawak (area B) and in the provinces of Kelantan and Keday on Malakka (area B).Mali WHO area C
Morocco Very low risk in some remote areas.
Mexico Touristic areas: No risk of malaria in areas above 1000 m (also Mexico City). In most tourist areas the risk is very low. For a well organised trips, general measures are enough. the same goes for Yucatan.
Remote areas: WHO area AIn some areas beneath 1000 m, the risk is higher, namely when going outside the cities in primitive conditions, especially in the provinces of Oaxaca, Chiapas, Guerrero, Campeche, Quintana Roo, Sinaloa, Michoacan, Nayarit, Chihuahua, Hidalgo and Tabasco. There is Falciparum malaria in Quintana Roo and Tabasco.
MyanmarWHO area CRisk of malaria beneath 1000 m. In the border areas with Thailand, doxycycline is preferred above Lariam.
Nepal Narrow border area with India (Terai): WHO area AOther areas no risk.
Peru There's no malaria in the big cities, nor in all areas above 1500 metres altitude.In the coastal areas west of Andesmountains (except in some Northern provinces), the risk of malaria is very small.In the Northern coastal areas bordering Ecuador (Tumbes/Piura/Lambayeque), and also in the provinces of Amazone area between Ecuador, Colombia, and Amazone area of Brasil North of 10°: WHO area COther areas: WHO area A
Philippines Big cities, areas above 600 m and islands of Bohol, Catanduanes and Cebu: No risk of malaria
Other areas WHO area B
Senegal WHO area A
South Africa Northern and North Eastern part bordering Botswana, Zimbabwe and Mozambique, the North Eastern part of Mpumalanga province (formerly Transvaal), including Krugerpark, the North Eastern part of Kwa Zulu/Natal till the Tugela river South of Richard's Bay.
WHO area B/CThere's a risk of malaria in the lowland savannah, outside the big cities from October till may.
Other areas: No risk
Sri Lanka
WHO area BNo risk in Colombo, coast from Negombo to Galle and in Nuwara Eliya.
Syria WHO area ARisk for Vivax malaria in some rural areas and the border area with Turkey only from May till October.
Tanzania WHO area CMalaria only in areas beneath 1800 m.
Thailand Touristic places No risk in Bangkok and resorts like Pattaya and Phuket.
Risk is low in all other touristic areas. Only general measures are needed.No risk in Chiang Mai and Chiang Rai. When doing excursions by day, no prophylaxis is needed. However, when doing extensive trekkings with overnight stay in the jungle, take Lariam or Doxy.
Border with Myanmar and Cambodia WHO area CRisk can be very high in certain places. When staying more then 10 days, Doxy is to be used.
Personal note: A very good article on Malaria in Thailand was published in 1995. It was an analysis of data from 1992. I'll try to give the results in short:
-
Highest risk Trat province (coastal province on the border with Cambodia, including Koh Chang, although risk here is somewhat lower 4-10%) has the highest number of malaria cases (> 10% per year among locals). Peak incidences are in January and at the beginning of the rainy season (June). Nearby Chantaburi has a somewhat lower risk (4-10%).
Tak province (around Mae Sot) also has a high risk of > 10% per year, peak incidence January and July, lowest in April.
Kanchanaburi province also has a risk of > 10% per year. However, this risk is mainly confined to a couple of remote villages along the Thai-Burmese border. Peak transmission June-July.
- Intermediate risk Mae Hong Son has an intermediate risk with a single transmission peak from June to August.
Whatever people in tourist business tell you, there IS still malaria in both Chiang Mai (3102 cases) and Chiang Rai (1641 cases in 1992)(between 2 to 4% per year for locals). But the transmission risk is also confined to the June to August period.
- No risk Bangkok and the central plain AND also Phuket are malaria free.
Venezuela Provinces Amazonas, Bolivar, Delta Amacuro and provinces Apure, Barinas, Sucre and Tachira: WHO area B/CNo risk in the biggest area and in the cities and the isles of Margarita.There is risk for Falciparum malaria in the lowland jungle of the province of Amazonas, Bolivar, Delta Amacuro (B-area).
There is Vivax malaria in some rural areas of Apure, Barinas, Sucre and Tachira.
Other provinces No risk of malaria.
Vietnam WHO area CNo risk in big cities like Hanoi, Danang and Ho Chi Minh and in the delta of the Red river.Risk in the Mekong Delta is low.No risk in coastal areas North of Nha Trang.Risk is highest in the plateaus of the hilly areas in the innerland.For an organised trip from city to city, there's no prophylaxis needed, general measures are OK.
Yemen WHO area BRisk from September to February, not in Sana and Aden
Article Comments:
| 07/27/2006 |
| N (1) |
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I had terrible side effect when taking Lariam, after the first pill. Be careful! Gasp for air, cold shaking, sweating, panic
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| 05/12/2006 |
| Suzanne Timmons (1) |
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When traveling to the yucatan in Mexico is there good cause for a pregnant women to take anti-malarial drugs or other protections against bites enough?
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