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Malaria |
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What Causes
Malaria?
- Plasmodium falciparum
- Plasmodium vivax
- Plasmodium malariae
- Plasmodium ovale
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Malaria parasites have a
complex life cycle. In order to live, they need to have both a human
and a mosquito host.
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The mosquito host can't be
just "any" mosquito. It has to be a mosquito of the genus
Anopheles.
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The mosquito picks up the
malaria parasites from the blood of an infected human when it feeds.
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The malaria parasite
reproduces itself in the gut of the Anopheles mosquito. The malaria
parasites need the mosquito to continue their life cycle. Then, the
mosquito passes the malaria parasites to the human through its
salivary glands.
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The four different species
of malaria parasites cause types of malaria that are somewhat
different from each other.
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The worst type is caused by
Plasmodium falciparum. Infection with Plasmodium falciparum kills
approximately 1-2% of those who come down with it. Falciparum malaria
is a serious illness characterized by fever, headache, and weakness.
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Complications of falciparum
malaria include cerebral malaria, in which the brain is infected,
severe malaria, in which the parasitic infection essentially
"runs out of control," and placental malaria, in which
falciparum is a grave complication of pregnancy, and coma. Each of
these complications is very serious and often fatal.
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Falciparum malaria is the
major type found in subSaharan Africa, where 90% of the world's
malaria cases occur.
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Unfortunately, falciparum
malaria is also frequently resistant to drugs and is becoming more
common in high elevation areas of Africa, and in portions of Asia.
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The other species of
malaria cause a debilitating illness characterized by spells of
chills, fever and weakness. This illness generally lasts 10-14 days,
and is self-limiting in nature. The malaria caused by these species is
rarely fatal.
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Malaria caused by
Plasmodium vivax and Plasmodium malariae can relapse [come back] if it
is not properly treated with medicine.
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Unfortunately, in places
where Plasmodium vivax has become more common, such as India, the more
dangerous Plasmodium falciparum hasn't been far behind
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Where Does Malaria Occur?
Malaria occurs in many locations of the tropical world and in some
locations of the subtropics. It is most common between the latitudes of
23.5o North (Tropic of Cancer) and 23.5o South but
cases (often seasonal) also occur outside of these latitudes in areas such
as portions of South Africa (Kruger National Park and surrounding area -
25o South) and New Delhi, India (28.5o North).
- Africa: Malaria is very common in SubSaharan
Africa. The predominant species is Plasmodium falciparum. Plasmodium
falciparum is the most dangerous of the four species of human
malaria. Malaria causes an estimated 2.7 million deaths per year,
with most of these deaths occurring in Africa. Ninety percent of the
world's malaria cases occur in Africa. Chloroquine resistance is
widespread in Africa. Now, malaria outbreaks are being reported in
some locations of Africa that had been previously thought to be at
elevations too high for malaria transmission, such as the highlands
of Kenya. Some scientists hypothesize this is due to climatic
change, while others hypothesize that this is due to human
migration. Also, malaria has resurged in certain locations of Africa
that had previously had effective control programs, such as
Madagascar, South Africa, and Zanzibar.
- Asia: Malaria is widespread in numerous countries
in Asia and Oceania, including India, Pakistan, Bangladesh,
Thailand, Vietnam, Laos, Myanmar, Cambodia, Indonesia, Papua New
Guinea. Malaria also occurs in portions of Iran and the Middle East.
Plasmodium falciparum is common, as is Plasmodium vivax. Plasmodium
falciparum infections unfortunately increased during the 1990s in
India and Sri Lanka. Resistance in Plasmodium falciparum to multiple
drugs is present in portions of Cambodia, Myanmar, Thailand, and
Laos, and chloroquine resistance is widespread in Asia. Plasmodium
malariae also occurs in this area.
- South America: Malaria occurs at altitudes below
1000 m in portions of countries in South America, including Brazil,
Peru, Colombia, Bolivia, Ecuador, Venezuela, Guyana, Suriname,
French Guiana. The most common species in this area is Plasmodium
vivax, although there is an unfortunate increase in Plasmodium
falciparum cases, particularly in regions where control programs
have deteriorated or been abandoned since the early 1990s.
- Central America and Southern Mexico: Malaria
occurs in low-altitude areas of the countries of Central America
including Honduras, Nicaragua, and Guatemala. Limited numbers of
cases occur in Panama, Costa Rica, and southern Mexico. Active
control programs are in place in several of these countries.
Plasmodium vivax is the dominant species, and fortunately, remains
susceptible to chloroquine.
- Caribbean: Malaria remains eliminated from
several countries of the Caribbean. However, malaria [P. falciparum]
occurs in Haiti and in limited numbers of cases in the Dominican
Republic.
- Europe: Malaria [Plasmodium vivax] occurs in
Turkey, Armenia, and Azerbaijan.
- North America: Malaria eradication programmes
during the 1940s and 1950s, along with widespread use of screening,
eliminated malaria from this region, and there is no year-to-year
local transmission. However, isolated, rare cases of local
transmission have occurred. North America, the Caribbean region,
Europe, Australia, and Mexico and Central America are the major
success stories of malaria vector control efforts.
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Malaria prevention in Chiang Mai
The re-emergence of malaria along certain order areas is giving the Public
Health Ministry a terrible headache. However, like Aids, the deadly disease can
be avoided if you have proper protection. (Not the same kind of protection, of
course.) It would be a pity if you let malaria come between you and the splendor
of nature.
Malaria is caused by a tiny parasite called Plasmodium, which is carried
around by infected Anopheles mosquitoes. The only known way these bloody
parasites can be transmitted to you is through mosquito bites. So if you don't
get bitten by the mosquitoes - which attack people during the early hours of the
night - you don't get malaria. It's that simple. Preventive medication is not
recommended as the disease may then be harder to detect. The best thing to do is
to have your blood checked if you don't feel well a week or two after a visit to
the forest. A hospital for tropical diseases is usually the best place.
Normally, treating malaria is less of a problem if it is detected early.
Also, while you are in the forest, covering yourself with proper clothing and
applying a tad of insect repellent on exposed parts should do the trick.
Sleeping gear is also important. In some areas, a mosquito net is recommended
even if you sleep in park accommodation. Tents are safe since most of them are
equipped with mosquito nets. However, a lot of Thai nature lovers prefer
hammocks to tents because they are more practical in our tropical forests. But
the bad news is that despite the fact netted hammocks have long been available
on the market, most trekkers still opt for unknotted ones, which at about 200
Baht a piece are three to five times cheaper.
But the high price of netted hammocks is still a lot cheaper than the
hospital bills you would have to pay if you hit the malarial jackpot..
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| Have a doubt, Please Read Malaria |
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