Travel Medicine Consult..Malaria

Ok,
I said I would continue to post information for the traveller to Ethiopia, here is a post about Malaria.

Malaria is caused by a parasite that lives within the red blood cells. It is transmitted by the bite of a mosquito, the Anopheles mosquito to be exact. This mosquito is found in almost all countries in the tropics and sub-tropics. As an interesting side note this mosquito used to be in Canada, near Ottawa approx 200 years ago.
The Anopheles mosquito bites between dusk-dawn (feeds at night), so transmission of Malaria occurs doing this time. Malaria can also be transmitted from a pregnant woman to her baby, blood transfusion, or contaminated medical equipment.
There are 4 types of parasite (plasmodium) that cause Malaria. Each of these types has different treatement recommendations and infection patterns. These are: P. falciparum (the big bad dangerous one), P. vivax, P.ovale, and P. malariae
There is documented Malaria in 103 countries of the world.
Risk to the traveller is determined by itinerary, length of stay and time spent outdoors. Travel to Sub Saharan Africa is considered the most dangerous.
There is no vaccine, but nearly all cases of Malaria can be treated with Anti Malarials.

What is the disease?
Malaria starts out with a "flu-like" illness, you get chills, sweats, myalgia (achey body) and a headache. You can also have vomiting, diarrhea, abdominal cramping and a cough. If infected with P.falciparim usually symptoms start 10-12 days after you have been bitten.
Malaria, contrary to popular belief, is a serious medical condition. Without fast treatment infection with Malaria can give the parasites in the red blood cells time to accumulate in end-organ capillaries. This can lead to cerebral malaria, renal failure, pulmonary edema, shock and death.
Infection with the other species can take 14 days to months to cause symptoms and rarely lead to death.

So if you came into my office and were heading to Ethiopia, this is what we would discuss:
Firstly, where are you going? If you are only going to Addis Ababa or other areas higher than 6500 feet you would not need anti malarials. Addis is excluded from the Malaria risk zone. The rest of the country is a risk zone. So if you were planning to leave the highlands and travel into Ethiopia a bit, I would strongly recommend anti-malarials.

What kind of anti-malarials are out there?

Mefloquine: Effective in Ethiopia

Usually patients come in and have heard about Mefloquine (Larium) and don't want to take medication because of it.
Mefloqine is a very effective antimalarial. The only place in the world with resistance to Mefloquine is South East asia, particularly the borders of Thailand, so it is a good option for some.
What is nice about Mefloquine is that you only have to take it 1x/ week. You start 1 week prior to departure, continue weekly during your stay, and for 4 weeks after you return.
There are potential side effects to Mefloquine. For starters, if you have a history of anxiety, depression or psychosis (or a strong family history of such) Mefloquine can induce these effects as it can cause psychiatric symptoms. It can also cause vivid dreams and dizziness. Symptoms occur in 1:200 or 1:500 patients.

Doxycycline: Effective in Ethiopia

Doxycycline is a tetracycline antibiotic and is fairly effective against malaria. Doxycycline is started 2 days before entering a malarious area, taken daily while there and for 28 days after leaving the area. It is cheap. Approximately $1/ day.
Although effective, many people don't want to take Doxy due to it's side effects.
It can cause (you are more sensitive to the light)
Yeast infections in women, (if on doxy always travel with anti-fungal treatment such as canesten or monistat)
Stomach or esophagus upset, so you must take it with a meal. photosensitivity
And you must stay upright (not lie down) for 30 minutes after taking it to prevent esophageal upset.
Doxycycline is also very dangerous to the developing fetus and should not be used by pregnant women.

Malarone (Combination drug: Atovaquone/ Proguanil): Effective in Ethiopia

Malarone is very effective, and appears to be very safe. However, the big draw back to Malarone is that it is very expensive, $5/ tablet.
You start Malarone 1 day before entering a Malarial area, continue daily during your stay and for 1 week after leaving. It is the best option for short trips into Malarial areas and has very few side effects.
It can upset your stomach, so it is recommended you take it with food.
It should not be used by pregnant women (data is somewhat controversial)
It should not be used by people with renal failure.
Overall, the Malarone is the preffered option due to the low incidence of side effects, but often cannot be taken due to the cost.

Chloroquine: NOT effective in Ethiopia

Chloroquine is an older drug that most of the parasites have now developed resistance to.
It can also make your skin sensitive to the sun
Can be dangerous in combination with cardiac medications
Can upset your stomach
Can cause retinal damage (which appears to be reversible)
You start it 1 week prior to entering a malarial area that is sensitive to this drug (Central America)
continue weekly while you are there and for 4 weeks after you return.
Again, there is widespread resistance to this medication, so use with caution and make sure you are travelling to an area that it will work in.

There are other kinds of antimalarials, some are not licenced in Canada, and some require a series of blood testing before commencing. They are rarely prescribed, so I won't go into details here.
Other things you can do to reduce your risk of Malaria is: use mosquito repellent. Preferably something that has 30% deet in it. I know many people are hesitant to use a chemical such as deet and there are natural options available. However, although the natural options do work, they need to be applied every 8-10 minutes to be effective, so a high level of commitment is required. Mosquito nets are also important, and you can buy ones that are treated for Malaria with a chemical called Permethrin. They work very well.
You can also avoid going outside after dusk and before dawn (doesn't always work).
Alcohol does not prevent Malaria (many people believe that if they are drinking they won't get bitten by mosquitos).

So for a consult to Ethiopia, only travelling to Addis Ababa, I would not recommend anti-malarials, but if the person was planning to do some sight-seeing, I would recommend taking a small supply of Malarone with them for the trip.

More travel consults to come...I plan to go into greater depth on Yellow Fever, Dengue Fever and fresh water parasites.