Illnesses rarely seen in the US, Vol 3: Malaria

IV started, quinine running, labs being drawn.......

Mid morning one day last week, a 2 year old girl was brought in by her family for evaluation of the acute onset of fever, chills, and lethargy. Her initial examination showed her to be lying flat on the bed, sleepy but rousable, with a temp of 104 and with very pale conjunctivae. Her neck was not stiff as would be seen with bacterial meningitis, her lungs were clear, and her spleen was a bit enlarged. Since this is a common way that cerebral malaria presents here in Togo, we started treatment immediately. Within 10 minutes of arrival, she had an intravenous line and Quinine was running - we have preprinted order sheets and tables based upon weight that help speed the calculations of how much quinine to give. Based on how pale she was, a transfusion was ordered for as soon as possible. Labs were drawn (see picture) which showed severe anemia with hematocrit of 15% (less than half of normal), and a GE (goutte epaisse which is French for "thick drop" blood smear) which was positive for malaria. Thankfully, the child responded well to treatment and, by the next morning, her fever was diminished,and she was alert and sitting up. She did so well that she went home the following day on oral treatment to complete her course.

Malaria is a protozoan infection transmitted by the Anopheles mosquito and is the most important parasitic disease of man. In at risk areas, there are estimated to be about 500 million cases each year with 2 million deaths, mostly in infants and small children. There are four types of malaria with the most feared being that caused by Plasmodium Falciparum.

...much better the next morning !!!

Malaria is mostly seen in the tropics and subtropics at altitudes of less than 5000 feet above sea level - such areas provide the warmth and humidity needed for the mosquito carriers to live long enough for the malaria organism to become infective.

When the mosquito bites a person, infective malaria forms are injected and home in to the liver where they multiply in liver cells which ultimately burst, releasing a different type of malaria form into the bloodstream where they then invade red blood cells. After multiplication in red blood cells, they too can rupture...and so the cycle repeats. About 1-2 weeks after the mosquito bite, the patient becomes ill usually with fever, chills and in the case of children, sometimes lethargy, coma, or seizures. In extremely severe cases, there can also be kidney failure and respiratory difficulties.

Adults who have had multiple bouts of malaria build up partial immunity so generally do not get nearly as sick as children who have not been previously exposed.

So, why do children get so very sick??  FIRST, most come in with severe anemia (low hematocrit  or red blood cell count). This is due to destruction of red blood cells by the invading malaria parasites, suppression by infection of the bone marrow (where blood cells are made), and an enlarging spleen that acts like a sponge and "soaks up" some red cells. SECOND, some red cells affected by malaria organisms develop "sticky knobs" that cause them to stick together and "sludge" in small blood vessels, thus blocking microvessel circulation. Especially serious is sludging in the central nervous system (brain) which can cause lethargy, coma, or seizures. In this so-called "cerebral malaria", somewhere around 20% of patients may die and half of those may be left with some long term residual neurologic complications. Sludging in the kidneys or lungs can cause those organs to have varying degrees of dysfunction as well.

Thankfully, there is effective treatment  for malaria !! For severe, life threatening cases like the girl above, intravenous quinine can be dramatically effective. Another effective drug is one of several of the artemisinin compounds given either intramuscularly or intravenously. After a patient improves, they are usually switched to an oral combination to complete treatment.

For less severe cases that can be treated as outpatients, the World Health Organization now recommends ACT (Artemisinin Combination Therapy) as first line. Older regimens that included oral quinine still are effective but have significant side effects. One of the ACT drugs, CoArtem, recently became available in the United States so travellers to tropical areas no longer need fear that effective treatment will be difficult to get if they come down with malaria after returning from their trip.

Are there ways to decrease the spread of malaria?? YES !!  In endemic areas, mosquito breeding grounds like standing water should be drained, people should use insecticide impregnated sleeping nets (since most bites occur between dusk and dawn), and expecting mothers should be treated with several doses of an antimalarial medicine during pregnancy to prevent the disease which can cause troubles with the developing fetus. Folks like us who are visiting a malaria endemic area should take preventative doses of a drug that can help prevent malaria - we take a daily dose of doxycycline. Thankfully, active research is underway, funded by organizations such as the Bill and Melinda Gates Foundation, searching for an effective vaccine which, if found, could dramatically change the natural history of this disease.