American Medical Association Family Medical Guide - American Medical Association [656]
In most forms of malaria, a person usually has repeated attacks unless the disease is treated. Each attack signals the release of plasmodia into the bloodstream. If malaria is not treated, attacks can occur for years. However, as the immune system slowly builds up a defense against the disease, the attacks occur less and less frequently.
The Anopheles mosquito is found in the southeastern and western United States and in tropical and semitropical countries. Mosquito abatement programs have virtually eradicated malaria in the United States. With the exception of a few cases each year, nearly all cases of malaria in the United States are brought back by people who have traveled to other countries.
Symptoms
The symptoms of malaria depend on the type of plasmodium carried by the mosquito and usually appear about 8 to 30 days after a mosquito bite. A full day of headache, fatigue, and nausea is followed by 12 to 24 hours of chills alternating with fever. A sudden chill is followed by a stage of fever with no sweating, and rapid breathing. A drop in temperature accompanies a final sweating stage. Similar bouts occur whenever more plasmodia are released into the bloodstream, generally every 2 or 3 days.
Children with malaria are likely to have prolonged high fever without chills. The fever sometimes affects the brain, causing unconsciousness or seizures (see page 686).
In falciparum malaria, the most severe form, all the plasmodia are released from the liver into the bloodstream at the same time, resulting in a single extremely severe attack. The alternating chills and fever can last 2 or 3 days. If the person recovers, however, the attacks do not recur.
Diagnosis and Treatment
If you develop symptoms of malaria, see your doctor immediately. He or she will order blood tests. Because it is not always easy to detect the presence of plasmodia in the blood, you may need to have blood tests periodically. If blood tests show that you have malaria, the doctor will prescribe an antimalarial medication.
Prevention
To protect against malaria, when you are planning to visit an area in which the disease is prevalent, your doctor will prescribe antimalarial drugs. You need to start taking the drugs before your trip and continue to take them after you return. In many parts of the world, malaria parasites have become resistant to some of the more common drugs used against them such as chloroquine, but newer and more effective drugs are constantly being developed.
Amebic Dysentery
Amebic dysentery, also known as amebiasis, is an intestinal illness caused by infection with a microscopic parasite (ameba). Amebic dysentery is prevalent in developing countries that have poor sanitation. Contaminated water and lack of proper hygiene among food handlers can spread the organisms that cause amebic dysentery. In the United States, amebic dysentery is transmitted most frequently through oral-anal sex.
Symptoms
The main symptom of amebic dysentery is diarrhea, which can contain blood and may persist for weeks if not treated (resulting in weight loss). Other symptoms include abdominal cramps, excessive gas, and fatigue. After the diarrhea subsides, it may recur from time to time. In rare cases the organisms spread from the digestive tract into the bloodstream and settle in the liver, where they form abscesses (pus-filled sacs).
Diagnosis and Treatment
If you have symptoms of amebic dysentery, your doctor