Amebic Infection, Treatment and Prevention
Amebiasis is a disease caused by a certain organism known as Endamoeba histolytica. It effects mainly the colon, but may also extend to the liver and other organs. Amebic dysentery is the term applied to severe cases in which there is diarrhea with blood and mucus in the stools. The disease usually occurs in epidemics due to water supplies being contaminated with infected sewage.
The parasites passes through two phases, the active or trophozoite phase, and the cyst. Active parasites are responsible for changes in the tissue and organs. Later these change into the cyst form, and these are largely responsible for the transmission of the disease.
Unlike many other intestinal parasites, amebic infection are not limited to tropics, but are found in every country in the world. However, there are more prevalent in the warmer areas, especially where sanitation is poor. In areas devoid of proper sanitary facilities, more than half the population may have this disease.
Infection usually occurs because the water supply is contaminated with human sewage containing amebic cysts. Various food may be contaminated by being fertilized with human sewage, or by flies exposed to the infection or by careless food handlers who have the disease. Children may infect themselves by playing soil contaminated with amebic cysts. One of the outbreak occurred in 1933 in Chicago, Illinois (USA), because of faulty plumbing. Someone had accidentally connected to sewage pipe to a water main. There were 1,400 cases and more than 100 deaths before the epidemic was brought under control.
In severely infected cases, patients complain of abdominal cramps, diarrhea, and bloody mucoid stools, similar to that seen in other forms of dysentery. Milder infections may have only rather vague symptoms, such as gastrointestinal disturbance with occasional, slightly loose, watery stools and some distention of the abdomen. Vomiting is not common and abdominal pain be mild. Some people are “carriers” in that although not suffering very much from the condition themselves, they constitute a source of infection to others. A few patient notice due fatigue, fever vague aching in the muscle, backache, arthritis, nervousness, irritability, and even dizziness at times. Liver abscess is the most serious complication due to amebic infection. The patient complains of pain over the liver, fever, loss of weight, and sweating. If the abscess is located at the top of the liver, it may penetrate into the chest, forming a more serious condition known as pulmonary abscess.
Diagnosis is not always easy in cases of diarrhea. A study of the stools should always be done, preferably using fresh specimens. The complement fixation reaction is also of some value in making the diagnosis.
In severe amebic infection, emetine hydrochloride, 1.0 cc., is given intramuscularly each day for six days. This should be followed by sulfasuxidine, 1.0 gm four times a day by mouth, and penicillin, 500,000 units intramuscular each day, for several days. This can be followed by Diodoquine, one tablet four times a day, for the next three weeks. If desired, Carbarsone, 0.25 gm. tablet three times a day for ten days, may be then used.
If there is only moderate diarrhea and no fever, the emetine is omitted, but the penicillin and sulfasuxidine are given, followed by the course of Diodoquine and Cabarsone. If the patient is suspected of having a liver abscess, chloroquine (Aralen) is used, the dose being one tablet three times a day, for two weeks. A large liver abscess may have to be drained surgically.
Unfortunately, ordinary chlorination of water cannot be relied upon to kill amebic cyst, but chlorination plus proper filtration seem to be effective. A special iodine tablet known as Globaline is useful for small scale for household drinking water. When in doubt boil all drinking water for this will not only kill the amebic cyst, but any other organism present. Sanitary disposal of human sewage and avoiding it use of garden fertilization will greatly lower the incidence of this disease. Proper control of flies and through treatment of all cases, including food handlers in particular, will usually brings this disease under control.