Snail Fever—Slow Death for Millions
By “Awake!” correspondent in Liberia
IF A vicious enemy came to your home to kill you off inch by inch, would you let him in? Unwittingly millions around the world do just that when they expose themselves to the disease known as schistosomiasis or snail fever.
In parts of Africa, the Orient and Latin America, an estimated two to three hundred million people are infected. More get infected or are reinfected every day because of carelessness or ignorance. What is the cause of this debilitating disease?
The enemy in this case is three species of microscopic worms called schistosomes, from which the disease gets it name, schistosomiasis. These multiply by the hundreds inside several species of freshwater snails. The Oriental variety is attracted to almost any mammal. The other two types depend almost exclusively on man for survival. Within two days of leaving the snail these small fork-tailed worms or flukes must find suitable flesh in which to burrow, or they die. But how do they get inside the human body?
These tiny “arrows” secrete an enzyme or chemical that, in effect, digests a hole through the skin of a person who has been wading in infected waters. This brings on itching and blisters. Then they sink into the flesh until they reach the bloodstream and eventually the liver.
Within several months they are sexually mature, measuring from one fourth of an inch to one inch long. During this incubation period the person infected is essentially symptom free. Now, however, this dreaded enemy is ready to kill his victim slowly. How does this occur?
Effect of the Worms on the Body
After copulation the worms travel from the liver through the portal veins to the smaller blood vessels of the abdominal organs. Here the female produces from 300 to 3,500 eggs a day, and this for as many as 10 to 30 years, unless killed by medication. Feeding on the nutrients of the blood and living in the bloodstream, they are in a constant supply of food.
When egg production starts, the one infected goes into the acute stage of the disease, which is four to six weeks after being invaded by “schisto.” Severe headache, general weakness, high fever and diarrhea are experienced, along with blood in the urine. While some eggs are excreted in the feces, the majority of them are carried by the bloodstream to the liver, spleen, bladder and sometimes the brain.
The accumulating eggs, along with the live and dead worms, mass together in these organs and blood vessels and bring on the chronic stages of the illness. The defensive mechanism of the body fights a losing battle against the invasion as the bloodstream gets more and more polluted. Slow and agonizing death processes have, now set in. Life may be prolonged for several decades, depending upon the worm load and treatments received, but the victim’s resistance and strength are so weakened that premature death is usually just a matter of time.
But what of those eggs that are passed from the body when the one infected goes to the toilet? Very often they are excreted in waters where the host snails live. The eggs soon hatch and the released larvae quickly seek out a snail and burrow themselves into its soft flesh to keep alive, starting the cycle anew.
Efforts to Control the Disease
The answer to the problem would seem to be educating people on what they can do to protect themselves from this disease and to prevent its spread. But the efforts of doctors and health officials are often met with indifference. So many are infected in endemic areas that it is considered normal for everyone to have the chronic troubles associated with the disease. As a World Health Organization (WHO) report admitted: “It is hard to change people’s habits.”
However, if a person really cares for himself and his fellowman, he will be motivated to comply with common-sense protection measures. The same WHO report pointed out: “If human wastes are kept away from water then the snail cannot become infected. Bilharziasis [another name for the disease] would soon disappear if everybody used latrines (communal toilets).”
Efforts are being put forth to control the disease by developing poisons that kill the snails. But this is difficult, since other animal and plant life is often affected by the same chemicals. A measure of success has been had by introducing predators that eat up the snails in the streams. A few countries are making progress in stabilizing the spread of the disease. But some authorities feel that schistosomiasis may pass malaria as the world’s number one parasitic health problem. The opening of many new irrigation ditches and huge man-made lakes in recent years concerns health officials.
But where communities are slow to take action to stop snail fever, what can a person do to protect himself?
Protecting Yourself Against Infection
Check with health officers in your area to see if local waters are infested with harmful parasites. In Africa, relatively few stream are free from schistosomes. For home use, well water is best. If it is necessary to take water from a stream, a fast-moving one is safer, since the delicate flukes are easily killed in a rapid current. Boil drinking water for at least fifteen minutes. Storing water in tubs for forty-eight hours will destroy any schistosomes therein. But care should be exercised in fetching the water. If exposed to the parasite, quickly drying off briskly with a towel will help to prevent infection.
Unless one is certain that “schisto” is not present, do not bathe or wash in a stream. This is a factor to consider, too, in selecting baptism sites. The parasite does not survive in salt water, thus the ocean is free of this pest. Steps should be taken to keep one’s rice fields or canals from contamination. Wear rubber boots when fishing or otherwise wading in strange waters. Use care, however, in removing them.
If a person suspects that he has contracted “schisto,” it is wise to consult a doctor. It is easier to treat, and less damage is done to the body, if treated soon. The standard treatment for years has been the giving of antimonial drugs by injections over a period of days, a painful and somewhat dangerous process. All the more reason to avoid this disease. Some significant advancements have been made in improved methods of eliminating the worms from the body, but very little can be done to repair the serious damage done to the body organs in the chronic stage. Moreover, it does little good to divest the body of worms if the victim goes right back into infested waters to become infected with “schisto” again.
So for your own good keep this lethal enemy—snail fever—from taking up residence in your body. This will spare you much pain and help you to enjoy longer life.
[Diagram on page 21]
(For fully formatted text, see publication)
Man infects the snail; the snail infects man. Man has the power to break the cycle and eliminate snail fever
EGG
SNAIL
FLUKES
MAN