[...]
[The Filariasis Research and Control Unit, Georgetown, British Guiana presents]
[Filariasis in British Guiana]
[Produced by The British Guiana - United States of America Technical Assistance Development Organization Ministry of Labor, Health and Housing]
[and the U.S. Agency for International Development]
This is Georgetown, capital of British Guiana on the northern coast of South America.
It is populated by the descendants of Africans, East Indians, Portuguese, Chinese, Europeans, and South American Indians.
The commercial center of Georgetown lies close to the waterfront. Here are modern buildings, department stores, and supermarkets.
There are also churches and cinemas.
The coastal railroad parallels the coastal highway running eastward from Georgetown. Another paved highway runs 25 miles south to Atkinson airfield.
British Guiana has an agricultural economy, chiefly sugar and rice. The industrious Guianese tend their farms well. This is a native rice plantation.
Fishing is popular and productive and helps to vary the diet.
In American Indian villages, women make bread and many dishes from cassava, their staple food.
Local high schools prepare students for university entrance and a national university is being established.
The people of British Guiana are great sports enthusiasts. If these people were deprived of the use of their limbs,
they would not only be denied much pleasure, but they could no longer tend their farms or make a living.
That is why it is so important that they understand British Guiana's crippling disease, filaria.
Filaria, or filariasis, is carried by mosquitoes and may lead to swelling of the legs, arms, and other parts of the body after years of repeated infection.
The disease is more often seen in females because their legs are exposed.
Before a swelling appears, the blood of the infected person contains young embryo worms called micro filari.
These micro filari can be seen in the infected person's blood only at night.
When a female filaria mosquito feeds on the infected person's blood, it sucks up these micro filari which then pass into the stomach of the mosquito.
In the mosquito's stomach, the micro filaria remains active for a short while, then bores through the wall of the stomach and moves to the thorax, or chest region of the mosquito.
In a muscle fiber of the thorax, the young larva grows short and thick, until it becomes shaped like a sausage.
Then it enters into the second stage and gradually grows longer and narrower until it becomes an infective larva.
It wriggles its way from the thorax to the head of the mosquito and enters the proboscis, or beak.
When the infected mosquito bends down to bite again, the infective larva crawls out of the proboscis and drops onto the skin of the person being bitten.
Then it goes into the skin and travels around the person's body. In about a year, it becomes a sexually mature male or female worm.
The worms mate and the eggs develop into micro filari, which appear in the person's blood, thus completing the cycle.
One of the main methods of detecting whether one has filaria before the swelling appears is by making a blood smear.
Blood is taken from a finger at night. Early in the morning the micro filari go deep into the body. If there is at least one micro filaria present, the person is said to have positive blood.
If his blood is negative it does not necessarily mean that he is free of infection. This is because the worms may have entered the person's body recently and are not mature enough to produce the micro filari.
Also when a person already has a swelling, his blood is usually negative.
There are many effects of filaria. Long-standing infection may lead to swelling of the limbs called elephantiasis. At first, tissue fluid or lymph accumulates, but later there are permanent changes in the tissues themselves.
The disease cripples physically, mentally, economically, and socially. The most damaging effect is felt by the wage earner and his family.
A job is not readily given to a person who has elephantiasis if he has to stay on his feet all day long.
Young girls having elephantiasis usually are denied romance and marriage because of their permanently swollen limbs.
The depressing state which this disease leads to is one of its most damaging effects. If he does have a job, he has to carry out his duties the best he can even with his legs swollen.
Convinced that something could be done about the filaria problem, the governments of British Guiana and the United States of America have been working together to solve it.
On April the 29, 1961, representatives of the Ministry of Health and the United States Agency for International Development agreed to finance a joint filariasis research and control project.
This project comes under the Technical Assistance Development Organization, abbreviated as TADO.
The United States Government has supplied money, equipment and three experts:
A medical entomologist who studies the mosquitoes in order to determine which ones transmit filariasis from person to person,
a parasitologist who studies the parasites or worms which cause the disease, and a health educator who informs the public concerning the disease and secures their cooperation while control measures are being undertaken.
The Ministry of Health has long worked to control filariasis. In 1955, an energetic Guianese doctor began a countrywide campaign to control the disease.
This campaign was carried out for about six years prior to the present joint program.
In the filariasis clincs, Guianese doctors studied increase or decrease in size of limbs by displacement of water.
The patient steps into a water-filled drum; water comes out of the spout and is measured.
Blood tests are also taken at night in the filariasis clinics so that the patient's case history will be complete.
Clinics are held, not only in Georgetown, but also in the coastal villages having much filariasis.
In the headquarters building of the filariasis research and control unit, there are offices and laboratories for entomology, parasitology, clinical, and health education sections.
The United States medical entomologist has trained Guianese personnel in many apects of entomological work with filaria mosquitoes, both in the field and the laboratory.
The United States parasitologist has trained Guianese in taking blood smears and identification of filaria parasites found in the smears.
A typical filarial area along the east coast, including Buxton and surroundings, was selected as the first area for working techniques of controlling filarial mosquitoes and the filarial worms.
The health education section of the filariasis unit has prepared pamphlets and posters for educating the public concerning the nature and cause of filariasis and how the public can cooperate to help control the disease.
Lectures, conferences, and discussions are held just before the night blood survey teams visit a filarial area.
After the health educators have paved the way, the night blood-survey teams go from house to house in the filarial villages and take a blood smear on each member of every family.
This provides important basic information as to the number of persons having young filarial worms in their blood.
In the interior of British Guiana, the native Indians have two other types of filariasis which do not result in swellings.
Blood surveys among these Indians can be held in the day because the micro filari are present in the blood at all times.
The blood smears are taken to the parisitology laboratory where they are stained so that the worm-like micro filari can be easily seen.
Each morning, entomology field teams spend the first two working hours in collecting adult and aquatic stages of mosquitoes.
All kinds of mosquitoes are collected in order to determine how many different kinds are carrying the filarial worms.
Inside houses, filarial mosquitoes are found mostly on walls and on hanging objects such as clothing, curtains, and mosquito nets.
They are also found on or under furniture and in empty containers or receptacles.
The mosquitoes are sucked into a collecting tube and transferred to cages.
Another type of filarial mosquito is usually found in bushy areas.
In the coastal trains, mosquitoes can easily be transported for many miles.
In British Guiana, drums containing water are a second source of breeding of the main filaria mosquito which is called Culex.
The filaria mosquito also breeds in large tanks, some of which are inaccessible for control work.
In this country, the main filaria mosquito breeds in drains only when they have become contaminated with waste.
The female Culex mosquito lays its eggs on the surface of the water. They are cemented together to form a small raft about one-eighth of an inch long.
A single dip into a latrine will often yield hundreds of wormlike larvae and comma-shaped pupae of Culex. The adult mosquito emerges from the pupa, dries itself, and flies away.
It usually takes only seven to ten days for the complete development from the egg to the adult.
The water stages of the second kind of filarial mosquito, which is called mansonia, are found associated with certain water plants, especially the water lettuce.
The mansonia larvae and pupae cannot breath the air at the surface of the water like Culex. Instead, they attach themselves to roots and leaves of water plants which have air cavities and suck up the oxygen which they need.
The larvae feed while hanging from their place of attachment.
The Culex mosquito can be controlled in two ways. First, pit latrines are sprayed with gas oil. Only one such spraying is needed each month to prevent breeding of the Culex mosquito.
Each time the latrine is sprayed it is marked with paint. This provides a record of the number of times the latrine has been sprayed.
The easiest way to control filaria mosquito breeding in drums is to empty them and keep them turned upside down when water is not being stored.
If it is necessary to store up water, a tight-fitting drum cover should be made of wood or metal.
It should be tightly replaced after each time that water is drawn from the drum.
The cover should be solid if the drum is not kept under a drain pipe.
If it is kept under a pipe, the hole in the center of the cover should be covered with a fine screen in order to prevent the mosquito from laying its eggs on the water.
There should be no gap or hole whatsoever in the fitted cover.
Sleeping under a mosquito net will prevent the mosquito from sucking infected blood or depositing filarial worms on the skin.
The most important means of controlling filariases is by giving out a drug called Vanicide or Hetrazan.
When taken as directed, this drug kills the micro filari in the blood. In British Guiana, a single course of treatment is taken over a period of seven days in gradually increasing dosages.
After the first day while the drug is acting on the micro filari, the person may not feel well. In spite of this you should continue with the full treatment, because the illness indicates that the drug is killing the worms in the blood.
After the very active micro filari are killed, the blood becomes free of filaria worms. The filaria mosquitoes cannot then pick up the worms while feeding on this person.
The control of filaria cannot be done in a short time. It involves much cooperation between the public and health personnel.
If each person who is given the drug takes it in full without fail, then elephantiasis will become a thing of the past.
The worms in the blood will be killed and the mosquito will not be able to pass them on to another person.
When the night blood collecting teams come to your house, cooperate with them and let them take blood from your finger.
Don't let yourself become deprived of the use of your legs. You can avoid becoming crippled by filaria.
Take the advice of the health authorities who have been doing their utmost to help eliminate this crippling scourge.
[Technical Advice and Photomicrography: George Burton, Ph.D., Public Health Service. Photography: M. Ali, audiovisual, Spec. Ministry of Health. British Guiana]
[The End M-673]