Filariasis is one of the important public health pro­blems in the different states of the India Union except Punjab, Delhi, Rajasthan, Himachal Pradesh and Jammu and Kashmir The extent of its prevalence varies from state to state. Rough estimates based on available information show that at least about 30 million persons live in the known fallacious areas of the country. The disease is widely distributed and has remained a challenge to the public health workers.

Mode of Transmission:

The filarial worm is very much shorter and thinner and is transmitted from one person to another by mosqui­toes. But the filarial carrying mosquito and malaria carrying mosquito are two entirely different types.

The malaria mosquito called Anopheles mosquito has wings with black and white spots, while the filarial mosquito known as Culled or Pest mosquito has uniformly brownish wings. The former sits on the wall with its whole body in one straight line, while the latter has a bend with both the head and tail ends pointing to the wall.

ADVERTISEMENTS:

When the infected filarial carrying mosquito bites a person, she injects in to the human body a number of tiny worms known as the infective filarial larvae. Those larvae travel in the body and settle down generally in the armpit or the groin. That is why the elephantoid swelling is commonly noticed in the hands or legs. When the swellings develop on the hands in cases where the worms settle in the armpits and on the legs if the worms settle in the groins.

The worms grow in these glands and produce young ones known as microfilaria which later appear in the blood circulation. It is these young worms that are taken by the mosquito and latter develop inside the body of the mosquito into infective larvae. The life cycle of the worms there­fore, partly takes place in the man and partly in the mos­quito.

Now question arises how long does it take between the bite of such an infective mosquito and the development of the visible disease in person so bitten?

It takes a long time often months or years. Some people may just continue to have the infection but never develop any swellings. The infective worms settle down in the lymph glands and develop. When they are fully grown they produce young microfilaria.

ADVERTISEMENTS:

Incubation Period:

This is probably a matter of 4 or 5 years.

Clinical Features:

The results produced by the adult worms are variable and include:

ADVERTISEMENTS:

(i) Lymphangitis:

Painful red lines form under the skin and the neighboring lymph nodes are enlarged. During this stage the person may show signs like pain and swelling in the glands and fever. And if the blood is examined under the microscope the microfilaria can often be detected. But the microfilaria has a peculiar habit of appearing in the circulating blood at night when the person is resting. They hide themselves in the internal organs during day time. So it becomes necessary to examine the blood taken at night to detect the infection more easily.

(ii) Elephanteid Fever:

Periodical attacks of fever with an initial rigor and terminal sweating occur, somewhat resembling malaria. The deep lymph nodes are probably inflamed.

ADVERTISEMENTS:

(iii) Elephantiasis:

Filarial fever which in its chronic stages leads to large painful swelling of legs and arms. This condition according to doctors is called ‘Ele­phantiasis” meaning legs like an elephant. If there will be timely treatment and examination of blood then the chronic horrors of the disease can be easily prevented. Some believe that it is hereditary and some other believe that elephantiasis is the result of eating some highly juicy fruits like water melon or some vegetables raised by using sewage water. But all such believes are not correct. The disease elephantiasis is the result of long standing infection with filarial worms.

Treatment:

As it is impracticable to pick out only the infected persons by examining every individual among the millions of residents, the doctors give the drug to all the persons living in the fallacious area for five consecutive days. They presume that every individual in the fallacious area has the infection. Biocide is the drug of choice.

ADVERTISEMENTS:

Prevention and Control Measures:

(i) Mosquito breeding places should be sterilized and electric fans and mosquito nets should be used;

(ii) The houses should be sprayed periodically with D.D.T., by the spraying squads;

(iii) The premises should be kept free from the collec­tion of dirty water to obviate mosquito breeding;

ADVERTISEMENTS:

(iv) Filarial teams should examine people and their blood should be taken at night to detect the presence of infection;

(v) The teams should supervise whether the people are taking the drugs regularly, on all the five days or not.