Mass drug prophylaxis against filariasis

To eliminate lymphatic filariasis, the Kerala State Government Health Department has launched a  mass drug administration (MDA) programme  in 11 districts in the State on Novemeber 11,2009.
A lot of confusion is there in the minds of many among the public about the need and possible side effects of this mass drug administration.

Why this mass anti-filarial drug administration in healthy persons?

Let me try to clarify.

What is Lymphatic filariasis?

Lymphatic filariasis is a parasitic disease caused by microscopic, thread-like worms. The adult worms only live in the human lymph system. The lymph system maintains the body's fluid balance and fights infections. Lymphatic filariasis is spread from person to person by mosquitoes.

People with the disease can suffer from lymphedema and elephantiasis and in men, swelling of the scrotum, called hydrocele. Lymphatic filariasis is a leading cause of permanent disability worldwide

Disease burden

Although lymphatic filariasis very rarely causes death, it is a major cause of clinical suffering, disability and handicap. More than 1.3 billion people in 83 countries and territories (Map) — approximately 18% of the world's population — live in areas at risk of infection with lymphatic filarial parasites. Approximately one third of those at risk live in India, one third in Africa and the remainder in Asia, the Pacific and the Americas.
It is estimated that around 120 million people in tropical and subtropical areas of the world are infected. Almost 25 million men suffer from genital disease (most commonly hydrocoele); an estimated 15 million people — the majority of them women — have lymphoedema or elephantiasis of the leg.

Indian Situation

Filariasis is endemic in 19 States/union territories in India. Estimates based on surveys by Filariasis Survey Units suggested that: about 454 million people (120 million in urban areas) are living in known endemic areas; there are 29 million filariasis cases in the country and 22 million micro-filaria carriers.

The magnitude of infection in children has become much better understood in recent years; indeed, most infections appear to be acquired in childhood, with a long period of subclinical asymtomatic period  that progresses to the characteristic, clinical manifestations of adults.

Global Programme to Eliminate Lymphatic Filariasis

 In 1997, as a result of advances in the diagnosis and treatment of lymphatic filariasis (LF), the disease was classed as one of six infectious diseases considered to be “eradicable” or “potentially eradicable”. Consequently, the World Health Assembly adopted resolution 50.29, calling for elimination of the disease as a global public health problem.
 
Elimination strategy


The strategy proposed by WHO to achieve the goal of elimination comprises two components:
1.interruption of transmission of filarial infection in all endemic countries through drastic reduction of microfilariae prevalence levels;

2.prevention and alleviation of disability and suffering in individuals already affected by LF.

Interruption of transmission of infection can only be achieved if the entire population at risk is covered by mass drug administration (MDA) for a period long enough to ensure a reduction in the level of microfilariae in the blood to a point where transmission can no longer be sustained.
That's why mass administration of anti filarial drugs are advised in healthy individuals living in areas of risk.

The following recommended drug regimens must be administered once a year for at
least 5 years, with a coverage of at least 65% of the total at-risk population:

a.6 mg/kg diethylcarbamazine citrate (DEC) + 400 mg albendazole; or

b.150 µg/kg ivermectin + 400 mg albendazole (in the case of co-endemicity with onchocerciasis).

c.A third option is to follow a treatment regimen using DEC-fortified cooking salt daily for a period of 12 months.

As a part of this programme 11 Districts in Kerala has started the second round of MDA this Novemeber using DEC and Albendazole.

Side effects of the drugs.

There has been reports in the media about children becoming sick after taking the tablets. Is this true? Is it serious?

Both DEC and Albendazole is best taken in full stomach. Many temporary side effects can be prevented by taking care to eat well before ingesting the medicines.
Side effects due to these medicines are rare, not serious and lasts for few minutes to hours only.
Most common side effects are dizziness,nausea,vomiting,headache and fatigue. Some may develop fever and skin rashes which may indicate succesful elimination of microfilaria.

Children below 2 years and elderly people above 65 are not required to take the drugs.
All others are advised to take the drugs.

 Let us try to eliminate the dreaded elephantiasis from our community.