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What is lymphatic filariasis?
Lymphatic Filariasis (LF) is one
of the most debilitating and disfiguring scourges among all diseases. The
infection is caused by parasitic, thread-like worms or filariae
inhabiting the lymphatic system of the human body. They live for about five
years, producing millions of immature microfilariae
(minute larvae) that circulate in the blood and cause extensive damage to the
lymphatic system, often leading to gross swelling of the limbs
(elephantiasis) and scrotum (hydrocele).
What are the signs
and symptoms of LF?
The initial clinical symptoms are fever often with rigours, swelling in the limbs and thickening of the
skin. Severe swelling or lymphoedema may occur in
arms, legs, breasts and genitals due to collection of fluid caused by damage
to the lymphatic system. However, many LF affected persons may never manifest
visible clinical symptoms. The infection is usually acquired in early childhood
and chronic clinical symptoms generally appear in adulthood. Both males and
females are susceptible.
Why is LF a public
health problem?
Worldwide 1.1 billion people are at risk of infection and
about 120 million people are infected in 83 countries. Nine out of the 11
countries in the South-East Asia (SEA) Region are known to be endemic for filariasis(The
2 non-endemic countries are Bhutan
and DPR Korea). More than 63% of the global population at risk and half of
the global infected cases are from the SEA region. It is, therefore, one of
the major public health problems in the SEA Region.
How do people get
the disease?
The disease is transmitted by mosquitoes breeding in dirty
and stagnating water. Inadequate sanitation, over-crowding, lack of personal
protective measures such as insect-proofing of houses, and lack of bed-nets
all contribute to the transmission of the disease. LF is primarily found in
remote rural areas and unplanned, crowded and neglected urban communities. It
is a disease predominantly affecting the most impoverished and marginalized
populations
Can I contract LF
from blood transfusion or food/water?
No. The disease is transmitted by mosquitoes only. The
parasite larva has to undergo an essential stage in the mosquito to be infective
to man.
What is the social
and economic impact of LF in the affected countries?
LF predominantly afflicts the poor and marginalized
population groups. The resulting disabilities prevent people from having a
normal working life, further reducing household income and thereby increasing
poverty levels. Though the disease is not fatal, it is responsible for
considerable morbidity and social stigma among men, women and children. It
also has an adverse impact on reproductive, maternal and child health.
In South-East Asia alone,
the productivity losses due to LF are estimated at about US$ 1.4 billion per
year. The elimination of LF will contribute to poverty alleviation.
Can LF be
eliminated?
The South-East Asia Region aims to eliminate LF as a public
health problem by 2020, defined as a Microfilaraemia
rate of < 1%. WHO recommends mass drug administration (MDA) with two
drugs, DEC+albendazole, to the entire eligible
population once a year for five to six years. This
reduces microfilaraemia (mf) levels and thereby
reduces transmission.
All endemic countries have the required infrastructure and
human resources to deliver the recommended intervention strategy. All of them
also have national programmes for elimination of LF
backed by political will. WHO has
developed guidelines for all aspects of implementation of the national programmes.
However, the endemic countries require additional funds and technical support
to intensify efforts towards elimination.
How can we prevent
disabilities?
Disability prevention and alleviation is an essential
component of the LF elimination programme. Simple home-based self-help
methods of hygiene are shown to provide significant relief or prevent
debilitating acute episodes. New surgical techniques have demonstrated speedy
recovery from clinical manifestations. However, massive chronic
manifestations are unfortunately irreversible.
From where can I
get treatment or further advice?
If you are in an endemic country, your local doctor/health
worker will usually help and refer if required. During the annual Mass Drug
Administration rounds in endemic areas, the health workers usually visit
house-to-house to distribute the drugs or arrangements are made for
collection of the drugs at specified health centres
or other facilities.
In many endemic areas, there are special campaigns or
community-based programmes for alleviation of
disabilities caused due to LF.
What is the role of
WHO in LF elimination?
The fiftieth World Health Assembly (1997) adopted a
resolution WHA50.29 calling upon Member states to bestow greater attention to
the problem of LF and work towards its elimination as a public health
problem. In order to support the elimination efforts, the Global Alliance to
Eliminate Lymphatic Filariasis (GAELF), was formed.
GAELF is a partnership of many organizations, including major donors and
national governments.
At the Regional level, the Regional Programme Review Group
(RPRG) was formed in 2001 following a Memorandum of Understanding (MoU) between drug donor, GlaxoSmithKline, and
WHO. The RPRG serves as a technical advisory group and also as an approving
body for free supply of MDA drugs. WHO functions as the secretariat to the RPRG.
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