Filariasis, a parasitic infection caused by nematodes transmitted through mosquito bites, remains a major public health problem in the Philippines. It was first discovered in the country in 1907 and prevalence rates in 1998 were estimated at 9.7% nationally. The disease primarily affects poorer areas and can lead to lymphedema, elephantiasis, and hydrocele if left untreated. The Philippines aims to eliminate filariasis as a public health problem by 2017 through mass drug administration campaigns, disability prevention programs, and surveillance of endemic areas after treatment.

2.  Filariasis is a major parasitic infection, which
continues to be a public health problem in the
Philippines. It was first discovered in the Philippines in
1907 by foreign workers. Consolidated field reports
showed a prevalence rate of 9.7% per 1000
population in 1998. It is the second leading cause of
permanent and long-term disability. The disease
affects mostly the poorest municipalities in the country
about 71% of the case live in the 4th-6th class type of
municipalities.

3.  The World Health Assembly in 1997 declared
“Filariasis Elimination as a priority” and followed by
WHO’s call for global elimination. A sign of the DOH’s
commitment to eliminate the disease, the program’s
official shift from control to elimination strategies was
evident in an Administrative Order #25-A,s 1998
disseminated to endemic regions. In support to the
program, an Administrative Order declaring
“November as Filariasis Mass Treatment Month was
signed by the Secretary of Health last July 2004 and
was disseminated to all endemic regions.

4.  Vision: Healthy and productive individuals and
families for Filariasis-free Philippines
 Mission: Elimination of Filariasis as a public
health problem thru a comprehensive approach
and universal access to quality health services

5.  Goal: To eliminate Lymphatic Filariasis as a
public health problem in the Philippines by year
2017
 General Objectives: To decrease Prevalence
Rate of filariasis in endemic municipalities to
<1/1000 population.

6. Specific Objectives:
The National Filariasis Elimination Program
specifically aims to:
1. Reduce the Prevalence Rate to elimination level
of <1%;
2. Perform Mass treatment in all established
endemic areas;
3. Develop a Filariasis disability prevention program
in established endemic areas;
4. Continue surveillance of established endemic
areas 5 years after mass treatment.

7.  Human Lymphatic Filariasis is a chronic parasitic
infection caused by nematode parasites known as
wuchereria bancrofti, brugia malayi or brugia
timori.The young and adult worms live in
lymphatic vessels and lymph nodes while the
microfilariae are usually found in blood. The life-span
of the adult parasites is about 10 years ( but
a 40-year life- span has been reported)while
microfilariae live for about a year at the most.

8.  The disease is transmitted to a person through
bites from a infected female mosquito primarily
Aedes poecillius that bites at night.

9.  The filarial life cycle, like that of all nematodes,
consists of 5 developmental (larval) stages in a
vertebral host and an arthropod intermediate host and
vector. Adult female worms produce thousands of first-stage
larvae, or microfilariae, which are ingested by a
feeding insect vector. Some microfilariae have a
unique daily circadian periodicity in the peripheral
circulation. The arthropod vectors (mosquitoes and
flies) also have a circadian rhythm in which they obtain
blood meals. The highest concentration of
microfilariae usually occurs when the local vector is
feeding most actively.

10.  Microfilariae undergo 2 developmental changes in
the insect. Third-stage larvae then are inoculated
back into the vertebral host during the act of
feeding for the final 2 stages of development.
These larvae travel through the dermis and enter
regional lymphatic vessels. During the next 9
months, the larvae develop into mature worms
(20-100 mm in length). An average parasite can
survive for about 5 years.

11.  The prepatent period is defined as the interval
between a vector bite and the appearance of
microfilariae in blood, with an estimated duration
of about 12 months.

12.  The quantity of accumulating adult worm antigen
in the lymphatics
 The duration and level of exposure to infective
insect bites
 The number of secondary bacterial and fungal
infections
 The degree of host immune response

13.  Filarial infection generates significant
inflammatory immune responses that participate in
the development of symptomatic lymphatic
obstruction. Increased levels of immunoglobulin E
(IgE) and immunoglobulin G4 (IgG4) secondary to
antigenic (from dead worms) stimulation of Th2-
type immune response have been demonstrated.

14.  Studies have shown that there is a familial tendency to
lymphatic obstruction, providing support for the
hypothesis that host genes influence lymphedema
susceptibility. Studies also suggest that microfilaremia
may be increased in individuals with low levels of
mannose-binding lectin, suggesting a genetic
predisposition.Further, a propensity to develop chronic
disease has been demonstrated in patients with
polymorphisms of endothelin-1 and tumor necrosis
factor receptor II.

15.  Prenatal exposure seems to be an important
determinant in conferring greater immune
tolerance to parasite antigen. Thus, individuals
from endemic areas are often asymptomatic until
late in the disease when they have high worm
burden, whereas nonimmune expatriates tend to
have brisk immune responses and more severe
early clinical symptoms, even in light infections.

16.  Studies have shown that lymphatic filarial
parasites contain rickettsialike Wolbachia
endosymbiotic bacteria. This association has been
recognized as contributing to the inflammatory
reaction seen in filariasis.

17.  The incubation period which starts from the entry
of the infective larvae to the development of
clinical manifestation is variable. Nevertheless, it
ranges from 8-16 months.

18. ASYMPTOMATIC STAGE:
 Characterized by the presence of microfilariae in the
peripheral blood
 No clinical signs and symptoms of the disease
 Some remain asymptomatic for years and in some
instances for life
 Others progress to acute and chronic stages
 Microfilariae rate increases with age and then levels off
 In most endemic areas including the Philippines the
Philippines, men have higher microlariae rate than
women.

19. Starts when there are already manifestation such
as:
 Lymphadenitis ( Inflammation of lymph nodes)
 Lymphangitis ( inflammation of lymph vessels)
 In some cases, the male genitalia is affected
leading to funiculitis, epidydimitis, or orchitis
( redness, painful and tender scrotum)

20.  Develop 10-15 years from the onset of the first
attack
 Immigrants from areas where filariasis is not
endemic tend to develop this stage more often
and much sooner (1-2 years) than do the
indigenous population of endemic areas.

21.  Hydrocoele (swelling of the scrotum)
 Lymphedema ( temporary swelling of the upper
and lower extremities)
 Elephantiasis ( enlargement and thickening of the
skin of the lower and/or upper extremeties,
scrotum, breast)

22.  Physical examination is done in the main health
center or during scheduled survey bites in the
community
 History taking
 Observation of the major and minor signs ang
symptoms

23.  STRATEGY 1. Endemic Mapping
 STRATEGY 2. Capability Building
 STRATEGY 3. Mass Treatment (integrated with
other existing parasitic programs)
 STRATEGY 4. Support Control
 STRATEGY 5. Monitoring and Supervision
 STRATEGY 6. Evaluation
 STRATEGY 7. National Certification
 STRATEGY 8. International Certification

24.  Nocturnal Blood Examination (NBE)- blood are
taken from the patient at the patient’s residence or
in the hospital after 8:00 pm
 Immunochromatographic Test (ICT)- it is the rapid
assessment method. It is an antigen test that can
be done at daytime.

25.  1. Selective Treatment – treating individuals found
to be positive for microfilariae in nocturnal blood
examination.
Drug: Diethylcarbamazine Citrate
Dosage: 6 mg/kg body weight in 3 divided doses for
12 consecutive days (usually given after meals)

26. 2. Mass Treatment – giving the drugs to all
population from aged 2 years and above in all
established endemic areas.
 Drug: Diethlcarbamazine Citrate (single dose
based on 6 mg/kg body wt) plus Albendazole
400mg given single dose given once annually to
people 2 yrs & above living in established
endemic areas

27.  3. Disability Prevention thru home-based or
community-based care for lymphedema &
elephantiasis cases. Surgical management for
hydrocele patients.

28.  PROVINCES THAT REACHED ELIMINATION
STAGE: Southern Leyte, Sorsogon, Biliran,
Bukidnon, Romblon, Agusan Sur, Dinagat island,
Cotabato Province and COMVAL

29.  1. Assist low performing areas to increase the MDA
coverage in order to interrupt the transmission of the LF.
 2. Assist implementing Units to reach the goal of
elimination.
 3. Strengthen integration with other NTD programs.
 4. Strengthen the disability prevention strategy thru
community-based or home –based care & thru integration
with leprosy.
 5. Implement an integrated vector management
 6. Implement a sustainability plan for provinces that
have reached elimination level.

30. Basic Components
1. Hygiene
2. Prevention & cure
of entry lesions
3. Exercise
4. Elevation of foot
5. Use of proper
footwares
Lymphoedema
management helps
 to eliminate the bad odour
 to prevent & heal entry
lesion
 to help patients self-confident
 to reduce the size of the
lyphoedema
 to prevent disability
 to prevent economic loss

32.  Filariasis patients are advised to observe personal
hygiene by washing the affected areas with soap
and water at least twice a day or prescribed
antibiotics or anti- fungals for super infection.

33. A.Measures aimed to control the vector
 Environmental sanitation such as proper drainage
and cleanliness of surroundings
 Spraying with insecticides may also produce
harmful effects)

34. B. Measures aimed to protect the individual and
families in endemic areas
 Use of mosquito nets
 Use of long sleeves, long pants and socks
 Application of insect repellants screening of
houses
 Health education

35.  The prognosis in filariasis is good if infection is
recognized and treated early. Filarial diseases are
rarely fatal, but the consequences of infection can
cause significant personal and socioeconomic
hardship for those who are affected.

36.  The morbidity of human filariasis results mainly
from the host reaction to microfilariae or
developing adult worms in different areas of the
body. The WHO has identified lymphatic filariasis
as the second leading cause of permanent and
long-term disability in the world.

37. References:
 Cuevas, Frances Prescilla L.et al;2007 Public
Health Nursing in the Philippines 10th
edition,pp257-260
 www.chd7.gov.ph