Filaria in Guyana a historical and current
perspective
Lloyd Validum MD. Malariologist.
There may be few persons in Guyana today who have not at some
time in the past made reference to someone "having big
foot"to describe that well known tropical disease,Lymphatic
Filariasis.Even though not as evident as malaria,Bancroftian
Filariasis is still prevalent in Guyana today,the extent of which
is yet to be properly determined. Caused by Wuchereria bancrofti
a nematode filarialworm,filaria has a preference for the
lymphatic system.The disease can cause a myriad of symptoms
ranging from mild to severe in intensity.The first commonly
recognizable sign is usually a small painful swelling in the
groin (lymphadenitis),with a line of inflamed area leading down
the postero-medial(inner) side of the leg to the inner side of
the ankle("inflamed vein" as put by most patients).
Among other common forms of presentation are
hydrocele,lymphangitis,abscesses and
eventually the classical "big foot". ( Below Case
of Eliphantitis as a result of lymphatic filariasis Guyana 1998)
Filaria was first reported in the colony of British Guiana in
1877 by one Hillis. Subsequently much work was carried out on the
subject.It was already known that the disease was transmitted
from a sick person to a healthy one by the bite of a mosquito,and
the one responsible for the local transmission of the disease was
found to be the Culex fatigans (quinquefaciatus).
The mosquito bred in a wide variety of habitats from storage
containers for drinking water, to flooded pit latrines, septic
tank overflows,and sewers.The insect in this setting is a
domestic creature quite suited to maintaining the transmission of
the disease within the community. Knowing all of this,it was not
however uncommon for there to be the stigma of"a big foot
family" to be attached to any family who had a "big
foot granny" in the home.Inheritance was definite in the
minds if many.As a matter of fact quite a few other household
myths may have sprung from the presence of the disease.Giglioli
noted in 1960 that it was commonly thought that repeated
successive exposure to heat then cold was particularly dreaded by
some as being the cause of filarial attacks, thus in those days a
maid who had been cooking or ironing could not be made to open a
refrigerator for fear of causing a filarial attack.
There is really no definite conclusion as to the how filaria
originally came to our shores,though various opinions are voiced
about the probable importation with different batches of
immigrants to the colony. However quite a bit of emphasis was
placed on studying the distribution of the disease by various
parameters such as ethnic groups,sex,age, place of residence,
sanitary conditions and place of work.
The most consistent findings indicated that there was
definitely a link between incidence of filaria and poor living
conditions which led to high mosquito populations and human
overcrowding. Studies suggested that filaria seemed to be on the
increase since the previous century,with an all high rate of 30.5
percent being recorded in a city survey during 1921 by Anderson
(515 persons examined).It was also noted that different ethnic
groups possessed different susceptibility and response to the
disease.
The geographical distribution of the disease seemed to be all
along the coastal,but more heavily concentrated in the highly
populated centers than in the rural estates.New Amsterdam was not
to be spared and the mental hospital was because of the long term
nature of its patients,a focus for repeated study of the disease
The disease was and is a difficult one to study.This is mainly
due to its nocturnal periodicity in appearing in the peripheral
bloodstream where in can be detected,usually in the early hours
of the morning. Furthermore once contracted there may be an
incubation period(hidden development) within the person for
almost two years before it becomes evident that filaria is
present,usually with the appearance of one of the symptoms
mentioned before.What may be surprising to many is that a large
number of persons testing positive for the disease do not have
any symptoms,while persons with symptoms frustratingly are less
often test positive.
The main areas of the city mentioned in previous studies on
filaria are Alberttown,Lodge,Kitty,Newtown,and La Penitance,while
on the coast Buxton,Plantation Lusignan,Cane Grove and New
Amsterdam were the most studied.Between 1924 and 1953 a series of
events aided the reduction of transmission of the disease in
these areas.In 1947 studies in the same area of Georgetown as
studied by Anderson in 1927,showed a prevalence rate of only 12.6
percent compared with the 30.5 percent found previously.
This apparent reduction in the disease can probably be
attributed to a combination of various factors.
a)In Georgetown the introduction of a sewage system between
1924 to 1936 caused the reduction of the number of breeding sites
available there,the subsequent decrease in number of mosquitoes
resulted in a comparable decrease in incidence of filaria in
these areas. In the suburbs the sanitary situation improved
somewhat with better housing and on the plantations the range or
barrack type of family lodging were slowly being replaced by
housing schemes,where workers were afforded house lots of 1/10
acre and long term soft loans to build houses which became the
property of the workers once the loans were repaid.
b)The Yellow fever control service was started in Georgetown
in 1939. The program though focussed on the Aedes aegypti
mosquito,did help to reduce the incidence of Culex mosquitoes in
the sewers areas of the city ,in the suburbs however the
continued presence of pit latrines made things a bit more
difficult .
c)Treatment of cases with diethylcarbamazine (DEC,popularly
known as "banocide" still the main drug in use today).
d)The effect of the residual spraying of DDT intended to
control malaria also present.Anopheles darlingi the targeted
malaria vector,(Mosquito which transmitted malaria) was also
capable of transmitting filaria.The elimination of this insect
and the curtailment of the population of the Culex mosquito
population along the coast during the 5 to 6 years of the
spraying operations,seems to be of the greatest importance of
these factors in the overall reduction in incidence of filaria.
It is important to note that filaria much like malaria,
typhoid and cholera are community dependent and are sometimes
termed diseases of poverty or underdevelopment. Adequate
conditions can also be created by unplanned or misguided
settlement of populations in housing projects without adequate
sanitation perplexing for the site,for example as in the case of
squatting settlements.
During the last thirty or so years the limits of the city of
Georgetown has expanded considerably.Additions of the Ruimveldts
and movement of people from the rural areas to Georgetown and its
environs,has increased the population exposed to the disease.In
fact recent data suggest that the prevalence of filariasis is on
the increase.What is evident is that due to the long period of
it's evolution,the disease is usually not recognized until
entering it's chronic stage.T
he disease usually only dramatic during the flare-ups may
well have been overlooked by many a physician unacquainted with
it's history in Gyuana.Furthermore alternative diagnoses and
blind use of antibiotics or other drugs may have contributed to
the insidious increase of filaria over the years..
Some of the areas which within the last two years have been
shown to harbor a filaria problem,are exemplified by the
following localities from which cases have been detected, In
Georgetown; Wortmanville,Riumveldt(all sections),Lodge
(historically a problem area),Kingston,Alberttown,Kitty,
Cambleville,La Penitance,Prashad Nagar,Werkenrust, and not the
least Charlestown. On the East Coast of Demarara;
Victoria,Buxton,Mahaica,and annandale figure the most While on
the East Bank of Demarara Agricola,Grove and Friendship are
notable areas. Evident however is that diagnosis and treatment of
the individual cases will certainly not eliminate the disease
from the community .A better and permanent approach will be to
pursue an environmental management program,which will eliminate
the conditions favoring filaria and other mosquito borne disease
transmission.
This is by no means an easy task, but a necessary one if we
are to avoid stop-gaping whenever an epidemic rears it's ugly
head.As start it would be very beneficial for there to be greater
interaction between housing community development authorities and
relevant areas of the public health system In wrapping up this
brief summary of a topic which can consume much more time ,it is
not with the intention of alarming the reader that we should
mention that two other species of filaria can be found in
Guyana.They are however generally restricted to interior
locations,and are considered non-pathogenic (not necessarily
harmful to the infected person).A third species found in a
neighboring country has not been detected in Guyana to date.
References;
1960 Giglioli G,Beadnell H.H.S.G. Filariasis in British Guiana
some industrial medical problems .Indian Journal of Malariology
14 4 December 1960
1948 Giglioli G Malaria Filariasis and Yellow Fever in British
Guiana Mosquito Control Service Medical Department British Guiana
1990 Nathan M.B ,Stroom V Prevalence of Wuchereria bancrofti
in Georgetown Guyana Bulletin of PAHO 24(3) 1990
1989,1990 Annual reports of the Vector Control Service
Ministry of Health.