Culture Results From FNAC Specimens Suggestive Of Tuberculous Lymphadenitis
Abstract
The incidence of tuberculosis is high in Kenya and remains a senous health
problem. Moreover the appearance of multi drug resistant strains of Mycobacteria
tuberculosis (MDR- TB) and the high rate of association with acquired
immunodeficiency syndromes (AIDS) Human Immunodeficiency virus (HIV) has
increased the need for rapid diagnostic methods. In 1999 there were a total of
60,000 cases of Tuberculosis with a weighted national HIV / prevalence rate in
T.B of 40%.
FINE NEEDLE ASPIRATION CYTOLOGY(FNAC) IS the main method of
diagnosis of Tuberculous lymphadenitis (T.B. Lymphadentitis). Confirmation is
done by demonstration of Acid Alcohol Fast Bacilli(AAFBs) with special stains
such as Ziehl Neelsen(ZN) from cultured specimens or on direct smear
microscopy.
The main objective was to establish culture results in cases suggestive of T.B.
lymphadenitis on cytology but with a negative Ziehl-Neelsen test (ZN) for Acid
Alcohol Fast Bacilli (AAFBs). This was aimed at assessing and ascertaining
whether FNAC should be assumed as a test with high rapidity and fast turn around
time in diagnosing suspected T. B lymphadenopathy in Kenya. The method of
study involved culturing of a residual material using BACTEC CULTURE
SYSTEM for such cases.
This was a prospective study of cases referred to the fine needle aspiration (FNA)
clinic for investigation for the cause for lymphadenopathy. A total of 365 cases
were presented in this clinic in a twelve month period between August 2000 and
August 2001 out of which 195(54%) were reported to be as a result of tuberculous
lymphadenitis by cytology. This compared well with a similar histological study
done at Muhimbili in Tanzania where 173 (67%) cases out of a total of 257 were
confirmed histologically as T. B lymphadenitis.
The study was conducted at Kenyatta National Hospital. Culturing of the
specimens took place in the department of Pathology, at Nairobi Hospital. The
study was carried out between months of April and August year 2001. A total of
60 specimens were submitted for culture at The Nairobi Hospital pathology
laboratories where 17/60 (i.e. 280/0)specimens were positive for Acid Alcohol Fast
Bacilli (AAFBs). There was no significant statistical difference between the
performance of cytology and histology in terms of diagnosis. Statistically
significant difference was only noted between culture results from FNAC
specimens and those of cultured histological specimens. The results reaffirmed
cytology as one of the simplest, safe and cheap method of diagnosing T. B.
lymphadenitis. The importance of this finding is realized in consideration of
increasing cases HIV /AIDS associated tuberculosis. The study also identified the
need for increased application and adoption of cytology as diagnostic and
screening test for T. B. lymphadenitis especially in peripheral health units where
histopathology services are not available due to the limited number of pathologists
and lack of appropriate facilities in Kenya. It is also highly recommended that
K.N.H being a tertiary medical institution should be equipped with modem culture
facilities for Mycobacterium. Currently the hospital does not have any facility for
T. B. culture including the conventional ones i.e Lowenstein Jensen media.
Citation
Master of science (Clinical Cytology)Publisher
University of Nairobi