Abstract

Background
Accurate diagnosis to establish the presence of Mycobacterium tuberculosis is critical in the
control of TB because of the mode of transmission of the disease. Although both ZN and
kinyoun are over 100 years old, these methods are most economical in terms of processing
time, needed equipment and personnel. These smear detection tests differentiate infectious
from noninfectious cases. The use of cold method on processed sputum is increasing in low
income, high prevalent countries as it is less demanding. Objective
The main objective of this study was to prospectively evaluate the two smear microscopy
methods for the detection of tubercle bacilli in the sputum by comparing the sensitivity,
specificity and validities of kinyoun method against ZN. The study also compared the
sensitivities of kinyoun and ZN against culture as the gold standard of TB diagnosis.
Materials and Method
The work was carried out at the Zonal Reference Laboratory of the University of Jos Teaching
Hospital (JUTH), Plateau State. Seventy-two concentrated early morning sputum from
treatment-naïve pulmonary tuberculosis suspects were simultaneously stained by ZN and
kinyoun and then cultured on Lowenstein-Jensen media.
Result
x

Fifty-four (75%) of the patients in the economically productive age groups of 15-30 years and
31-40 years were sputum positive with either of the microscopy or culture. The kinyoun
method was 100% sensitive and 98.3% specific when compared with ZN, while its positive
and negative predictive values were 92.3% and 100%, respectively. Fifteen (20.8%) samples
out of the 72 samples were culture positive, out of which 7 (46.7%) each were positive for the
ZN and kinyoun methods.
Conclusion
The comparison of the sensitivities of ZN and kinyoun show that the kinyoun method is 100%
as sensitive and 98.3% as specific as ZN. The kinyoun method being less hazardous than the
ZN can be used as a supplementary method in Nigeria which has a high TB burden. The two
staining methods can be relied upon for TB diagnosis in parts of Nigeria where sputum
culture is not routinely carried out

A COMPARATIVE STUDY OF TWO STANING METHODS FOR THE DETECTION OF PULMONARY MYCOBACTERIUM TUBERCULOSIS IN JOS