Re-emergence of tuberculosis in the Caribbean: how ready are the Caribbean laboratories in 1997

ABSTRACT

WHO declared tuberculosis a "Global Emergency" in 1994. The incidence of tuberculosis is increasing in the English speaking Caribbean. Sporadic occurrence of multiple drug resistance M. tuberculosis has been reported in a few countries in this region. It is well recognized that the laboratory plays an important role in the control of tuberculosis through rapid detection, isolation, idenfification of and drug susceptibility testing of M. tuberculosis. Twenty one laboratories were surveyed to assess the current practices and capabilities that exist in laboratories for the detection isolation and drug susceptibility testing of M. tuberculosis in the Caribbean. Sixteen laboratories perform laboratory diagnosis of tuberculosis. Microscopic examination of sputum for acid fast bacilli (AFB) is being performed in 12 laboratories by the direct method. The most commonly used method is the Kinyoun technique (10/16). Only one laboratory is practising fluorochrome methods for the rapid detection of AFB in sputum and other clinical specimens. Only five laboratories culture for mycobacteria. None of the laboratories perform either nucleic acid probes or BACTEC NAP for the identification of mycobacteriae other than tuberculosis (MOTT). Only three laboratories perform antimicrobial susceptibility testing in the Caribbean. All susceptibility testing for M. tuberculosis is done on solid media (LJ slants). The major antibiotics test are rifampicin, isoniazid, ethambutol and stretomycin. Sixty three percent of laboratories do not have a policy on monitoring of laboratory personnel by tuberculosis testing. The use of disposable bacteriological loops and bacticinerator as a minimal safety procedure is 57 percent and 63 percent respectively. Centrifuges with safety carriers are being used in only 13 percent of laboratories. Eight laboratories (50 percent) use Level 2 containment biological safety cabinet while processing of all specimens for mycobacterial infections. Reporting of smear results to hospital, physician or the ministry of health/public health department is mainly done by telephone; but some laboratories report by writing and telephone. Thirty seven percent (6/16) laboratories do not report positive smear AFB results to the public health department. The time required to report AFB smear microscopy results take on an average of over 48 hrs in 75 percent of laboratories.