Improved laboratory safety by decontamination of unstained sputum smears for acid-fast microscopy.
Tubercle bacilli may survive in unstained heat-fixed sputum smears and may be an infection risk to laboratory staff. We compared the effectiveness of 1% and 5% sodium hypochlorite, 5% phenol, 2% glutaraldehyde, and 3.7% formalin in killing Mycobacterium tuberculosis present in smears prepared from 51 sputum samples. The smears were decontaminated by the tube and slide techniques. Phenol at 5%, glutaraldehyde at 2%, and buffered formalin at 3.7% for 1 min (tube technique) or for 10 min (slide technique) were effective in decontaminating sputum smears and preserved cell morphology and quantitative acid-fast microscopy results.
Giacomelli
Luiz Roberto Bigão
LR
Departamento de Análises Clínicas, Universidade Estadual de Maringá, PR, Brazil. betofla@teracom.com.br
Helbel
Cesar
C
Ogassawara
Roger Leandro Nunes
RL
Barreto
Angela Maria Werneck
AM
Martins
Fátima Moreira
FM
Cardoso
Celso Luíz
CL
Leite
Clarice Queico Fujimura
CQ
D003666:Decontamination / Q000379:methods*; D006801:Humans; D007753:Laboratories; D008853:Microscopy; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D012449:Safety; D013048:Specimen Handling; D013183:Sputum / Q000382:microbiology*