Detection of Mycobacterium leprae DNA by polymerase chain reaction in the blood and nasal secretion of Brazilian household contacts.
DNA samples from blood and nasal swabs of 125 healthy household contacts was submitted to amplification by polymerase chain reaction (PCR) using a Mycobacterium leprae-specific sequence as a target for the detection of subclinical infection with M. leprae. All samples were submitted to hybridization analysis in order to exclude any false positive or negative results. Two positive samples were confirmed from blood out of 119 (1.7%) and two positive samples from nasal secretion out of 120 (1.7%). The analysis of the families with positive individuals showed that 2.5% (n = 3) of the contacts were relatives of multibacilary patients while 0.8% of the cases (n = 1) had a paucibacilary as an index case. All positive contacts were followed up and after one year none of them presented clinical signs of the disease. In spite of the PCR sensitivity to detect the presence of the M. leprae in a subclinical stage, this molecular approach did not seem to be a valuable tool to screen household contacts, since we determined a spurious association of the PCR positivity and further development of leprosy.
Almeida
Elza Carmen de
EC
Laboratório de Hanseníase, Departmento de Medicina Tropical, Instituto Oswaldo Cruz-Fiocruz, Av. Brasil, 4365, 21045-900 Manguinhos, Rio de Janeiro, RJ, Brazil.
Martinez
Alejandra Nóbrega
AN
Maniero
Viviane Câmara
VC
Sales
Ana Maria
AM
Duppre
Nádia C
NC
Sarno
Euzenir Nunes
EN
Santos
Adalberto Rezende
AR
Moraes
Milton Ozório
MO
D016358:Contact Tracing; D004269:DNA, Bacterial / Q000032:analysis* / Q000097:blood; D005260:Female; D006801:Humans; D007918:Leprosy / Q000175:diagnosis* / Q000635:transmission; D008297:Male; D009166:Mycobacterium leprae / Q000235:genetics* / Q000302:isolation & purification; D009297:Nasal Mucosa / Q000378:metabolism / Q000382:microbiology; D016133:Polymerase Chain Reaction; D012680:Sensitivity and Specificity
D004269:DNA, Bacterial