Ml. Moro et al., AN OUTBREAK OF MULTIDRUG-RESISTANT TUBERCULOSIS INVOLVING HIV-INFECTED PATIENTS OF 2 HOSPITALS IN MILAN, ITALY, AIDS, 12(9), 1998, pp. 1095-1102
Objective: To describe an outbreak of multidrug-resistant tuberculosis
(MDR-TB), amongst HIV-infected patients, spread from one hospital in
Milan to another. Design: Descriptive epidemiological investigation an
d molecular typing. Methods: All cases identified by intensive case-fi
nding were described in terms of clinical characteristics, previous no
socomial exposure to an infectious MDR-TB patient, previous stays in o
ther institutional settings where exposure to MDR-TB could have occurr
ed, and restriction fragment length polymorphism (RFLP) pattern. Resul
ts: Between October 1991 and July 1995, 116 cases of MDR-TB were ident
ified (85 at hospital A and 31 at hospital B). A single case patient,
infected at hospital A, introduced the strain into hospital B. Eighty-
two of the 92 strains available for fingerprinting revealed an identic
al pattern; 10 strains had unique RFLP patterns. Nosocomial exposure t
o an infectious MDR-TB patient was ascertained for 39 of the 56 patien
ts with the 'outbreak' RFLP strain at hospital A (69.6%) and for 24 of
the 26 patients at hospital B (92.3%). The median duration of exposur
e was 32 days at hospital A and 40 days at hospital B. For eight patie
nts with the outbreak strain, exposure was determined to have probably
occurred in other hospitals, in the community or in prison. Conclusio
ns: This is the largest nosocomial outbreak of MDR-TB reported in Euro
pe. Exposure to MDR-TB cases in other institutions caring for HIV-infe
cted patients probably contributed to the spread of this epidemic. Str
ict control measures should be immediately adopted in order to prevent
the spread of TB amongst HIV-infected patients in institutional setti
ngs in Europe. (C) 1998 Lippincott-Raven Publishers.