Cluster of human tuberculosis caused by Mycobacterium bovis: evidence for person-to-person transmission in the UK.
BACKGROUND
Despite a recent resurgence in the incidence of bovine tuberculosis in UK cattle herds, no associated rise in the number of cases in man has been noted. Disease due to human Mycobacterium bovis infection usually occurs in older patients, in whom drinking unpasteurised milk in the past is the probable source of infection. Person-to-person transmission is very rare.


METHODS
After identification of two epidemiologically-linked cases of human M bovis infection through routine laboratory and surveillance activities, all patients identified with M bovis infection in the Midlands from 2001-05 (n=20) were assessed by DNA fingerprinting (MIRU-VNTR and spoligotyping), with additional interviews for patients with a clustered strain.


RESULTS
A cluster of six cases was identified. All clustered cases were young and UK-born; five patients had pulmonary disease, and one patient died due to M bovis meningitis, with four patients possessing factors predisposing to tuberculosis. All patients had common social links through visits to bars in two different areas. With the exception of the first case, there was an absence of zoonotic links or consumption of unpasteurised dairy products, suggesting that person-to-person transmission had occurred.


CONCLUSIONS
This report of several instances of M bovis transmission between people in a modern urban setting emphasises the need to maintain control measures for human and bovine tuberculosis. Transmission and subsequent disease was probably due to a combination of host and environmental factors. Prospective surveillance and DNA fingerprinting identified the cluster, enabling health protection teams to set up control measures and prevent further transmission.
Evans
Jason T
JT
Regional Centre for Mycobacteriology, West Midlands Public Health Laboratory, Health Protection Agency, Birmingham Heartlands Hospital, Birmingham B9 5SS, UK. Electronic address: jason.evans@heartofengland.nhs.uk.
Smith
E Grace
EG
Regional Centre for Mycobacteriology, West Midlands Public Health Laboratory, Health Protection Agency, Birmingham Heartlands Hospital, Birmingham B9 5SS, UK.
Banerjee
Ashis
A
Health Protection Agency Regional Surveillance Unit (West Midlands), Birmingham, UK.
Smith
Robert Mm
RM
Zoonoses Surveillance Unit, National Public Health Service for Wales, Communicable Disease Surveillance Centre, Cardiff, UK.
Dale
James
J
TB Research Group, Veterinary Laboratories Agency, Weybridge, UK.
Innes
John A
JA
Birmingham Chest Clinic, Heart of England NHS Foundation Trust, Birmingham, UK.
Hunt
David
D
Health Protection Agency Regional Surveillance Unit (West Midlands), Birmingham, UK.
Tweddell
Alan
A
Herefordshire and Worcestershire Health Protection Unit, UK.
Wood
Annette
A
Birmingham and Solihull Health Protection Unit, UK.
Anderson
Charlotte
C
Tuberculosis Section, Health Protection Agency Centre for Infections, London, UK.
Hewinson
R Glyn
RG
TB Research Group, Veterinary Laboratories Agency, Weybridge, UK.
Smith
Noel H
NH
TB Research Group, Veterinary Laboratories Agency, Weybridge, UK.
Hawkey
Peter M
PM
Regional Centre for Mycobacteriology, West Midlands Public Health Laboratory, Health Protection Agency, Birmingham Heartlands Hospital, Birmingham B9 5SS, UK; Division of Immunity and Infection, Medical School, University of Birmingham, Birmingham, UK.
Sonnenberg
Pam
P
Tuberculosis Section, Health Protection Agency Centre for Infections, London, UK; Department of Primary Care and Population Sciences, University College London, London, UK.
D000328:Adult; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D005260:Female; D006801:Humans; D008297:Male; D009163:Mycobacterium bovis / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity; D012307:Risk Factors; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000453:epidemiology / Q000635:transmission; D006113:United Kingdom / Q000453:epidemiology