Molecular epidemiology of a hepatitis C virus epidemic in a haemodialysis unit: outbreak investigation and infection outcome.
BACKGROUND
HCV is a leading cause of liver chronic diseases all over the world. In developed countries the highest prevalence of infection is reported among intravenous drug users and haemodialysis (HD) patients. The present report is to identify the pathway of HCV transmission during an outbreak of HCV infection in a privately run haemodialysis (HD) unit in Italy in 2005.


METHODS
Dynamics of the outbreak and infection clinical outcomes were defined through an ambi-directional cohort study. Molecular epidemiology techniques were used to define the relationships between the viral variants infecting the patients and confirm the outbreak. Risk analysis and auditing procedures were carried out to define the transmission pathway(s).


RESULTS
Of the 50 patients treated in the HD unit 5 were already anti-HCV positive and 13 became positive during the study period (AR = 28.9%). Phylogenic analysis identified that, all the molecularly characterized incident cases (10 out of 13), were infected with the same viral variant of one of the prevalent cases. The multivariate analysis and the auditing procedure disclosed a single event of multi-dose vials heparin contamination as the cause of transmission of the infection in 11 out of the 13 incident cases; 2 additional incident cases occurred possibly as a result of inappropriate risk management.


CONCLUSIONS
More than 30% of all HCV infections in developed countries results from poor application of standard precautions during percutaneous procedures. Comprehensive strategy which included: educational programmes, periodical auditing on standard precaution, use of single-dose vials whenever possible, prospective surveillance for blood-borne infections (including a system of prompt notification) and risk assessment/management dedicated staff are the cornerstone to contain and prevent outbreaks in HD CONCLUSIONS: The outbreak described should serve as a reminder to HD providers that patients undergoing dialysis are at risk for HCV infection and that HCV may be easily transmitted whenever standard precautions are not strictly applied.
Lanini
Simone
S
Istituto Nazionale per le Malattie Infettive Lazzaro Spallanzani via Portuense 292 00149 Rome, Italy. simone.lanini@inmi.it
Abbate
Isabella
I
Puro
Vincenzo
V
Soscia
Fabrizio
F
Albertoni
Franceso
F
Battisti
Walter
W
Ruta
Amilacare
A
Capobianchi
Maria R
MR
Ippolito
Giuseppe
G
D000368:Aged; D016000:Cluster Analysis; D003428:Cross Infection / Q000453:epidemiology* / Q000821:virology; D004196:Disease Outbreaks; D005260:Female; D005838:Genotype; D006436:Hemodialysis Units, Hospital; D016174:Hepacivirus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D006526:Hepatitis C / Q000453:epidemiology* / Q000821:virology; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D016896:Treatment Outcome
D012367:RNA, Viral
Am J Kidney Dis. 2006 Oct;48(4):629-37
16997059
Euro Surveill. 2008 May 22;13(21):
18761967
MMWR Recomm Rep. 2001 Apr 27;50(RR-5):1-43
11349873
J Hepatol. 1999;31 Suppl 1:107-12
10622571
Dig Liver Dis. 2006 Jul;38(7):445-51
16735144
Ann Intern Med. 2009 Jan 6;150(1):33-9
19124818
Infect Control Hosp Epidemiol. 2005 Sep;26(9):752-60
16209381
Infect Control Hosp Epidemiol. 2005 Sep;26(9):789-92
16209386
J Clin Microbiol. 2005 Jun;43(6):2750-5
15956393
J Clin Microbiol. 1998 Oct;36(10):3040-3
9738063
Am J Kidney Dis. 2001 May;37(5):1004-10
11325683
Infect Control Hosp Epidemiol. 2002 Jun;23(6):328-34
12083237
Lancet Infect Dis. 2005 Sep;5(9):558-67
16122679
Infect Control Hosp Epidemiol. 2009 Feb;30(2):156-62
19125681
MMWR Morb Mortal Wkly Rep. 2008 Aug 15;57(32):875-6
18701878
MMWR Morb Mortal Wkly Rep. 2008 May 16;57(19):513-7
18480743
Lancet Infect Dis. 2007 Apr;7(4):282-8
17376385
Semin Dial. 2007 Sep-Oct;20(5):416-22
17897248
Am J Infect Control. 2007 Dec;35(10 Suppl 2):S65-164
18068815
Nephrol Dial Transplant. 2004 Apr;19(4):904-9
15031348
Am J Epidemiol. 2004 Apr 1;159(7):702-6
15033648
Infect Control Hosp Epidemiol. 2005 Sep;26(9):762-7
16209382
MMWR Morb Mortal Wkly Rep. 2003 Sep 26;52(38):901-6
14508437