Hepatitis C virus infection among dialysis patients in Tunisia: Incidence and molecular evidence for nosocomial transmission

Abstract

In order to study the incidence of hepatitis C virus (HCV) infection in Tunisian haemodialysis patients and detect its nosocomial transmission, 395 patients were enrolled in a prospective study (November 2001-2003). HCV serological and virological status was determined initially using, respectively a third generation ELISA and an RT-PCR qualitative assay. The genotype of the HCV isolates was determined by sequencing NS5B region. The issue of nosocomial transmission was addressed by sequencing the HVR-1 region of the E2 gene. About 20% of the patients had anti-HCV antibodies and HCV-RNA was detected in 73% of the anti-HCV positive patients. Two cases of de novo HCV infection were identified in two dialysis centers, during virological follow-up of patients susceptible to HCV infection. The incidence of de novo HCV infection was 0.5%. Determining the genotypes in the first center disclosed that all HCV-positive patients were infected with genotype 1b; sequencing of the HVR-1 region of the E2 gene provided strong evidence that the isolate from the newly infected patient and another infected dialysis patient were closely related, confirming nosocomial contamination. The investigation of the second center is pending. Besides, one patient with negative HCV serology had detectable HCV-RNA at the beginning of the study. This case had HCV genotype 1b, two other infected dialysis patients in the same unit had HCV genotypes 4k and 3a; thus precluding nosocomial transmission. Thanks to molecular and phylogenetic methods, one case of nosocomial HCV transmission in haemodialysis was confirmed. Epidemiological investigation suggested nosocomial transmission via the medical and/or nursing staff.

Hepatitis C in Hemodialysis Patients: Current Global Magnitude, Natural History, Diagnostic Difficulties, and Preventive Measures

“…Those studies that prospectively followed HD patients for their HCV status presented an annual incidence rate of de novo HCV infection of 0.4% in France [79], 0.5% in Tunisia [65], 0.5% in the Netherlands [52], 0.83% in Italy [50], 1.38% [80] and 2.1% [81] in the USA, 0.33% [28], 2.59% [30], and 3.1% in Japan [82], 3.7% [72] and 5.5% [69] in Brazil, and 6.2% in Greece [46]. …”

“…The current risk of transfusion-associated hepatitis C is approximately 1 in 2 million [83] or even lower [84]. A history of organ transplantation [25, 43, 46, 52], older age [64, 65, 85], younger age [55], dialysis in multiple centers [24, 48, 64, 73], hepatitis B infection [43, 82], human immunodeficiency virus infection [65, 81], and diabetes mellitus [36, 39] are other factors that have been suggested to be associated with HCV positivity by some investigators.…”

Incidência de hepatite viral C em pacientes em hemodiálise no Brasil entre 2000 e 2003

“…As evidências da transmissão do HCV entre pacientes em hemodiálise são sustentadas na literatura pela associação entre prevalência e incidência do vírus em algumas unidades de hemodiálise 10,27,28 , além da menor incidência deste em pacientes em diálise peritoneal 11 e da homogeneidade dos genótipos encontrados nas unidades de diálise 16,23 . No Brasil, estudo conduzido em seis unidades de diálise na cidade de Cuiabá, entre 2002 e 2005, acompanhou 433 pacientes em hemodiálise e registrou incidência de soroconversão para anti-HCV, a qual variou de 0 até 30,5 casos por 1.000 pacientes/mês 12 .…”

Management of hepatitis C virus infection in hemodialysis patients

“…are surely the result of nosocomial patient-to-patient transmission [45,[47][48][49][50] . The infection risk usually increases with the prevalence of HCV, and the number and length of hemodialysis exposure in corresponding hemodialysis units [4,5,31,40] .…”

“…It has been adopted by many medical centers to assign HCV-infected patients to dedicated hemodialysis machines in a dedicated room in order to separate HCV positive patients from the negative patients, and this has been considered to be able to decrease the risk of HCV transmission [53] . In those hemodialysis units with high HCV prevalence but without fulltime medical staff on HCV-infection control, this strategy may help decrease the risk of HCV transmission among patients [3] ; but for hemodialysis units with strict universal precautions against HCV transmission, some specialists consider that the dedicated hemodialysis machine in a dedicated room for HCV-infected patients is somewhat unjustified and unnecessary [49,54] . Universal precautions, especially stringent adherence of all necessary biosafety measures during hemodialysis, are considered to be the keystones to minimize HCV transmission related to hemodialysis and have maximized ideal prophylactic effects [45,47,53] .…”