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Genotype Distribution and Homological Analysis of Hepatitis C Virus in Maintenance Hemodialysis Patients by molecular epidemiology
2013, 12 (08):
425-431.
doi: 10.3969/j.issn.1671-4091.2013.08.00
Objective To determine the genotype distribution and homology of hepatitis C virus (HCV) by the way of phylogenetic tree in maintenance hemodialysis (MHD) patients of Shenzhen second people’s hospital. To provide scientific evidence for preventing HCV infection in hemodialysis unit with molecular epidemiology. Methods The anti-HCV positive dialysis patients were screened for HCV RNA in sera.When the viral load levels were 1×103 IU/mL and more, fragment of HCV 5’UTR and NS5B was severally amplified by nest RT—PCR. The cloned sequences were analyzed using Sequence Scanner v1.0. The genotype of each sample was determined by comparing its nucleotide sequence with those of HCV prototype representing different genotype obtained from sequence database. The DNA alignments were performed with Muscle program.The phylogenetic tree was constructed with MEGA 5.1 software using neighbor-joining method and Kimura-two parameter and its reliability was assessed by bootstrap 1000. Homologies of sequences were analyzed by Blat software. Results Of the 183 MHD patients enrolled in this study, anti-HCV positive results presented in 13 patients, and HCV infection rate was 7.1%. There were 9 patients with HCV RAN ≥1×103 IU/mL, including 7 with genotype 1b and 2 with genotype 6a. In genotype 1b samples, genetic distance between PC1 and PC2, between PC2 and PBC17, between PC29 and PBC31, between PC32 and PC34 , was 0.000, 0.008 , 0.035 and 0.102 , respectively. In genotype 6a samples, genetic distance between PC11 and PC20 was 0.068. Homology between PC1 and PC2, between PC2 and PBC 17, between PC29 and PBC31, between PC32 and PC34 ,between PC11 and PC20 was 100%, 99.23%, 96.63%, 90.64% and 93.63%, respectively. The nine patients infected HCV for（67.4±26.3） months and dialysis lasted for （81.5±38.1） months. Four patients (sample PC2, PC11, PC29 and PBC31) were imported, another five patients (sample PC1, PBC17, PC20, PC32 and PC34) were found HCV infection during 8 to 77 months of hemodialysis. In the five new infected patients, two had been blood transfusion and changed hemodialysis unit history. Another three patients had denied risk factors of HCV infection, such as blood transfusion, chang hemodialysis unit and renal transplant, except hemodialysis. According to the results of clinical epidemiological investigation, among the three homologous patients (PC1, PC2 and PBC17), two new infected patients (PC1 and PBC17) had dialyzed in the same or neighboring round and been operated by the same nurse with the imported patients PC2. Conclusions Anti-HCV positive rate is 7.1% in this hemodialysis unit of Shenzhen second people’s hospital. Genotype 1b is the most common in MHD patients with HCV in the second people’s hospital of Shenzhen, followed by Genotype 6a. Three patients (sample PC1, PC2 and PBC17) have the same HCV epidemic strain（homology over 99%）and PC2 is the imported infection source that is testified to epidemiological data. Among the three homologous patients, the underlying transmission route is attributed not to partition space, segregate positive and negative patients with given management , replace gloves between different patients, stress importance hand hygiene of nurse or abide by standard operating procedure. In our hemodialysis unit, there are no new. In recently three years, there are no fresh HCV infections in our hemodialysis unit , which prove that segregate positive (including HCV and HBV )and negative patients with given management and space, use special hemodialysis machine and strict implement blood purification standard operating procedure(SOP) can effectively control cross infection in hospital. This study provides important scientific evidence for preventing nosocomial infection of HCV in hemodialysis unit.
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