Hepatitis C virus (HCV) subtypes were determined in 125 Iranian patients by phylogenetic analysis within the NS5B or 5'-UTR/core regions. Subtypes 1a and 3a were predominant accounting for 47 and 36%, whereas 1b and 4 accounted for 8 and 7%. This subtype distribution differs from that of Turkey and Pakistan, where subtypes 1b and 3a dominate and also from neighbouring Arabic countries where subtype 4 is the prevalent genotype. The Iranian 1a and 3a strains formed subclusters in the dendrogram indicating that these subtypes are indigenous to Iran. In contrast, the 1b strains intermixed with strains derived worldwide. Subtype 1a was frequent in South Iran (70%), while 3a was more prevalent in North-West Iran (83%), a region with a high proportion of Turkish inhabitants. Patients infected by blood products had more frequently subtype 1a (57%), while younger drug users had more frequently subtype 3a (54%). Genotype 4 was over-represented among haemodialysis patients in Tehran. One strain, most similar to genotype 5, was highly divergent in the NS5B region and further analysis is needed to assess the systematic status of this strain. In half of the patients with unknown source of infection only the 5'-UTR could be amplified, most of which were from North-West Iran and from patients younger than those with unknown source of infection with typable strains, mean age 29 versus 43 years. In conclusion, the NS5B sequence data revealed population based subtype patterns in Iran, the further study of which may help to understand the molecular epidemiology of HCV in a low-endemic area.

Leishmania RNA virus (LRV) was first detected in members of the subgenus Leishmania (Viannia), and later, the virulence and metastasis of the New World species were attributed to this virus. The data on the presence of LRV in Old World species are confined to Leishmania major and a few Leishmania aethiopica isolates. The aim of this study was to survey the presence of LRV in various Iranian Leishmania species originating from patients and animal reservoir hosts. Genomic nucleic acids were extracted from 50 cultured isolates belonging to the species Leishmania major, Leishmania tropica, and Leishmania infantum. A partial sequence of the viral RNA-dependent RNA polymerase (RdRp) gene was amplified, sequenced and compared with appropriate sequences from the GenBank database. We detected the virus in two parasite specimens: an isolate of L. infantum derived from a visceral leishmaniasis (VL) patient who was unresponsive to meglumine antimoniate treatment, and an L. major isolate originating from a great gerbil, Rhombomys opimus. The Iranian LRV sequences showed the highest similarities to an Old World L. major LRV2 and were genetically distant from LRV1 isolates detected in New World Leishmania parasites. We could not attribute treatment failure in VL patient to the presence of LRV due to the limited number of specimens analyzed. Further studies with inclusion of more clinical samples are required to elucidate the potential role of LRVs in pathogenesis or treatment failure of Old World leishmaniasis.

Hepatitis C virus (HCV) genotypes, multiple genotypes infection and HCV seroprevalence were investigated among 98 thalassemia patients and 76 haemophiliacs in Markazi province, Iran. HCV antibody was detected in 5 (5.1%) of the first group and 33 (43.4%) of the latter. Risk factors associated with anti-HCV antibody were also determined. Anti-HCV positivity in thalassemiacs were related to the number of blood transfusion units, splenectomy and duration of thalassemia. Analysis of risk factors in haemophiliacs revealed that seropositivity was significantly associated with duration of transfusion (P =0.009) and severity of disease (P = 0.000). The prevalence of HCV antibody in thalassemia subjects dropped from 8.1% to 0% after implementation of anti-HCV screening (1996). It was found that higher prevalence of HCV antibody in haemophiliacs (43.4%) compared with thalassemia patients (5.1%) correlated with clotting factor concentrates. Of the 34 seropositive haemophilia patients, HCV RNA was detected in 23 (67.7%). HCV genotype distribution was one in 50%, three in 18.2%, two in 4.54% and mixed in 27.3% (1 + 2 in 9.1%, 1 + 3 in 4.54%, 1 + 4 in 9.2% and 2 + 3a in 4.54%) cases. Among the five anti-HCV-positive thalassemiacs, two (40%) were positive for HCV RNA and one sample was found to be subtype 3a. This study confirms that multitransfused patients in Markazi province had similar genotype distribution as those previously reported form some other regions of Iran. Considering the possibilities of HCV mixed genotype among patients with haemophilia and thalassemia, accuracy and precision should be highly concerned in the detection of genotypes and their subsequent treatment.

Injecting drug users (IDUs) are the main at-risk population for hepatitis C virus (HCV) transmission. We studied HCV infection, risk factors, and genotype distribution in relation to the year of first injection among Iranian IDUs. Of a total of 126 specimens positive for HCV antibody, 93 (74 %) had detectible HCV RNA, and the NS5B gene was sequenced for 83, with genotype 3a (n = 48, 58 %) being predominant, followed by 1a (n = 35, 42 %). Tattooing was an independent predictor for HCV infection. No significant difference was found between HCV genotypes and IDU characteristics. Although there was no change in the distribution of prevalent genotypes before and after 1997, a slight variation in the prevalence was observed (p = 0.71). The difference in the prevalence of subtypes 1a and 3a (9.1 % in the period 1984-1996 and 18.2 % in the period 1997-2009) during 25 years was 9.1 %. These findings indicate a high prevalence of HCV infection among Iranian IDUs and highlights HCV-3a as the most prevalent subtype for the past 25 years. Harm-reduction strategies appear to be the most important measures to reduce the transmission of HCV in Iran.