Human T-Lymphotropic Virus Type 1 Prevalence in Northeastern Iran, Sabzevar: An Epidemiologic-Based Study and Phylogenetic Analysis

Abstract

Human T-lymphotropic virus type 1 (HTLV-I) is an important global health problem in the world mainly in the endemic areas of HTLV-I infection. It was previously reported that Mashhad, in northeastern Iran, is a new endemic region of HTLV-I. The aim of this study was to examine the prevalence and phylogenetic analysis of HTLV-I in Sabzevar, located in the southeast of Mashhad. In this cross-sectional study 1445 individuals were selected by multistage cluster sampling. Serum samples were screened for anti-HTLV-I antibody using enzyme-linked immunosorbent assay (ELISA); all of the ELISA-positive samples were confirmed by polymerase chain reaction (PCR). Long terminal repeat (LTR) sequencing was carried out to determine the type of HTLV-I in Sabzevar. In the primary screening by ELISA, 26/1445 (1.8%) of those sampled were reactive for HTLV-I antibody. Twenty-four out of 26 samples were confirmed HTLV-I infection by PCR (24/1445). The overall prevalence of HTLV-I infection in Sabzevar is 1.66%. The prevalence of the virus infection in men and women was 2.42% (11/455) and 1.31% (13/989), respectively. Seroprevalence was associated with age, increasing significantly among those older than 30 years (p=0.015), and a history of surgery (p=0.002), imprisonment (p=0.018), and hospitalization (p=0.005). Three out of 24 positive HTLV-I samples were selected for sequencing and phylogenetic analysis of LTR. The results showed that HTLV-I in Sabzevar belonged to the cosmopolitan subtype. The present study showed Sabzevar is a new endemic area for HTLV-I infection. Our study emphasizes that systemic HTLV-I screening of blood donors in Sabzevar and other cities in Khorasan province is important and should be taken into account.

Epidemiological Aspects and World Distribution of HTLV-1 Infection

“…According to the type of studies and of tested populations, HTLV-1 prevalence is estimated to range from 0.77 to 3% in adults (Safai et al, 1996; Abbaszadegan et al, 2003; Rafatpanah et al, 2011). A more recent study indicates an HTLV-1 prevalence of 1.66% in adults from the city of Sabzevar located in the Southeast of Mashad and confirmed that HTLV-1 is highly endemic in this region (Azarpazhooh et al, 2012). Furthermore, relatively large series of ATL as well as TSP/HAM cases originating from the Mashad region are reported in Iran (Sidi et al, 1990; Kchour et al, 2009) but also in Iranian immigrants living in European countries, the United States, or Israël (Sidi et al, 1990; Gabarre et al, 1993; Miller et al, 1998).…”

Adult T-Cell Leukemia: A Review of Epidemiological Evidence

“…Northeast province of Iran (Mashhad, Sabzevar, and Neyshabour) and Urmia are known to be an endemic area for HTLV-1, where the prevalence of HTLV-1 infection was reported to be 0.34–0.77% in blood donors (Abbaszadegan et al, 2003; Khameneh et al, 2008), 1.7–12% in cross-sectional studies (Meytes et al, 1990; Safai et al, 1996; Hedayati-Moghaddam et al, 2011; Azarpazhooh et al, 2012), and 2–3% in community-based population (Rafatpanah et al, 2011). …”

Triple Therapy with Prednisolone, Pegylated Interferon and Sodium Valproate Improves Clinical Outcome and Reduces Human T-Cell Leukemia Virus Type 1 (HTLV-1) Proviral Load, Tax and HBZ mRNA Expression in Patients with HTLV-1-Associated Myelopathy/Tropical Spastic Paraparesis

“…In Iran, HTLV-1 is endemic at least in 2 provinces, including Khorasan Razavi and Northern Khorasan. However, HTLV-1-associated disorders have been reported from other provinces such as Golestan, Alborz, and East Azarbayejan [3,[6][7][8]. About 2-5 % of infected people develop adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) [9,10].…”