Low Prevalence of Human T-Cell Lymphotropic Virus Type 1 (HTLV-1) in a Hospital Triage Population in Tehran During...

Human T-cell lymphotropic virus type 1 (HTLV-1) is a retrovirus that is associated to adult T-cell leukemia/lymphoma (ATLL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) as two major diseases of the virus. Due to limited data on its prevalence in general populations in Tehran and as this virus is endemic in Iran, this study aimed to assess HTLV-1 prevalence among patients attending the triage unit of Imam Khomeini Hospital during 2024-2025.

In this cross-sectional study conducted between 2024 and 2025, patients presenting to the triage unit were randomly selected. Exclusion criteria included active infection with HBV, HCV, or HIV, and receiving antiretroviral therapy (ART). After obtaining informed consent, 5 mL of whole blood was collected from each participant. The DNJIA kit (ROJE Technologies, Iran) was used to extract DNA. We used primers that targeted the HBZ and Tax regions of the viral genome to do PCR amplification to find HTLV-1.

Out of 197 individuals enrolled in this cross-sectional study, 1 participant (0.51%) was positive for HTLV-1. The HTLV-1-positive case was a 40-year-old single male with a history of both blood transfusion and prior surgery, but no history of organ transplantation, substance addiction, or travel. Most of the people who took part were men (54.3%) and married (58.9%), and their average age was 39.7 ± 12.1 years. Fisher's exact test showed a statistically significant association between HTLV-1 positivity and a history of blood transfusion (p = 0.015) and a significant link with a history of surgery (p = 0.020). History of blood transfusion, organ transplantation, surgery, and addiction were reported by 3 (1.5%), 1 (0.5%), 4 (2.0%), and 1 (0.5%) participants, respectively. Foreign travel was reported by 77 (39.1%) participants, whereas 100 (50.8%) had a history of domestic travel. The most frequently visited foreign destinations were Turkey (n = 25) and the United Arab Emirates (n = 20). Among domestic destinations, the most commonly visited cities were Isfahan (n = 22) and Mazandaran (n = 19).

The only positive case (0.51%) had known risk factors associated to HTLV-1 infection including prior surgery and blood transfusion. Given the higher reported prevalence of HTLV-1 in endemic regions including Iran, and the increased risk among certain populations-such as individuals with a history of intravenous drug use, multiple sexual partners, or co-infection with other viruses-future studies should focus on these high-risk groups and the virus prevalence over time. Targeted screening in such populations may provide a more accurate picture of the virus's distribution during different time frames for more effective control and prevention measures.