Human T-lymphotropic Virus Type II Infection inVietnamese Thalassemic Patients.

Area of Science:

• Virology
• Epidemiology
• Public Health

Background:

• Thalassemia major patients require frequent blood transfusions, increasing exposure risk to transfusion-transmissible infections.
• Human T-lymphotropic virus type I/II (HTLV-I/II) are retroviruses with significant global health implications.
• Screening for HTLV-I/II is crucial in transfusion-dependent populations.

Purpose of the Study:

• To investigate the prevalence of HTLV-I/II infection in thalassemia major patients in Vietnam.
• To characterize the phylogenetic subgroup of detected HTLV-II strains.
• To elucidate potential routes of HTLV-II introduction into Vietnam.

Main Methods:

• Screening of anti-HTLV-I/II antibodies using particle agglutination test in 66 thalassemia major patients.
• Confirmation of HTLV-II infection by Western blot and/or polymerase chain reaction (PCR).
• Phylogenetic analysis of long terminal repeat (LTR) sequences from HTLV-II proviruses.

Main Results:

• HTLV-II infection was confirmed in 6 out of 66 patients (9.1%).
• Phylogenetic analysis of LTR sequences from 5 patients indicated their belonging to the HTLV-IIb subgroup.
• These HTLV-IIb strains clustered with those found in intravenous drug users from North America and Europe.

Conclusions:

• Transfusion-dependent thalassemia major patients in Vietnam are at risk of HTLV-II infection.
• The findings suggest that HTLV-IIb was introduced into Vietnam through international blood supply.
• This highlights the importance of rigorous blood donor screening to prevent transfusion-transmitted retroviral infections.