HTLV-1/2 is rare among Eastern-European intravenous drug users (IDUs)

Background

HTLV-1/2 and HIV likely share the same transmission routes and thus in Europe HTLV occurs mainly among IDUs, interests in clinical implications of HTLV-1/2 co-infection on HIV disease progression have risen. So far the available evidence suggests a protective role of HTLV-2 and adverse effect of HTLV-1 on HIV infection. In Europe, the overall prevalence of HTLV infection is up to 18% among IDUs and less than 1% among blood donors. However, there is no data regarding the overall prevalence of HTLV-1/2 in Eastern-European IDU population where the HIV epidemic mainly lies. We aimed to determine the prevalence of HTLV among IDUs in Estonia and compare it with the rate in healthy volunteers.

Methods

The study included 345 Caucasian IDUs and 145 healthy volunteers from Estonia. The presence of HTLV-1/2 was determined by nested PCR in 5’ long-terminal repeat region; positive controls were used in every PCR run.

Results

The analysed IDUs resembled IDUs of HIV epidemic in Estonia: the IDU population was mainly male (79%) with median age of 30 years (interquartile range [IQR] 25-34), and had prolonged duration of illegal drug usage (11 years; IQR=7-14). The rate of co-infections was high – 50% were HIV+, 88% hepatitis C positive, 67% hepatitis B positive. 64% of IDUs reported receptive needle sharing in the past and 18% at least once a month during last six months. None of the IDUs carried HTLV-1 but there was a case of HTLV-2 (prevalence 0.3 %; 95% CI 0.05-0.0162). Healthy volunteers were HTLV-1 and HTLV-2 PCR negative.

Conclusion

This is the first study investigating the prevalence of HTLV-1/2 among high risk population and healthy volunteers in Estonia. Our results suggest that HTLV is a rare co-infection among IDUs in Estonia.