EDGEWOOD, Ky. (AP) — Health officials say an investigation into a cluster of HIV infections in northern Kentucky has turned up more cases and they are encouraging intravenous drug users to get tested.

The Northern Kentucky Health Department said in a statement on Thursday that 43 cases of HIV have been reported as of Feb. 21, and 20 of those reported injection drug use as a risk factor.

The health department said in a statement last month that it began an investigation after the number of intravenous drug users who tested positive for HIV last year more than tripled from the previous year, jumping from five to 18. The total number of HIV cases increased to 37 from 25.

Health officials say they have expanded opportunities for testing. Seven clinics around northern Kentucky now offer testing to walk-ins.