1.   Cocaine users who share snorting straws.

2.   Holland speculated people may be spreading the virus by sharing straws to snort cocaine.

3.   Snorting cocaine can rupture tiny blood vessels in the nostrils and allow tainted blood to be passed when coke straws are shared.

4.   Similarly, many doctors suspect that people can transmit the virus by sharing straws used to inhale cocaine, but researchers are not sure whether that has occurred.