11.   No scientist would infect a person with HIV deliberately, they point out.

12.   Scientists have made strides unlocking the mysteries of how the virus operates after it infects a person.

13.   Shortly after a person becomes infected, the virus count in the blood rises, prompting an aggressive immune response.

14.   Some viruses may not produce disease until years after a person is infected, and some that may cause minimal symptoms in animals might be lethal to humans.

15.   Studies, including the newest one, have shown that a person may be infected with both viruses.

16.   The laboratory work, however, seems to run counter to what occurs when a person is simultaneously infected by both strains of the virus.

17.   The laboratory work, however, seems to run counter to what occurs when a person is simultaneously infected by both viral strains.

18.   The virus starts in the duck, leaps to the pig and, by airborne delivery, infects a person.

19.   The viruses that cause mononucleosis and chickenpox remain in the body forever after a person gets infected, but the immune system usually keeps them in check.

20.   Unapproved self-administered test kits have a high risk of producing inaccurate results, often showing the absence of HIV even though the person is in fact infected.