Final answer:
Heather and her uncle need not worry about HIV transmission from a kiss on the cheek, as HIV cannot be transmitted through casual contact and is not present in saliva unless mixed with blood.
Step-by-step explanation:
HIV Transmission and Casual Contact
Heather and her uncle should not be concerned about HIV transmission through a kiss on the cheek. HIV is a blood-borne, sexually transmitted disease that requires direct contact with infected body fluids such as blood, semen, or breast milk to spread. Casual contacts like kissing on the cheek, touching, or sharing utensils do not pose a risk for transmitting the virus, as HIV is not spread through saliva in the absence of blood. Additionally, other body fluids like urine and sweat do not contain the virus, and it cannot be contracted through contact in swimming pools, coughing, or sneezing.
It is important to dispel myths about HIV and educate on the reality of its transmission to reduce stigma and promote better understanding. Since Heather's uncle only kissed her on the cheek—an act involving contact that is not a transmission route for the virus—they need not worry about HIV transmission in this scenario.