There are HIV positive orphans waiting in Ethiopia. See the Adoption Stories page to see many wonderful children who are now home with their families in America, or in the process of being adopted. The program is now a 2 trip process in the $30K range which often takes longer than one year.
It is rare for a child under 3 to be waiting for adoption. There is a waiting list of adoptive parents hoping to adopt HIV+ babies and toddlers from Ethiopia. This is a great program for PAPs interested in adopting preschool and school age children. You will find information on this site about children waiting in Ethiopia by visiting the Waiting Children page.
The most experienced agency placing HIV+ children in families is Adoption Advocates International (AAI) and there are several other agencies as well – click and scroll down to Adoption Agencies.
Yahoo groups include Single Adopt Ethiopia and Adopt Ethiopia.
Requirements according to Adoption.State.Gov, and AAI.
Age Requirements: If single, the prospective adoptive parent must be at least 25 years of age. If married, there is no minimum age. There also is no maximum age limit for adoptive parents (according to the US Dept of State). The max age of 43 can be flexible for those adopting HIV+ children (according to AAI).
Marriage Requirements: Single persons may adopt HIV+ children.
Other Requirements: No restrictions on family size.