Thus, it is recommended that HIV be considered in people presenting an unexplained fever who may have risk factors for the infection.

Between 50 and 70% of people also develop persistent generalized lymphadenopathy, characterized by unexplained, non-painful enlargement of more than one group of lymph nodes (other than in the groin) for over three to six months.

Because of its relatively poor capacity for transmission, HIV-2 is largely confined to West Africa.

After the virus enters the body there is a period of rapid viral replication, leading to an abundance of virus in the peripheral blood.

Many species of mammals are infected by lentiviruses, which are characteristically responsible for long-duration illnesses with a long incubation period.

Lentiviruses are transmitted as single-stranded, positive-sense, enveloped RNA viruses.

Another group consists of those who maintain a low or undetectable viral load without anti-retroviral treatment, known as "elite controllers" or "elite suppressors".

They represent approximately 1 in 300 infected persons.Preventive treatment involves the mother taking antiretrovirals during pregnancy and delivery, an elective caesarean section, avoiding breastfeeding, and administering antiretroviral drugs to the newborn.Lentiviruses share many morphological and biological characteristics.Due to their nonspecific character, these symptoms are not often recognized as signs of HIV infection.Even cases that do get seen by a family doctor or a hospital are often misdiagnosed as one of the many common infectious diseases with overlapping symptoms.Sexual assault is also believed to carry an increased risk of HIV transmission as condoms are rarely worn, physical trauma to the vagina or rectum is likely, and there may be a greater risk of concurrent sexually transmitted infections.