Many species of mammals are infected by lentiviruses, which are characteristically responsible for long-duration illnesses with a long incubation period.
It is also linked to the breakdown of the immune surveillance system of the gastrointestinal mucosal barrier caused by the depletion of mucosal CD4 The CDC's classification system is more frequently adopted in developed countries.
Since the WHO's staging system does not require laboratory tests, it is suited to the resource-restricted conditions encountered in developing countries, where it can also be used to help guide clinical management.
If a woman is untreated, two years of breastfeeding results in an HIV/AIDS risk in her baby of about 17%. Due to the increased risk of death without breastfeeding in many areas in the developing world, the World Health Organization recommends either: (1) the mother and baby being treated with antiretroviral medication while breastfeeding being continued (2) the provision of safe formula.
Lentiviruses share many morphological and biological characteristics.
As the infection progresses, it interferes more with the immune system, increasing the risk of developing common infections such as tuberculosis, as well as other opportunistic infections, and tumors that rarely affect people who have working immune systems.
Due to their nonspecific character, these symptoms are not often recognized as signs of HIV infection.They represent approximately 1 in 300 infected persons.HIV is transmitted by three main routes: sexual contact, significant exposure to infected body fluids or tissues, and from mother to child during pregnancy, delivery, or breastfeeding (known as vertical transmission).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.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.