**3.1. Clinical features of HIV infection**

In primary infection of HIV-1, patients may be asymptomatic though sometimes the disease is self-limiting. Within the incubation period of about 6 weeks, patients can present with a mononucleosis-like syndrome, which is characterized by fever, cough, painful swallowing, myalgias, arthralgias, diarrhea as well as maculopapular rash and lymphadenopathy [5]. In most circumstances, the symptoms are usually mild as contrasted to severe cases, where pneumonitis, oropharyngeal and esophageal ulcers may occur. Encephalitis, meningitis, neuropathy, radiculopathy and myelopathy are not common sickneses in HIV infection. Although the true incidence of this syndrome is not precisely known, it may also depend on the degree of exposure to the virus, it may be as high as over 50% in persons who acquire HIV-1 infection [5].

World Health Organization [6] categorized an adult or adolescent (aged > 12 years) as having AIDS in presence of at least two of the major signs in combination with one of the minor signs (Table 2).


\* Persistent cough for more than 1 month should be considered as a minor sign in patients with tuberculosis

**Table 2.** Major and minor signs of HIV infection [6].
