Lesson 6: HIV and AIDS
Organism Human immunodeficiency virus (HIV) either type 1 (HIV-1) or type 2 (HIV-
2), HIV-1 being more pathogenic.
Clinical features :HIV infection leads to a disruption of the helper T4 cell-mediated
immune mechanisms, resulting in an increased susceptibility to opportunistic infections. This breakdown of the body’s defence system and the range of symptoms produced is called acquired immunodeficiency syndrome (AIDS). Presentation is generally by the symptoms of the opportunistic infection, so can be many and varied.
Initially, there may be an acute retroviral infection with fever, sweating and myalgia, but after this subsides, there is a dormant period for months or years, after which symptoms of an opportunistic infection occur. The opportunistic infections are:
. oral, vulvovaginal candidiasis, or of the oesophagus, trachea, bronchi or lung;
. pulmonary or extrapulmonary tuberculosis
. atypical disseminated mycobacteriosis;
. severe bacterial infections, such as pneumonia or pyomyocitis;
. Pneumocystis carinii pneumonia
. non-typhoid Salmonella septicaemia;
. oral hairy leucoplakia;
. reactivated varicella
. cytomegalovirus of an organ other than liver, spleen or lymph nodes;
. herpes simplex, visceral or not resolving mucocutaneous;
. disseminated mycosis, such as histoplasmosis, coccidioidomycosis or penicilium;
. cryptococcosis, extrapulmonary;
. cryptosporidiosis with diarrhoea
. isosporiasis or microsporidiosis with diarrhoea;
. toxoplasmosis of the brain
. intractable scabies not responding to treatment
. disseminated Strongyloides
. florid Chagas’ disease with acute myocarditis or meningoencephalitis
. reactivated leishmaniasis
. Kaposi’s sarcoma
. HIV encephalopathy
. progressive multifocal leucoencephalopathy.
Any process that stresses the immune mechanism, such as repeat infections, will accelerate progression to AIDS. Tuberculosis and leprosy are affected by the disruption of the immune process. Any person with tuberculosis who contracts HIV infection will progress more rapidly, while tuberculoid leprosy cases can convert to lepromatous.