Emergency Medicine

Infectious Disease and Foreign Travel Emergencies 153

Human Immunodeficiency Virus Infection

(ii) The exposed person requires follow-up for 6 months, should

practise safe sex, should not donate blood and should avoid

pregnancy.

(iii) Assure confidentiality and sensitivity for all concerned.

HUMAN IMMUNODEFICIENCY VIRUS INFECTION

DIAGNOSIS

1 HIV is a cytopathic RNA retrovirus. It is transmitted by sexual contact, by
syringe sharing in i.v. drug abusers, transplacentally and rarely now by blood
transfusion.
(i) Remember acute HIV infection may present after international
travel.

2 HIV risk groups include:
(i) Men who have sex with men.
(ii) Intravenous drug users.
(iii) Partners of HIV/AIDS patients.
(iv) Children of HIV/AIDS affected mothers.
(v) Blood product recipients in the early 1980s.

3 The revised Classification System for HIV Infection and Expanded Surveil-
lance Case Definition for AIDS Among Adolescents and Adults was published
by the US Centers for Disease Control and Infection in 1992 and emphasized
the clinical importance of the absolute CD4+ T lymphocyte count or its
percentage of the total lymphocyte count.
(i) Three categories of CD4+ count were recognized for medical
management purposes:
(a) CD4 count ≥500/mm^3
(b) CD4 count 200–499/mm^3
(c) CD4 count <200/mm^3
(ii) A CD4+ count <200/mm^3 or 14% may be used to define acquired
immune deficiency syndrome (AIDS).

4 Presentation varies according to the disease group.
(i) Group 1 – Acute infection:
(a) 50–70% of patients infected with HIV develop an acute
illness with lethargy, fever, pharyngitis, myalgia, rash and
lymphadenopathy about 2 weeks after exposure. Acute
meningitis or encephalitis are occasionally seen
(b) although the patient is infectious, serology for HIV antibodies
at this early stage will be negative.