Primary
HIV Infection
Acute
retroviral syndrome occurs at the time the infection is acquired in 60% to 80%
of HIV infected persons. The illness resembles infectious mononucleosis from infection
with Epstein-Barr virus (EBV). Risk factors for transmission of HIV include
history of a sexually transmitted disease, especially genital ulcers; unprotected
anal or genital intercourse; and multiple sexual partners.
I.
Clinical signs and symptoms
A.
The
period between acquisition of HIV and onset of symptoms is about 14
days, and the characteristic signs and symptoms range from a mild fever
and sore throat to a severe mononucleosis-type syndrome with high spiking
fevers and a measles-like rash.
B.
In
those patients with symptomatic seroconversion, the five most common
signs and symptoms are fever, fatigue, pharyngitis, weight loss, and
myalgias. Characteristic symptoms of acute retroviral syndrome occur in
50% to 90% of patients.
II.
Laboratory features
A.
Primary
HIV infection is diagnosed by a positive plasma HIV RNA obtained on the same
day as a negative Western blot assay. When suspicion for acute infection is
high, such as in a patient with a report of recent risk behavior in association
with symptoms and signs of acute HIV
nfection, a test for HIV RNA should be
performed.
B.
Clinical
evaluation of possible primary HIV infection often includes a heterophil
antibody (Monospot) test to rule out EBV mononucleosis, cytomegalovirus antigen
or antibody, acute and convalescent serologic tests for rubella and
toxoplasmosis, rapid plasma reagin test, Western blot assay for herpes simplex
virus, and serologic tests for hepatitis (including hepatitis C virus RNA
polymerase chain reaction).
III.
Initial management
A.
When
the diagnosis of primary HIV has been established, the patient should be
examined for syphilis, herpes simplex, venereal warts, gonorrhea, and
hepatitis.
B.
If
the patient was identified as HIV RNA-positive and HIV EIA-negative, a
follow-up HIV antibody test should be obtained 2 to 3 weeks after resolution of
symptoms to establish that seroconversion has taken place.
C.
A
baseline CD4+ count should be obtained at the time of diagnosis. In the earliest
stages of infection, the CD4+ count can sometimes be below 200 cells/:L. After
the first several weeks of infection, a rebound in the CD4+ count to near
normal levels may occur.
IV.
Treatment of Primary HIV Infection
A.
The
therapeutic regimen for acute HIV infection should include a combination
of two nucleoside reverse transcriptase inhibitors and one potent
protease inhibitor. Potential combinations of agents are the same as
those used in established infection and include the following regimens:
B. Patient
Follow-Up
1.
Testing for plasma HIV RNA levels
and CD4+ T cell count and toxicity monitoring should be performed on initiation
of therapy, after 4 weeks, and every 3-4 months thereafter.
2.
Antiretroviral agents should be
continued indefinitely because viremia has been documented to reappear or
increase after discontinuation of therapy.
C. Postexposure
prophylaxis
1.
Combination chemotherapy results in
fewer transmissions, and use of combination chemotherapy, including a protease
inhibitor, is suggested following a significant intravenous exposure.
2.
Postexposure prophylaxis should also
be initiated following sexual exposure.
3.
Postexposure prophylaxis treatment
regimens
a.
Zidovudine (ZDV): 300 mg PO bid and
b.
Lamivudine (3TC, Epivir): 150 mg
bid
c.
Protease Inhibitor: Indinavir (Crixivan)
800 mg q8h or Nelfinavir 750 mg tid (if needed to ensure 2 new antiviral drugs
or for very risky exposure).
