There is no consistency between so-called 'HIV' tests.

" A week after that, he tested negative on an antibody test and
had a very high viral load - 2,515,000 copies/ml. His physician
initiated antiretroviral therapy. "

Alex

http://www.aidsmap.com/en/news/EB0472C2-12DC-4C88-810D-9C8B90A11AAD.asp

Devan Nambiar, Friday, January 26, 2007

Three case reports from the United States highlight shortcomings in a
method of HIV testing that is being employed to detect early infection
with HIV. In the February 1st edition of Clinical Infectious Diseases,
investigators from Washington State report on instances when HIV
nucleic acid testing (NAT) and HIV antibody tests failed to detect
HIV infection in individuals with recent exposure to HIV and
symptoms consistent with HIV seroconversion illness. The cases
underlined the importance of interpreting test results in the context
of individual HIV risk assessments.

Because HIV antibody tests may be unable to detect HIV infection
for up to three months after infection with HIV, pooled HIV NAT
is increasingly being used to detect acute HIV infection. However,
like HIV antibody tests, pooled NAT testing does not have 100%
sensitivity or specificity and the results need careful interpretation,
taking into account the local epidemiology of HIV.

Investigators from Washington State in the US encountered three
unusual cases involving individuals being screened for acute HIV
infection.

The first two patients were a gay couple, patient A and B, who
had engaged in unprotected anal sex with each other and outside
of their relationship. Patient A reported symptoms of fever, rash,
headaches, night sweats, swollen lymph nodes in the neck,
fatigue, and muscle pain for four days. Upon physical examination
he had a rash on his face, torso and both arms. His HIV
diagnosis was confirmed by an HIV RNA test which
indicated the patient had a viral load of 70,000 copies/ml.

Patient B was asymptomatic on his first visit. He tested HIV-negative
on a standard ELISA antibody test and pooled HIV RNA test.
A week later, he started experiencing symptoms of fever,
headache, fatigue and muscle pain. Two days later, he was
re-tested, had a viral load of 621,000 copies/ml and a CD4
cell count of 219 cells/mm3 . A week after that, he tested
negative on an antibody test and had a very high viral load -
2,515,000 copies/ml. His physician initiated antiretroviral therapy.

The clinical history and viral sequence analysis confirmed
patient A transmitted HIV to patient B.

A frozen unpooled HIV NAT serum specimen of patient B,
taken four days after his exposure, showed no evidence of
HIV infection.

Patient C, presented nine days after unprotected receptive
anal sex with a partner of unknown HIV status. His symptoms
were sore throat, diarrhoea and nasal congestion. He tested
negative on ELISA and Western blot assays, but had a viral
load of 923 copies/ml, and a CD4 cell count of 1,264 cells/mm3.
A week later, he again tested negative on the ELISA assay,
but had a high viral load of a little over 1,000,000 copies/ml.
The following week, he, once again, tested negative on ELISA
and Western blot assays but had an enormous viral load -
26,785,000 copies/ml. His CD4 cell count had fallen
dramatically to 336 cells/mm3 .

The investigators believe that these three cases highlight the failure
of routine antibody testing and HIV NAT to correctly identify
individuals during acute HIV infection. They stress that pooled
HIV NAT tests may provide a false-negative result for individuals
at high risk of HIV infection. Healthcare providers should, the
researchers write, be aware of the various characteristics of
HIV tests, such as ELISA, HIV NAT and rapid HIV antibody
test. Additionally, the cases underline the importance of
recognising the symptoms of acute HIV infection and the
offering of appropriate care and treatment to individuals.

Reference

Stekler J et al. Screening for acute HIV infection: lessons learned.
Clin Infect Dis 44: 459-461, 2007