7
Coinfection and Comorbidity Laboratory Tests
Tuberculosis Screening
Î Upon initiation of care, HIV-infected patients without a history of
tuberculosis or a prior positive tuberculosis screening test result
should be tested for Mycobacterium tuberculosis infection by either a
tuberculin skin test (TST) or by an interferon-γ release assay (IGRA)
(SR-H). Those with positive test results should be treated for latent
M tuberculosis infection after acute tuberculosis has been excluded
(SR-H).
Î Repeat testing is recommended in patients with advanced HIV disease
who initially had negative TST or IGRA results but subsequently
experienced an increase in the CD4 cell count to >200/μL on ART and
who may thus have developed sufficient immunocompetence to mount
a positive reaction (SR-H).
Î HIV-infected patients who are close contacts of persons with
infectious tuberculosis should be treated for latent M tuberculosis
infection regardless of their TST or IGRA results, age, or prior courses
of tuberculosis treatment. Active tuberculosis should be excluded first
(SR-H).
Serologic Testing for Toxoplasma gondii
Î All HIV-infected patients should be tested for prior exposure to T
gondii by measuring anti-Toxoplasma immunoglobulin G (IgG) upon
initiation of care (SR-M).
Î Toxoplasma-seronegative adults, representing 70%-90% of the US
population, should be counseled on how to avoid new infection (WR-M).
Viral Hepatitis Screening and Vaccination Recommendations
Î HIV-infected patients should be screened for evidence of hepatitis B
virus (HBV) infection upon initiation of care by detection of hepatitis
B surface antigen (HBsAg), hepatitis B surface antibody (HBsAb), and
antibody to hepatitis B total core antigen (anti-HBc; also abbreviated
as HBcAb) (SR-H), and those who are susceptible to infection should be
vaccinated against HBV (SR-H). HBsAb testing should be repeated 1-2
months after the third vaccine is given, or at the next scheduled visit
after the third vaccine is given, to assess for immunogenicity. A second
series of vaccination is recommended for those whose HBsAb levels
are negative or <10 IU/mL after the primary vaccine series (SR-H).
Î Vaccination should be recommended for nonimmune sexual partners
of patients who are positive for HBsAg (SR-H).
