he incubation period from exposure to clinical disease averages 3 to 6 weeks. Acute HIV infection is similar to many other viral syndromes and usually lasts less than 10 days. Common symptoms, if any, include fever, fatigue, rash, headache, lymphadenopathy, pharyngitis, myalgias, nausea, and diarrhea. After symptoms abate, the level of viremia usually decreases to a set point, and patients with the highest viral burden at this time progress more rapidly to AIDS and death (Fauci, 2007). According to the CDC, AIDS is defined by a CD4 T-cell count <200 cells/lLL, by CD4 T-cells comprising < 14 percent of alirlymphocytes, or one of several AIDS-defining illnesses (Schneider, 2008; Selik, 2014). Route of infection, the pathogenicity of the infecting viral strain, the initial viral inoculum, and the immunological status of the host all afect the rapidity of progression.
he CDC (2006b) and the American College of Obstetricians and Gynecologists (2016e) recommend prenatal HIV screening using an opt-out approach. his means that a woman is notiied that HIV testing is included in a comprehensive set of antenatal tests, but that testing may be declined. Women are given information regarding HIV but are not required to sign a specific consent. hrough the use of such opt-out strategies, HIV testing rates have increased. Specific state laws concerning screening vary and can be found at: ww.cdc.gov/hiv/policies/ law / states/ testing.h tml.
Repeat testing during the third trimester, preferably before 36 weeks' gestation, is considered for all pregnant women. Retesting is recommended for those at risk for acquiring HIV or for women in high-risk areas, namely, those with rates of HIV infection of 1 per 1000 pregnant women screened (Workowski, 2015). At-risk factors include injection drug use, prostitution, a suspected or known HIV-infected sexual partner, multiple sexual partners, or a diagnosis of another STD (American College of Obstetricians and Gynecologists, 20 16e).
he initial laboratory screening test for HIV is an antigen/ antibody combination immunoassay that detects antibodies against HIV-1 and HIV-2 and detects HIV-1 p24 antigen (Centers for Disease Control and Prevention, 2014). Antibody can be detected in most patients within 1 month of infection, and thus, antibody serotesting may not exclude early infection. Instead, for acute primary HIV infection, identiication of viral p24 core antigen or viral RNA is possible. No further testing is required for specimens that are negative on the initial immunoassay unless a known exposure to HIV has occurred.
As shown in Figure 65-7, specimens with a "reactive" (that is, a positive) antigen/antibody combination immunoassay result should be tested with an antibody immunoassay that diferentiates HIV-1 antibodies from HIV-2 antibodies. The HIV-1/ HIV-2 antibody diferentiation immunoassay is resulted as positive or negative for HN-1 antibodies, for HN-2 antibodies, or for HIV antibodies, undiferentiated. If these two serial immunoassays are discordant, an HIV -1 NAA T -qualitative or quantitative HIV RNA test-is performed (Centers for Disease Control and Prevention, 2014).