Serologic Tests for the Diagnosis of HIV-1 or HIV-2 Infection

Serologic Tests for the Diagnosis of HIV-1 or HIV-2 Infection - Flowchart

«Flowchart»

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A SEROLOGIC TESTS IN THE DIAGNOSIS OF HIV-1 OR HIV-2 INFECTION

A SEROLOGIC TESTS IN THE DIAGNOSIS OF HIV-1 OR HIV-2 INFECTION A A

B HIV-1/2 ANTIGEN/ANTIBODY COMBINATION IMMUNOASSAY

B HIV-1/2 ANTIGEN/ANTIBODY COMBINATION IMMUNOASSAY B B

Retest in 3–6 months if clinically indicated

Diagnosis of HIV-1 infection

Diagnosis of HIV-2 infection

End

HIV-2 EIA

Repeat in 4-6 weeks^*

^* ^*

A. Algorithm including the use of a Western blot.

A. A.

^* Stable indeterminate Western blot 4-6 weeks later makes HIV infection unlikely. However, it should be repeated twice at 3-month intervals to rule out HIV infection. Alternatively, one may test for HIV-1 p24 antigen or HIV RNA.

B. CDC algorithm not including the use of a Western blot.

B. B.

indicates reactive test result

indicates nonreactive test result

Negative for HIV-1 and HIV-2 antibodies and p24Ag

HIV-1/HIV-2 antibody differentiation immunoassay

HIV-1
HIV-2

HIV-1 antibodies detected

HIV-1
HIV-2

HIV-1 antibodies detected

HIV-1

HIV-1
HIV-2

HIV-2 antibodies detected

HIV-1
HIV-2

HIV-2 antibodies detected

HIV-1

HIV-1
HIV-2

HIV antibodies detected

HIV-1
HIV-2

HIV antibodies detected

HIV-1

HIV-1 or indeterminate HIV-2

HIV-1 NAT

HIV-1 NAT
Acute HIV-1 infection

HIV-1 NAT

HIV-1 NAT
Negative for HIV-1

HIV-1 NAT

Screening HIV-1/HIV-2 EIA

Repeat HIV-1/HIV-2 EIA

HIV-1 Western blot

Indeterminate

HIV-2 EIA

HIV-2

Repeat in 4-6 weeks^*

^* ^* Repeat in 4-6 weeks[*]

HIV-2 Western blot

Indeterminate

EIA, enzyme immunoassay.