The Advisory Committee on Immunization Practices (ACIP) recommended that dengue pre-vaccination screening tests for Dengvaxia administration have at least 98% specificity and 75% sensitivity. This study evaluates the performance of commercial anti-DENV IgG tests to identify tests that could be used for pre-vaccination screening. First, for seven tests, we evaluated sensitivity and specificity in early convalescent dengue virus (DENV) infection, using 44 samples collected 7-30 days after symptom onset and confirmed by RT-PCR. Next, for the five best-performing tests and two additional tests (with and without an external test reader) that became available later, we evaluated performance to detect past dengue infection among a panel of 44 specimens collected in 2018-2019 from healthy 9- to 16-year-old children from Puerto Rico. Finally, a full-scale evaluation was done with the four best-performing tests using 400 specimens from the same population. We used virus focus reduction neutralization test and an in-house DENV IgG ELISA as reference standards. Of seven tests, five showed ≥75% sensitivity in detecting anti-DENV IgG in early convalescent specimens with low cross-reactivity to the Zika virus. For the detection of previous DENV infections, the tests with the highest performance were the Euroimmun NS1 IgG ELISA (sensitivity 84.5%, specificity 97.1%) and CTK Dengue IgG rapid test R0065C with the test reader (sensitivity 76.2% specificity 98.1%). There are IgG tests available that can be used to accurately classify individuals with previous DENV infection as eligible for dengue vaccination to support safe vaccine implementation. IMPORTANCE: The Advisory Committee on Immunization Practices (ACIP) has set forth recommendations that dengue pre-vaccination screening tests must exhibit at least 98% specificity and 75% sensitivity. Our research rigorously assesses the performance of various commercial tests against these benchmarks using well-characterized specimens from Puerto Rico. The findings from our study are particularly relevant given FDA approval and ACIP recommendation of Sanofi Pasteur's Dengvaxia vaccine, highlighting the need for accurate pre-vaccination screening tools.

Zika virus (ZIKV) has recently caused a large epidemic in the Americas associated with birth defects. Although ZIKV is primarily transmitted by Aedes spp. mosquitoes, ZIKV RNA is detectable in blood and semen of infected individuals for weeks or months, during which time sexual and other modes of transmission are possible. However, viral RNA is usually detectable for longer than infectious virus is present. We determined the frequency of isolation of infectious virus from semen and serum samples prospectively obtained from a cohort of patients in Puerto Rico. We confirmed positive isolation by tissue culture cytopathic effect, increase in virus genome copy equivalents (GCE), immunofluorescence, and quantitation of infected cells by flow cytometry. These criteria confirmed infectious virus in semen from 8 of 97 patients for up to 38 days after initial detection when virus loads are higher than 1.4x106 GCE/mL. Two serum isolates were obtained from 296 patients. These findings can help guide important prevention guidelines for persons that may potentially be infectious and transmit ZIKV sexually.