Dengue is an acute illness caused by the positive-strand RNA dengue virus (DENV). There are four genetically distinct DENVs (DENV-1-4) that cause disease in tropical and subtropical countries. Most ...patients are viremic when they present with symptoms; therefore, RT-PCR has been increasingly used in dengue diagnosis. The CDC DENV-1-4 RT-PCR Assay has been developed as an in-vitro diagnostic platform and was recently approved by the US Food and Drug Administration (FDA) for detection of dengue in patients with signs or symptoms of mild or severe dengue. The primers and probes of this test have been designed to detect currently circulating strains of DENV-1-4 from around the world at comparable sensitivity. In a retrospective study with 102 dengue cases confirmed by IgM anti-DENV seroconversion in the convalescent sample, the RT-PCR Assay detected DENV RNA in 98.04% of the paired acute samples. Using sequencing as a positive indicator, the RT-PCR Assay had a 97.92% positive agreement in 86 suspected dengue patients with a single acute serum sample. After extensive validations, the RT-PCR Assay performance was highly reproducible when evaluated across three independent testing sites, did not produce false positive results for etiologic agents of other febrile illnesses, and was not affected by pathological levels of potentially interfering biomolecules. These results indicate that the CDC DENV-1-4 RT-PCR Assay provides a reliable diagnostic platform capable for confirming dengue in suspected cases.
The emergence and spread of Zika virus (ZIKV) presented a challenge to the diagnosis of ZIKV infections in areas with transmission of dengue (DENV) and chikungunya (CHIKV) viruses. To facilitate ...detection of ZIKV infections, and differentiate these infections from DENV and CHIKV, we developed the Trioplex real-time RT-PCR assay (Trioplex assay). Here, we describe the optimization of multiplex and singleplex formats of the assay for a variety of chemistries and instruments to facilitate global standardization and implementation. We evaluated the analytical performance of all Trioplex modalities for detection of these three pathogens in serum and whole blood, and for ZIKV in urine. The limit of detection for the three viruses and in different RNA-extraction modalities is near 10
genome copy equivalents per milliliter (GCE/mL). Simultaneous testing of more than one specimen type from each patient provides a 6.4% additional diagnostic sensitivity. Overall, the high sensitivity of the Trioplex assay demonstrates the utility of this assay ascertaining Zika cases.
Impacts of COVID-19 mitigation measures on seasonal respiratory viruses is unknown in sub-tropical climates.
We compared weekly testing and test-positivity of respiratory infections in the 2019-2020 ...respiratory season to the 2012-2018 seasons in southern Puerto Rico using Wilcoxon signed rank tests.
Compared to the average for the 2012-2018 seasons, test-positivity was significantly lower for Influenza A (p<0.001) & B (p<0.001), respiratory syncytial virus (RSV) (p<0.01), respiratory adenovirus (AdV) (p<0.05), and other respiratory viruses (p<0.001) following March 2020 COVID-19 stay at home orders.
Mitigation measures and behavioral social distancing choices may have reduced respiratory viral spread in southern Puerto Rico.
We report a dengue outbreak in Key Largo, Florida, USA, from February through August 2020, during the COVID-19 pandemic. Successful community engagement resulted in 61% of case-patients ...self-reporting. We also describe COVID-19 pandemic effects on the dengue outbreak investigation and the need to increase clinician awareness of dengue testing recommendations.
Dengue was first reported in Puerto Rico in 1899 and sporadically thereafter. Following outbreaks in 1963 and 1969, the Centers for Disease Control and Prevention has worked closely with the Puerto ...Rico Department of Health to monitor and reduce the public health burden of dengue. During that time, evolving epidemiologic scenarios have provided opportunities to establish, improve, and expand disease surveillance and interventional research projects. These initiatives have enriched the tools available to the global public health community to understand and combat dengue, including diagnostic tests, methods for disease and vector surveillance, and vector control techniques. Our review serves as a guide to organizations seeking to establish dengue surveillance and research programs by highlighting accomplishments, challenges, and lessons learned during more than a century of dengue surveillance and research conducted in Puerto Rico.
During May 2022-April 2023, dengue virus serotype 3 was identified among 601 travel-associated and 61 locally acquired dengue cases in Florida, USA. All 203 sequenced genomes belonged to the same ...genotype III lineage and revealed potential transmission chains in which most locally acquired cases occurred shortly after introduction, with little sustained transmission.
BACKGROUND: In 2007, a total of 10,508 suspected dengue cases were reported in Puerto Rico. Blood donations were tested for dengue virus (DENV) RNA and recipients of RNA‐positive donations traced to ...assess transfusion transmission.
STUDY DESIGN AND METHODS: Blood donation samples from 2007 were maintained in a repository and tested individually for DENV RNA by transcription‐mediated amplification (TMA); a subset was further tested by an enhanced TMA (eTMA) assay. TMA‐reactive samples were considered confirmed if TMA (including eTMA) was repeat reactive (RR). All TMA‐RR samples were tested by quantitative, DENV type–specific reverse transcriptase–polymerase chain reaction (RT‐PCR) and for anti‐DENV immunoglobulin (Ig)M by enzyme‐linked immunosorbent assay. Samples positive by RT‐PCR were further tested for infectivity in mosquito cell culture. Patients receiving components from TMA‐RR donations were followed.
RESULTS: Of 15,350 donation samples tested, 29 were TMA‐RR for a prevalence of 1 per 529 (0.19%). DENV Types 1, 2, and 3 with viral titers of 105 to 109 copies/mL were detected by RT‐PCR in 12 samples of which all were infectious in mosquito culture. Six TMA‐RR samples were IgM positive. Three of the 29 recipients receiving TMA‐RR donations were tested. One recipient in Puerto Rico transfused with red blood cells containing 108 copies/mL DENV‐2 became febrile 3 days posttransfusion and developed dengue hemorrhagic fever. The recipient was DENV‐2 RNA positive by RT‐PCR; both the donor and the recipient viruses had identical envelope sequences.
CONCLUSIONS: High rates of viremia were detected in blood donors in Puerto Rico coupled with the first documented transfusion transmission of severe dengue disease, suggesting that further research on interventions is needed.
We reconstructed the SARS-CoV-2 epidemic caused by Omicron variant in Puerto Rico by sampling genomes collected during October 2021-May 2022. Our study revealed that Omicron BA.1 emerged and replaced ...Delta as the predominant variant in December 2021. Increased transmission rates and a dynamic landscape of Omicron sublineage infections followed.
Background After Zika virus (ZIKV) emerged in the Americas, laboratory-based surveillance for arboviral diseases in Puerto Rico was adapted to include ZIKV disease. Methods and findings Suspected ...cases of arboviral disease reported to Puerto Rico Department of Health were tested for evidence of infection with Zika, dengue, and chikungunya viruses by RT-PCR and IgM ELISA. To describe spatiotemporal trends among confirmed ZIKV disease cases, we analyzed the relationship between municipality-level socio-demographic, climatic, and spatial factors, and both time to detection of the first ZIKV disease case and the midpoint of the outbreak. During November 2015-December 2016, a total of 71,618 suspected arboviral disease cases were reported, of which 39,717 (55.5%; 1.1 cases per 100 residents) tested positive for ZIKV infection. The epidemic peaked in August 2016, when 71.5% of arboviral disease cases reported weekly tested positive for ZIKV infection. Incidence of ZIKV disease was highest among 20-29-year-olds (1.6 cases per 100 residents), and most (62.3%) cases were female. The most frequently reported symptoms were rash (83.0%), headache (64.6%), and myalgia (63.3%). Few patients were hospitalized (1.2%), and 13 (0.1%) died. Early detection of ZIKV disease cases was associated with increased population size (log hazard ratio HR: -0.22 95% confidence interval -0.29, -0.14), eastern longitude (log HR: -1.04 -1.17, -0.91), and proximity to a city (spline estimated degrees of freedom edf = 2.0). Earlier midpoints of the outbreak were associated with northern latitude (log HR: -0.30 -0.32, -0.29), eastern longitude (spline edf = 6.5), and higher mean monthly temperature (log HR: -0.04 -0.05, -0.03). Higher incidence of ZIKV disease was associated with lower mean precipitation, but not socioeconomic factors. Conclusions During the ZIKV epidemic in Puerto Rico, 1% of residents were reported to public health authorities and had laboratory evidence of ZIKV disease. Transmission was first detected in urban areas of eastern Puerto Rico, where transmission also peaked earlier. These trends suggest that ZIKV was first introduced to Puerto Rico in the east before disseminating throughout the island.
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