Project description:Sequencing of dengue virus type 1 (DENV-1) strains isolated in Key West/Monroe County, Florida, indicate endemic transmission for >2 years of a distinct and predominant sublineage of the American-African genotype. DENV-1 strains isolated elsewhere in Florida grouped within a separate Central American lineage. Findings indicate endemic transmission of DENV into the continental United States.
Project description:Dengue virus (DENV) is transmitted to humans through the bite of mosquitoes. In November 2010, a dengue outbreak was reported in Monroe County in southern Florida (FL), including greater than 20 confirmed human cases. The virus collected from the human cases was verified as DENV serotype 1 (DENV-1) and one isolate was provided for sequence analysis. RNA was extracted from the DENV-1 isolate and was used in reverse transcription polymerase chain reaction (RT-PCR) to amplify PCR fragments to sequence. Nucleic acid primers were designed to generate overlapping PCR fragments that covered the entire genome. The DENV-1 isolate found in Key West (KW), FL was sequenced for whole genome characterization. Sequence assembly, Genbank searches, and recombination analyses were performed to verify the identity of the genome sequences and to determine percent similarity to known DENV-1 sequences. We show that the KW DENV-1 strain is 99% identical to Nicaraguan and Mexican DENV-1 strains. Phylogenetic and recombination analyses suggest that the DENV-1 isolated in KW originated from Nicaragua (NI) and the KW strain may circulate in KW. Also, recombination analysis results detected recombination events in the KW strain compared to DENV-1 strains from Puerto Rico. We evaluate the relative growth of KW strain of DENV-1 compared to other dengue viruses to determine whether the underlying genetics of the strain is associated with a replicative advantage, an important consideration since local transmission of DENV may result because domestic tourism can spread DENVs.
Project description:We describe sequences of six strains of dengue virus (DENV): three DENV-1 isolates and two DENV-4 isolates from Puerto Rico, and a DENV-1 strain from Key West, Florida, obtained from blood donors during 2010 epidemics. Phylogenetic analysis revealed that the Puerto Rico DENV-1 strains constitute a new lineage within genotype V different from those that circulated in Puerto Rico during the past two decades. The newer Puerto Rico DENV-1 strains associated with strains from the Caribbean and South America. The DENV-1 strain from Key West, Florida clustered with a strain isolated from mosquito pools collected in that area and with a number of strains from Nicaragua and Mexico circulating during 2006-2009. The Puerto Rico DENV-4 isolates of genotype II associated with strains that have circulated on the island throughout the 1980s and 1990s and with strains from the Caribbean region and Central America. Introduction and circulation of novel DENV lineages in dengue-endemic regions have the potential to increase the severity of dengue cases.
Project description:The Florida Keys Mosquito Control District has deployed dry ice-baited light traps to monitor mosquito (Diptera: Culicidae) populations throughout the Florida Keys starting in 1998. American Biophysics Company traps were deployed throughout the year at the same collection point. Traps were placed in the late afternoon and collected the following morning. Common mosquitoes are the black salt marsh mosquito, Aedes taeniorhynchus (Wiedemann), the crabhole mosquito, Deinocerites cancer Theobald, the Bahamian Culex, Culex bahamensis Dyar and Knab, and Anopheles atropos Dyar and Knab.
Project description:Florida (USA), particularly the southern portion of the State, is in a precarious situation concerning arboviral diseases. The geographic location, climate, lifestyle, and the volume of travel and commerce are all conducive to arbovirus transmission. During the last decades, imported dengue cases have been regularly recorded in Florida, and the recent re-emergence of dengue as a major public health concern in the Americas has been accompanied by a steady increase in the number of imported cases. In 2009, there were 28 cases of locally transmitted dengue in Key West, and in 2010, 65 cases were reported. Local transmission was also reported in Martin County in 2013 (29 cases), and isolated locally transmitted cases were also reported from other counties in the last five years. Dengue control and prevention in the future will require close cooperation between mosquito control and public health agencies, citizens, community and government agencies, and medical professionals to reduce populations of the vectors and to condition citizens and visitors to take personal protection measures that minimize bites by infected mosquitoes.
Project description: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.
Project description:The Florida Keys Mosquito Control District began deploying Biogents® BG Sentinel traps to monitor Aedes aegypti (Diptera: Culicidae) populations in Key West during a small autochthonous dengue outbreak that began in November 2009. This paper provides weekly data for twelve collection points from January 2010 through December 2020. BG Sentinel traps were baited with dry ice and proprietary BG Lure and were set in the afternoon and retrieved the following morning totalling 19 collection hours. Trap collections also included Culex quinquefasciatus and thus data for that species is also included. The collection data could provide insight into dengue transmission in a small sub-tropical US city.
Project description:Molecular analysis of West Nile virus (WNV) isolates obtained during a 2010 outbreak in Maricopa County, Arizona, USA, demonstrated co-circulation of 3 distinct genetic variants, including strains with novel envelope protein mutations. These results highlight the continuing evolution of WNV in North America and the current complexity of WNV dispersal and transmission.
Project description:After a 75-year absence from Florida, substantial local transmission of dengue virus (DENV) occurred in Key West, Monroe County, Florida in 2009 and continued in 2010. The outbreak culminated in 85 reported cases. In 2011 and 2012, only isolated cases of local DENV transmission were reported in Florida, none were reported in Key West. In 2013, a new outbreak occurred, but this time in Martin County about 275 miles North of Key West with 22 reported cases. As the Key West and Martin County outbreaks involved DENV serotype 1 (DENV-1), we wanted to investigate whether the same strain or a different strain of DENV was responsible for the outbreaks. In this study, we report the sequence and phylogenetic analysis of the E generegion from a patient diagnosed with dengue in Martin County. Our results indicate that the 2013 Martin County DENV-1 strain is distinct from the 2009-2010 Key West DENV-1 and that it is most closely related to viruses from a recent expansion of South American DENV-1 strains into the Caribbean. We conclude that the 2013 Martin County outbreak was the result of a new introduction of DENV-1 in Florida.
Project description:In 2016, four clusters of local mosquitoborne Zika virus transmission were identified in Miami-Dade County, Florida, USA, generating "red zones" (areas into which pregnant women were advised against traveling). The Miami-Dade County Mosquito Control Division initiated intensive control activities, including property inspections, community education, and handheld sprayer applications of larvicides and adulticides. For the first time, the Mosquito Control Division used a combination of areawide ultralow-volume adulticide and low-volume larvicide spraying to effectively control Aedes aegypti mosquitoes, the primary Zika virus vector within the county. The number of mosquitoes rapidly decreased, and Zika virus transmission was interrupted within the red zones immediately after the combination of adulticide and larvicide spraying.