Flaviviruses are important pathogens for humans and animals (Dengue viruses, Yellow fever virus, Zika virus and West Nile virus). Culex flavivirus (CxFV) is an insect-specific virus of the genus Flavivirus, detected in a wide variety of mosquito species. To detect Flavivirus in mosquitoes of a tropical region of the Colombian Caribbean. In 2014, an entomological surveillance of arboviruses was conducted in the department of Cordoba area of the Caribbean, Colombia. A total of 8270 mosquitoes were captured as follow: Mansonia (n = 3271/39.5%), Culex (n = 2668/32.26%), Anopheles (n = 840/10.15%), Aedeomyia (n = 411/4.9%), Psorophora (n = 397/4.8%), Coquilletidia (n = 369/4.46%), Uranotaenia (n = 261/3.15%) and Aedes (n = 53/0.6%). All mosquito species were collected in dry tropical forest of the Caribbean area. Universal primers for NS5 gene (958 pb), RT-PCR for flavivirus and sequencing were used for molecular identification of viruses detected. Two pools belonging to Culex coronator were positive for flavivirus RNA sequence by RT-PCR. The sequences of the PCR amplicons, matched that of the Culex flaviviruses, CxFv COL PM_149 (GenBank: KR014201) and CxFv COL PM_212 (GenBank: KT307717). Phylogenetic analysis of the NS5 protein sequences of the Culex flaviviruses sequences with those of reference sequences available in GenBank indicated viruses of Genotype II, closely related to the Brazilian strain, BR_SJRP_01_ (GenBank: KT726939), from Culex sp. The alignment of Culex flavivirus sequences CxFv COL_ PM 212 and CxFv COL_ PM 149 with sequences of strains detected in different geographical regions grouped the strains in a Latin American clade reported in Brazil, Argentina and Mexico. The present work illustrated that CxFV was circulating among vectors of human pathogenic arboviruses in Colombia, but the impact of CxFV on other flaviviruses which are endemic in the study area still remains to be explored.

Arboviruses belonging to the genera Flavivirus and Alphavirus were detected in mosquitoes in a rural area of San Bernardo del Viento (Córdoba, Colombia). A total of 22,180 mosquitoes were collected, sorted into 2,102 pools, and tested by generic/nested reverse transcription-polymerase chain reaction. Venezuelan equine encephalitis virus, dengue virus, West Nile virus, St. Louis encephalitis virus, yellow fever virus, and Culex flavivirus were detected and identified by sequencing. The detection of arboviral pathogens in this zone represents possible circulation and indicates a human health risk, demonstrating the importance of virological surveillance activities.

Saint Louis encephalitis virus (SLEV) is a member of the Japanese-encephalitis virus serocomplex of the genus Flavivirus. SLEV is broadly distributed in the Americas and the Caribbean Islands, where it is usually transmitted by mosquitoes of the genus Culex and primarily to birds and mammalian-hosts. Humans are occasionally infected by the virus and are dead-end hosts. SLEV causes encephalitis in temperate regions, while in tropical regions of the Americas, several human cases and a wide biological diversity of SLEV-strains have been reported. The phylogenetic analysis of the envelope (E) protein genes indicated eight-genotypes of SLEV with geographic overlap. The present paper describes the genotyping of two SLEV viruses detected in mosquito-pools collected in northern Colombia (department of Cordoba). We used reverse transcription-polymerase chain reaction to amplify a fragment of theE-gene to confirm the virus identity and completeE-gene sequencing for phylogenetic analysis and genotyping of the two-SLEV viruses found circulating in Córdoba. This is the first report of SLEV genotype IV in Colombia (Córdoba) in mosquitoes from a region of human inhabitation, implicating the risk of human disease due to SLEV infection. Physicians should consider SLEV as a possible aetiology for undiagnosed febrile and neurologic syndromes among their patients who report exposure to mosquito-bites.

West Nile virus (WNV) is a member of the genus Flavivirus, and it is transmitted between Culex sp. mosquitoes and avian hosts. Equids and humans are commonly infected with WNV as dead-end hosts, and the signs and symptoms of infection range from mild illness to neurologic symptoms as encephalitis, meningitis and sometimes death. Previous phylogenetic studies have classified WNV into six genetically distinct lineages and provided valuable insight on WNV dispersal patterns within the Americas and its emergence in different geographic areas. In this study, we isolated, sequenced and genetically characterized the NS5 and envelope genes for two WNV strains detected from Northern of Colombia. Herein we describe the evolutionary relationships with representative WNV-strains isolated in a variety of epidemic outbreaks and countries, to define the phylogeographic origin and possible implications in the epidemiology of this emergent virus in Colombia. Fragments of the NS5 and Envelope genes were amplified with RT-PCR and sequenced to obtain 1186-nt and 1504-nt portions, respectively. Our sequences were aligned with 46 sequences from WNV-strains collected in the U.S., Mexico and Argentina for phylogenetic reconstruction using Bayesian methods. Sequence analyses identified unique non-synonymous substitutions in the envelope gene of the WNV strains we detected, and our sequences clustered together with those from the attenuated Texas – 2002 genotype. A new strain closely related to attenuated strains collected in Texas during 2002 was identified from Colombia by phylogenetic analysis. This finding may explain the absence of human/equine cases of WNV-encephalitis or severe disease in Colombia and possibly other regions of South America. Follow-up studies are needed in ecosystems used by migratory birds areas and virological/entomological surveillance.

This study aimed to analyse the patterns of diversity, blood sources andLeishmaniaspecies of phlebotomines in a focus of cutaneous leishmaniasis in Arboledas, Eastern Colombia. In total, 1729 phlebotomines were captured in two localities (62.3% Siravita and 37.7% Cinera) and five environments of Norte de Santander. We identified 18 species of phlebotomines:Pintomyia ovallesi(29.8%),Psychodopygus davisi(20.3%),Pi. spinicrassa(18.5%) andLutzomyia gomezi(15.8%) showed the highest abundance. Species diversities were compared between Cinera (15.00) and Siravita (20.00) and among five microenvironments: forest remnants (19.49), coffee plantations (12.5), grassland (12.99), cane plantations (11.66) and citrus plantations (12.22).LeishmaniaDNA was detected in 5.8% (80/1380) of females, corresponding mainly toPi.ovallesi(22/80; 27.2%),Lu.gomezi(17/80; 21.3%) andPi.spinicrassa(11/80; 13.8%).Leishmaniaspecies were 63.1%L. braziliensis, 18.5%L.panamensis, 13.2%L.infantumand 6.1%L.amazonensis. The most frequent feeding sources wereHomo sapiens(50%),Bos taurus(13.8%) andCanis lupus familiaris(10.3%). This focus of cutaneous leishmaniasis has a high diversity ofLeishmania-carrying phlebotomines that feed on domestic animals. The transmission of leishmaniasis to human hosts was mainly associated withLu.gomezi,Pi.ovallesiandL.braziliensis.