Atrial thrombi in elective patients considered for atrial fibrillation rhythm control: Risk factors and prognostic value.

The prognostic value of atrial thrombi (AT) among elective patients with atrial fibrillation (AF) referred for a rhythm control strategy is unclear. In this study, clinical variables were correlated with the presence of AT and long term survival among 205 patients submitted to transesophageal echocardiography before elective AF cardioversion or ablation. Atrial thrombi were present in 7.8% of cases and were significantly associated with reduced survival. Obesity was the only independent clinical predictor of AT [OR 4.27 (1.15-15.79), p = 0.03]. In patients with AF, AT appear to be associated with adverse outcomes, possibly indicating more advanced atrial cardiomyopathy.

Mating Competitiveness of Transgenic Aedes aegypti (Diptera: Culicidae) Males Against Wild-Type Males Reared Under Simulated Field Conditions.

Efforts directed at genetic modification of mosquitoes for population control or replacement are highly dependent on the initial mating success of transgenic male mosquitoes following their release into natural populations. Adult mosquito phenotypes are influenced by the environmental conditions experienced as larvae. Semifield studies conducted to date have not taken that under consideration when testing male mating fitness, and have compared mating success of males reared under identical environmental conditions. We performed pairwise mating challenges between males from a genetically modified laboratory strain (BF2) versus males from a recent Trinidad field isolate of Aedes aegypti (L.), a major vector of multiple arboviruses. We utilized larval density and nutrition to simulate environmental stress experienced by the Trinidad males and females. Our results indicated that environmental stress during larval development negatively influenced the competitiveness and reproductive success of males from the Trinidad population when paired with optimum reared BF2 males. Small (0.027 m3) and large (0.216 m3) trials were conducted wherein stressed or optimum Trinidad males competed with optimum BF2 males for mating with stressed Trinidad females. When competing with stress reared Trinidad males, optimum reared BF2 males were predominant in matings with stress reared Trinidad females, and large proportions of these females mated with males of both strains. When competing with optimum reared Trinidad males, no difference in mating success was observed between them and BF2 males, and frequencies of multiple matings were low. Our results indicate that future mating competition studies should incorporate appropriate environmental conditions when designing mating fitness trials of genetically modified males.

Identification of Host Blood Meals of Mosquitoes (Diptera: Culicidae) Collected at the Aripo Savannas Scientific Reserve in Trinidad, West Indies.

Surveillance for blood-fed female mosquitoes was performed between August 2015 and February 2016 at sites along the periphery of the Aripo Savannas Environmentally Reserve (ASSR) located in northeastern Trinidad, West Indies. We collected engorged female mosquitoes representing 13 species. DNA extractions from dissected abdomens were subjected to PCR amplification with three primer pairs targeting the mitochondrial cytochrome oxidase I and cytochrome b gene sequences. High-quality sequence information and host identification were obtained for 42 specimens representing eight mosquito species with at least one primer combination. A broad range of vertebrates including humans were identified, but the majority were nonhuman mammals, both domestic and wild. Domestic dogs were the most common host and may represent potential sentinel species for monitoring local enzootic arbovirus activity in Trinidad. Culex declarator Dyer and Knab and Culex nigripalpus Theobald were the most common blood-fed mosquito species comprising 79.1% of the total number identified. These species obtained blood meals from birds, nonhuman mammals, and human hosts, and therefore pose significant risks as potential bridge vectors for epizootic arbovirus transmission in the ASSR area as well as other sylvan areas in Trinidad. These data represent the first such results for Trinidad.