Predictive model for microclimatic temperature and its use in mosquito population modeling.

Mosquitoes transmit several infectious diseases that pose significant threat to human health. Temperature along with other environmental factors at breeding and resting locations play a role in the organismal development and abundance of mosquitoes. Accurate analysis of mosquito population dynamics requires information on microclimatic conditions at breeding and resting locations. In this study, we develop a regression model to characterize microclimatic temperature based on ambient environmental conditions. Data were collected by placing sensor loggers at resting and breeding locations such as storm drains across Houston, TX. Corresponding weather data was obtained from National Oceanic and Atmospheric Administration website. Features extracted from these data sources along with contextual information on location were used to develop a Generalized Linear Model for predicting microclimate temperatures. We also analyzed mosquito population dynamics for Aedes albopictus under ambient and microclimatic conditions using system dynamic (SD) modelling to demonstrate the need for accurate microclimatic temperatures in population models. The microclimate prediction model had an R2 value of ~ 95% and average prediction error of ~ 1.5 °C indicating that microclimate temperatures can be reliably estimated from the ambient environmental conditions. SD model analysis indicates that some microclimates in Texas could result in larger populations of juvenile and adult Aedes albopictus mosquitoes surviving the winter without requiring dormancy.

Prevalence of Shiga-toxigenic Escherichia coli in House Flies (Diptera: Muscidae) in an Urban Environment.

House flies (Musca domestica L. [Diptera: Muscidae]) can act as a mechanical vector for food-borne pathogens including Shiga toxin-producing Escherichia coli (Migula; Enterobacteriales: Enterobacteriaceae) (STEC) in and around cattle feedlots. The present study assessed the prevalence of STEC in house flies from a restaurant area of a town in northeastern Kansas. Two hundred twenty-four house flies were collected over 10 wk, surface sterilized, individually homogenized, and cultured by a multifaceted approach of direct plating on selective media and an enrichment broth, followed by the immunomagnetic separation. Bacterial isolates were screened for eight serogroups of E. coli: O103, O104, O26, O111, O45, O145, O121, and O157 using multiplex polymerase chain reaction (PCR). Furthermore, O-serogroup-positive isolates were tested for virulence genes stx1, stx2, eae, and ehxA by PCR. The majority (91.5%) of flies carried enteric bacteria, and the mean value of enteric concentration on the modified Possé agar was 6.7 ± 1.1 × 106 colony forming units per fly. Thirty-nine of the 224 flies (17.4%) were positive for one or more E. coli serogroup of interest; with the majority O103 (10.7%), followed by O26 (3.1%), O121 (1.3%), O45 (1.3%), and O104 (0.9%). However, none of the serogroup-positive isolates carried any of the virulence genes tested. Results of our study show that house flies in the urban environment do not carry STEC. Nevertheless, detection of E. coli O-serogroups with the potential to acquire virulence traits indicates that house flies in an urban environment represent a public health risk.

New records of Ornithodoros puertoricensis Fox 1947 (Ixodida: Argasidae) parasitizing humans in rural and urban dwellings, Panama.

The presence of ticks inside human constructions was evaluated in two localities from Colon province (Charco La Piedra and Espinar) and one from Panama province (Ancon, City of Panama). In two of houses, eight people from Charco La Piedra and one from Ancón reported "insect bites," which produced blisters for several weeks. The investigation resulted in the collection of argasid ticks, which were identified by morphology and sequencing the 16s ribosomal RNA gene, and later evaluated for the presence of relapsing fever Borrelia DNA. All ticks were identified as Ornithodoros puertoricensis. While spirochetal DNA was not detected by PCR in the ticks, our report highlights the potential for relapsing fever borreliosis in rural and urban localities in Panama.