County Records for Aedes japonicus in Georgia.

Consolidating and updating distributional data for mosquito species within a state is a good practice. These updates have an immediate impact by providing documented species distribution information for public use and by serving as a resource to researchers who need background information about a species's state distribution. In Georgia, Aedes japonicus, an introduced species, was peer review reported from 7 counties (2002-06): Fulton, Habersham, Lumpkin, Rabun, Towns, Union, and White. No further records were found in peer-reviewed journals or in the Symbiota Collections of Arthropods Network. This study consolidated the 7 peer-reviewed county records for Ae. japonicus with 73 new county records from surveillance data collected by the Georgia Department of Public Health. This study documented the presence of Ae. japonicus in 80 of the 159 counties in Georgia.

Aedes aegypti in Georgia, USA.

Aedes aegypti, commonly known as the yellow fever mosquito, is closely linked to the human environment and directly influenced by the availability of water-holding containers for oviposition and larval development. The discovery of an active population of Ae. aegypti in Columbus, GA, was deemed an important public health matter, and extensive surveillance was initiated to monitor, delineate, and suppress this population.

Distribution of Culex coronator in the USA.

In 1920, Culex coronator was reported from San Benito, Texas, and later in Arizona, New Mexico, and Oklahoma. In 2005, this species was reported to be spreading across the southeastern USA. Now reported in 14 states, it has been found as far north as northern Oklahoma; Memphis, TN; and Suffolk, VA. The public health significance of Cx. coronator is not firmly established, even though it has been implicated as a potential vector of several arboviral diseases. This study aims to document additional Cx. coronator county-level records, to provide information about its continued expansion across the southern USA, and to provide a short research update into its vector potential. Data acquired through multistate collaborations and author collections resulted in 146 new county records from Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, Oklahoma, South Carolina, and Texas. No new county records were presented for Arizona, New Mexico, Tennessee, or Virginia, which had previously reported this species. With these new data, this species has been documented in 386 counties in 14 states of the continental USA.

It's Best to Be Prepared: Lessons Learned from the Past Prepared Georgia for Hurricane Michael.

Onsite assessments for mosquito larval habitat sites are critical after a hurricane makes landfall. Due to lack of forward assessment activities and the uncertain path of Hurricane Irma, it was difficult to determine what areas would be most affected, making it challenging to determine the availability of Department of Public Health Environmental Health Strike Team members from unaffected areas. However, lessons learned from assessing the public health response to Hurricane Irma (2017) helped improve the response to Hurricane Michael (2018).

Georgia's Collaborative Approach to Expanding Mosquito Surveillance in Response to Zika Virus: Year Two.

With the continued increase in international travel and immigration to Georgia, the Department of Public Health (DPH) continued its mission to prevent and respond to Zika virus (ZIKV) transmission. METHODS: We analyzed surveillance data from the DPH to compare the geographical distribution of counties conducting surveillance, total number, and overall percentage of mosquito species collected in 2016 and 2017. Mosquito surveillance in 2017 was mapped by county and species using ArcMap 10.2.0. RESULTS: From 2016 and 2017, mosquito surveillance increased from 60 to 159 counties (165% increase). A total of 145,346 mosquitoes were trapped and identified in 2016 compared to 152,593 in 2017 (5.43% increase). There was a difference in the type of mosquito species found by year. Some species collected in previous years were not collected in 2017, while other species found in 2017 were not previously collected during mosquito surveillance. Also, certain mosquito species were found outside of their expected geographical range. CONCLUSION: The continued collaborative response to ZIKV by the DPH allowed a continued increase in its surveillance program. Existing and new partnerships continued to develop with military and local health departments to expand and share data. This additional surveillance data allowed DPH to make sound public health decisions regarding mosquito-borne disease risks and close gaps in data related to vector distribution.

Georgia's collaborative approach to expanding mosquito surveillance in response to Zika virus: a case study.

Zika virus (ZIKV) was declared an international public health emergency by the World Health Organization on February 1, 2016. Due to the known and estimated range of the ZIKV mosquito vectors, southern and central US states faced increased risk of ZIKV transmission. With the state of Georgia hosting the world's busiest international airport, a climate that supports the ZIKV vectors, and limited surveillance (13 counties) and response capacity, the Department of Public Health (DPH) was challenged to respond and prevent ZIKV transmission. This case study describes and evaluates the state's surveillance capacity before and after the declaration of ZIKV as a public health emergency. METHOD: We analyzed surveillance data from the DPH to compare the geographical distribution of counties conducting surveillance, total number, and overall percentage of mosquito species trapped in 2015 to 2016. Counties conducting surveillance before and after the identification of the ZIKV risk were mapped using ArcMap 10.4.1. Using SAS (version 9.2) (SAS Institute, Inc, Cary, NC), we performed the independent 2 sample t test to test for differences in prevalence in both years, and a χ² analysis to test for differences between numbers of species across the 13 counties. In addition, weighted frequency counts of mosquitoes were used to test (χ²) an association between major mosquito vector species and 7 urban counties. Lastly, using data from 2012-2016, a time-trend analysis was conducted to evaluate temporal trends in species prevalence. RESULTS: From 2015 to 2016, surveillance increased from 13 to 57 (338% increase) counties geographically dispersed across Georgia. A total of 76,052 mosquitoes were trapped and identified in 2015 compared to 144,731 (90.3% increase) in 2016. Significant differences between species (P<.001) and significant associations (P<.0001) between 7 urban counties and major mosquito vectors were found. Significant differences in prevalence were found between several species and year highlighting species-year temporal trends. CONCLUSIONS: The DPH collaborative response to ZIKV allowed a rapid increase in its surveillance footprint. Existing and new partnerships were developed with the military and local health departments to expand and share data. This additional surveillance data allowed DPH to make sound public health decisions regarding mosquito-borne disease risks and close gaps in data related to vector distribution.

A Multiagency Approach to Reducing West Nile Virus Risk in Richmond County, Georgia, in 2015.

The Richmond County Mosquito Control program's mission statement is to incorporate strategies of integrated mosquito control management that are effective, practical, and environmentally safe and protect the health of Richmond County residents, as well as promote public education, in order to prevent large mosquito populations and the diseases that they transmit. To this end, the program coordinates efforts with other county agencies in order to provide better service. This is a small program with limited resources, so in an effort to provide better integrated mosquito management, the mosquito control program and the Phinizy Center for Water Sciences joined efforts to trap mosquitoes at sites across the county, identify the species, and send the mosquitoes off for viral testing. These data help determine locations of disease-carrying mosquitoes so the county can more efficiently control the mosquito populations and reduce the risk of West Nile virus transmission.

Mansonia titillans: New Resident Species or Infrequent Visitor in Chatham County, Georgia, and Beaufort County, South Carolina, USA.

In September, October, and November 2014, adult Mansonia titillans were collected at 4 separate sites near Savannah in Chatham County, Georgia, and 1 site in Muscogee County, GA, during routine mosquito surveillance. Although previously recorded from Beaufort County, SC, and several inland southern Georgia counties, recent reports of this species from coastal Georgia or South Carolina are lacking. These newly captured Ma. titillans specimens represent the first documented records for Muscogee County and Chatham County, GA, and may indicate a recent northern expansion or reintroduction of this species along the Georgia and South Carolina coast.

Long term impacts of combined sewer overflow remediation on water quality and population dynamics of Culex quinquefasciatus, the main urban West Nile virus vector in Atlanta, GA.

BACKGROUND: Combined sewers are a significant source of urban water pollution due to periodic discharges into natural streams. Such events (called combined sewer overflows, or CSOs) contribute to the impairment of natural waterways and are associated with increased mosquito productivity and elevated risk of West Nile virus transmission. OBJECTIVES: We investigated the impact of CSOs on water quality and immature mosquito productivity in the city of Atlanta, Georgia, one year before and four years after CSO facility remediation. METHODS: Water quality (ammonia, phosphate, nitrate and dissolved oxygen concentrations), immature mosquitoes (larvae and pupae), water temperature and rainfall were quantified biweekly between June-October at two urban creeks during 2008-2012. A before-after control-intervention design tested the impact of remediation on mosquito productivity and water quality, whereas generalized linear mixed-effect models quantified the factors explaining the long term impacts of remediation on mosquito productivity. RESULTS: Ammonia and phosphate concentrations and late immature (fourth-instar and pupae) mosquito populations were significantly higher in CSO than in non-CSO creeks, while dissolved oxygen concentrations were lower. Remediation significantly improved water quality estimates (particularly ammonia and dissolved oxygen) and reduced the number of overflows, mosquito productivity and the overall contribution of CSO-affected streams as sources of vectors of West Nile virus. CONCLUSIONS: The quality of water in CSOs provided a suitable habitat for immature mosquitoes. Remediation of the CSO facility through the construction of a deep storage tunnel improved water quality indices and reduced the productivity of mosquito species that can serve as vectors of West Nile virus.

Culex flavivirus and West Nile virus in Culex quinquefasciatus populations in the southeastern United States.

Little is known of the interactions between insect-only flaviviruses and other arboviruses in their mosquito hosts, or the potential public health significance of these associations. The specific aims of this study were to describe the geographic distribution, prevalence, and seasonal infection rates of Culex flavivirus (CxFV) and West Nile virus (WNV) in Culex quinquefasciatus Say in the Southeastern United States, investigate the potential association between CxFV and WNV prevalence in Cx. quinquefasciatus and describe the phylogenetic relationship among CxFV and WNV isolates from the Southeastern United States and around the world. Using ArboNET records, 11 locations were selected across Georgia, Mississippi, and Louisiana that represented a range of WNV human case incidence levels. Cx. quinquefasciatus were trapped weekly throughout the summer of 2009 and pools were screened for flavivirus RNA by reverse transcriptase polymerase chain reaction. Cx. quinquefasciatus from Georgia had significantly higher CxFV infection rates than either Mississippi or Louisiana. CxFV was not detected in Mississippi after July, and no CxFV was detected in Cx. quinquefasciatus in Louisiana. In Georgia, CxFV infection rates were variable between and within counties and over time. WNV infection rates were not significantly different across states or months, and WNV sequences from all three states were identical to each other in the envelope and NS5 gene regions. Phylogenetically, NS5 and E gene sequences from Georgia CxFV isolates clustered with CxFV from Japan, Iowa, and Texas. Multiple CxFV genetic variants were found circulating simultaneously in Georgia. No evidence was found supporting an association between WNV and CxFV infection prevalence in Cx. quinquefasciatus.

Detection of Dirofilaria immitis (Nematoda: Filarioidea) by polymerase chain reaction in Aedes albopictus, Anopheles punctipennis, and Anopheles crucians (Diptera: Culicidae) from Georgia, USA.

Potential mosquito vectors of Dirofilaria immitis (Leidy) (Nematoda: Filarioidea), the causative agent of dog heartworm in the southeastern region of the United States, were collected with CDC light traps and gravid traps in seven counties in the state of Georgia, USA. The presence of D. immitis in these mosquitoes was detected by polymerase chain reaction using species-specific primers for the D. immitis surface or cuticular antigen. Overall, 1,574 mosquitoes of 13 species in seven genera were collected; 92% of the specimens were Aedes albopictus (Skuse), Aedes vexans (Meigen), or Anopheles punctipennis (Say). Ae. albopictus, An. punctipennis, and Anopheles crucians Wiedemann were positive for D. immitis DNA. Ae. albopictus had the highest maximum likelihood rate of infection (2.30%; 95% confidence interval [CI] = 1.15-4.00%) followed by An. crucians (1.38%: 95% CI = 0.04-6.93%), and An. punctipennis (0.85%: 95% CI 0.03-4.29%). The detection of D. immitis DNA in the heads and thoraxes of Ae. albopictus (0.40%; 95% CI = 0.12-2.02%) indicates that these mosquitoes can support the development of D. immitis to the infective stage 3 larvae.

The risk of West Nile Virus infection is associated with combined sewer overflow streams in urban Atlanta, Georgia, USA.

BACKGROUND: At present, the factors favoring transmission and amplification of West Nile Virus (WNV) within urban environments are poorly understood. In urban Atlanta, Georgia, the highly polluted waters of streams affected by combined sewer overflow (CSO) represent significant habitats for the WNV mosquito vector Culex quinquefasciatus. However, their contribution to the risk of WNV infection in humans and birds remains unclear. OBJECTIVES: Our goals were to describe and quantify the spatial distribution of WNV infection in mosquitoes, humans, and corvids, such as blue jays and American crows that are particularly susceptible to WNV infection, and to assess the relationship between WNV infection and proximity to CSO-affected streams in the city of Atlanta, Georgia. MATERIALS AND METHODS: We applied spatial statistics to human, corvid, and mosquito WNV surveillance data from 2001 through 2007. Multimodel analysis was used to estimate associations of WNV infection in Cx. quinquefasciatus, humans, and dead corvids with selected risk factors including distance to CSO streams and catch basins, land cover, median household income, and housing characteristics. RESULTS: We found that WNV infection in mosquitoes, corvids, and humans was spatially clustered and statistically associated with CSO-affected streams. WNV infection in Cx. quinquefasciatus was significantly higher in CSO compared with non-CSO streams, and WNV infection rates among humans and corvids were significantly associated with proximity to CSO-affected streams, the extent of tree cover, and median household income. CONCLUSIONS: Our study strongly suggests that CSO-affected streams are significant sources of Cx. quinquefasciatus mosquitoes that may facilitate WNV transmission to humans within urban environments. Our findings may have direct implications for the surveillance and control of WNV in other urban centers that continue to use CSO systems as a waste management practice.

A new, cost-effective, battery-powered aspirator for adult mosquito collections.

We report the development of a new mosquito aspirator with the same aspiration capacity (airflow) of the CDC Backpack Aspirator (CDC-BP), but smaller and lighter (0.8 kg without battery), less expensive (US$45-70), easier to build, and compatible with the use of telescoping extension poles to access hard-to-reach locations. The performance of this new aspirator, named "Prokopack," was compared with the CDC-BP in laboratory settings as well as in paired collections in combined sewer overflow (CSO) tunnels in Atlanta, GA, and indoor mosquito collections in Iquitos, Peru. The difference in suction power between both aspirators (average, 0.29-0.43 m/s) was negligible. However, 2.3 times more mosquitoes were collected using the Prokopack in the upper wall (>1.5 m) and ceilings of CSO tunnels than with the CDC-BP in lower walls. Indoor collection in Iquitos yielded significantly more total mosquito numbers [including Culex pipiens complex, Culex (melanoconion) sp., and Mansonia sp.] and Aedes aegypti (L.) in the Prokopack than in the CDC-BP. Our results demonstrate the effectiveness of the Prokopack to collect different mosquito species in different epidemiological settings.

Commercial mosquito trap and gravid trap oviposition media evaluation, Atlanta, Georgia.

Field trials evaluating the effectiveness of selected gravid trap oviposition media and commercially available mosquito traps were conducted in southern Fulton County (Atlanta), GA, from June 9 to June 18 and June 24 to July 4, 2002, respectively. Total number of mosquitoes and number of each species captured during the tests were compared using a Latin square design. For the gravid trap infusion media, significant differences were found for total number of mosquitoes collected where sod > or = hay > or = hay side-by-side diluted hay > dilute hay side-by-side hay > or = oak > diluted hay. Only Aedes albopictus (oak), Culex quinquefasciatus (sod and both concentrated hay infusions), and Culex restuans (sod) were captured in significantly greater numbers using a particular infusion. Significant differences for the total number of mosquitoes collected were also observed in the commercial mosquito traps such that the gravid trap > ultra violet up-draft > or = Mosquito Magnet Pro > or = omnidirectional Fay-Prince trap with CO2 > up-draft CDC-style with CO2 > or = CDC-style with CO2. Significant differences in numbers collected among traps were noted for several species, including Aedes vexans, Aedes albopictus, Cx. quinquefasciatus, Cx. restuans, and Culex salinarius. Results from these field trap and infusion evaluations can enhance current surveillance efforts, especially for the primary vectors of West Nile virus and other arboviruses.