2011 SEASON IN REVIEW

2011 SEASON IN REVIEW

Priscilla Matton & Wayne Andrews

Bristol County Mosquito Control Project

140 North Walker Street
Taunton, MA 02780

ABSTRACT

Three major events took place in Bristol County during the 2011 mosquito season: two EEE human cases, expansion of Ae. albopictus and significant Cs. melanura collections from resting boxes. The two human cases were both located within the town of Raynham along the Plymouth County border associated with the Hockomock Swamp complex. The first positive EEE human biting mosquito for Bristol County occurred on August 15th in Cq. perturbans in Raynham, followed by a second on August 22nd. The first human case with a reported onset of August 27th resulted in the state’s first and only death from EEE in 2011. A second case was confirmed in an out-of-state woman who visited the Raynham area during the same time. Her onset date was determined to be August 25th but confirmation did not occur until October 7th. These are believed to be the first confirmed human cases from the town of Raynham based on the records of the past EEE outbreaks dating back to the 1930’s.

BCMCP saw an expansion of the Asian Tiger Mosquito- Ae. albopictus, away from its historical New Bedford location. We collected 34 Ae. albopictus from the New Bedford site located in close proximity to a tire recycling plant, compared to the 2 collected in 2010. We began asking residents of Bristol County to call if they believed they had Ae. albopictus in their area. We responded to many calls from Fairhaven, New Bedford and Acushnet but did not collect any further specimens. On August 25th, we received a call from a resident in Westport, near a steel and scrap facility and placed a modified BG Sentinel trap. We collected one female Ae. albopictus from the location. We moved further south in Westport based on another claim, away from businesses and industry. On September 13th, using a modified BG Sentinel trap, we collected 10 Ae. albopictus from this site. Further investigation, using trapping and outreach is necessary to determine location and movement of this species.

BCMCP placed 10 resting boxes on the Freetown/ New Bedford line adjacent to the Bolton Cedar Swamp complex to measure Cs. melanura activity in the region. The resting boxes collected low numbers of Cs. melanura for the beginning of the season with a significant increase by mid-June and continued high collections until mid-July. Early August saw a decline in population with another spike in late August, with collections of over 1,000 Cs. melanura from the boxes. In 2011, 5 pools tested positive, mostly during Epi-Week 33 (week-ending August 27) including one pool that tested positive for both EEE and WNV. Despite the population of Cs. melanura collected in the resting boxes, EEE was scarce in New Bedford and the surrounding areas.