Case Studies Demonstrating the Value of Different Bed Bug Monitoring Methods

Editor's note: Included in August PCT was a bed bug supplement. Due to the amount of bed bug-related stories, press releases and product announcements PCT receives, we did not have room to include all of our coverage in print. One such article is the following case studies from Rutgers University researcher Dr. Changlu Wang that document the value of different monitoring methods for detecting bed bug infestations and evaluating treatment efficacy.

Case study 1 – Using ClimbUp interceptors to detect infestations. A 223-unit apartment building had 4 years of bed bug infestation history and was serviced by a pest control company. In May 2010, the pest control contractor recorded 4 bed bug infestations in its monthly service report. Within 10 days, we installed ClimbUp interceptors in 64 apartments that were previously infested or were suspected having bed bugs.  After 2 weeks, interceptors detected 21 infestations. Thus, 17 infested apartments were not identified by the contractor.
 

Case study 2 – Using ClimbUp interceptors to detect infestations. A 360-unit apartment building had 19 known bed bug infestations in 2010 according to the management office. A pest control contractor conducted basic visual inspection (only searching the bed area). They found an additional 17 infestations. After visual inspections, the contractor installed ClimbUp interceptors in all units. Inspection of the interceptors one week later revealed 26 additional infestations that had not been previously been reported and were missed by visual inspections.

 
Case study 3 – Using NightWatch monitors to address a “biting” insect complaint in a commercial office building.  Several employees reported being bitten by something in the workplace. The employees did not see what was “biting” them but believed their itchy rash-like symptoms were occurring from a pest problem at work. All four of the affected employees shared adjoining cubicles.  The pest control contractor installed a Nightwatch device under the desk in each of the four cubicles occupied by staff complaining of bite.  Within one week bed bugs were captured in two of the cubicles confirming that bed bugs were indeed present. Four insect sticky traps were also installed in each cubicle at the same time period. Bed bugs were not captured in any of the sticky traps and would have not have been detected during the one week monitoring period had the NightWatch devices not been installed.

Case study 4: - Using Canine Scent detection and NightWatch monitors to evaluate a large office building.  Bed bugs had been positively identified in three different cubicles on three separate floors in a ten story commercial office building (approximately 500,000 ft²). Three canine scent dog/handler teams were subcontracted by the pest control contractor to inspect the entire building. Multiple teams were used to ensure that the dogs were not overworked during the large scale inspection as well as to enable cross inspection in areas of concern.  All areas of historical activity were independently inspected by all three dog teams as were any areas where one of the dogs alerted.  The inspection took two days (total of 10 hours inspection time) to complete. Mixed results occurred in one work station (one dog alerted, two dogs did not alert). Positive alerts (all three dogs alerted) were recorded in two locations where bed bugs were not previously suspected. Visual inspection revealed bed bug activity in only one of the three locations. The pest control contractor treated the area where bed bug activity had been confirmed and then monitored the cubicle and surrounding cubicles with NightWatch monitors. After four weeks of no bug capture, the NightWatch monitors were removed. The other two cubicles where the dogs alerted but where bugs were not confirmed were also monitored with Nightwatch units. After four consecutive weeks of monitoring, no bed bugs activity was detected. As a result of the combined inspection methods, treatment was limited to the areas where activity was confirmed and the problem was resolved.

Case study 5 - Using ClimbUp interceptors to evaluate treatment effectiveness. Fourteen bed bug infested one-bedroom apartments in a high rise apartment building were monitored using ClimbUp interceptors for 12 weeks. The interceptors were installed under furniture (bed and/or sofa) legs and were inspected and serviced (replaced or cleaned) every one to two weeks. The building received monthly pest control service provided by a contractor. Each month, two to four technicians visited the building for 1-2 days. They used visual inspection and insecticide spray and/or dusts to control bed bugs. After one week after installation, bed bugs were found in all apartments by interceptors, with an average of 13 bed bugs per apartment. At week 12, 10 apartments still had bed bugs based on interceptors. The mean bed bug count per apartment was 2.5 (adjusted to one week trapping period). The results demonstrate that monthly pest control service was not able to eliminate bed bug infestations within a reasonable period.

Case study 6 - Using dry ice monitors to evaluate treatment effectiveness. A heavily infested one bedroom apartment was treated by Wang with a combination of hot steam and Phantom (0.5% chlorfenapyr) spray. More than 500 bed bugs were found on a sofa before treatment. The apartment became vacant approximately 6 days after treatment. A dry ice trap was placed where the infested sofa was located on the 12th day after treatment. Prior to setting up the trap, a trained technician conducted a 10 minutes visual inspection and did not find bed bugs. After overnight, 505 bed bugs were found in the dry ice trap. A dry ice trap was placed in the room again on the 20th day. After overnight, 113 bed bugs were found in the trap. The results indicate: a) the treatment was not effective; b) the apartment needs to be treated again before allowing new tenant to move in; c) visual inspection is highly unreliable; and d) using dry ice monitors in vacant rooms is helpful for evaluating treatment effectiveness.