Seasonal distribution of cockroaches, a major source of indoor allergens, in seoul metropolitan area

Kim, Woo Kyung; Kim, Cheol Hong; Lee, Kyung Eun; Shon, Myung Hyun; Jang, Gwang Cheon; Kim, Kyu Earn; Lee, In Young; Jeong, Kyoung Yong; Lee, Jong Weon; Yong, Tai Soon; Kim, Cheol Woo; Park, Jung Won; Hong, Chein Soo

Abstract

PURPOSE: Home exposure to aeroallergens are an important environmental factor in allergic sensitization and in the development and exacerbation of asthma. Most studies of aeroallergens were dust mite in Korea, but cockroach distribution was little been known in Korea. The aim of this study was to evaluate species of cockroaches and seasonal distribution of cockroaches in Seoul area.
METHODS
The study was performed during April 2000 through January 2001, from 63 houses in Korea. The total of 63 residential homes from different districts in Seoul were selected for the home environment survey. Bait traps (10 x 20 x 4 cm2, Zoro Zoro, Taisho Pharmacy, Tokyo, Japan) were placed on four different places of kitchen floor and one in the side of balcony in the house and left for 5 days to capture cockroaches.
RESULTS
The cockroaches were captured in 23 houses(36.5%) out of 63 houses. And the inhabitant density of cockroaches was highest in the autumn(43.3%) followed by summer (29.2%), spring(18.3%) and winter(9.2%). In only 3 species were collected in Seoul area. The most common species were Blattella germanica showing 72.5% of the collected cockroaches, followed by Periplaneta japonica(25.2%) Periplaneta americana(2.3%). The total number of captured cockroaches was 504 and the number of nymph was 314(62.2%). Isolated house type showed higher trapping rates than the apartment. Positive skin test rates were 46.2% in the healthy control group and 43.8% in the allergy patients.
CONCLUSION
Periplaneta americana was captured in Seoul area, which had not been found previously. The inhabitant density of cockroaches was the lowest in the winter.