New York has retained its spot as the United States' most bed-bug infested city, according to research released May 25.

The ranking, compiled by pest control firm Terminix, ranked New York as the bed-bug hot spot for the second year in a row, although there were some new additions to the list of cities which have everyone's least favorite roommate.

Baltimore, Dallas and San Francisco appear on the list for the first time this year, replacing Indianapolis, Cleveland and Minneapolis, said Terminix.

The number of infestation reports has risen since this time last year, the company said, with most states seeing an increase of the tiny pests - the ranking was compiled using data from 350 Terminix branches across the US.

New York received considerable notoriety last year when news of the infestation spread, leading Mayor Michael Bloomberg to announce a comprehensive strategy to tackle the problem - although it doesn't seem to be working.

Terminix said that the problem is growing in scope and severity, adding that the movement isn't expected to slow any time soon.

Checking hotel sheets and mattresses for spots, hanging clothes in cupboards and storing baggage away from the bed are all tips recommended to avoid infection, along with washing clothes on a hot wash as soon as you've returned home.

For the really paranoid, a clever new electronic bed bug detector might do the trick - it can identify the pests' pheromones in the air and could go on sale soon for about $200, reports CNet.

The 2011 most bedbug-infested cities include:

1. New York 
2. Cincinnati
3. Detroit
4. Chicago
5. Philadelphia
6. Denver
7. Washington, DC
8. Los Angeles
9. Boston
10. San Francisco
11. Columbus, OH
12. Dayton, OH
13. Baltimore
14. Louisville, KY
15. Dallas