As a hands on landlord I know my tenants quite well. We got our very first case of bed bugs in 2007 via used furniture.
I educated my tenants about that issue and since then my tenants have stopped bringing in used furniture. But we still averaged about two cases of bed bugs per year out of 36 suites.
That works out to about a six percent per year infestation rate. Over time I started noting patterns in who got bed bugs and who did not get bed bugs. In my experience a quiet tenant who simply goes to work and has nothing to do with anyone who has bed bugs (which is most of the building) rarely brings home bugs – perhaps a 3% infestation rate per year or once every 35 years on average. On the other hand two tenants made up half (or the other 3%) of all bed bug cases in my building with multiple cases each.
So what made these two tenants so susceptible to bed bugs? I got one answer as I was contracted to treat another landlord’s rooming houses for bed bugs. I noticed that one tenant had at least two friends living in these infested rooming houses. Given that my building offered much better socializing conditions than a rooming house my tenant’s suite became a gathering point. And my tenant was infested three times in three years as a result.
The other tenant was a very nice immigrant family that enjoyed sponsoring church related events in their home on a weekly basis and later, unknownst to me, sponsored their three adult children to live in their 1 bedroom apartment. Overall this one family was responsible for about half the total visitor traffic for the entire building. And this family brought in two cases of bed bugs about 4 years apart. This family has since moved on to other rental accommodations.
Of the single cases of bed bugs I addressed in my building there is one more common denominator – two separate tenants came to me with a concern that they found bed bugs climbing off their visitor’s clothing. When I questioned the tenants it was admitted that their friends did in fact have active bed bugs in their homes and precautions were not taken.
So we see that a good predictor for acquiring bed bugs is associating with other people that have bed bugs or bringing in extraordinarily large numbers of guests which raises the probability of bed bug transmission to the suite. As a result my educational material for tenants now includes a section on precautions that must be taken when associating with people with bed bugs. There are other ways of getting bed bugs but I have not yet experienced large numbers of them in my building.
January 14, 2014 update
The gentleman who associated with infested rooming house tenants has now officially infested himself 6 times in five years. Impressive. None of the neighbours ever have bugs – just him. This tenant is under a permanent monitoring arrangement to catch the bugs early. Eviction is difficult because of the Residential Tenancies Branch. This case clearly illustrates the dangers of visiting, or receiving visitors, from infested homes. The bugs come in with the infested clothing.