At the 2008 International Conference on Urban Pests in Budapest, researchers from the Danish Pest Infestation Laboratory (DPIL) presented a historical view of the bed bug inquiries received at the laboratory. The laboratory keeps annual data since 1953 and monthly data since 1965:
A problem, however, with the data is the variation in the overall activity, for example a drop in the total number of inquiries from around 12,000 in the late 1990s to around 6,000 in recent years. The most important reason for this decrease is the introduction of an internet-based advisory system, growing in popularity all the time. Around the peak in the mid-1980s (Figure 1) the number of inquiries on bed bugs alone was around 300 cases per year whereas in the last years the number has stayed at approx. 120-130 cases per year. However, 2007 resulted in 13,000 downloads of the bed bug fact sheet from the DPIL homepage, indicating that part of the need for advice is now being fulfilled via the internet.
A PDF is available for download (PDF) [2/11: edited to add link] (you should read this—it is immensely interesting, containing among other things, remarks noting the history of available pesticides, marking the current resurgence from 1995, and establishing present resistance to pyrethroids):
Bed bug problems in Denmark, with a European perspective. / Kilpinen, Ole ; Jensen, Karl-Martin Vagn ; Kristensen, Michael. In: Bed bug problems in Denmark, with a European perspective. Ungarn : OOK-Press Kft., 2008. p. 395-399
Again that rise in the 1980s… we’ve seen that in the UK. In the US, of course, no data is available to us, but newspaper reports may give us an idea of a similar rise, if only we had the tools to do this research.
I had been wanting to read the Denmark paper for some time and when I did I remembered seeing the early 80s Denmark inquiries mentioned in J.R. Busvine’s John Hall Grundy lecture. I will quote a bit more from Busvine in the hope that you will share my fascination with the way the history of bed bugs has been told and retold so that we have accepted without questioning that which we should be more inquisitive about:
In the years just before the last War there had been a kind of crusade against bed bug infestations in the slums. Another of my old professors, J W Munro, used to call it the ‘slum-bug’, pointing out that it tended to perpetuate bad housing conditions, since the presence of the bug drove away the better tenants. Both the Medical Research Council and the Ministry of Health set up committees to investigate the problem and supported research on the subject.
A great deal was learnt about bug biology, much of it by my former colleague C G Johnson; but no very satisfactory control measures were found.
Because the bugs were hidden in inaccessible crevices by day, they were protected from most of the insecticides available at the time apart from the dangerous hydrogen cyanide gas, which in any case could not be successfully used in leaky ill-constructed houses. Accordingly, some of those concerned with the problem advocated vigorous attacks with soap and water; in other words, better hygiene by the housewife.
As with lice, the situation was entirely changed by the introduction of DDT and other synthetic insecticides which formed residues lethal to bugs which crawled over them subsequently and which could be used easily and cheaply in human dwellings. As a result, bug infestation in most temperate countries was substantially reduced but I am sorry to say that the trouble smoulders on in persistant cases of infestation. There are hardly any statistics available, but in Denmark where records are kept by the Government Pest Control Laboratory, there are sugestions of increases, shown by enquiries about bugs rising from about 20 a year in the 1960s to 262 in 1982. Moreover, in many places, and especially in tropical countries, control is handicapped by resistance to many convenient residual insecticides.
Busvine James R. 1984. John Hall Grundy lecture. Reflections on some human ectoparasites. Journal of the Royal Army Medical Corps. 130(2):126-133.
Heartfelt thanks to a friend of New York vs Bed Bugs for pointing me to the ICUP Denmark paper.