Bed Bugs: Clinical Relevance and Control Options Stephen L. Doggett, a Dominic E. Dwyer, b Pablo F. Peñas, c and Richard C. Russell d Department of Medical Entomology, ICPMR, Westmead Hospital, Westmead, New South Wales, Australia a ; Centre for Infectious Diseases and Microbiology Laboratory Services, ICPMR, Westmead Hospital, and Sydney Institute for Emerging Infectious Diseases and Biosecurity, University of Sydney, Westmead, New South Wales, Australia b ; Department of Dermatology, Westmead Hospital, Westmead, New South Wales, Australia c ; and Department of Medical Entomology, University of Sydney at Westmead Hospital, Westmead, New South Wales, Australia d INTRODUCTION ............................................................................................................................................164 BED BUG IDENTIFICATION AND BIOLOGY .................................................................................................................165 CLINICAL RELEVANCE ......................................................................................................................................167 Clinical Overview .........................................................................................................................................167 Bed Bug Bite Reactions ...................................................................................................................................167 Diagnosis and Misdiagnosis ..............................................................................................................................170 Bite Treatment ............................................................................................................................................171 The Bite: Clinical Complications ..........................................................................................................................171 Infectious Diseases .......................................................................................................................................171 Miscellaneous Health Impacts ............................................................................................................................175 Mental Health Impacts ...................................................................................................................................176 Health Benefits? ..........................................................................................................................................178 Clinical Relevance Summary..............................................................................................................................178 BED BUG CONTROL ........................................................................................................................................179 Control Overview.........................................................................................................................................179 Bed Bug Prevention (Risk Management) .................................................................................................................179 Nonchemical Control .....................................................................................................................................180 Insecticidal Control .......................................................................................................................................181 The Future of Insecticides ................................................................................................................................183 BED BUGS: THE FUTURE ....................................................................................................................................184 ACKNOWLEDGMENTS......................................................................................................................................185 REFERENCES ................................................................................................................................................185 INTRODUCTION I n recent years, bed bugs have undergone a major resurgence in the number of infestations, leading to clinical and control prob- lems. This rise in activity is truly a global event, with increases in numbers of infestations reported for the Americas (153, 238, 246), Australia (99, 102, 104), Europe (37, 44, 170, 196, 232, 254), Asia (145, 149, 177, 282, 284), and Africa (227). Although bed bugs have a long association with humans, for a period from the 1950s to almost the start of the 21st century, this pest had become relatively uncommon, particularly in the more economically advantaged nations. Not only was the reappearance of this pest unexpected, but the degree of the resurgence has al- most been met with awe by many in the pest management indus- try. A survey of Australian professional pest managers in 2006 indicated that numbers of infestations rose by over 4,500% in the early years of the 21st century (102), comparable to what has been seen in other parts of the world (189, 246, 254). Bed bugs have become especially problematic in the United States, being re- ported in all 50 states; now, an estimated 1 out of 5 Americans either has had a bed bug infestation in their home or knows some- one who has encountered them (220). Currently, there is no peer- reviewed published data on the actual prevalence of bed bug in- festations across the United States. However, two of the largest pest control firms in the United States have released information on the most affected cities, based on the numbers of bed bug treatments undertaken by their respective companies, and this information corresponds well to hits on a dedicated bed bug web- site (http://www.bedbug.org.au). Despite limitations and poten- tial biases in these data (Table 1), the information probably rep- resents a moderately accurate indication of the current situation, with the most problematic cities being Chicago, New York, De- troit, Cincinnati, and Philadelphia (Table 1 and Fig. 1). Data from New York City showed that the number of bed bug complaints to the city council rose from 537 in 2004 to 10,985 in 2009 (43). Thus, bed bugs have rapidly become a widespread societal pest, and the risk of exposure through normal daily life appears to be increas- ing. In addition to homes and hotels, infestations are appearing in the office and retail environment, in the health and transport sec- tors, and in cinemas; in fact, they can be found in almost any location where people sleep or sit (103). What is particularly confounding about the resurgence is that it involves two species: the common bed bug, Cimex lectularius L., and the tropical bed bug, Cimex hemipterus F. The involvement of these two species makes the ascertainment of the reasons for this global resurgence more challenging. Various factors have been postulated to be responsible for the resurgence. Resistance to carbamate and pyrethroid insecticides (45, 167, 171, 185, 209, 261, 284), and, more recently, to the or- Address correspondence to Stephen L. Doggett, Stephen.Doggett@swahs.health.nsw.gov.au. Copyright © 2012, American Society for Microbiology. All Rights Reserved. doi:10.1128/CMR.05015-11 164 cmr.asm.org 0893-8512/12/$12.00 Clinical Microbiology Reviews p. 164 –192