[The worldwide expansion of bed bugs also constitutes a problem in Germany]

Participatory epidemiological approaches for risk assessment of bed bug (Insecta: Hemiptera: Cimicidae) infestation in public hospitals in the city of Faisalabad, Punjab, Pakistan

This study was to determine risk assessment associated with bed bugs (Insecta: Hemiptera: Cimicidae) using participatory epidemiological tools in the selected public hospitals of district Faisalabad, Punjab, Pakistan. Bed bugs were collected and morphologically identified through a standard taxonomic key. A descriptive cross-sectional survey of patients using a pre-designed questionnaire containing open-ended and closed-ended questions was conducted for six months between January 2023 and June 2023. Of the 384 participants, 113 (29.43%) had experienced itching or skin irritation presumably from the bed bug feeding activity. The study further revealed patients above age 40 (35.43%) and males (30.57%) experienced greater skin irritation responses compared to other participants. Among administrative divisions (tehsils) in the city of Faisalabad, Tehsil Sadar had the highest number of participants with itching or skin irritation (35.48%), while Tehsil Chak Jhumra had the lowest number (24.62%). Most observations of bed bugs by patients were in their beds (10.42%), with chairs (3.91%) being the second most reported location. However, we found bed bugs from only 17 (4.42%) beds and 5 (1.30%) from chairs. A majority of patients (60.9%) reported daily change of bedding; however, a significant proportion (29.9%) reported infrequent changes. About 25.5% of the patients shared beds with others and about 77.1% of patients brought their own bedding or clothing to the hospitals. The current study concluded that the bed bug infestation is a problem in the public hospitals of Faisalabad, Punjab, Pakistan. Risk factors such as sharing a bed, infrequent change of bedding, and bringing personal bedding to hospital while having medical treatment pose a concern.

A Novel Simulated-Use Test for Determining the Efficacy of Insecticides Against Bed Bugs (Hemiptera: Cimicidae)

The common bed bug Cimex lectularius L. has undergone a worldwide expansion in recent years, due to increased opportunities for dispersal and development of insecticide resistance. For successful control, efficacy testing of products against bed bugs and determination of insecticide resistance under practical conditions are of outstanding importance. A new test system mimicking the practical use situation of residual insecticides was developed and evaluated. Bed bugs were attracted by CO2 and heat to cross surfaces treated with alpha-cypermethrin and bendiocarb. In contrast to the complete efficacy of alpha-cypermethrin (less than 1% surviving bed bugs [with one exception of 5%]), only 45.3, 46, and 29% of insecticide-susceptible bed bugs showed lethal damage 7 d after contact with freshly bendiocarb-treated wallpaper or insecticide aged for 1 or 2 wk. Results show that the efficacy of different insecticides can be assessed with this new test system. Moreover, susceptibility to deltamethrin of five bed bug field strains, collected from infested apartments in Berlin, Germany, was determined in a filter paper contact bioassay. Resistance ratios (RRs) ranged between 4.3 and 20.7. In the novel simulated-use test, efficacy of alpha-cypermethrin was tested against the bed bug strain with the highest RR. In contrast to the insecticide-susceptible laboratory strain, alpha-cypermethrin was not effective against the field strain, where 26-50% of the bed bugs survived and even laid eggs. These results provide evidence for the presence of practically relevant pyrethroid resistance in bed bugs in Germany.

Insecticide resistance and resistance mechanisms in bed bugs, Cimex spp. (Hemiptera: Cimicidae)

The worldwide resurgence of bed bugs [both Cimex lectularius L. and Cimex hemipterus (F.)] over the past two decades is believed in large part to be due to the development of insecticide resistance. The transcriptomic and genomic studies since 2010, as well as morphological, biochemical and behavioral studies, have helped insecticide resistance research on bed bugs. Multiple resistance mechanisms, including penetration resistance through thickening or remodelling of the cuticle, metabolic resistance by increased activities of detoxification enzymes (e.g. cytochrome P450 monooxygenases and esterases), and knockdown resistance by kdr mutations, have been experimentally identified as conferring insecticide resistance in bed bugs. Other candidate resistance mechanisms, including behavioral resistance, some types of physiological resistance (e.g. increasing activities of esterases by point mutations, glutathione S-transferase, target site insensitivity including altered AChEs, GABA receptor insensitivity and altered nAChRs), symbiont-mediated resistance and other potential, yet undiscovered mechanisms may exist. This article reviews recent studies of resistance mechanisms and the genes governing insecticide resistance, potential candidate resistance mechanisms, and methods of monitoring insecticide resistance in bed bugs. This article provides an insight into the knowledge essential for the development of both insecticide resistance management (IRM) and integrated pest management (IPM) strategies for successful bed bug management.

Bed bugs and possible transmission of human pathogens: a systematic review

The global population of bed bugs (Cimex lectularius and Cimex hemipterus, family Cimicidae) has undergone a significant resurgence since the late 1990s. This is likely due to an increase in global travel, trade, and the number of insecticide-resistant bed bugs. The global bed bug population is estimated to be increasing by 100-500 % annually. The worldwide spread of bed bugs is concerning, because they are a significant socioeconomic burden and a major concern to public health. According to the United States Environmental Protection Agency, bed bugs are "a pest of significant health importance." Additionally, 68 % of U.S. pest professionals reported that bed bugs are the most challenging pest to treat. Upwards of 45 disease pathogens have been reported in bed bugs. Recent studies report that bed bugs may be competent vectors for pathogens, such as Bartonella quintana and Trypanosoma cruzi. However, public health reports have thus far failed to produce evidence that major infectious disease outbreaks have been associated with bed bugs. Since many disease pathogens have previously been reported in bed bugs and the worldwide bed bug population is now drastically increasing, it stands to reason to wonder if bed bugs might transmit human pathogens. This review includes a literature search on recently published clinical and laboratory studies (1990-2016) investigating bed bugs as potential vectors of infectious disease, and reports the significant findings and limitations of the reviewed studies. To date, no published study has demonstrated a causal relationship between bed bugs and infectious disease transmission in humans. Also, we present and propose to expand on previous hypotheses as to why bed bugs do not transmit human pathogens. Bed bugs may contain "neutralizing factors" that attenuate pathogen virulence and, thereby, decrease the ability of bed bugs to transmit infectious disease.

[On the relevance of the official lists for notified products and measures for disinfection, disinfestation and control of vertebrate pests ordered by an authority on the legal basis of § 18 IfSG (German Protection against Infection Act)]

In order to protect human health against communicable diseases, the German Protection against Infection Act (IfSG) requires the use of officially approved products and methods for officially ordered disinfection, disinfestation (control of arthropods) as well as measures for the management of vertebrate pests that spread pathogens. Official approval is granted by registration in lists published by the responsible federal health authorities and only for products and methods that have been tested and found to be sufficiently effective and do not have an unacceptable impact on health and the environment (§ 18 IfSG). It is not compulsory for manufacturers to have their products and methods listed in accordance with § 18 IfSG. In particular listing is not a prerequisite for access to the German market. Users are free to choose a product as long as no officially ordered measure, i.e. disinfection, disinfestation or measures against vertebrate pests, according to § 18 IfSG applies. However, it is highly recommended to use approved products included in the abovementioned lists even for routine application, as these registered products and methods have been tested, i.e. the efficacy has been proven by means of specific, recognized and quality assured testing procedures or by expert reports which have been confirmed by independent institutions.