Improving care for delusional infestation patients: What can dermatologists learn from an entomologist?

Delusional Infestation (DI), represents one of the most difficult patient encounters that dermatology practitioners may experience. It is common for DI patients to doctor shop. Thus, dermatologists are one of several disciplines that may encounter DI patients in their practices. Others include veterinarians, epidemiologists, emergency departments, mental health practitioners, and entomologists. In this article, entomologist, Dr. Gale E. Ridge, with extensive DI experience, was interviewed to find out what an entomologist's perspective has been and what we, the dermatology providers, can learn from that. This is followed by a discussion by the dermatology experts on how the experience of entomologists compares to our experience and what we can learn from them.

Human immunoglobulin G responses to Cimex lectularius L. saliva.

AIMS: To investigate the immunoglobulin (Ig) G response after being fed upon by Cimex lectularius L. METHODS AND RESULTS: Participants were fed upon by three male C lectularius insects weekly for a month. Blood was obtained before the feeding and at the last feeding, which was used for immunoblots against bed bug salivary gland extract, with antihuman Immunoglobulin G (IgG) secondary antibodies. No consistent IgG changes developed in 11 humans serially fed upon by C lectularius. Two participants had new IgG responses to proteins at molecular weights of approximately 12-13 kDa, and one had an IgG response to a protein at approximately 40 kDa. At the last study visit, more intense IgG bands to proteins at molecular weights of 12-13 kDa had developed in 55% of participants (6/11) and at molecular weights of ≈30, ≈40 and ≈70 kDa in 45% (5/11) compared with the first study visit. Nitrophorin and apyrase were the most common C lectularius proteins identified with liquid chromatography-tandem mass spectrometry in both crushed bed bug salivary gland extract and post-bed bug feeding extract. CONCLUSIONS: Human participants did not have consistent IgG responses to crushed C lectularius salivary gland extract.

A screen of pharmaceutical drugs for their ability to cause short-term morbidity and mortality in the common bed bug, Cimex lectularius L.

The common bed bug, Cimex lectularius L., is a hematophagous ectoparasite that preferentially feeds on humans. Pharmaceuticals present in a person's blood may adversely affect C. lectularius when it feeds. We fed >10,000 C. lectularius on blood samples containing more than 400 different drug doses and drug combinations using an in vitro feeding system to determine insect mortality. The majority of drug doses approximated the peak plasma concentration in humans taking those drugs. Twenty-one drugs were found to cause >17% 12-14-day mortality compared to 8.5% mortality in the control (p < 0.05), but postliminary testing of three of the drugs, famotidine, ethambutol, and primaquine, did not demonstrate an increase in C. lectularius mortality. We also tested 23 drugs for their effects on C. lectularius fecundity. The results may have implications for understanding C. lectularius population dynamics in an infestation.

Toxicity and potential utility of ivermectin and moxidectin as xenointoxicants against the common bed bug, Cimex lectularius L.

The recent resurgence of the common bed bug Cimex lectularius L. throughout western industrialized nations has been facilitated in part by the insect becoming pesticide-resistant. Novel control strategies, including xenointoxication, should be considered to combat C. lectularius. Ivermectin, a U.S. Food and Drug Administration (FDA)-approved treatment for several human parasites, and the antiparasitic drug moxidectin, currently being explored in human clinical trials, were evaluated for efficacy against C. lectularius. Results showed that C. lectularius fed on ivermectin or moxidectin blood concentrations of >25 ng/mL and had significantly higher mortality (50-100 %) than controls (0-6 %) by day 13. Bed bugs that survived a blood meal containing >2.5 ng/mL of ivermectin suffered long-term sequelae including reduced fecundity, feeding difficulty, and incomplete ecdysis. Some insects that survived a blood meal containing ≤75 ng/mL moxidectin were able to feed and reproduce.

Engineered Nanoparticles, Natural Nanoclay and Biochar, as Carriers of Plant-Growth Promoting Bacteria.

The potential of biochar and nanoparticles to serve as effective delivery agents for beneficial bacteria to crops was investigated. Application of nanoparticles and biochar as carriers for beneficial bacteria improved not only the amount of nitrogen-fixing and phosphorus-solubilizing bacteria in soil, but also improved chlorophyll content (1.2-1.3 times), cell viability (1.1-1.5 times), and antioxidative properties (1.1-1.4 times) compared to control plants. Treatments also improved content of phosphorus (P) (1.1-1.6 times) and nitrogen (N) (1.1-1.4 times higher) in both tomato and watermelon plants. However, the effect of biochars and nanoparticles were species-specific. For example, chitosan-coated mesoporous silica nanoparticles with adsorbed bacteria increased the phosphorus content in tomato by 1.2 times compared to a 1.1-fold increase when nanoclay with adsorbed bacteria was applied. In watermelon, the situation was reversed: 1.1-fold increase in the case of chitosan-coated mesoporous silica nanoparticles and 1.2 times in case of nanoclay with adsorbed bacteria. Our findings demonstrate that use of nanoparticles and biochar as carriers for beneficial bacteria significantly improved plant growth and health. These findings are useful for design and synthesis of novel and sustainable biofertilizer formulations.

Rabbit Bot Fly Furuncular, Tracheopulmonary, and Human Bot Fly Infestations in Connecticut (Oestridae: Cuterebrinae).

Endemic and tropical human bot infestations are relatively uncommon or unreported in the United States. We report two cases in Connecticut: an unusual furuncular and respiratory myiasis by the rabbit bot Cuterebra buccata (Fab.) (Diptera: Oestridae) in a 74-yr-old male and a case of human bot fly, Dermatobia hominis (L.) (Diptera: Oestridae), myiasis in a 4-yr-old female with a tropical travel history with her family. Identification of C. buccata was based morphologically, in part, on spinal armature and further corroborated by DNA sequencing of the mitochondrial COI gene and comparison to the National Center for Biotechnology Information GenBank DNA sequence database. The resulting annotated sequence data were deposited into the National Center for Biotechnology Information GenBank. The unique medical aspects, and limitations and specifics on bot fly larval habits and identification are discussed.

An enhanced procedure for urban mobile methane leak detection.

Leaked methane from natural gas distribution pipelines is a significant human and environmental health problem in urban areas. To assess this risk, urban mobile methane leak surveys were conducted, using innovative methodology, on the streets of Hartford, Danbury, and New London, Connecticut, in March 2019. The Hartford survey was done to determine if results from a 2016 survey (Keyes et al., 2019) were persistent, and surveys in additional towns were done to determine if similar findings could be made using an identical approach. Results show that Hartford continues to be problematic, with approximately 3.4 leaks per road mile observed in 2016 and 4.3 leaks per mile estimated in 2019, similar to that previously found in Boston, Massachusetts (Phillips et al., 2013). A preliminary estimate of methane leaks in Hartford is 0.86 metric tonnes per day (or 313 metric tonnes per year), equivalent to 42,840 cubic feet per day of natural gas, and a daily gas consumption of approximately 214 U.S. households. Moreover, the surveys and analyses done for Danbury and New London also reveal problematic leaks, particularly for Danbury with an estimated 3.6 leaks per mile. Although road miles covered in New London were more limited, the survey revealed leak-prone areas, albeit with a range of methane readings lower than those in Hartford and Danbury. Data collection methods for all studies is first reported here and are readily transferable to similar urban settings. This work demonstrates the actionable value that can be gained from data-driven evaluations of urban pipeline performance, and if supplemented with a map of leak-prone pipe geo-location, and information on pipeline operating pressures, will provide a spatial database facilitating proactive repair and replacement of leak-prone urban pipes, a considerable improvement compared to reactive mitigation of human-reported leaks. While this work pertains to the selected urban towns in the Northeast, it exemplifies issues and opportunities nationwide in the United States.

Ivermectin and Moxidectin Can Incapacitate Different Strains of the Common Bed Bug Cimex lectularius L.: A Study.

The common bed bug Cimex lectularius L. (C. lectularius) is a hematophagous ectoparasite that has recently resurged in many western industrialized nations, in part due to pesticide resistance. Using a laboratory feeding system, we found that the antiparasitic drugs ivermectin and moxidectin did not show higher incapacitation rates in pyrethroid-resistant strains of C. lectularius compared to a pyrethroid-susceptible strain. Additionally, we developed a high-performance liquid chromatography (HPLC) and mass spectroscopy (MS) assay to measure the concentrations of ivermectin inside C. lectularius and found that ivermectin persists in the insects for up to one month. HPLC/MS will be useful in understanding the pathophysiology behind the long-term morbidity observed in C. lectularius that consumes a sublethal dose of ivermectin.

The Benefit of a Single Oral Dose of Ivermectin in Humans: The Adverse Effects on Cimex lectularius L. Populations and Fecundity.

Objective To measure the population size and fecundity of the common bed bug Cimex lectularius L. (C. lectularius) after feeding it with the blood obtained from human subjects who have consumed a single dose of ivermectin. Methods  Serial blood samples were obtained from two human subjects at hour 0 (control) and 4-96 hours after they received a single 0.2 mg/kg dose of ivermectin. The blood samples were then fed to 2,273 bed bugs. Bed bug incapacitation rates, fecundity, and population sizes were recorded over a 54-day period. Whole blood ivermectin levels were measured in the human subjects and the insects. Results  The fold change in the size of the control group population over the course of the experiment was found to be 2.16. This was significantly greater (p: <.001) than for all the post-ivermectin feeding groups (range: -11.04-1.43). Two weeks after the experiment, the number of eggs laid per live adult female bed bug per day was 10.74 for controls, which was significantly different (p: <0.001) compared to all the post-ivermectin feeding groups (range: 0-4.28). Conclusions  There were significant reductions in C. lectularius population size and fecundity in insects that fed on blood obtained from human study subjects up to 96 hours after they have consumed a single oral dose of ivermectin.

Xenointoxication of a Rabbit for the Control of the Common Bed Bug Cimex lectularius L. Using Ivermectin.

Human bed bug infestations have undergone a recent global resurgence. The human antiparasitic drug ivermectin has been proposed as a strategy to help control bed bug infestations, but in vivo data are lacking. We allowed separate populations of the common bed bug, Cimex lectularius L., to feed once on a rabbit before and after it was injected subcutaneously with 0.3 mg/kg of ivermectin, and bed bug morbidity and mortality were recorded. Ivermectin levels in the rabbit were measured using high-performance liquid chromatography and mass spectroscopy. Ivermectin blood levels of ∼2 ng/mL caused reductions in bed bug fecundity, and levels of >8 ng/mL caused bed bug death and long-term morbidity including reductions in refeeding, mobility, reproduction, and molting. Gut bacterial cultures from the fed bed bugs showed that ivermectin altered the bed bug gut microbiome.

The First Evidence of Nanism in Ixodes (Ixodes) scapularis (Acari: Ixodidae), Found Parasitizing a Human Host.

Ixodes scapularis Say 1821, the primary vector of several human pathogens in the northeastern and upper Midwestern United States, has considerable genetic and morphological variation throughout its range. Recently, developmental or teratological abnormalities have been observed in this species for the first time, further complicating morphological identification. Here, we report the first evidence of nanism (dwarfism) in I. scapularis, found parasitizing a human host. We used molecular methods and scanning electron microscopy to identify the specimen. Morphological identification confirmed that the specimen is substantially smaller, approximately half the size, than a typical I. scapularis female. Here we discuss the recent reports of teratological abnormalities in I. scapularis, particularly from the Hudson River valley region of the northeastern United States, and highlight the need for additional studies of teratology in this important species and its potential implications in disease transmission.

Paederus dermatitis in a seafarer diagnosed via telemedicine collaboration.

Seafarers are traveling workers, subject to unique exposures and generally isolated from adequate medical care. This case report of paederus dermatitis diagnosed at sea highlights the importance of a multidisciplinary diagnostic approach and telecommunication in providing remote medical advice to isolated traveling workers such as seafarers.