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Indian Journal of Dermatology,... 2013Insects are a class of living creatures within the arthropods. Insect bite reactions are commonly seen in clinical practice. The present review touches upon the... (Review)
Review
Insects are a class of living creatures within the arthropods. Insect bite reactions are commonly seen in clinical practice. The present review touches upon the medically important insects and their places in the classification, the sparse literature on the epidemiology of insect bites in India, and different variables influencing the susceptibility of an individual to insect bites. Clinical features of mosquito bites, hypersensitivity to mosquito bites Epstein-Barr virus NK (HMB-EBV-NK) disease, eruptive pseudoangiomatosis, Skeeter syndrome, papular pruritic eruption of HIV/AIDS, and clinical features produced by bed bugs, Mexican chicken bugs, assassin bugs, kissing bugs, fleas, black flies, Blandford flies, louse flies, tsetse flies, midges, and thrips are discussed. Brief account is presented of the immunogenic components of mosquito and bed bug saliva. Papular urticaria is discussed including its epidemiology, the 5 stages of skin reaction, the SCRATCH principle as an aid in diagnosis, and the recent evidence supporting participation of types I, III, and IV hypersensitivity reactions in its causation is summarized. Recent developments in the treatment of pediculosis capitis including spinosad 0.9% suspension, benzyl alcohol 5% lotion, dimethicone 4% lotion, isopropyl myristate 50% rinse, and other suffocants are discussed within the context of evidence derived from randomized controlled trials and key findings of a recent systematic review. We also touch upon a non-chemical treatment of head lice and the ineffectiveness of egg-loosening products. Knockdown resistance (kdr) as the genetic mechanism making the lice nerves insensitive to permethrin is discussed along with the surprising contrary clinical evidence from Europe about efficacy of permethrin in children with head lice carrying kdr-like gene. The review also presents a brief account of insects as vectors of diseases and ends with discussion of prevention of insect bites and some serious adverse effects of mosquito coil smoke.
Topics: Animals; Bedbugs; Culicidae; Diptera; Humans; Hypersensitivity; Insect Bites and Stings; Pediculus; Randomized Controlled Trials as Topic
PubMed: 23442453
DOI: 10.4103/0378-6323.107629 -
Microbiology Spectrum Aug 2016Epidemic typhus caused by Rickettsia prowazekii is one of the oldest pestilential diseases of humankind. The disease is transmitted to human beings by the body louse... (Review)
Review
Epidemic typhus caused by Rickettsia prowazekii is one of the oldest pestilential diseases of humankind. The disease is transmitted to human beings by the body louse Pediculus humanus corporis and is still considered a major threat by public health authorities, despite the efficacy of antibiotics, because poor sanitary conditions are conducive to louse proliferation. Epidemic typhus has accompanied disasters that impact humanity and has arguably determined the outcome of more wars than have soldiers and generals. The detection, identification, and characterization of microorganisms in ancient remains by paleomicrobiology has permitted the diagnosis of past epidemic typhus outbreaks through the detection of R. prowazekii. Various techniques, including microscopy and immunodetection, can be used in paleomicrobiology, but most of the data have been obtained by using PCR-based molecular techniques on dental pulp samples. Paleomicrobiology enabled the identification of the first outbreak of epidemic typhus in the 18th century in the context of a pan-European great war in the city of Douai, France, and supported the hypothesis that typhus was imported into Europe by Spanish soldiers returning from America. R. prowazekii was also detected in the remains of soldiers of Napoleon's Grand Army in Vilnius, Lithuania, which indicates that Napoleon's soldiers had epidemic typhus. The purpose of this article is to underscore the modern comprehension of clinical epidemic typhus, focus on the historical relationships of the disease, and examine the use of paleomicrobiology in the detection of past epidemic typhus outbreaks.
Topics: Animals; Bacteriological Techniques; Disease Outbreaks; Fossils; Global Health; History, 18th Century; History, 19th Century; History, 20th Century; History, 21st Century; Humans; Paleopathology; Pediculus; Polymerase Chain Reaction; Rickettsia prowazekii; Typhus, Epidemic Louse-Borne
PubMed: 27726780
DOI: 10.1128/microbiolspec.PoH-0010-2015 -
Epidemiology and Infection Jan 2019Louse-borne relapsing fever (LBRF) is an epidemic disease with a fascinating history from Hippocrates' times, through the 6th century 'Yellow Plague', to epidemics in... (Review)
Review
Louse-borne relapsing fever (LBRF) is an epidemic disease with a fascinating history from Hippocrates' times, through the 6th century 'Yellow Plague', to epidemics in Ireland, Scotland and England in the 19th century and two large Afro-Middle Eastern pandemics in the 20th century. An endemic focus persists in Ethiopia and adjacent territories in the Horn of Africa. Since 2015, awareness of LBRF in Europe, as a re-emerging disease, has been increased dramatically by the discovery of this infection in dozens of refugees arriving from Africa.The causative spirochaete, Borrelia recurrentis, has a genome so similar to B. duttonii and B. crocidurae (causes of East and West African tick-borne relapsing fever), that they are now regarded as merely ecotypes of a single genomospecies. Transmission is confined to the human body louse Pediculus humanus corporis, and, perhaps, the head louse P. humanus capitis, although the latter has not been proved. Infection is by inoculation of louse coelomic fluid or faeces by scratching. Nosocomial infections are possible from contamination by infected blood. Between blood meals, body lice live in clothing until the host's body temperature rises or falls, when they seek a new abode.The most distinctive feature of LBRF, the relapse phenomenon, is attributable to antigenic variation of borrelial outer-membrane lipoprotein. High fever, rigors, headache, pain and prostration start abruptly, 2-18 days after infection. Petechial rash, epistaxis, jaundice, hepatosplenomegaly and liver dysfunction are common. Severe features include hyperpyrexia, shock, myocarditis causing acute pulmonary oedema, acute respiratory distress syndrome, cerebral or gastrointestinal bleeding, ruptured spleen, hepatic failure, Jarisch-Herxheimer reactions (J-HR) and opportunistic typhoid or other complicating bacterial infections. Pregnant women are at high risk of aborting and perinatal mortality is high.Rapid diagnosis is by microscopy of blood films, but polymerase chain reaction is used increasingly for species diagnosis. Severe falciparum malaria and leptospirosis are urgent differential diagnoses in residents and travellers from appropriate geographical regions.High untreated case-fatality, exceeding 40% in some historic epidemics, can be reduced to less than 5% by antibiotic treatment, but elimination of spirochaetaemia is often accompanied by a severe J-HR.Epidemics are controlled by sterilising clothing to eliminate lice, using pediculicides and by improving personal hygiene.
Topics: Animals; Anti-Bacterial Agents; Borrelia; Female; Humans; Insect Vectors; Male; Pediculus; Relapsing Fever
PubMed: 30869050
DOI: 10.1017/S0950268819000116 -
Microbiology Spectrum Aug 2016Lice are a classic example of cospeciation. Human lice confirm this cospeciation with lice specialized in hominids which differ from those of gorillas and chimpanzees.... (Review)
Review
Lice are a classic example of cospeciation. Human lice confirm this cospeciation with lice specialized in hominids which differ from those of gorillas and chimpanzees. Head lice and body lice seem to belong to closely related species with different ecotypes and a different geographical distribution which may reflect population movements. Paleo-entomology allows us in some cases to trace the migrations of archaic human populations. The analysis of lice found on mummies in Egypt and South America has clarified a certain number of these migrations, also the study of lice and the diseases they transmit has shed a new light on the epidemics of the past.
Topics: Americas; Animals; Egypt; Entomology; Human Migration; Humans; Paleopathology; Pediculus
PubMed: 27726759
DOI: 10.1128/microbiolspec.PoH-0005-2014 -
International Journal of Infectious... Jul 2020Parasitic infections of the eye are a major cause of ocular-surface diseases globally. While most infections are treatable, parasites can cause varying levels of damage...
INTRODUCTION
Parasitic infections of the eye are a major cause of ocular-surface diseases globally. While most infections are treatable, parasites can cause varying levels of damage mostly due to late diagnosis or misdiagnosis as a result of doctors' unfamiliarity with their characteristics of latency and crypsis, as well as lack of awareness by the patients.
CASE REPORTS
In this study, we present three cases of phthiriasis palpebrarum, thelaziasis, and ophthalmomyiasis, respectively. Two of the cases were treated at the clinic and did not recur. One patient refused treatment and was lost to follow-up.
DISCUSSION
By evaluating the natural histories, morphology, symptoms, clinical findings, and treatment of these parasitic diseases, we systematically analyzed several distinct and unique parasite characteristics, especially latency and crypsis. Furthermore, we have proposed specific examination techniques and methods as well as prevention and treatment strategies from these specific perspectives, aiming to prompt timely diagnoses and early interventions for these diseases by health care workers and improve the public's awareness of parasitic infections.
CONCLUSION
Parasitosis on the ocular surface is a global infectious disease, and prevention strategies include maintaining personal and environmental hygiene and limiting contact with animals. We recommend that health care workers should enhance their ability to detect and diagnose these diseases while promoting the public's awareness of them in the context of our new perspectives.
Topics: Aged, 80 and over; Animals; Child; Delayed Diagnosis; Diagnostic Errors; Eye Infections, Parasitic; Eyelashes; Female; Humans; Lice Infestations; Male; Middle Aged; Myiasis; Phthirus; Recurrence; Spirurida Infections; Thelazioidea
PubMed: 32447120
DOI: 10.1016/j.ijid.2020.05.061 -
BMJ Case Reports Apr 2013
Topics: Animals; Blepharitis; Diagnosis, Differential; Female; Humans; Lice Infestations; Mercury Compounds; Middle Aged; Ointments; Oxides; Phthirus
PubMed: 23580689
DOI: 10.1136/bcr-2013-009272 -
Frontiers in Cellular and Infection... 2019is an obligate bloodsucking ectoparasite of human that includes two ecotypes, head louse and body louse, which differ slightly in morphology and biology, but have... (Review)
Review
is an obligate bloodsucking ectoparasite of human that includes two ecotypes, head louse and body louse, which differ slightly in morphology and biology, but have distinct ecologies. Phylogenetically, they are classified on six mitochondrial clades (A, B, C, D, E, and F), head louse encompasses the full genetic diversity of clades, while body louse belongs to clades A and D. Recent studies suggested that not only body louse, but also head louse can transmit disease, which warrants greater attention as a serious public health problem. The recent sequencing of body louse genome confirmed that has the smallest genome of any hemimetabolous insect reported to date, and also revealed numerous interesting characteristics in the nuclear and mitochondrial genomes. The transcriptome analyses showed that body and head lice were almost genetically identical. Indeed, the phenotypic flexibility associated with the emergence of body lice, is probably a result of regulatory changes, perhaps epigenetic in origin, triggered by environmental signals. Current lice control strategies have proven unsuccessful. For instance, ivermectin represents a relatively new and very promising pediculicide. However, ivermectin resistance in the field has begun to be reported. Therefore, novel opportunities for pest control strategies are needed. Our objective here is to review the current state of knowledge on the biology, epidemiology, phylogeny, disease-vector and control of this fascinating and very intimate human parasite.
Topics: Animals; Bacteria; Communicable Disease Control; Evolution, Molecular; Genome; Humans; Insect Vectors; Insecticide Resistance; Insecticides; Lice Infestations; Mitochondria; Pediculus; Phylogeny; Phylogeography
PubMed: 32039050
DOI: 10.3389/fcimb.2019.00474 -
International Journal of Dermatology Mar 2021Head louse infestations continue to be a concern of public health in most countries, including the most developed ones. The present recommendations are intended to... (Review)
Review
Head louse infestations continue to be a concern of public health in most countries, including the most developed ones. The present recommendations are intended to inform and stress the role and impact of the different authorities, institutions, industry, and the public in the control of head lice in order to reduce the prevalence of this parasite. We encourage health authorities to pursue more effective methods to correctly identify such infestations, and evaluate existing and new pediculicides, medical devices, louse repellents, and louse- and nit-removal remedies. Pediculicides and medical devices must have verifiable claims in the instructions for use and should be tested periodically to document current levels of resistance by lice to the active ingredients and to the formulated products. Where the prevalence of lice is claimed to be epidemic, children should be periodically evaluated objectively to document the actual level of prevalence. Continuing education for health providers and the general population promises to correct misinformation regarding the biology, prevention, and management of lice. Parents should regularly inspect their children for head lice and treat as necessary. Health authorities are encouraged to eliminate policies and practices that rely upon school exclusion as a means to reduce incidence and prevalence, e.g., the 'no-nit' policy which lacks scientific justification, and are counterproductive to the health and welfare of children.
Topics: Animals; Child; Humans; Lice Infestations; Pediculus; Prevalence; Public Health; Scalp Dermatoses; Schools
PubMed: 32767380
DOI: 10.1111/ijd.15096 -
Emerging Infectious Diseases 1998Rickettsial diseases, important causes of illness and death worldwide, exist primarily in endemic and enzootic foci that occasionally give rise to sporadic or seasonal... (Review)
Review
Rickettsial diseases, important causes of illness and death worldwide, exist primarily in endemic and enzootic foci that occasionally give rise to sporadic or seasonal outbreaks. Rickettsial pathogens are highly specialized for obligate intracellular survival in both the vertebrate host and the invertebrate vector. While studies often focus primarily on the vertebrate host, the arthropod vector is often more important in the natural maintenance of the pathogen. Consequently, coevolution of rickettsiae with arthropods is responsible for many features of the host-pathogen relationship that are unique among arthropod-borne diseases, including efficient pathogen replication, long-term maintenance of infection, and transstadial and transovarial transmission. This article examines the common features of the host-pathogen relationship and of the arthropod vectors of the typhus and spotted fever group rickettsiae.
Topics: Animals; Arthropod Vectors; Dermacentor; Humans; Pediculus; Rickettsia; Rickettsia Infections; Rocky Mountain Spotted Fever; Siphonaptera; Typhus, Epidemic Louse-Borne
PubMed: 9621188
DOI: 10.3201/eid0402.980205 -
FEBS Letters Jun 2001Eukaryotes have developed an elaborate series of interactions with bacteria that enter their bodies and/or cells. Genome evolution of symbiotic and parasitic bacteria... (Review)
Review
Eukaryotes have developed an elaborate series of interactions with bacteria that enter their bodies and/or cells. Genome evolution of symbiotic and parasitic bacteria multiplying inside eukaryotic cells results in both convergent and divergent changes. The genome sequences of the symbiotic bacteria of aphids, Buchnera aphidicola, and the parasitic bacteria of body louse and humans, Rickettsia prowazekii, provide insights into these processes. Convergent genome characteristics include reduction in genome sizes and lowered G+C content values. Divergent evolution was recorded for amino acid and cell wall biosynthetic genes. The presence of pseudogenes in both genomes provides examples of recent gene inactivation events and offers clues to the process of genome deterioration and host-cell adaptation.
Topics: Adaptation, Physiological; Animals; Aphids; Buchnera; Energy Metabolism; Evolution, Molecular; Genome, Bacterial; Humans; Pediculus; Rickettsia prowazekii; Symbiosis
PubMed: 11412844
DOI: 10.1016/s0014-5793(01)02459-0