Efficacy of Afoxolaner (NexGard®) in the treatment of furuncular myiasis caused by Dermatobia hominis fly (Diptera: Cuterebridae) in naturally infested dogs.

Furuncular myiasis due to Dermatobia hominis is the second most common skin diseases in dogs that live in tropical climates in Central and South America, causing discomfort and injuring in the connective tissue of the affected dog. Therefore, the objective of the study was to evaluate the effectiveness of Afoxolaner (Nexgard®) in the treatment of canine furuncular myiasis. Twenty-five dogs naturally infested with D. hominis were selected and received a single oral dose of 2.5 mg/kg body weight of Afoxolaner (NexGard®). Larval infestations were classified as light (< 2 larvae), moderate (2 to 5 larvae) and severe (> 5 larvae), according to the number of larvae found in the wound. Twenty-four hours post-treatment, infested lesions were inspected, and all larvae were mechanically removed from the lesion site. All removed larvae were identified as D. hominis larvae and were found dead within 24 h after treatment, demonstrating 100% larvicidal efficacy of Afoxolaner against D. hominis larvae.

Antennal transcriptome analysis reveals sensory receptors potentially associated with host detection in the livestock pest Lucilia cuprina.

BACKGROUND: Lucilia cuprina (Wiedemann, 1830) (Diptera: Calliphoridae) is the main causative agent of flystrike of sheep in Australia and New Zealand. Female flies lay eggs in an open wound or natural orifice, and the developing larvae eat the host's tissues, a condition called myiasis. To improve our understanding of host-seeking behavior, we quantified gene expression in male and female antennae based on their behavior. METHODS: A spatial olfactometer was used to evaluate the olfactory response of L. cuprina mated males and gravid females to fresh or rotting beef. Antennal RNA-Seq analysis was used to identify sensory receptors differentially expressed between groups. RESULTS: Lucilia cuprina females were more attracted to rotten compared to fresh beef (> fivefold increase). However, males and some females did not respond to either type of beef. RNA-Seq analysis was performed on antennae dissected from attracted females, non-attracted females and males. Transcripts encoding sensory receptors from 11 gene families were identified above a threshold (≥ 5 transcript per million) including 49 ATP-binding cassette transporters (ABCs), two ammonium transporters (AMTs), 37 odorant receptors (ORs), 16 ionotropic receptors (IRs), 5 gustatory receptors (GRs), 22 odorant-binding proteins (OBPs), 9 CD36-sensory neuron membrane proteins (CD36/SNMPs), 4 chemosensory proteins (CSPs), 4 myeloid lipid-recognition (ML) and Niemann-Pick C2 disease proteins (ML/NPC2), 2 pickpocket receptors (PPKs) and 3 transient receptor potential channels (TRPs). Differential expression analyses identified sex-biased sensory receptors. CONCLUSIONS: We identified sensory receptors that were differentially expressed between the antennae of both sexes and hence may be associated with host detection by female flies. The most promising for future investigations were as follows: an odorant receptor (LcupOR46) which is female-biased in L. cuprina and Cochliomyia hominivorax Coquerel, 1858; an ABC transporter (ABC G23.1) that was the sole sensory receptor upregulated in the antennae of females attracted to rotting beef compared to non-attracted females; a female-biased ammonia transporter (AMT_Rh50), which was previously associated with ammonium detection in Drosophila melanogaster Meigen, 1830. This is the first report suggesting a possible role for ABC transporters in L. cuprina olfaction and potentially in other insects.

Molecular epidemiology of the Old World screwworm fly (OWSF) in Iraq, and the genetic structure of various OWSF populations worldwide.

Despite being endemic in Iraq, no reports have been published in the past 10 years to update the molecular epidemiology of the Old World screwworm fly (OWSF), Chrysomya bezziana, in this country. In the present study, 130 sheep from 10 Iraqi governorates were found infected with C. bezziana larvae, whose identities were PCR-confirmed based on the cytochrome b (Cytb) gene, and 23 isolates from various tested governorates were successfully sequenced. Although most isolates (n = 20) belonged to the common haplotype circulating in Iraq, two new haplotypes were detected. Significant changes in OWSF epidemiology in Iraq were also suggested, since infestations were detected, for the first time, in Nineveh governorate. Isolates of the present study were combined to those previously published from Iraq and worldwide, collected after searching the GenBank, and various genetic and population structure analyses were conducted. These isolates displayed a great statistically significant value when tested for the purifying (negative) selection, suggesting the limited occurrence of genetic variations, which was evidenced by the high sequence conservation (C = 0.937) value detected. A few isolates from Africa were revealed during our search, and clustered in a separate lineage other than that of the Asian isolates. The latter displayed different genetic variation patterns when compared. For example, isolates from geographically separate regions, e.g., the Gulf Arab countries and South-Eastern Asia had marked genetic differences. On the other hand, isolates from regions with close geographic proximity (the Gulf Arab countries and Iran) had limited genetic subdivision. This is not the case when comparing isolates from 10 islands in the Indonesian Archipelago. Populations from Sumatra and Sumba were isolated and displayed high genetic variations toward the other populations. On the contrary, populations from Sulawesi, Lombok and Sumbawa displayed limited genetic variations. This is particularly important, since it can help detecting the dynamics of establishing the sterile insect technique over various regions as an effective control strategy against the OWSFs.

Uterovaginal prolapse complicated by urogenital myiasis.

Urogenital myiasis is a rare entity that is usually manifested in women belonging to lower socioeconomic status residing in tropical or subtropical nations with poor hygiene or intellectual disability. It is caused by fly larvae capable of penetrating body orifices and healthy or necrotic tissue. The larvae penetrate the skin, forming painful, inflammatory nodules that can form fistula to the internal organs or the skin's surface. Serous and haemorrhagic exudation, along with crawling larvae, are encountered. Some complications, such as secondary infection and tetanus, have been documented. The prognosis is generally good, and treatment consists of removing the parasitic larvae and thoroughly cleansing the affected area.We present a case of a postmenopausal woman with parity 3 and live issue 1 in her early 50s from lower socioeconomic status diagnosed with uterovaginal prolapse complicated by myiasis. The patient was managed successfully with systemic antibiotics, manual removal of myiasis and hysterectomy.

Ophthalmomyiasis Case Caused by Two Blow Fly (Diptera: Calliphoridae) Species in North America.

Ophthalmomyiasis is the result of fly larvae feeding on the tissues of the eye. Commonly associated with poor hygiene and open wounds, this condition is rare and often stigmatized. Treatment can be straightforward, and full recovery is common. Identifying the species responsible for ophthalmomyiasis is important for the medical, forensic, and entomological communities. Here, we present a case of ophthalmomyiasis where 30-40 blow fly (Diptera: Calliphoridae) larvae were removed from the eye of a human male. A representative subsample of five larvae was used for taxonomic identification via two approaches (a) DNA analysis, via sequencing of the complete mitochondrial genome (mtGenome) and comparison of the mtGenome and mitochondrial COI barcode region to GenBank, and (b) morphology, examination of the posterior spiracles using microscopy, and comparison to published larval descriptions of blow flies. Two species of blow flies were identified from the DNA analysis: Lucilia coeruleiviridis and Phormia regina. Morphological examination could only confirm L. coeruleiviridis as being present. To our knowledge, finding two blow fly species causing ophthalmomyiasis in a single individual has not been previously reported in the scientific literature. Neither P. regina nor L. coeruleiviridis prefers living tissue for larva development, but since they fill similar ecological niches, perhaps this was a show of competition rather than a normal feeding habit. Knowing these blow fly species can resort to this behavior, and that it can affect human populations, is valuable to the education of patients and providers.

Case Report: Ophthalmomyiasis Externa Caused by Cordylobia anthropophaga Masquerading as a Lid Abscess.

Myiasis is a neglected tropical disease caused by the larvae of dipterous flies. Cutaneous infestation is the predominant type documented in sub-Saharan Africa, and ocular involvement is uncommon. We report the rare occurrence of a case of eyelid ophthalmomyiasis caused by Cordylobia anthropophaga in a Nigerian female to raise awareness among practitioners in both tropical and nonendemic areas.

First record of nasopharyngeal myiasis caused by Cephalopina titillator (Clark, 1816) in camel (Camelus dromedarius Linnaeus, 1758) in Uzbekistan.

Nasopharyngeal myiasis caused by the camel nasal bot, Cephalopina titillator, is very common in old world camelids and is usually found at necropsy or during meat inspection. Herein we report massive infection with C. titillator in a 9 years old female one-humped camel slaughtered on February 18, 2024 in the village of Kizil Uy, Nukus District, Republic of Karakalpakstan, northwestern Uzbekistan. A total of 69 larvae: 20 first stage larva (28.9%), 31  second stage larva (44.9%), and 18 third stage larva (26.0%) were detected in the nasal passages and pharynx of the camel. Morphological and morphometrical characters of all larval stages are illustrated and detailed in this article. To our knowledge this is the first record of camel nasal bot infestation in Uzbekistan. Future epidemiological studies are needed to shed light on the prevalence, seasonal fluctuation, clinical impact and economic burden of nasopharyngeal myiasis in dromedary camels of the country.

Cutaneous myiasis caused by Dermatobia hominis (Diptera: Oestridae) in a Polish traveller to South America - a case report.

Myiasis, an infestation caused by dipteran larvae, commonly known as maggots, is one of the most common parasitic skin disorders in the tropical regions. Authors report a case of cutaneous myiasis caused by Dermatobia hominis (Diptera: Oestridae) in a Polish traveller returning from a self-organized trip to South America. Species biology, prophylaxis, and medical implications of this tropical parasitosis are discussed.

Prevalence and seasonal aspects of parasitism by Oestrus ovis (Diptera: Oestridae) in sheep from Mato Grosso State, Brazil.

Oestrus ovis larvae are obligate parasites of vertebrates and cause cavitary myiasis (oestrosis) in sheep and goats. It is also reported as a zoonosis causing ophthalmomyiasis and nasopharyngeal myiasis. Despite being relatively common in Brazil, epidemiological studies on O. ovis are scarce. Considering that the infestation is influenced by the climate and biomes of the studied region, we aimed to investigate the seasonal prevalence of O. ovis among slaughtered sheep in the northern region of the state of Mato Grosso, Brazil. The heads of sheep (n=697) slaughtered at a slaughterhouse in the municipality of Terra Nova do Norte (November 2011 to November 2013) were collected to count, catalog, and identify the larvae found in the upper respiratory tract. Overall, 45.77% (319/697) of the animals were infested with 2,412 recovered larvae, 96.89% (2,337/2,412) of which were identified at the species level as O. ovis. Seasonal variations in prevalence ranged from 41% (spring) to 56% (summer); however, no correlation was observed between prevalence and season, mean humidity, or temperature. In conclusion, parasitism by O. ovis in sheep in the studied area, occurs year-round, considering the occurrence of larvae (L1, L2, and L3) throughout the year, probably because of the area's environmental conditions.

Complete Mitochondrial Genome for Lucilia cuprina dorsalis (Diptera: Calliphoridae) from the Northern Territory, Australia.

The Australian sheep blowfly, Lucilia cuprina dorsalis, is a major sheep ectoparasite causing subcutaneous myiasis (flystrike), which can lead to reduced livestock productivity and, in severe instances, death of the affected animals. It is also a primary colonizer of carrion, an efficient pollinator, and used in maggot debridement therapy and forensic investigations. In this study, we report the complete mitochondrial (mt) genome of L. c. dorsalis from the Northern Territory (NT), Australia, where sheep are prohibited animals, unlike the rest of Australia. The mt genome is 15,943 bp in length, comprising 13 protein-coding genes (PCGs), two ribosomal RNAs (rRNAs), 22 transfer RNAs (tRNAs), and a non-coding control region. The gene order of the current mt genome is consistent with the previously published L. cuprina mt genomes. Nucleotide composition revealed an AT bias, accounting for 77.5% of total mt genome nucleotides. Phylogenetic analyses of 56 species/taxa of dipterans indicated that L. c. dorsalis and L. sericata are the closest among all sibling species of the genus Lucilia, which helps to explain species evolution within the family Luciliinae. This study provides the first complete mt genome sequence for L. c. dorsalis derived from the NT, Australia to facilitate species identification and the examination of the evolutionary history of these blowflies.

Human myiasis in Sub-Saharan Africa: A systematic review.

BACKGROUND: Human myiasis is a parasitic dipteran fly infestation that infects humans and vertebrates worldwide. However, the disease is endemic in Sub-Saharan Africa and Latin America. In Sub-Saharan Africa, it is under-reported and therefore its prevalence is unknown. This systematic review aims to elucidate the prevalence of human myiasis, factors that influence the infection, and myiasis-causing fly species in SSA. The review also dwelled on the common myiasis types and treatment methods of human myiasis. METHODS: Here, we collect cases of human myiasis in Sub-Saharan Africa based on literature retrieved from PubMed, Google Scholar and Science Direct from 1959 to 2022. A total of 75 articles and 157 cases were included in the study. The recommendations of PRISMA 2020 were used for the realization of this systematic review. RESULTS: In total, 157 cases of human myiasis in SSA were reviewed. Eleven fly species (Cordylobia anthropophaga, Cordylobia rodhaini, Dermatobia hominis, Lucilia cuprina, Lucilia sericata, Oestrus ovis, Sarcophaga spp., Sarcophaga nodosa, Chrysomya megacephala, Chrysomya chloropyga and Clogmia albipuntum) were found to cause human myiasis in SSA. Cordylobia anthropophaga was the most prevalent myiasis-causing species of the reported cases (n = 104, 66.2%). More than half of the reported cases were from travelers returning from SSA (n = 122, 77.7%). Cutaneous myiasis was the most common clinical presentation of the disease (n = 86, 54.7%). Females were more infected (n = 78, 49.6%) than males, and there was a higher infestation in adults than young children. CONCLUSION: The findings of this study reveals that international travelers to Sub-Saharan Africa were mostly infested therefore, we recommend that both international travelers and natives of SSA be enlightened by public health officers about the disease and its risk factors at entry points in SSA and the community level respectively. Clinicians in Sub-Saharan Africa often misdiagnose the disease and most of them lack the expertise to properly identify larvae, so we recommend the extensive use of molecular identification methods instead.

Efficacy of eprinomectin 5 mg/mL topical solution administered pour on at 1 mg per kg body weight against Oestrus ovis myiasis in sheep and goats.

The larvae of the nasal bot, Oestrus ovis, mainly parasitize sheep and goats and some species of wild Caprinae but other mammals and humans are also vulnerable to infestation. Eprinomectin 5 mg/mL topical solution (EPRINEX® Multi, Boehringer Ingelheim) administered at 1 mg eprinomectin per kg body weight pour on was recently authorized as an anthelmintic for sheep and goats with zero hours milk withdrawal in several countries in Europe. As the product in cattle has claims against a broad range of parasites including insect parasites and activity against O. ovis has previously been reported following extra-label use in sheep, its therapeutic efficacy against ovine and caprine O. ovis myiasis was evaluated in three regulatory compliant, masked clinical studies. Pre-study recovery of O. ovis larvae from five or six of six randomly selected animals per study site (Bulgaria, one site, sheep; Greece, two sites, sheep or goats) supported the inclusion of the animals from those sites into the studies. The study animals (34 animals per study) were ranked based on bodyweight and allocated randomly to remain untreated (control) or to be treated with eprinomectin 5 mg/mL topical solution at 1 mL per 5 kg body weight pour on. Treatment efficacy was determined based on O. ovis larval counts of eprinomectin 5 mg/mL topical solution-treated vs. untreated animals three weeks after treatment administration. Live O. ovis larvae, including all three instars in each study, were recovered from 13 or 16 of the 17 control animals in the sheep studies (range, 1 to 14 or 5 to 18 larvae, respectively) and from all 17 controls in the goat study (range, 7 to 18 larvae). In each study, eprinomectin 5 mg/mL topical solution-treated animals had significantly (p < 0.001) fewer live O. ovis larvae than the controls. Efficacy of the treatment was 100% and 91.3% against the combined parasitic O. ovis larval stages in sheep and in goats, respectively. The treatment was well accepted by all animals and no health problems were observed throughout the studies. The results of these studies demonstrated eprinomectin 5 mg/mL topical solution administered pour on at 1 mL per 5 kg body weight to be an efficacious and safe treatment of ovine and caprine oestrosis.

Psychodid flies and their implicated role in human myiasis and pseudomyiasis.

Several psychodid flies are commonly associated with human-inhabited environments and have been increasingly implicated in cases of human myiasis. However, the basic biology of psychodid larvae is not well-suited for survival in the human intestinal or urogenital tract, making true, prolonged myiasis unlikely. In this review, we performed a systematic literature review of published cases of purported myiasis caused by psychodid flies, their identification, associated clinical findings, and treatment. We also discuss the anatomy and lifecycle of psychodid flies in relation to their purported ability to use human tissue as a nutritive source and survive in the human alimentary or urogenital tracts. Based on the range of non-specific and varied reported clinical manifestations, lack of observed collections, life cycle patterns of psychodid flies, the mechanics of their mouthparts, and breathing requirements, we conclude that most cases likely represent incidental findings, or in rare cases possibly pseudomyiasis, rather than true myiasis, and provide recommendations for clinical evaluation and reporting so that disease misclassification and unnecessary therapy do not occur.

A Case of Myiasis Caused by Cordylobia anthropophaga (Diptera: Calliphoridae) in an Italian Traveler Returning from Senegal.

PURPOSE: Myiases are infestations of human and animal tissues by fly larvae. These conditions are widespread in tropical countries and travelers in those areas are at risk of becoming infested. Although Cordylobia anthropophaga (Blanchard & Berenger-Feraud, 1872) is one of the most common myiasis-causing species, few high-quality images and molecular sequences are available for this fly. We present a case of C. anthropophaga infestation in an Italian patient returning from Senegal, with the aim of increasing both visual and molecular data for this species. METHODS: After removal, the larva was determined following standardized morphological keys and photographed under a digital microscope. Molecular characterization of the Cytochrome c oxidase subunit I (COI) was performed using universal primers. RESULTS: The general appearance, the structural organization of the cephalic region, of the cephaloskeleton, and of the posterior tracheal spiracles suggested that the causative agent of the myiasis was a third instar larva of C. anthropophaga. The morphological data are further supported by the molecular data: the COI sequence showed high levels of identity with the already published verified COI sequences of C. anthropophaga. CONCLUSION: We provide high-quality morphological and molecular data useful for the identification of larvae of C. anthropophaga. We highlight that myiasis might be common in Senegal and better data about its prevalence in travelers and in the endemic countries are needed to understand the burden of this condition.

Transcriptomic profiling of different developmental stages reveals parasitic strategies of Wohlfahrtia magnifica, a myiasis-causing flesh fly.

BACKGROUND: Wohlfahrtia magnifica is an obligatory parasite that causes myiasis in several warm-blooded vertebrates. Adult females deposit the first-stage larvae directly onto wounds or natural body orifices (e.g., genitalia) of the host, from where they quickly colonize the host tissue and feed on it for development. The infestation of W. magnifica can lead to health issues, welfare concerns, and substantial economic losses. To date, little is known about the molecular mechanisms of the W. magnifica-causing myiasis. RESULTS: In this study, we collected parasitic-stage larvae of W. magnifica from wounds of naturally infested Bactrian camels, as well as pupae and adult flies reared in vitro from the wound-collected larvae, for investigating the gene expression profiles of the different developmental stages of W. magnifica, with a particular focus on examining gene families closely related to the parasitism of the wound-collected larvae. As key proteins related to the parasite-host interaction, 2049 excretory/secretory (ES) proteins were identified in W. magnifica through the integration of multiple bioinformatics approaches. Functional analysis indicates that these ES proteins are primarily involved in cuticle development, peptidase activity, immune response, and metabolic processes. The global investigation of gene expression at different developmental stages using pairwise comparisons and weighted correlation network analysis (WGCNA) showed that the upregulated genes during second-stage larvae were related to cuticle development, peptidase activity, and RNA transcription and translation; during third-stage larvae to peptidase inhibitor activity and nutrient reservoir activity; during pupae to cell and tissue morphogenesis and cell and tissue development; and during adult flies to signal perception, many of them involved in light perception, and adult behavior, e.g., feeding, mating, and locomotion. Specifically, the expression level analysis of the likely parasitism-related genes in parasitic wound-collected larvae revealed a significant upregulation of 88 peptidase genes (including 47 serine peptidase genes), 110 cuticle protein genes, and 21 heat shock protein (hsp) genes. Interestingly, the expression of 2 antimicrobial peptide (AMP) genes, including 1 defensin and 1 diptericin, was also upregulated in the parasitic larvae. CONCLUSIONS: We identified ES proteins in W. magnifica and investigated their functional distribution. In addition, gene expression profiles at different developmental stages of W. magnifica were examined. Specifically, we focused on gene families closely related to parasitism of wound-collected larvae. These findings shed light on the molecular mechanisms underlying the life cycle of the myiasis-causing fly, especially during the parasitic larval stages, and provide guidance for the development of control measures against W. magnifica.

An Atypical Presentation Of Cutaneous Myiasis Of The Scalp In North Punjab: A Case Report.

Myiasis is an ectoparasitic infestation caused by larvae of arthropods in the group Diptera. Cutaneous myiasis is the infection of skin and includes the following types: furuncular, migratory and wound myiasis. Out of all the organisms responsible for this disease, Wohlfahrtia vigil is the most common causative agent in Pakistan, usually seen from June to September with nearly all presentations occurring at a young age. In our case, a patient without a history of trauma, skin erosion or animal exposure has a unique presentation of cutaneous myiasis. Here, an effort was made to treat a 15- year-old otherwise healthy female with a multisegmented treatment modality. A follow up visit was conducted every three days for three months at the end of which a 60% decrease in the size of the open wound was observed.