Patient with tracheostomy parasitized in hospital by larvae of the screwworm, Cochliomyia hominivorax

Myiasis in humans: Case reports in Northeastern Brazil including multispecies co-infestation by Sarcophagidae

Myiasis is a parasitosis characterized by an infestation of living vertebrates (humans and other animals) by Diptera larvae, whose occurrence and etiological identification are still neglected by health professionals. Here we analyzed the human myiasis cases registered from 2010 to 2018 in health care units in the municipality of Natal, Northeast region of Brazil. Specifically, we aimed to: I) analyze the medical records of cases documented from 2010 to 2017; II) list the patients predisposing factors; and III) monitor the recent cases diagnosed in health units between August 2017 and March 2018 and report the taxonomic identity of the infesting species. Our data revealed that myiases mainly affect the elderly and individuals with predisposing medical conditions (e.g. senility, filariasis). Regarding the new cases, larvae of Calliphoridae (C. hominivorax (Coquerel, 1858)) and Sarcophagidae [Sarcophaga (Liopygia) ruficornis (Fabricius, 1794), Peckia (Sarcodexia) lambens (Wiedemann, 1830), and Helicobia morionella (Aldrich, 1930)] were identified. Furthermore, this was the first report of a co-infestation with three Sarcophagidae species and also the presence of H. morionella in a human wound. These results reinforce that myiasis is an underreported parasitosis, which may underestimate the ability of previously unreported fly species to feed on living human tissues in the Neotropical Region.

Prevalence of tracheopulmonary myiasis amidst humans

Myiasis is a parasitic infestation of live vertebrates with the dipteran larvae that grow within the host while feeding on its living or dead tissue. Human myiasis is prevalent among individuals in close association of domestic animals and those inhabiting the unhygienic conditions. Open neglected suppurative wounds are the favourable sites that attract and stimulate the gravid female flies for oviposition. However, the poor personal hygiene, ignorance and the mental illness further add to it. Tracheopulmonary myiasis involves the infestation of foul smelling nasal and oral orifices or neglected wounds like tracheostomal incisions with the parasitic dipteran larvae which may extend up to the trachea, bronchi and lungs leading to serious health complications. Despite the incidence of human tracheopulmonary infestation is rare, the severe medical impediments and heterogeneous worldwide distribution signify the medical importance of this condition. The present manuscript reviews and summarizes the worldwide reported cases of human tracheopulmonary myiasis and the predisposing risk factors for onset of the same, as future reference for parasitologists and medical professionals.

A review on the occurrence of Cochliomyia hominivorax (Diptera: Calliphoridae) in Brazil

Cochliomyia hominivorax (Coquerel, 1858), the New World screwworm, causes primary myiasis in wild and domestic animals in tropical and subtropical regions of Brazil. Although this species is considered to occur throughout the country, organized information about its recorded distribution has not been available until now. This article aimed to provide a comprehensive review of the historical and current data published on both immature (myiasis) and adult stages of C. hominivorax in Brazil. A total of 174 articles were found; of these, 141 articles reported myiasis cases in cattle (146 records), humans (68 records), and other mammalian hosts (40 records), and captures of adult flies were reported in 33 articles. C. hominivorax is widespread in Brazil, having been recorded in 208 municipalities in all major biomes of the country.

Umbilical Myiasis by Cochliomyia hominivorax in an Infant in Colombia

Myasis is the infestation by fly larvae (Diptera) in live vertebrates including humans. Myasis has been reported most commonly in tropical and subtropical areas around the world with poor sanitation and presence of cattle. Neonatal umbilical myiasis is an important cause of death in bovines and produces major economic losses in the livestock industry. However, its presentation in humans is rare, with a few cases reported worldwide. Moreover, umbilical myasis can be life-treating due to the risk of larvae migration to deeper tissues of the abdomen, omphalitis, and sepsis. We describe the case of a 7-day-old infant admitted to the hospital due to umbilical cord myiasis. In total, 55 larvae were removed from the wound and identified as Cochliomyia hominivorax. The patient recovered satisfactorily after treatment with ivermectin and amoxicillin. A literature search was performed in Pubmed, Medline, Lilacs and Google Scholar, with 64 cases of myasis by C. hominivorax being reviewed. Oral cavity, wounds, scalp and natural orifices are the main affected anatomical areas. Risk factors include the extremes of age, male sex, poor hygiene, alcohol and drug use, cancer, and mental disability. Programs for human myiasis prevention and surveillance are needed in neotropical areas where living conditions make it difficult to implement control strategies.

Intratracheal myiasis followed by tracheal-esophageal fistula: report of a rare case and literature review

BACKGROUND

To enhance awareness of the clinical features and prevention of endotracheal myiasis.

CASE PRESENTATION

A case of intratracheal myiasis is reported. A 61-year-old male patient with a history of laryngectomy was admitted to hospital due to tracheostomal hemorrhage of 3 h duration. Intratracheal myiasis was confirmed by bronchoscopy, and the patient underwent bronchoscopic intervention, which was complicated by a tracheal-esophageal fistula and resolved by endotracheal stenting. Twenty months after stent placement, the fistula had not healed.

CONCLUSION

Intratracheal myiasis has serious complications and is difficult to treat. For post-tracheostomy patients, healthcare providers and caregivers should pay attention to the care and monitoring of wounds and maintenance of a tidy, clean living environment to prevent intratracheal myiasis.

Myiasis in humans-a global case report evaluation and literature analysis

Myiasis refers to the infestation of living humans and vertebrates with fly larvae that feed on necrotic or vital tissue of the host. Since the invasion of new fly species in Europe is currently being observed, which live obligatorily parasitically or are close relatives of such species, the aim of this study is to obtain a global overview of the distribution of myiasis-causing fly species in times of climate change and to assess the possible consequences for Western Europe. A systematic literature search was conducted using Pubmed/Medline for the years 1997 to 2017 and a total of 464 international case reports from 79 countries were evaluated. The described cases were caused by 41 different species. In 99.4% of the cases, it was a colonization by just one species, a maximum of three species were detected in a human. Casuistics from Western Europe mostly describe myiasis as a "holiday souvenir" from tropical regions. Reports of autochthonous cases are rare in comparison to other regions. With regard to rising temperatures and the invasion of new fly species, a noticeable increase in the number of cases in Western Europe is to be assumed, which could be an increasing problem in the clinical area and in care, which is why thorough monitoring for professional identification and treatment seems important in the future.

Case Report: Myiasis due to Cochliomyia hominivorax and Dermatobia hominis: Clinical and Pathological Differences between Two Species in Northern Peru

Infestations caused by fly larvae (Myiasis) have been observed in patients with risk factors and in tropical zones. The aim of our study was to describe the clinical and epidemiological aspects and the risk factors associated with the occurrence of obligatory myiasis, as well as the therapeutic approach to patients. We identified the cases of myiasis diagnosed in two referral hospitals in northern Peru from January 2012 to December 2015 and included patients in whom larval development and a compatible clinical profile were observed. Epidemiological, clinical, analytical, diagnostic, therapeutic, and follow-up data were collected from clinical files. Nine clinical cases were compatible with a diagnosis of myiasis; of these, two were pediatric patients, one was a middle-aged adult, and six were elderly patients. Four of the nine patients were male. The identified species were Dermatobia hominis and Cochliomyia hominivorax. The therapeutic approach included antiparasitic therapy with ivermectin, antibacterial, and in some cases, anti-inflammatory drugs. Dermatobia hominis and C. hominivorax are the predominant species causing myiasis in northern Peru.

Traumatic Myiasis: A Neglected Disease in a Changing World

Traumatic myiasis, the parasitic infestation by fly larvae in traumatic lesions of the tissues of living vertebrates, is a serious medical condition in humans and a welfare and economic issue in domestic animals. New molecular studies are providing insights into its evolution and epidemiology. Nevertheless, its incidence in humans is generally underreported, particularly in tropical and subtropical regions. Myiasis in domestic animals has been studied more extensively, but continuous management is difficult and expensive. A key concern is the inadvertent introduction and global spread of agents of myiasis into nonendemic areas, facilitated by climate change and global transport. The incursion of the New World screwworm fly (Cochliomyia hominivorax) into Libya is the most notable of many such range shifts and demonstrates the potential risks of these parasites and the costs of removing them once established in a geographic area. Nevertheless, the insect agents of myiasis can be of societal benefit to forensic science and in medicine as an aid to wound treatment (larval therapy).

Myiasis of the Tracheostomy Wound Caused by Sarcophaga (Liopygia) argyrostoma (Diptera: Sarcophagidae): Molecular Identification Based on the Mitochondrial Cytochrome c Oxidase I Gene

Wound myiasis is the infestation of open wounds of mammalian hosts caused by larvae of various species of flies. This kind of myiasis can be a serious problem for immobilized patients with open wounds. Here, we identify a dipteran larva found in the tracheostomy wound of a child affected by a severe spinal muscular atrophy. The collected larva was dissected and microscopically analyzed. DNA was extracted from part of the larva and used for the molecular identification. A 487 bp fragment, including part of 5.8 S, the internal transcribed spacer 2 (ITS2), and part of 28S, was amplified using a novel PCR assay to be cloned and sequenced. The barcode region of cytochrome oxidase I (COI) was also cloned and sequenced after PCR amplification. The larva, designated as SASI1, was identified as a third instar of Sarcophaga sp. The COI sequencing confirmed a low similarity with Sarcophaga ruficornis (F.) (95%), yet COI showed a 100% similarity with Sarcophaga argyrostoma (Robineau-Desvoidy, 1830) species. Therefore, SASI1 was identified as a S. argyrostoma larva on the basis of its COI barcode. This is one of the rare cases of myiasis of tracheostomy wound and the first caused by S. argyrostoma.

First Report of Pharyngostomy Wound Myiasis Caused by Chrysomya bezziana (Diptera: Calliphoridae) in Iran

Wound or traumatic Myiasis is the infestation of animal and human orifices or wounds by dipterous larvae. It is more common in tropical and sub-tropical countries. Chrysomya bezziana is a major agent of wound myiasis throughout the tropical regions of the Old World. In Iran many cases of human myiasis due to C. bezziana were reported from south and south-east of country. This study reports a case of wound myiasis in a 3-year-old pharyngostomized girl who referred to the Pediatric Hospital in Bandar Abbas for pharyngological follow-up. During the examination, several live and mobile larvae were removed from the lesion. The patient received antibiotics and then transferred to pediatric ward for respiratory care. The specimens were identified as C. bezziana according to the morphological characters of fully grown larvae. This is the first report of the pharyngostomy wound myiasis caused by C. bezziana in Iran. This finding also confirms the results of previous studies indicating the occurrence of the Old World screwworm fly, C. bezziana as a causative agent of human myiasis in the south of Iran.