Wound myiasis in a wild boar by Lucilia caesar (Diptera: Calliphoridae): First case and current status of animal myiasis by this species

The first case of myiasis caused by Lucilia caesar (L.) (Diptera: Calliphoridae) in a wild boar, Sus scrofa L. (Artiodactyla: Suidae) is described. The myiasis occurred in October 2019 in Southern Italy and the identification of the agent was based on adult male morphology. The wild boar had a wound on its right side, near the neck, which was largely infested by larvae. The ecology, distribution and current literature status about cases of animal myiasis by this species is also included.     

Conjunctival myiasis. 23 cases in the Tunisian Sahel

Conjunctival lesions of ocular myiasis are common in the mediterranean region. The authors report 23 cases of conjunctival myiasis. This affection is caused by fly's larvae: Oestrus ovis presenting typically with inflamed and oedematous eyes. We diagnose the affection by directly showing the larvae on conjunctiva. The treatment consisted to extirpate larvae one by one.     

Clinical and parasitological observations on a case of disseminated furuncular myiasis caused by Cordylobia rodhaini in a man in Ethiopia]

A severe case of myiasis is reported in an Italian technician working in a forest yard in Illubabor (Ethiopia). The patient returned to Italy with fever, malaise and scattered skin lesions: these were papular at first, and later developed into furuncle-like, intensely burning boils which spread all over the body. Neutrophilic leukocytosis was present associated with increased IgA. From the lesions, 150 larvae were recovered and identified as Cordylobia rodhaini Gedoelst (Diptera, Calliphoridae), a myiasis agent adapted to various thin-skinned mammals in African forests, rarely observed in man. This is the first case recorded in Ethiopia and represents the most massive invasion by Cordylobia spp. published so far. The 3rd stage larva is described with some morphological details not reported by previous authors.     

Intestinal myiasis due to Eristalis tenax: report of a new case in Spain

We describe a new case of accidental intestinal myiasis by Eristalis tenax in Spain. Only about 20 cases have been reported worldwide, two of them occurring in Spain. A 51-year-old patient with nonspecific abdominal pain and occasional diarrhoea expelled larvae in her stool. Macroscopic analysis of these larvae revealed morphology compatible with that of Eristalis tenax. The larva analysis showed its autofluorescence as parasitological feature described for the first time.     

The evolution of myiasis in humans and other animals in the Old and New Worlds (part I): phylogenetic analyses

Myiasis, the infestation of live vertebrates with dipterous larvae, seems to take two distinct forms that, it has been suggested, evolved from two distinct phylogenetic roots: saprophagous and sanguinivorous. However, the convergent evolution of morphological and life-history traits seems to have had a major role in simplifying this overall assessment of the evolutionary routes by which myiasis arose. Moreover, this somewhat simplistic division is further complicated by the existence of both ectoparasitic and endoparasitic species of myiasis-causing Diptera, the evolutionary affinities of which remain to be resolved. To understand how different forms of parasitism arose, the evolution of the various groups of myiasis-causing flies must be separated from the evolution of the myiasis habit per se. Until recently, evolutionary studies of myiasis-causing flies were little more than discussions of morphology-based taxonomy. Since the mid-1990s, however, several formal phylogenies - based on both morphological and, increasingly, molecular data - have been published, enabling reassessment of the hypotheses concerning myiasis evolution. In part I of this review, we focus on some recent landmark studies in this often-neglected branch of parasitology and draw together phylogenetic studies based on molecular and morphological data to provide a framework for the subsequent analysis of biochemical, immunological, behavioural, biogeographical and fossil evidence relating to the evolution of myiasis.     

Traumatic Myiasis Caused by an Association of Sarcophaga tibialis (Diptera: Sarcophagidae) and Lucilia sericata (Diptera: Calliphoridae) in a Domestic Cat in Italy

We describe here a rare case of traumatic myiasis occurred in August 2014, caused by an association of 2 Diptera species, Sarcophaga tibialis Macquart (Diptera: Sarcophagidae) and Lucilia sericata (Meigen) (Diptera: Calliphoridae), in a domestic cat in northern Italy. Species identification was based on adult male morphology. The present case is the first report of S. tibialis as an agent of myiasis in Italy, and also the first ever report of myiasis caused by an association of S. tibialis and L. sericata. The cat developed an extensive traumatic myiasis in a large wound on the rump, which was treated pharmacologically and surgically. The biology, ecology, and distribution of S. tibialis and L. sericata are also discussed. A literature review is provided on cases of myiasis caused by S. tibialis, and cases of myiasis by L. sericata involving cats worldwide and humans and animals in Italy.     

Incidence of myiasis in Panama during the eradication of Cochliomyia hominivorax (Coquerel 1858, Diptera: Calliphoridae) (2002-2005)

We present the results of a study on myiasis in Panama during the first years of a Cochliomyia hominivorax eradication program (1998-2005), with the aim of investigating the behavior of the flies that produce myiasis in animals and human beings. The hosts that registered positive for myiasis were cattle (46.4%), dogs (15.3%), humans (14.7%), birds (12%), pigs (6%), horses (4%), and sheep (1%). Six fly species caused myiasis: Dermatobia hominis (58%), Phaenicia spp. (20%), Cochliomyia macellaria (19%), Chrysomya rufifacies (0.4%), and maggots of unidentified species belonging to the Sarcophagidae (3%) and Muscidae (0.3%). With the Dubois index, was no evidence that the absence of C. hominivorax allowed an increase in the cases of facultative myiasis.     

Human myiasis in Bahía Blanca, Argentina. Period 2000 / 2005

Myiasis is the infestation of live human and vertebrate animals with dipterous larvae which, at least for a short period, feed on the host's dead or living tissue, liquid body-substance, or ingested food. The objective of this study was to identify the flies producing myiasis in Bahía Blanca city, Argentina, from 01/03/2000 to 31/05/2005. Seventeen clinical cases were studied. The larvae obtained from lesions were forwarded from laboratories and from public and private hospitals. Part of the larvae were fixed in alcohol 70 masculine and processed according to the Mazza & J?rg technique (1939). The other part continued growing in flasks with meat in laboratory conditions to obtain the adults. The etiological agents of myiasis were identified by observing the diagnostic characteristics of the larvae III and of the adults, and by using taxonomic keys. Myiasis was produced by Cochlyiomia hominivorax (Coquerel) in thirteen of the cases and by Phaenicia sericata (= Lucila sericata) (Meigen) (Diptera: Calliphoridae) in the other four. The cases were traumatic and aural myiasis and happened from December to March. The ages of patients were four to eighty-six years and 76.5% of the cases occurred in male patients. Given the aggressiveness of these larvae, mainly C. hominivorax, in causing human myiasis, the importance of specific and quick diagnosis and of adequate treatment must be acknowledged.     

Current status of the New World screwworm Cochliomyia hominivorax in Venezuela

Abstract.  The geographical distribution and seasonality of the New World screwworm (NWS), Cochliomyia hominivorax Coquerel (Diptera: Calliphoridae), were monitored through the use of sentinel animals as part of a co-ordinated programme involving veterinarians and farmers, as well as undergraduate students and teachers from veterinary colleges in Venezuela. This surveillance activity made it possible to collect NWS egg masses or larvae from all 23 states in the country and to determine that the rainy season has a strong positive influence on the number of cases of myiasis caused by C. hominivorax in dogs. In addition, efforts were made to obtain the co-operation of the public health service in order to document the extent of human myiasis in the western–central region of Venezuela. Preliminary results revealed 241 cases over a 7-year period, with cases reported in infants as well as in elderly people. Larvae causing myiasis, other than C. hominivorax , were collected from primary myiasis in rabbit ( Lucilia eximia [Wiedemann]), dog (an unidentified sarcophagid species), birds ( Philornis sp.) and wild mice ( Cuterebra sp.). The economic impact of NWS in Venezuela has not been calculated in terms of loss of milk and meat production, damage to hides or death of animals. Control costs (e.g. cost of larvicides) have been estimated at US$ 2 m per year. Control of myiasis in animals is achieved through the use of chemical compounds, mainly organophosphorus (OP) compounds, macrocyclic lactones and, more recently, a foamy spray based on spinosad. Concerns about insecticide resistance to OP compounds have been raised.     

The evolution of myiasis in humans and other animals in the Old and New Worlds (part II): biological and life-history studies

Myiasis, which is the dipteran parasitism of living vertebrates, occurs in several forms - ranging from benign to fatal, opportunistic to obligate - and seems to have evolved through two distinct routes: saprophagous and sanguinivorous. However, the convergent evolution of morphological and life-history traits seems to have had a major role in confusing the overall picture of how myiasis evolved and this simplistic division is further complicated by the existence of both ectoparasitic and endoparasitic species of myiasis-causing Diptera, the evolutionary affinities of which remain to be resolved. As discussed in part I of this review, if we are to elucidate how the different forms of parasitism arose, it is essential to separate the evolution of the various groups of myiasis-causing flies from the evolution of the myiasis habit per se. Accordingly, whereas we focused on recent landmark phylogenetics studies in part I, we use this framework to analyse relevant biochemical, immunological, behavioural, biogeographical and fossil evidence to elucidate the evolution of myiasis in part II.     

Estimating the incidence of fly myiases in Australian sheep flocks: development of a weather-driven regression model

The blowfly, Lucilia cuprina Wiedemann (Diptera: Calliphoridae), is the primary myiasis (strike) fly of sheep in Australia. Most strike occurs in the anal-perineum area (crutch), but strike to the neck, shoulders, back and withers (body) is also important. Regression analysis was used to determine the extent to which the weekly incidence of flystrike can be explained by variations in fly abundance and/or recent changes in weather, pasture conditions or flock management. Strike and flock management data were collected by questionnaire surveys of 30-60 sheep properties in each of three major sheep-producing areas in southeastern Australia, namely, Gunning (southern New South Wales), Inverell (northern New South Wales) and Flinders Island (Bass Strait). After using simulation modelling to remove effects due to shearing, crutching and/or insecticide treatment, pasture growth index was found to be the most important explanatory variable affecting the incidence of all forms of myiasis. Others were average weekly air temperature, the amount and frequency of rainfall, relative humidity, dung quality index and a factor denoting seasonal effects. Together, these variables accounted for 48.4% of the variation in body strike, 56.8% of that in crutch strike and 51.9% of that in other forms of strike. Prediction was improved by the inclusion of additional lagged variables describing previous strike, fly abundance and fly activity. With these additions, the variation explained increased to 60.4% for body strike, 68.0% for crutch strike and 58.3% for other strikes.     

Effect of myiasis and acute restraint stress on plasma levels of immunoreactive beta-endorphin, adrenocorticotrophin (ACTH) and cortisol in the sheep

Cutaneous myiasis in sheep arising from the activity of Lucilia cuprina larvae can result in significant physiological changes in susceptible animals. The stress imposed on the pituitary-adrenal axis of the sheep in response to myiasis and acute restraint is the subject of this investigation. Merino wethers were exposed to handling restraint, and blood sampling, during examination for blowfly strike; where necessary, they were treated for cutaneous myiasis. Significant changes in the plasma concentrations of immunoreactive beta-endorphin (beta-EP), ACTH and cortisol were found in sheep with extensive myiasis, as compared with unstruck sheep or those with only localized myiasis. In five susceptible sheep with extensive cutaneous myiasis, mean plasma levels of beta-EP, ACTH and cortisol were 307 +/- 71 pg ml-1, 953 +/- 58 pg ml-1 and 232 +/- 46 nmol l-1 respectively, compared with 818 +/- 89 pg ml-1, 641 +/- 41 pg ml-1 and 107 +/- 17 nmol l-1 in six unstruck sheep handled similarly. Whereas significant increases in plasma ACTH and cortisol can result from pituitary-adrenal responses to acute emotional or surgical stress, and are usually accompanied by a concomitant release of beta-EP from the pituitary, the present findings indicate a marked reduction in beta-EP levels and a significant increase in ACTH and cortisol in sheep following blowfly strike and acute handling restraint. This result suggests that cutaneous myiasis in susceptible sheep can alter the pituitary-adrenal response to acute restraint stress, and this could occur either by an alteration of precursor processing in the pituitary or by the selective release of ACTH.     

Oral myiasis in an elderly patient

doi: 10.1111/j.1741‐2358.2010.00432.x Oral myiasis in an elderly patient Background: Myiasis is the invasion of living tissue of humans and other mammals by eggs or maggots of flies of the order of Diptera. It occurs mainly in the Tropics and is associated with inadequate public and personal hygiene. Oral myiases in an older man appears to be rare. Objective: To relate a case of oral myiases in a debilitated older man treated by mechanical removal of the maggots, identifying the adult insect that caused the infestation. Methods: The diagnosis of oral myiasis was established by the clinical examination and it was detected that the infestation involved only soft tissue and the sinus cavity. The patient was submitted to two mechanical removal of the visible maggots. Results: Total of 110 maggots was removed from the oral cavity of the patient and adult insects was identified as belonging to the Calliphoridae Family, Cochliomyia hominivorax species. The patient died two days after the second procedure by severe systemic complications. Conclusions: The mechanic removal and the identification of the maggots must be adopted as soon as possible to prevent further tissue damage and bacterial infection in cases of oral myiasis. Special attention should be given to the debilitated old patients that are particularly susceptible to oral myiasis infestation.     

First Report of Myiasis Caused by Cochliomyia hominivorax (Diptera: Calliphoridae) in a Diabetic Foot Ulcer Patient in Argentina

Myiasis is usually caused by flies of the Calliphoridae family, and Cochliomyia hominivorax is the etiological agent most frequently found in myiasis. The first case of myiasis in a diabetic foot of a 54-year-old male patient in Argentina is reported. The patient attended the hospital of the capital city of Tucumán Province for a consultation concerning an ulcer in his right foot, where the larval specimens were found. The identification of the immature larvae was based on their morphological characters, such as the cylindrical, segmented, white yellow-coloured body and tracheas with strong pigmentation. The larvae were removed, and the patient was treated with antibiotics. The larvae were reared until the adults were obtained. The adults were identified by the setose basal vein in the upper surface of the wing, denuded lower surface of the wing, short and reduced palps, and parafrontalia with black hairs outside the front row of setae. The main factor that favoured the development of myiasis is due to diabetes, which caused a loss of sensibility in the limb that resulted in late consultation. Moreover, the poor personal hygiene attracted the flies, and the foul-smelling discharge from the wound favoured the female''s oviposition. There is a need to implement a program for prevention of myiasis, in which the population is made aware not only of the importance of good personal hygiene and home sanitation but also of the degree of implication of flies in the occurrence and development of this disease.     

Antibacterial action of Myiasis-causing flies

Some species of calliphorid blowflies lay their eggs in wounds; their larvae develop by feeding on the tissue, and the infection is known as myiasis or fly-strike. But wounds, from whatever cause, are frequently contaminated with bacteria - many o f which can spread in the bloodstream causing septicaemia and/or toxaemia. For example, wound contamination with Clostridium welchii - leading to 'gas gangrene' - was a frequent cause of death amongst battlefield casualties. It is from such situations that early observations were made on the beneficial effect of some blowfly larvae in limiting the bacterial infection of wounds. Indeed, some military surgeons would deliberately infest wounds with blowfly maggots in order to prevent bacterial complications. Now, a century or two later, the search for new antibiotics had led researchers back to these early observations, and in this article, Gory Erdmann describes progress in understanding the antibacterial action of blowfly maggots.     

Suspected intestinal myiasis due to Dryomyza formosa in a Japanese schizophrenic patient with symptoms of delusional parasitosis

A third-stage larva of Dryomyza formosa (Wiedemann) (Diptera: Dryomyzidae) was found in the fresh stool of a 27-year-old Japanese woman resident of Shiobara, 150 km north of Tokyo, on 16 November 1998. This is the first record of myiasis due to Dryomyza. Detection of this maggot (2cm long) by the patient herself was associated with her longstanding delusion of abdominal parasitosis as a symptom of chronic schizophrenia. Circumstantial evidence agreed with this being a genuine case of intestinal myiasis, apparently due to accidental ingestion of the insect, with no signs that the patient had contrived the report, nor that the maggot had invaded the stool post-defaecation. This case draws attention to the likelihood that some personality states are predisposed to noticing and reporting myiasis, when it occurs. We review other conditions (mental and physical) that are more prone to myiasis.     

A Case of Oral Myiasis Caused by Lucilia sericata (Diptera: Calliphoridae) in Korea

We report here a case of oral myiasis in the Republic of Korea. The patient was a 37-year-old man with a 30-year history of Becker''s muscular dystrophy. He was intubated due to dyspnea 8 days prior to admission to an intensive care unit (ICU). A few hours after the ICU admission, 43 fly larvae were found during suction of the oral cavity. All maggots were identified as the third instars of Lucilia sericata (Diptera: Calliphoridae) by morphology. We discussed on the characteristics of myiasis acquired in Korea, including the infection risk and predisposing factors.     

Cloacal myiasis by Lucilia spp. (Diptera: Calliphoridae) in a rooster (Gallus gallus domesticus) and two Harris's hawks (Parabuteo unicinctus)

In this study, cloacal myiasis caused by dipterans of Lucilia genus was found in a rooster (Gallus gallus domesticus) and two Harris's hawks (Parabuteo unicinctus) from Peru. Larval dipteran were collected and preserved in ethanol. Morphological analysis indicated two species: Lucilia sericata in the rooster and in one Harris's hawk, and Lucilia cuprina in the other Harris's hawk. Molecular analysis confirmed the diagnosis by amplification of the nucleotide sequences of the cytochrome c oxidase subunit 1 gene and internal transcribed spacer 2 region. The sequences were compared with sequence references from a public sequence database, which showed a 100% matched identity. This study demonstrated for first time cloacal myiasis by L. sericata in a domestic bird from Peru and in Harris's hawk. Also, for the first time, L. cuprina was found in a bird of prey.     

Human nasal myiasis due to Oestrus ovis]

One case of human nasal myiasis caused by second and third instar larvae of Oestrus ovis was observed in Lille (North France). Oestrosis is a common myiasis of sheep and goats in Mediterranean and Tropical countries. The authors examine the oestrosis pathogenesis in the usual host (sheep) or in humans, and analyse the epidemiology, the symptomatology and the treatment of human oestrosis.     

A case of furuncular myiasis associated with systemic inflammation

Cutaneous myiasis is a common travel-associated dermatosis caused by fly larvae. We report an unusual case of furuncular myiasis caused by Dermatobia hominis that was associated with signs of systemic inflammation. In this case study, morphological and novel molecular approaches were used to identify and characterize the larvae responsible for human infestation.