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.     

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.     

Ovicidal,larvicidal and oviposition repelling action of a nanoemulsion of citronella essential oil (Cymbopogon winterianus) on Cochliomyia hominivorax (Diptera: Calliphoridae)

Cochliomyia hominivorax is the dipteran that causes the worst and most serious types of myiasis in animals and humans in the Americas. They are parasitic affections caused by the massive infestation of larvae of this species on the tissues of living mammals. The routine treatment uses chemosynthetic products that have high toxicity and can cause several injuries to animal and human health, besides environmental contamination. The development of more friendly alternatives to the treatment of this disease is an important knowledge gap nowadays. Citronella (Cymbopogon winterianus) is the most widely cultivated medicinal plant in tropical and subtropical regions. Essential oils have a recognised repellent and larvicidal activity against a wide variety of insects. This work aimed to evaluate the repellent, ovicidal and larvicidal efficacy of a topical commercial formulation composed of 15% (w/v) nanoemulsified Citronella essencial oil (Nano Citronela Plus®) in in vitro trials on specimens of C. hominivorax created under laboratory conditions. Nano Citronela Plus® is an oil-in-water nanoemulsion obtained by high-pressure homogenization method. The composition of tested nanoemulsion was Cymbopogon winterianus essential oil, vanillin, caprylic/capric triglyceride, polysorbate 80, sorbitan oleate, tocopheryl acetate, sodium benzoate and water. Nano Citronela Plus® demonstrated 100% lethality on eggs and first and second stage larvae of C. hominivorax. Mortality in the larvae of third stage was 69.33% and inhibited the oviposition of C. hominivorax females. Nano Citronela Plus® proved to be a possible herbal alternative for the control and treatment of myiasis caused by C. hominivorax. In vivo studies may test this hypothesis.     

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.     

Evolutionary profile of the family Calliphoridae,with notes on the origin of myiasis

The family Calliphoridae is a group of heterogenous calyptrate flies with a worldwide distribution including species of ecological, veterinary, medical, and forensic importance. Notorious for their parasitic habits, the larvae of many blowflies are characterised – like some other dipteran larvae – by their ability to develop in animal flesh. When parasitism affects a living host, it is termed “myiasis”. This has led the Calliphoridae to be considered as a pivotal family in its relationship with a man. Nevertheless, even after more than 50 years of research, the phylogenetic relationships among calliphorid subfamilies together with the evolutionary origin of myiasis remain unclear. In order to elucidate these problems, we constructed three phylogenetic trees by using nucleotide sequence data from cytochrome oxidase subunit one (COI), representing a mitochondrial conservative gene, and nuclear 28S subunit of ribosomal RNA gene (28S rRNA) in order to interpret the evolutionary profile of myiasis in the family Calliphoridae. The sequenced data represented species associated with ectoparasitic life-styles, either saprophagy or facultative and obligate parasitism. A total number of 50 accessions were collected for 28S rRNA, 56 for COI, and 38 for combined sequences phylogeny. Molecular Evolutionary Genetics Analysis (MEGA) software was used to align 2197 nucleotide positions of 28S rRNA and 1500 nucleotide positions of COI with a gap opening penalties and gap extension penalties equalling 20 and 0.1 respectively. The results reveal the non-monophyly of the family Calliphoridae despite the stable monophyletic status of the Chrysomyinae, Luciliinae, and Auchmeromyiinae. Also, our findings recommend ranking the Toxotarsinae as a separate family. Furthermore, comparative analysis of the phylogenetic trees shows that the habit of obligatory myiasis originated independently more than five times. This strengthens our hypothesis that the origin of eating fresh meat is a case of convergent evolution that has taken place after speciation events millions of years ago. Finally, estimating the divergence dates between lineages from molecular sequences provides a better chance of understanding their evolutionary biology.     

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.     

Ignatzschineria larvae Bacteremia Following Lucilia sp. Myiasis in an Irregular Migrant: A Case Report

Bacteremia induced by wound myiasis is uncommon and therefore rarely suspected by clinicians when treating patients with neglected wounds. We present a case of Ignatzschineria larvae bacteremia as a complication of Lucilia sp. maggot wound myiasis in a young male migrant. This is the first reported human case of Ignatzschineria bacteremia in Slovenia and one of the 2 described in the literature where the fly larvae infesting the wounds of the patient with Ignatzschineria bacteremia were not only suspected to be Lucilia sp. but also entomologically identified.     

Sarcophaga (Liosarcophaga) dux (Diptera: Sarcophagidae): A flesh fly species of medical importance

Background

Although tropical climate of Thailand is suitably endowed with biodiversity of insects, flies of medical importance is not well investigated. Using information from literature search, fly survey approach and specialist’s experience, we review database of Sarcophaga (Liosarcophaga) dux Thomson (Diptera: Sarcophagidae), one of the priorities flesh fly species of medical importance in Thailand.

Results

This review deals with morphology, bionomics and medical involvement. Important morphological characteristics of egg, larva, puparia and adult were highlighted with illustration and/or micrographs. Search pertaining to molecular analysis used for fly identification and developmental rate of larvae were included. Medical involvement of larvae was not only myiasis-producing agent in humans and animals, but associated with human death investigations.

Conclusions

This information will enable us to accurate identify this species and to emphasis the increase medically important scene in Thailand.     

A retrospective and geographical epidemiological survey of traumatic myiasis in southern Italy

A survey on the prevalence and geographical distribution of traumatic myiasis in sheep, and the risk factors for the disease, was carried out in a region of southern Italy. A total of 138 sheep flocks were selected and visited to acquire data on the presence or absence of traumatic myiasis using both a questionnaire for retrospective analysis and animal inspection. Prevalences registered at the farm and animal levels, respectively, were 8.7% and 6.3% in 2010, and 5.8% and 5.0% in 2011. Records of the occurrence of the parasitic disease in this region are recent: a statistically significant (P < 0.01) progressive increase in the number of farms affected (from 0.7% to 8.7%) has been registered since 2007. Wohlfahrtiosis was found in 11 of 95 (11.6%) geographical units sampled and three significant (P < 0.05) clusters of spatial farm aggregation were identified in the southern part of the study area. A total of 158 presently uninfested farms were considered to be at high risk for transmission as a result of their proximity to infested farms. The spreading of Wohlfahrtia magnifica (Diptera: Sarcophagidae) in southern regions of Italy represents a warning that the risk for infestation may become more significant in other Italian regions, as well as other European countries.     

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.     

A Severe Case of Cutaneous Myiasis in S?o Gon?alo, Brazil, and a Simple Technique to Extract New World Screw-Worm Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae)

This work describes a severe case of myiasis by Cochliomyia hominivorax (Coquerel) in a 59-year-old patient living in an urban area of S?o Gon?alo, Rio de Janeiro. The patient had an open wound on the right shoulder parasitized by 287 larvae. In order to remove the larvae, the wound was washed with NaCl and solid vaseline was applied onto the wound and covered with gauze and adhesive tape. After 90?min, the larvae were killed by asphyxiation and were removed using sterile forceps and NaCl. This procedure left the wound completely clean.     

Traumatic myiasis in dogs caused by Wohlfahrtia magnifica and its importance in the epidemiology of wohlfahrtiosis of livestock

Abstract.  In the province of Al Hoceima, northern Morocco, and on two farms in Hungary, dogs were inspected for the presence of traumatic myiasis. Nine and four infested dogs were found in Morocco and Hungary, respectively. All the larvae and adults reared from them in the laboratory were identified as Wohlfahrtia magnifica (Schiner) (Diptera: Sarcophagidae). To our knowledge, these are the first cases of wohlfahrtiosis in dogs to be reported in these countries. All infested animals lived close to livestock, where wohlfahrtiosis was endemic. Infested body sites included limbs (six cases), external genitalia (two), ears (three), nose (one) and neck (one). Developing larvae caused severe welfare problems and tissue destruction in most cases. Although the number of cases reported here is small, wohlfahrtiosis in dogs may be very important from an epidemiological perspective because farm and stray dogs can act as both reservoirs and carriers of this parasitic fly species. Therefore, education of dog owners concerning the risk factors in endemic regions is recommended in order to reduce the prevalence of wohlfahrtiosis in dogs and thereby in livestock. Both owners and veterinarians should pay regular attention to any wounds and to the natural orifices of dogs, especially during the fly seasons.     

Multi-Level Determinants of Parasitic Fly Infection in Forest Passerines

The study of myiasis is important because they may cause problems to the livestock industry, public health, or wildlife conservation. The ecology of parasitic dipterans that cause myiasis is singular, as they actively seek their hosts over relatively long distances. However, studies that address the determinants of myiasis dynamics are very scarce. The genus Philornis include species that may be excellent models to study myiasis ecology, as they exclusively parasitize bird nestlings, which stay in their nests until they are fully fledged, and larvae remain at the point of entry until the parasitic stage is over, thus allowing the collection of sequential individual-level infection data from virtually all the hosts present at a particular area. Here we offer a stratified multi-level analysis of longitudinal data of Philornis torquans parasitism in replicated forest bird communities of central Argentina. Using Generalized Linear Models and Generalized Linear Mixed Models and an information theory approach for model selection, we conducted four groups of analyses, each with a different study unit, the individual, the brood, the community at a given week, and the community at a given year. The response variable was larval abundance per nestling or mean abundance per nestling. At each level, models included the variables of interest of that particular level, and also potential confounders and effect modifiers of higher levels. We found associations of large magnitude at all levels, but only few variables truly governed the dynamics of this parasite. At the individual level, the infection was determined by the species and the age of the host. The main driver of parasite abundance at the microhabitat level was the average height of the forest, and at the community level, the density of hosts and prior rainfall. This multi-level approach contributed to a better understanding of the ecology of myiasis.     

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.     

Gastrointestinal myiasis by larvae of Sarcophaga sp. and Oestrus sp. in Egypt: report of cases, and endoscopical and morphological studies

Four cases of gastric or intestinal myiasis are reported. The cases contain 2 males (1 child 10 years old, and 1 adult 40 years old) and 2 females (1 girl 18 years old, and 1 adult 50 years old) from Minia Governorate, Southern Egypt. Three of them, including cases no. 1, 3, and 4, were gastric myiasis, and complained of offensive hematemesis of bright red blood. Minute moving worms, larvae of the fly, were found in the vomitus. On the other hand, case no. 2 had intestinal myiasis, and complained of abdominal distention, nausea, vomiting, and diarrhea. The stool of case 2 was mixed with blood, and minute moving worms were observed in the stool. Endoscopy was performed to explore any pathological changes in the stomach of the patients. The larvae were collected and studied macroscopically, microscopically, and us-ing a scanning electron microscope (SEM) to identify their species. Three different types of larvae were identified. The larvae isolated from case 1 were diagnosed as the second stage larvae of Sarcophaga species, and the larvae isolated from case 2 were the third stage larvae of Sarcophaga species. On the other hand, the larvae isolated from cases 3 and 4 were diagnosed as the third stage larvae of Oestrus species.     

Human urogenital myiasis caused by the ‘rat-tailed’ larvae of Palpada scutellaris (Fabricius, 1805) in Santander,eastern Colombia: A case report

The Palpada genus, which belongs to the Diptera order (family, Syrphidae), has been rarely reported to cause accidental myiasis in humans. Herein, we report the first case of genitourinary myiasis caused by a larva of the Palpada genus in a 9-year-old girl from Colombia. The girl, who resided in a rural area in the municipality of Floridablanca, Santander, near Bucaramanga city, in eastern Colombia, presented with lower abdominal pain accompanied by oliguria, followed by the subsequent elimination of a larva through the urine. The next day, the patient visited a primary healthcare centre, and no signs or symptoms were observed on clinical examination. Haematological analysis showed high plateletcrit levels and platelet large cell counts. The results of the urine test revealed a decrease in specific gravity and a slight increase in bacterial content and mucus. DNA barcoding analyses showed that the etiological agent corresponded to a third instar larva of the Palpada scutellaris species. This is the first case to report genitourinary myiasis caused by larvae of the genus Palpada in humans. However, we believe that additional cases might be accurately detected if adequate tests are performed to confirm the clinical and molecular features associated with this infection.     

Accelerating elimination of sleeping sickness from the Guinean littoral through enhanced screening in the post-Ebola context: A retrospective analysis

BackgroundActivities to control human African trypanosomiasis (HAT) in Guinea were severely hampered by the Ebola epidemic that hit this country between 2014 and 2016. Active screening was completely interrupted and passive screening could only be maintained in a few health facilities. At the end of the epidemic, medical interventions were progressively intensified to mitigate the risk of HAT resurgence and progress towards disease elimination.Methodology/Principal findingsA retrospective analysis was performed to evaluate the medical activities that were implemented in the three most endemic prefectures of Guinea (Boffa, Dubreka and Forecariah) between January 2016 and December 2018. Passive screening using rapid diagnostic tests (RDTs) was progressively resumed in one hundred and one health facilities, and active screening was intensified by visiting individual households and performing RDTs, and by conducting mass screening in villages by mobile teams using the Card Agglutination Test for Trypanosomiasis. A total of 1885, 4897 and 8023 clinical suspects were tested in passive, while 5743, 14442 and 21093 people were actively screened in 2016, 2017 and 2018, respectively. The number of HAT cases that were diagnosed first went up from 107 in 2016 to 140 in 2017, then subsequently decreased to only 73 in 2018. A progressive decrease in disease prevalence was observed in the populations that were tested in active and in passive between 2016 and 2018.Conclusions/SignificanceIntensified medical interventions in the post-Ebola context first resulted in an increase in the number of HAT cases, confirming the fear that the disease could resurge as a result of impaired control activities during the Ebola epidemic. On the other hand, the decrease in disease prevalence that was observed between 2016 and 2018 is encouraging, as it suggests that the current strategy combining enhanced diagnosis, treatment and vector control is appropriate to progress towards elimination of HAT in Guinea.     

Myiasis of a perineal fistula

We report a case of myiasis of a rectocutaneous fistula in a subject suffering from bone metastases after surgical resection of a neoplastic bladder. The fistula was infested by maggots identified as third-instar larvae of flies belonging to the family Sarcophagidae, genus Sarcophaga. The infestation was neither intestinal nor pseudointestinal; it was probably caused by a fly ovipositing on the fistula of the patient while having wound care at home, even though the possibility that the infestation might have occurred during hospitalization cannot be ruled out.     

The role of Ixodes trianguliceps tick larvae in circulation of Babesia microti in the Middle Urals

The nested PCR method with primers flanking a conserved fragment of the Babesia microti ss-rDNA gene was used to examine 834 larvae of Ixodes trianguliceps ticks engorged to a varying degree, taken off 237 hosts of 12 species (rodents and insectivores). The hosts were collected in southern taiga forests in the lowmountain area of the Middle Urals (Chusovoi District, Perm Province) in 2003–2010. Babesia DNA was detected in 89 (10.7%) larvae from 8 species of small mammals. According to the data obtained by PCR and microscopic methods, either B. microti DNA or the parasites themselves were found in the blood of 45.2% of the mammals. The nucleotide sequences of 15 amplicons of Babesia DNA obtained from larvae of I. trianguliceps ticks and their hosts were identical to those of B. microti available in GenBank. In 13 cases, they were similar to B. microti US-type (a human pathogen) and in two cases (those from I. trianguliceps and from the vole Clethrionomys rufocanus from which it was removed), to B. microti of the Munich strain which is not pathogenic to humans. The duration of feeding on small mammals seems to exert the main influence on the infection rate of I. trianguliceps larvae. The fully engorged larvae contained B. microti DNA more often and usually in greater amounts than those collected during the first days of blood-sucking. The latter usually revealed Babesia DNA in the minimum quantity (< 0.064 ng/μl). According to the data obtained, transovarial transmission of Babesia in I. trianguliceps is unlikely. The processes of horizontal and transstadial transmission appear to be of crucial importance for the functioning of the natural foci of babesiosis.