Intestinal myiasis caused by Muscina stabulans

[DROSOPHILA MELANOGASTER GASTROINTESTINAL MYIASIS: ABOUT A MOROCCAN CASE REPORT]

Introduction

Myiasis is an infestation of humans or animals by larval forms of brachycetes. Commonly observed locations are otolaryngological and cutaneous. Gastrointestinal localization remains exceptional. In this work, we report the observation of a Moroccan case of gastrointestinal myiasis caused by Drosophila melanogaster. Observation. The patient was a 56-year-old man living in a rural region of northwest Morocco. He was being followed at the National Oncology Institute in Rabat for pulmonary and renal adenocarcinoma and was put on neo-adjuvant chemotherapy with concomitant radiochemotherapy. The patient presented vomiting twice containing about forty small white, circular and hairless worms measuring 4 mm in length. This sample was sent to the parasitology and mycology laboratory for identification. Microscopic study of the larvae and adult flies obtained after rearing in the laboratory of parasitology allowed the diagnosis of myiasis caused by Drosophila melanogaster.

Discussion/Conclusion

This observation is noteworthy for both its exceptional anatomical localization and the implicated parasite species.

Morphological and Molecular Identification of Oestrus ovis (Diptera: Oestridae) Larvae Collected from a Chinese Patient with Conjunctival Myiasis

PURPOSE

Human conjunctival myiasis, which is often misdiagnosed or missed clinically, is commonly caused by Oestrus ovis larvae. Here, pathogenic identification was performed for two maggots collected from a patient from China, to provide a clinical scientific basis for diagnosis and treatment.

METHODS

Morphological identification was performed using a microscope. Oestrus mtDNA cox1 and rDNA 28S were selected as target genes for duplex PCR amplification, followed by cloning, sequencing, and identification.

RESULTS

Morphological examination showed that the maggots were approximately 1.0-1.5 mm long, long-oval-shaped, segmented, and covered with small spines, with a pair of hooks in the scolex and claw-like spines at the telson. Therefore, they were identified as the first-instar larvae of O. ovis. Duplex PCR detected products of approximately 400 and 200 bp, consistent with the size of designed cox1 and 28S D7a gene fragments, respectively. Sequences of cox1 and 28S D7a from the samples in question had 99.5-100.0% and 96.2-100.0% similarity (respectively) to GenBank sequences of O. ovis specimens known to parasitize sheep, goats, and humans. However, some 28S D7a sequences exhibited 89.7-90.6% similarity to GenBank sequences of Oestrus sp. known to parasitize Capra pyrenaica (Artiodactyla: Bovidae) (Iberian ibex). Therefore, we considered that the larvae infecting the patient originated from sheep or goats, not Iberian ibex. The phylogenetic trees supported this conclusion.

CONCLUSION

This study implemented the first duplex PCR molecular identification of O. ovis larvae parasitizing human eyes in China as a complementary approach to morphological identification. Our results indicate that molecular tools can be utilized to aid in the diagnosis of opthalmomyiasis.

An Accidental Intestinal Myiasis Caused by Cochliomyia macellaria

Intestinal myiasis is recognized as pseudomyiasis or accidental myiasis caused by dipteran fly larvae transmitted to humans via contaminated food or water. A case of intestinal myiasis acquired via contaminated food is reported in this case study. The patient is a 4-year-old boy who had frequent episodes of crampy abdominal pain and diarrhoea and the passage of many live worms at each time. As the child had the habit of eating ripe guava from his garden, the infection source was suggested as ripe guava, and the possibility was explored. All larvae collected from faeces and fruit were morphologically similar, and it has been identified as Cochliomyia macellaria. The treatment with several antihelmintics failed, and the recovery was achieved with a simple measure of abstinence from eating guava that came from his garden.

Myiasis in patients with oral squamous cell carcinoma-a systematic review and protocol for management

BACKGROUND

Oral squamous cell carcinoma results in various morbidities like pain, bleeding on provocation, loss of function, facial disfigurement, extra oral fungation, and tissue necrosis. Other than these dreadful complications, sometimes in advanced and incurable stage, the wound gets infested with maggots. Oral myiasis in association with OSCC is rare, and a very few reports have been mentioned in the literature.

MATERIAL AND METHODS

A literature search was performed on PubMed, Medline, and Cochrane databases on 1st November 2018 for all the articles focusing on oral myiasis in patients with oral squamous cell carcinoma.

RESULTS

A total number of nine cases with oral myiasis in association with OSCC have been reported till date. Out of these nine cases, five cases have been reported from India and four from Brazil.

CONCLUSION

Oral myiasis is a possible risk for the patient with Oral squamous cell carcinoma. Good hygiene and general cleanliness along with educating the patients must be a practice to avoid this dreadful condition.

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.

Management of Malignant Wound Myiasis with Ivermectin, Albendazole, and Clindamycin (Triple Therapy) in Advanced Head-and-Neck Cancer Patients: A Prospective Observational Study

INTRODUCTION

Myiasis, tissue infestation by housefly larvae, is commonly found in malignant fungating wounds of cancer patients from climatic condition and lower socio-economic strata.

AIM OF STUDY

It was aimed to study the effectiveness of systemic Ivermectin, Albendazole& Clindamycin (Triple Therapy) in reducing signs & symptoms associated with maggots in malignant head and neck wounds.

METHOD

25 adult, advanced head and neck cancer patients presenting with maggots either from wound, oral cavity or nostril, with ECOG score 3 or less were enrolled in this study. Symptoms were assessed using Edmonton Symptom Assessment Scale (ESAS) and wound by Wound Assessment Tool - Hospice, at baseline and then Days 1, 3, 5, and 7. All patients received 3 days course of oral Ivermectin 12 mg per day, Albendazole 400 mg twice per day and Clindamycin 300 mg three times per day for 5 days along with Terpentine oil dressing. All patients received oral Morphine as per their pain score.

RESULTS

Mean age (yrs) and weight (Kg) were 42.15 ± 8.23 and 52.31 ± 5.18 respectively. 84% patients were male. Mean oral morphine dose was 100.38 mg. There was significant decrease in number of maggots from day 0 (77.28 ± 13.465) to day 1 (20.60 ± 7.263; 73.34% reduction) to day 3 (1.52 ± 2.104; 92.62% reduction). We found statistically significant improvement (P = <0.05) in scores of wound and all other related symptoms on days 1, 3, 5 & 7, except bleeding, edema, nausea, anxiety, appetite loss and feeling of wellbeing, which remained same on Day 1, but improved afterward. Side effects were self-limiting.

CONCLUSION

Systemic treatment with Ivermectin, Albendazole and Clindamycin (Triple Therapy) enhances the removal of maggots, early recovery and relief from distress and associated symptoms.

The colonisation of remains by the muscid flies Muscina stabulans (Fallén) and Muscina prolapsa (Harris) (Diptera: Muscidae)

In the field, the muscid flies Muscina stabulans (Fallén) and Muscina prolapsa (Harris) only colonised buried baits in June, July and August. The two-species co-occurred on baits buried at 5cm but only M. prolapsa colonised baits buried at 10cm. Other species of insect were seldom recovered from buried baits regardless of the presence or absence of Muscina larvae. In the laboratory, both M. stabulans and M. prolapsa preferentially colonised liver baits on the soil surface compared to those buried at 5cm. Baits buried in dry soil were not colonised by either species whilst waterlogged soil severely reduced colonisation but did not prevent it entirely. Dry liver presented on the soil surface was colonised and supported growth to adulthood but if there was no surrounding medium in which the larvae could burrow then they died within 24h. M. stabulans showed a consistent preference for ovipositing on decaying liver rather than fresh liver, even when it had decayed for 41 days. The results for M. prolapsa were more variable but it was also capable of developing on both fresh and very decayed remains. Blood-soaked soil and dead slugs and snails stimulated egg-laying by both species and supported larval growth to adulthood. Mushrooms, melon, and bananas also stimulated egg-laying although to a much lesser extent and very few larvae survived to adulthood. Horse faeces stimulated extensive egg-laying but the larvae invariably died during the first or second instar and none survived to pupariation. This information could be useful when determining the forensic significance of Muscina larvae recovered from dead bodies.

Morphology successfully separates third instar larvae of Muscina

Three representatives of the muscid genus Muscina Robineau-Desvoidy (Diptera: Musicidae), Muscina levida (Harris), Muscina prolapsa (Harris) and Muscina stabulans (Fallén), are well known for their medical, veterinary and forensic importance. However, data in the literature provide contradictory information for the identification of third instar larvae of these species. This hinders easy species differentiation because it requires the rearing of material to adult stages in order to facilitate reliable identification. Third instar larvae of these three Muscina species were studied in detail using light and scanning electron microscopy to provide thorough redescriptions of their morphology. Existing information concerning third instar morphology, with particular reference to its value for taxonomy and identification, is revised and discussed. Emden's spiracular distance factor (SDF) is considered here as inappropriate for identification purposes in third instar larvae of Muscina spp. because its values are not constant ratios but increase during larval maturation and overlap in the examined species. These species were, instead, discriminated here by differences in the spinulation patterns of their abdominal segments.

Incidence of myiasis among humans-a review

Myiasis, the infestation of tissues of live humans and other vertebrate animals with dipteran larvae (maggots), is a phenomenon of widespread occurrence throughout the tropical regions of the world. It is commonly seen in domestic and wild animals but occurs rarely in man also. The tissue invasion in man by maggots is generally a well-recognized complication of neglected wounds. The condition may be asymptomatic but occasionally results in more or less severe problems and even death when larvae invade body cavities or areas that forbid their direct visual examination. Many cases of myiasis, however, usually do not reach the attention of medical practitioners because of the tendency of the mature larvae to migrate out of the lesion for pupation. In the present study, the authors reviewed the past literature describing the cases of human myiasis, causative fly species and predisposing factors for the onset of the same. The aim of the present manuscript is to provide a database for the future reference of medical entomologists, medical practitioners and veterinarians. Review of literature revealed that 37 fly species belonging to ten families were responsible worldwide for the onset of human myiasis. The incidence of myiasis among humans can be correlated to increasing fly populations, poor hygienic conditions and presence of domestic animals in the close vicinity. Other factors responsible for myiasis include neglected open wounds and foul-smelling discharge from natural body openings. Moreover, ignorance plays a key role in its occurrence since people are generally unaware about the actual cause and often correlate the condition to their superstitious beliefs. It is emphasized that the patients should not neglect their wounds and should take proper medical care; otherwise, myiasis may supervene.

Persistent pediatric gastro-intestinal myiasis: a case report of fly larval infestation with Musca domestica with review of literature

The occurrence of dipterous fly larvae in human is termed as human myiasis. Human myiasis can be classified based on clinical condition it causes like cutaneous myiasis, ocular myiasis, urogenital myiasis and intestinal myiasis. Based on the need for a particular host, myiasis can be divided as specific myiasis, semi-specific myiasis. Accidental myiasis results when the fly larvae are deposited/ingested by human resulting in infestation, which is also called as pseudomyiasis. Fly larvae may be present on the dead and decaying organic matter and domestic animals like dog and cats which are naturally infested with fly larvae and can be source for infection in children. Very few cases have been retrieved from literature on the occurrence of intestinal myiasis in children throughout the world. We report a case of two siblings in the same family infested with dipterous fly larvae.

Myiasis

Myiasis is defined as the infestation of live vertebrates (humans and/or animals) with dipterous larvae. In mammals (including humans), dipterous larvae can feed on the host's living or dead tissue, liquid body substance, or ingested food and cause a broad range of infestations depending on the body location and the relationship of the larvae with the host. In this review, we deeply discuss myiasis as a worldwide infestation with different agents and with its broad scenario of clinical manifestations as well as diagnosis techniques and treatment.

First record of human myiasis caused by association of the species Chrysomya megacephala (Diptera: Calliplioridae), Sarcophaga (Liopygia) ruficornis (Diptera: Sarcophagidae), and Musca domestica (Diptera: Muscidae)

We report a rare case of myiasis caused simultaneously by three dipterous species. A 54 yr-old indigent patient was admitted to Andaraí Hospital with painful eruptions on the scalp. The parieto-occipital sulcus showed two lesions caused by scratching associated with deep, odoriferous and exudative pediculosis. Larvae removed with the help of forceps and vaseline produced 153 adults, identified in the laboratory as 114 specimens of Chrysomya megacephala (F., 1794), 38 of Sarcophaga (Liopygia) ruficornis (F., 1794), and one of Musca domestica (L., 1758).

Infestação por miíase em prolapso retal: relato de caso e revisão de literatura

INTRODUÇÃO: a miíase é uma afecção causada pela presença de larvas de moscas em órgãos ou tecidos do homem e de outros animais. Sua localização preferida em humanos é na pele, com ocorrências descritas nas cavidades naturais. Seu tratamento é baseado na remoção mecânica das larvas e no desbridamento cirúrgico de tecidos desvitalizados. OBJETIVO: descrição do caso de um paciente com prolapso retal associado à infestação por miíase, discutindo sua incidência, sintomatologia e tratamento. RELATO DO CASO: L.C.S, 36 anos, masculino, com prolapso retal há um ano. Habitante de região rural, com baixo nível sócio-econômico, não possuía banheiros ou qualquer tipo de saneamento básico em sua residência. Ao exame proctológico, evidenciava-se prolapso retal edemaciado, com áreas cavitárias com necrose, secreção purulenta e grande quantidade de larvas de míiase. Realizou-se retirada mecânica das larvas com posterior debridamento cirúrgico. Optou-se pela confecção de uma colostomia em alça do sigmóide, devido à extensa área cruenta com lesão esfincteriana interna. CONCLUSÕES: O acometimento da miíase retal em prolapsos é raro, e deve ser prontamente diagnosticado e tratado. Um simples exame proctológico é fundamental para este fim. Salienta-se a necessidade contínua da educação em saúde, bem como se enfatiza a importância dos hábitos de higiene na população.