Human Nasal Myiasis Caused by Oestrus ovis in the Highlands of Cusco, Peru: Report of a Case and Review of the Literature

Population diversity of sheep bot fly, Oestrus ovis (Linné, 1758) (Diptera: Oestridae: Oestrinae), using SDS polyacrylamide gel electrophoresis

The study was planned to evaluate the inter, and intra population genetic variation in general protein banding pattern in Oestrus ovis larvae, by using 10% sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE). The larvae were collected from slaughtered goats head from five different locations (AAS, PN, LA, GM, and BC) of Karachi, Pakistan. The data obtained was subjected to POPGENE (Population Genetic Analysis) software for analysis. The polymorphic loci within populations ranged from 45.45% to 90.91%. Polymorphic loci observed in all populations were 90.91%. The expected heterozygosity observed was 0.182 ± 0.096 in all populations. The chi-square test showed 5 out of 11 loci at H-W equilibrium. The overall fixation index (FST) value was 0.108, showing that the likelihood of subpopulations being differentiated from one another is about 11 percent. The gene flow value (Nm = 2.065) was higher, showing that genes flow occurs between populations. The values of genetic identity were greater, and genetic distance were smaller among all the populations, which means that all the populations were more alike and closer to each other. It was concluded that there was no sympatric and parapatric population differentiation observed among all the population of O. ovis and the populations of the five different locations were not genetically and reproductively isolated from each other.

Nasal myiasis in patients with disturbance of consciousness: A case report and literature review

Nasal myiasis is a rare parasitic disease. The growth of myiasis in the nasal cavity causes damage to the nasal cavity and paranasal sinuses. Once the dipeterous larvae are migrated, it causes damage to the surrounding structures such as eyes and skull cavity. Proper treatment and active prevention and control can reduce and avoid the occurrence of serious complications. On May 14, 2020, a patient with cerebral infarction and coma was admitted to Xiangya Hospital of Central South University and developed nasal myiasis. During the treatment of the primary disease, the patient was found to be infected with rhinomyiasis. The patient was treated with dehydration, cranial pressure reduction, brain protection, blood glucose control, blood pressure control, and anti-infection. Nasal endoscopy and nasal irrigation were carried out to treat nasal myiasis. The patient was properly placed and isolated for prevention and control so as to prevent the spread of myiasis in the ward. After 16 days, the patient regained consciousness, no worm was found in the nasal cavity, and was discharged from the hospital. The patient was followed-up for 6 months, no maggots were found in the nasal cavity of the patients, no complaints of nasal discomfort was occurred, and no other patients and medical staff were infected with myiasis. The prevention of myiasis is very important, and proper measures should be taken to reduce the risk of community and hospital infection.

Rhinomyiasis: clinical and surgical management

Myiasis by Oestrus ovis, the zoonotic infestation with Diptera larvae, primarily diagnosed in goats and rams in tropical and Mediterranean countries, is an uncommon disease in humans; indeed, literature data are still lacking. Nevertheless, few cases of human myiasis have been reported, leading to benign or severe complications. Here, we report a rare case of human rhinomyiasis detected in Northern Italy. A 39-year-old Italian woman, returning from vacation in Corsica, showed several sinusal symptoms and progressive asthenia and was therefore admitted at the Otorhinolaryngology Unit of Biella Hospital, Italy. Endoscopic examination of the nasal cavity revealed some formations, morphologically identified as O. ovis larvae. The patient then underwent endoscopic sinus surgery, followed by complete resolution of symptoms. Clinical presentation, diagnostic work-up and therapeutic procedures have been compared with few other cases found in the literature.

A Case and Review of Ophthalmomyiasis Caused by Oestrus ovis in the Central Valley of California, United States

Ophthalmomyiasis externa is the infestation of external ocular structures most commonly by Oestrus ovis, sheep nasal bot fly, which have a pupal stage in soil. Farmers and shepherds are commonly affected but rarely in urban areas. This is the first case of Oestrus ovis ophthalmomyiasis externa in California since Catalina Island 1986. No livestock exposure was noted. Manure fertilizer sourced from grazing fields of natural hosts was used on a local urban sports field and is the suspected source.

Rhinomyiasis by Oestrus ovis in a tourist returning from Corsica

In the Mediterranean basin, one of the most important agents of myiasis is Oestrus ovis Linnaeus 1758 (Diptera, Oestridae). Herein, we report a rare case of nasal myiasis with a secondary infection complication in a patient from northern Italy who had been visiting Corsica. A healthy, 39-year-old Italian woman spent 2 weeks of vacation in Corsica in June 2018. During her stay, she suddenly felt a foreign body inside her nose, followed by cough, pain, burning at the pharyngeal level, cephalalgia, and nasal congestion with secretions from the nostrils. The clinical examination showed a hyperemic and irritated mucosa and endoscopic examination of the patient's nose and right maxillary sinus revealed three tiny mobile larvae, morphologically and molecular identified as L1 instar larvae of Oestrus ovis. The patient's infestation was probably imported from Corsica, as Mediterranean islands are ideal geographical areas for the development of O. ovis, and the timing of infestation match with the period of O. ovis larviposition. Although rhinomyiasis is rare, it should be considered in people returning from abroad presenting with an acute-onset and foreign body sensation in the nose.

Oestrus ovis in Ecuador: Importance in the Andean sheep farming

Aim

This study aimed to determine the prevalence of Oestrus ovis in sheep meant for meat commercialization in the main slaughterhouse of the country.

Materials and Methods

Between October 2015 and December 2015, we assessed the occurrence of Oestrus myiasis in the main slaughterhouse localized in Quito. In total, 80 sheep heads were randomly inspected and necropsied. Larvae were removed from nasal cavities and paranasal sinuses and cleaned. ANOVA (generalized linear model) was used to estimate the relationship between sex, age, and place of origin and presence or absence of parasite larvae.

Results

Morphological identification confirmed that 19% (15/80) of the examined animals were positive for Oestrus ovis; from the positive cases, 21% were young animals <12 months old. We found that statistical differences by animal sex, males, were most infested 93% (14/15) than females 7% (1/15). Larvae's L2 were more abundant than other stages (62 of the total 149). 14 of the infested animals were from the Andean places at > 2500 meters above sea level (m.a.s.l.), and only one case from the coastal region at 250 m.a.s.l. with tropical environmental conditions.

Conclusions

Our results showed evidence of the presence of myiasis caused by O. ovis in Andean and coastal places in Ecuador and its adaptation to different environmental conditions from that reported previously in temperate regions from Europe and Africa.

Report of a rare case of severe allergic reaction due to nasal myiasis and a brief review of the literature in Turkey

Myiasis is defined as infestation of a mammal by fly larvae. It may occur on either living tissues (primary myiasis) or dead tissues (secondary myiasis). In this report, we present a patient with myiasis with an extremely rare clinical manifestation and severe allergic reaction, and we review the literature in order to reveal the current status. A 20-year-old female patient was admitted to our emergency department due to rush on face, cough and shortness of breath. The maggot came out of her nose was identified as Oestrus ovis. With a diagnosis of severe allergic reaction due to myiasis, she was treated diphenhidramine, prednisone and inhale albuterol in the emergency department. After treatment and further investigation, she was discharged with full recovery. Myiasis is a rare cause for severe allergic reaction in patients with definite diagnosis. Immediate diagnosis and treatment are milestones in preventing bad outcomes.

Treatment of nasal myiasis with ivermectin irrigation

We describe a case of nasal myiasis due to Musca domestica in a 97-year-old Peruvian farmer with a previously undiagnosed mucocutaneous leishmaniasis. Initial attempts to remove the fly larvae using manual extraction with a toothed forceps and normal saline irrigation were unsuccessful. On subsequent nasal irrigation with ivermectin solution, the patient self-expulsed approximately 50 larvae within 15 min. He also received a course of oral ivermectin. A post-treatment CT scan revealed clear sinuses. Here, we propose that ivermectin irrigation is a simple and effective treatment for nasal myiasis.