Oestrus ovis larvae are obligate parasites of vertebrates and cause cavitary myiasis (oestrosis) in sheep and goats. It is also reported as a zoonosis causing ophthalmomyiasis and nasopharyngeal myiasis. Despite being relatively common in Brazil, epidemiological studies on O. ovis are scarce. Considering that the infestation is influenced by the climate and biomes of the studied region, we aimed to investigate the seasonal prevalence of O. ovis among slaughtered sheep in the northern region of the state of Mato Grosso, Brazil. The heads of sheep (n=697) slaughtered at a slaughterhouse in the municipality of Terra Nova do Norte (November 2011 to November 2013) were collected to count, catalog, and identify the larvae found in the upper respiratory tract. Overall, 45.77% (319/697) of the animals were infested with 2,412 recovered larvae, 96.89% (2,337/2,412) of which were identified at the species level as O. ovis. Seasonal variations in prevalence ranged from 41% (spring) to 56% (summer); however, no correlation was observed between prevalence and season, mean humidity, or temperature. In conclusion, parasitism by O. ovis in sheep in the studied area, occurs year-round, considering the occurrence of larvae (L1, L2, and L3) throughout the year, probably because of the area's environmental conditions. As larvas de Oestrus ovis são parasitas obrigatórios de vertebrados e causam miíase cavitária (estrose) em ovinos e caprinos. Também é relatada como uma zoonose que causa oftalmomíase e miíase nasofaríngea. Apesar de relativamente comum no Brasil, os estudos epidemiológicos sobre O. ovis são escassos. Considerando que a infestação é influenciada pelo clima e biomas da região estudada, objetivou-se investigar a prevalência sazonal de O. ovis entre ovinos abatidos na região norte do estado de Mato Grosso, Brasil. Foram coletadas cabeças de ovinos (n=697) abatidos em frigorífico do município de Terra Nova do Norte (novembro de 2011 a novembro de 2013) para contagem, catalogação e identificação das larvas encontradas no trato respiratório superior. No geral, 45,77% (319/697) dos animais estavam infestados com 2.412 larvas recuperadas, das quais 96,89% (2.337/2.412) foram identificadas em nível de espécie como O. ovis. As variações sazonais na prevalência variaram de 41% (primavera) a 56% (verão); no entanto, não foi observada correlação entre prevalência e estação do ano, umidade média ou temperatura. Conclui-se que o parasitismo por O. ovis em ovinos na área estudada ocorre durante todo o ano, considerando a ocorrência de larvas (L1, L2 e L3) ao longo do ano, provavelmente devido às condições ambientais da área.

Myiasis is an ectoparasitic infection caused by the larvae of true flies (Diptera). We came across a rather rare case of myiasis in an immunocompetent 34-year-old man from French Guiana with advanced wound myiasis masquerading as cavitary myiasis and a history of cholesteatoma surgery in the left ear. The Diptera larvae responsible for the disease were isolated and identified using morphological and molecular approaches as Cochliomyia hominivorax. We underline the importance of this parasitosis as the second case of myiasis caused by C. hominivorax and the first case of wound myiasis in this overseas department of France and its incidence in pre-urban areas of the capital, Cayenne, in South America.

Larvae of the sheep bot fly, Oestrus ovis (Linnaeus, 1758), cause cavitary myiasis in domestic and wild hosts, including man. The complete circular O. ovis mitogenome was assembled, which is 16,584 bp in length and encodes 13 protein-coding genes, 22 tRNA genes, and two rRNA genes. The phylogenetic tree of O. ovis and 13 related Oestridae species, with Sarcophaga tuberosa as outgroup, was built.

Oestrosis, caused by the larvae of Oestrus ovis, commonly known as sheep nose bot, is an obligatory cavitary myiasis of sheep and goats. Oestrus ovis is a widespread parasite, but little is known about the prevalence of oestrosis at the global and broad geographical levels. The present study aimed to explore the epidemiology of oestrosis at the global and regional level to estimate prevalences and their associated factors using a systematic approach. This is, to the author's knowledge, the first meta-analysis of oestrosis in sheep and goats. Published articles were obtained from nine electronic databases (PubMed, CAB Abstracts, Web of Science, Scopus, UCB library, Medline, Biosis Citation Index, Indian journals and Google Scholar) reporting the prevalence of O. ovis in sheep and goats from 1970 to 2018. Pooled prevalences were estimated using a random effect meta-analysis model. Sixty-six studies were eligible, and data from 40,870 sheep and 18,216 goats were used for quantitative analysis. The random effect estimated prevalence of oestrosis at the global level in sheep was 51.15% (95% CI: 42.80-59.51%) and in goats was 42.19% (95% CI: 33.43-50.95%). The pooled prevalence estimates for Africa, Asia, Europe and the Americas were 47.85% (95% CI: 36.04-59.66%), 44.48% (95% CI: 33.09-55.87%), 56.83% (95% CI: 48.92-64.74%) and 34.46% (95% CI: 19.90-49.01%), respectively. Heterogeneity (I2 > 80%) was detected in most pooled estimates. Oestrosis is highly prevalent in many geographical regions of the world, especially in Europe and Africa. Factors that contribute to the pooled prevalence estimate of oestrosis need to be emphasised in any survey to estimate the true prevalence of oestrosis. Furthermore, there is a need for immunisation or implementation of other preventive measures to reduce the burden of oestrosis in sheep and goats and to improve the health and welfare status.

The presentation of sepsis and bacteremia in cutaneous and cavitary myiasis is uncommon. We present a patient, residing in a temperate region of the United States, with myiasis and sepsis from the emerging human pathogens Wohlfahrtiimonas chitiniclastica and Ignatzschineria indica. A 37-year-old male patient with an 8-month history of chronic lymphedema and ulcers of the lower left extremity presented with myiasis of the left foot and leg. The patient was initially seen by his family practitioner many times and was prescribed antibiotics which he could not afford. Debridement of the myiasis was not conducted by the family practitioner due to the belief that the patient's current state of myiasis would effectively debride and eventually heal the chronic ulcers along with multiple antibiotic regimens. Over the 8-month period, the patient developed a progressive, painful, necrotizing infection of his lower left extremity. Physical examination clearly showed myiasis of the patient's lower left extremity, believed to be caused by Lucilia sericata (green bottle fly). Blood cultures revealed the presence of Providencia stuartii, W chitiniclastica, and I indica to be the underlying cause of sepsis and bacteremia. All visible maggots were extracted, debridement of devitalized tissue was performed, and the leg ulcers were wrapped in pH neutral bleach. The patient was initially treated with a broad-spectrum antibiotic regimen of vancomycin, clindamycin, piperacillin, and tazobactam which, following clinical improvement, was de-escalated to cefepime. The fly larvae and maggots were removed from the extremity by scrubbing, pulse lavage, and filing away the callused tissue. Additionally, the patient's sepsis and bacteremia, caused by W chitiniclastica and I indica, were successfully treated through antibiotic intervention. Amputation was avoided. The use of pulse lavage and chlorhexidine-soaked brushes for the removal of cavitary myiasis is an effective and minimally invasive procedure which does not cause additional damage to surrounding tissue. W chitiniclastica and I indica are emerging bacteria that have known association to parasitic fly myiasis in humans and are capable of causing sepsis and/or bacteremia if not accurately identified and treated promptly.