Bot Fly Larvae Research Articles

Parasitism by Botflies Philornis Sp. on European Starlings Sturnus vulgaris, an Exotic Bird in Argentina

We studied the parasitism of the exotic European starling Sturnus vulgaris by native botflies Philornis spp. in Argentina. We installed thirty nest boxes in the northeastern Buenos Aires province in the 2010–2011 breeding season. In the first brood, subcutaneous larvae of Philornis (Muscidae) parasitised 34 nestlings (89.4%) of 11 clutches (91.6%) and only three nestlings fledged. In the second brood, Philornis parasitised 15 (48.3%) nestlings of seven clutches (70%) and all the nestlings died. Compared to the mortality of other Neotropical birds parasitised by Philornis, the mortality in European starling nests is the highest found in the region. Our results show that the studied population of European starling suffers a high level of parasitism by Philornis, although this factor was not directly associated with the high mortality of starling nestlings. The fact that most non-parasitised nestlings also died indicates that other factors are also affecting nestling survival. Experiments that allow us to isolate the effect of Philornis from other variables would be needed to evaluate the impact of botfly larvae on starling nestlings.

Myiase furonculoïde à Dermatobia hominis : diagnostic fortuit sur la coupe macroscopique extemporanée d’un nodule cutané

Furuncular myiasis is a parasitic disease caused by the development of human botfly larva in the skin. It affects people living in tropical countries and travelers returning from these countries and concerns a number of medical specialties. One form of treatment involves surgical extraction of the parasites. We report the case of a 47-year-old man returning from Guyana presenting two furuncle-like nodules of the skin on the right buttock and on the right shoulder blade. Extemporaneous intraoperative macroscopic examination of the buttock nodule resulted in diagnosis of myiasis caused by the human botfly, Dermatobia hominis. The diagnosis of furuncular myiasis is made primarily on clinical grounds and should be suspected on observation of an abscess in subjects returning from a tropical region. It is consequently rare to find D. hominis in biopsy specimens. In the present case, macroscopic examination showed an extremely rare image of the edge of the intact larva in a longitudinal cut, which to our knowledge has never been published to date.

Profiling of proteins and proteases in the products of the salivary gland, digestive tract and excretions from larvae of the camel nasal botfly, Cephalopina titillator (Clark).

Proteins and proteolytic activities in the contents of the salivary gland (SGc), digestive tract (DTc) and excretory-secretory products (ESP) from larvae of the camel nasal botfly Cephalopina titillator were separated electrophoretically, and characterized. The protein profiles of the different samples were qualitatively quite similar in the larval stages L2 and L3. Zymogram analysis of proteases in the samples indicated that the digestive tract contained a greater variety of proteases than the salivary gland or the excretory-secretory products. They are mainly serine proteases. Proteases of ESP and DTc (especially of 3rd instar) contain trypsin- and chymotrypsin-like serine proteases, while the serine proteases of SGc are not of the trypsin- or chemotrypsin-type.

An unusual case of an infected preauricular pit in a child

Abstract Preauricular pits/sinuses (PPS) are common congenital anomalies found in infants and children. Acutely infected PPS may present with cellulitis, furunculosis, or abscess formation. We present a case of a child, with a suspected infected PPS and localized furunculosis whose infection was recalcitrant to standard antibiotics and no recent travel history. On exam, a preauricular (PA) circular puncta with localized cellulitis, pruritus, and tenderness was found. During operative exploration, the PA infection was found to represent cutaneous furuncular myiasis (FM) from a botfly larva. This case highlights the need to consider FM in children, who present with atypical head and neck infections recalcitrant to standard therapy.

Antigen characterization from second instars of oestrid bot flies for the detection of anti-Cephenemyia stimulator antibodies by ELISA in roe deer (Capreolus capreolus).

A study to determine the most appropriate antigen for use in the serodiagnosis of Cephenemyia (Diptera: Oestridae) infestation in roe deer (Capreolus capreolus) was carried out using immunoenzymatic tests. Serum samples from 43 roe deer from northern Spain were obtained post-mortem and corresponding numbers of bot fly larvae established. Three antigen complexes were tested, including Cephenemyia stimulator Clark excretory/secretory antigens (CsES), C. stimulator somatic antigens (CsSA) and Oestrus ovis L. (Diptera: Oestridae) excretory/secretory antigens (OoES). In addition, the composition of each antigen was analysed using an electrophoresis system. Cephenemyia stimulator larvae were found in 25% of roe deer; the mean intensity of infection was 24.3 larvae per infested animal. In the antigen analysis, CsSA showed four exclusive bands of molecular weight (17-19, 62, 65 and 67-70 kDa). A positive correlation between immunoglobulin G (IgG) values and total number of larvae was found with CsES and CsSA. The highest sensitivity value, negative predictive value and negative likelihood ratio were obtained using CsES. The highest specificity value, positive likelihood ratio and kappa value were achieved with CsSA. The predictive values of the enzyme-linked immunosorbent assay (ELISA) using CsES and CsSA reached statistical significance and seroprevalence values were 26-44%. The use of ELISA with CsES and CsSA seems promising in the non-invasive diagnosis of Cephenemyia infestation in roe deer.

In vitro and in vivo effects of neem tree (Azadirachta indica A. Juss) products on larvae of the sheep nose bot fly (Oestrus ovis L. Díptera: Oestridae)

Two studies were carried out in order to test the effects of neem tree extracts (Azadirachta indica A. Juss) on sheep bot fly larvae (Oestrus ovis L. Diptera: Oestridae). First, aqueous extracts from neem seeds (ASNE) at 0, 5y 10% (w/v) concentrations were tested on larval mortality in vitro. In a second study, the effect of oral administration with neem seed meal (0, 100y 200mg/kg) and neem leaves (1% of diet) on number of larvae found at necropsy and larval development was evaluated in experimentally O. ovis-infected sheep. Results in Experiment 1 showed a significant (P<0.05) effect of ASNE on time to L1 mortality in a dosis-dependent manner. In Experiment 2, oral administration of seeds or leaves did not affect the number of larvae found at necropsy of the sheep, but interfered with larval development and there was a tendency to reduce larval weight at the end of the infection period (55d).

External ophthalmomyiasis: A case report

Ophthalmomyiasis is an infestation of the eye with larvae of most common sheep nasal botfly (Oestrus ovis). We describe a case of ophthalmomyiasis in a 50-year-old man who presented with ocular foreign body sensation, redness and tearing. The causative larvae were removed in the emergency room and sent to laboratory for identification. The patient symptoms improved after topical treatment with antibiotics–steroid combination therapy.

Resistance of beef cattle of two genetic groups to ectoparasites and gastrointestinal nematodes in the state of São Paulo, Brazil

The resistance to infestations by ectoparasites and infections by gastrointestinal nematodes was studied in 45 animals (males and females) of two genetic groups: purebred Nelore (NI, n=28) and Three-Cross (1/2 Angus+1/4 Canchim+1/4 Nelore – TC, n=17). The animals were monitored for 24months, during which they were left to graze in tropical pastures without receiving treatment for parasites. Each month the animals were examined for infestations by external parasites, to count the numbers of cattle ticks Rhipicephalus microplus with diameter greater than 4.5mm present on the left side, horn flies (Haematobia irritans) present in the lumbar region and botfly larvae (Dermatobia hominis) present on the entire body. The H. irritans counts were performed with the aid of digital photographs. At the time of examination, fecal samples were collected to count the eggs per gram (EPG) and to perform coprocultures, and peripheral blood samples were drawn to determine the packed cell volume (PCV) and to count the eosinophils. For statistical analysis, the count data were transformed into log10 (n+1), where n is the number of parasites. For PCV, significant effects (P<0.05) were found for collection month (CO), genetic group (GG) and gender (SX), with means and respective standard errors of 41.5±0.65% for the NI animals, 39.3±0.83% for the TC, 41.5±0.72% for the females and 39.3±0.77% for the males. Regarding the eosinophil counts, only the effect of sex was significant (P<0.01), with means and respective standard errors of 926.0±46.2/μL, for males and 1088.0±43.8/μL of blood, for females. The NI animals presented lower mean counts for all the external parasites compared to the TC animals (P<0.01). For ticks, the transformed means followed by standard errors for the NI and TC animals were 0.06±0.01 and 0.34±0.02, while for horn flies these were 0.92±0.05 and 1.36±0.06 and for botfly larvae they were 0.05±0.03 and 0.45±0.05, respectively. The average EPG values were only influenced by CO (P<0.01). The coprocultures revealed the presence of the following endoparasites: Haemonchus spp., Cooperia spp., Oesophagostomum spp. and Trichostrongylus spp., the last in smaller proportion. There were no significant differences between the genetic groups for the endoparasite loads, except for Cooperia spp., which were present in greater number (P<0.05) in the NI group. The results obtained in this experiment confirm previous findings of greater susceptibility of the Nelore breed to Cooperia spp. and high resistance to ectoparasites.

Philornis sp. bot fly larvae in free living scarlet macaw nestlings and a new technique for their extraction

Bot fly larvae (Philornis genus) are obligate subcutaneous blood-feeding parasites of Neotropical birds including psittacines. We analyze twelve years of data on scarlet macaw (Ara macao) nestlings in natural and artificial nests in the lowland forests of southeastern Peru and report prevalence and intensity of Philornis parasitism. Bot fly prevalence was 28.9% while mean intensity was 5.0 larvae per infected chick. Prevalence in natural nests (11%, N=90 nestlings) was lower than in wooden nest-boxes (39%, N=57) and PVC boxes (39%, N=109). We describe a new technique of removing Philornis larvae using a reverse syringe design snake bite extractor. We compare this new technique to two other methods for removing bots from macaw chicks and find the new method the most suitable.

External Ophthalmomyiasis which was Caused by Sheep Botfly (Oestrus ovis) Larva: A Report of 10 Cases

Myiasis is the infestation of the tissues and organs of animals or man by fly larvae. Ophthalmic myiasis has been reported from various world regions. In this study, we are presenting the clinical manifestations of external ophthalmomyiasis which was caused by the larvae of the sheep nasal botfly, Oestrus ovis, in 10 patients in the Tirunelveli and the Tuticorin districts of Tamil Nadu state India. All the patients were farmers, who worked in close contact with sheep and goats. All the patients presented with severe conjunctivitis. The larvae were observed in the bulbar conjunctiva and following their removal, the symptom of eye inflammation improved in a few hours.

Unilateral acute conjunctivitis due to Oestrus ovis in a veterinary doctor

Myiasis is the infestation of tissues and organs of animals or man by fly larvae. We report a human case of external ophthalmomyiasis caused by the larvae of a sheep nasal botfly, Oestrus ovis, for the first time in a veterinary doctor. A 25-year-old veterinary doctor presented with severe symptoms of conjunctivitis. The larvae, 3 in number, were observed in the bulbar conjunctiva and the symptoms of the eye improved within a few hours of their removal. It is important for ophthalmologists to be aware of larval conjunctivitis as a significant possibility in the veterinary fraternity especially during the summer season.

Safe and Successful Use of Permethrin for Extraction of Dermatobia hominis Larvae in a Patient With Cutaneous Myiasis

Cutaneous myiasis by Dermatobia hominis or human botfly larva infestation of skin and subcutaneous tissue is an increasingly rec- ognized health hazard in returning travelers from Central America, South America, and Mexico. Successful extraction of the subcutaneous larvae is important for proper diagnosis and treatment. We hereby report a safe and easy way of extraction of human botfly larvae by local application of 1% permethrin solution in a patient with cutaneous myiasis.

Simple and Effective Field Extraction of Human Botfly, Dermatobia Hominis, Using a Venom Extractor

After a trip to Belize, a 25-year-old man noticed an erythematous papule on his upper right chest that enlarged over a 6-week period and formed a central aperture. The patient reported feeling movement and intermittent lancinating pains under the skin. The history and examination were consistent with cutaneous myiasis, likely secondary to the human botfly, Dermatobia hominis. The objective of reporting this case is to present a simple method of extraction of a botfly larva using a commercial venom extractor. The patient's upper chest was prepared, and an occlusive dressing was placed over the lesion for 30 minutes. The Extractor Pump (Sawyer Products, Safety Harbor, FL) was applied and activated, and the larva was rapidly extracted completely intact with no significant discomfort to the patient. The wound fully healed without complication. D hominis is a common etiology of cutaneous myiasis endemic to Belize. The larva burrows under the skin of mammals where it develops for a period of weeks before erupting and falling to the soil to pupate. The diagnosis and treatment of botfly infestation is pertinent to doctors in the United States as Central and South America are common travel destinations for North Americans. In this case, a commercially available venom extractor was demonstrated to be a safe, noninvasive, and painless method for botfly extraction in the field without use of hospital resources.

Characteristics of roe deer bot fly infection in the southern part of the Great Hungarian Plain

I am investigating the occurance of one of the diseases caused by parasites in plain roe deer populations, namely a botfly larvae, Cephenemyiastimulator, (Clark, 1815) ranged among the Oestridae family. Nasal botfly larvae are common roe deer parasites and are generally spread nationwide. The subject of the present survey is the processing of the data gained about roe deer bucks of the year 2009 and their infestation indices. I investigated botfly larvae in 90 bucks’ nasal and pharyngeal cavity. We have found botfly larva in 18.9% of the examined bucks (prevalence), this means 17 infected specimen. I collected 218 pieces of larvae from the samples, with a 12.8 pieces average intensity. In my investigations prevalence was lower and mean intensity was higher than in previous Hungarian researches. This was manifested both in my overall data, and in our examinations by the different age groups.

First Report of Bot Fly (Cuterebra baeri) Infestation in Howler Monkeys (Alouatta palliata) from Mexico

We analyzed seven bot fly larvae extracted from six howler monkeys (Alouatta palliata) in Los Tuxtlas, Mexico. The spine distribution and structure of the larvae were consistent with those reported for Cuterebra baeri from Panama. This report sets the northern limit for its distribution in the Americas.

Free-ranging eastern chipmunks (Tamias striatus) infected with bot fly (Cuterebra emasculator) larvae have higher resting but lower maximum metabolism

Given the ubiquity and evolutionary importance of parasites, their effect on the energy budget of mammals remains surprisingly unclear. The eastern chipmunk ( Tamias striatus (L., 1758)) is a burrowing rodent that is commonly infected by cuterebrid bot fly ( Cuterebra emasculator Fitch, 1856) larvae. We measured resting metabolic rate (RMR) and cold-induced Vo2-max (under heliox atmosphere) in 20 free-ranging individuals, of which 4 individuals were infected by one or two larva. We found that RMR was significantly higher in chipmunks infected by bot fly larvae (mean ± SE = 0.88 ± 0.05 W) than in uninfected individuals (0.74 ± 0.02 W). In contrast, Vo2-max was significantly lower in chipmunks infected by bot fly larvae (4.96 ± 0.70 W) than in uninfected individuals (6.37 ± 0.16 W). Consequently, the aerobic scope (ratio of Vo2-max to RMR) was negatively correlated with the number of bot fly larvae (infected individuals = 5.74 ± 1.03 W; noninfected individuals = 8.67 ± 0.26 W). Finally, after accounting for the effects of body mass and bot fly parasitism on RMR and Vo2-max, there was no correlation between the two variables among individuals within our population. In addition to providing the first estimate of Vo2-max in T. striatus, these results offer additional evidence that bot fly parasitism has significant impacts on the metabolic ecology of this host species.

Parasitism by Oestrus ovis: Influence of sheep breed and nematode infections

Previous studies showed that Santa Ines (SI) hair sheep were more resistant to gastrointestinal nematode infections (GIN) than Ile de France (IF) sheep. The present experiment aimed to evaluate if that reported resistance difference against GIN also occurred against Oestrus ovis infestation and also to evaluate the influence of O. ovis infestation on the gastrointestinal nematodes (GIN) infections. SI (n=12) and IF (n=12) young male lambs were weaned at 2 months of age and moved to a paddock (0.3ha) with Brachiaria decumbens grass, where they also received concentrate ration. The animals were kept together during the experimental period (September to early December 2009). Fecal and blood samples were taken from all animals every 2 weeks and body weight and nasal discharge score (oestrosis clinic signs) were recorded on the same occasion. In early December 2009, all lambs were sacrificed and O. ovis larvae and GIN were recovered, counted and identified according to the larval stage. All animals were infested by different larval instars of O. ovis without any statistical difference between breeds (P>0.05). The SI lambs had an average of 24.8 larvae, and the intensity of infection ranged between 14 and 39 larvae, while the IF lambs showed an average of 23.5 larvae with the minimum and maximum from 11 to 36 larvae, respectively. SI lambs presented the lowest nematode fecal egg counts (FECs) and the lowest mean numbers of Haemonchus contortus, Trichostrongylus colubriformis and Strongyloides papillosus, however, there was no significant differences between group means (P>0.05). Inverse relationship between numbers of O. ovis larvae and gastrointestinal nematodes was observed in both breeds. SI sheep showed a significant increase in blood eosinophils and total IgE serum levels and these variables were negatively correlated with nematode FEC. A negative correlation was observed between total IgE serum level and H. contortus burden in both breeds. In conclusion, there was no breed difference regarding O. ovis infestation and in each breed, animals with more nasal bot fly larvae tended to display smaller worm burden.

Cuterebrid Myiasis (Diptera: Oestridae) in Captive Ring-Tailed Lemurs (Lemur catta) at a South Carolina Zoo

In September 2008, two ring-tailed lemurs (Lemur catta), comprising a mother-daughter pair, at the Greenville Zoo, Greenville, South Carolina, USA, were diagnosed with cuterebrid myiasis (Diptera: Oestridae) subsequent to sudden death of the adult lemur. On necropsy, a single bot warble was discovered in the subcutis of the axillary region. Histopathology revealed a severe eosinophilic bronchopneumonia. The juvenile lemur was inspected and found to have warbles on three separate dates in late September. One representative bot fly larva was identified as a Cuterebra sp. that normally infests lagomorphs in the southeastern United States. Cuterebrid myiasis is rarely reported in lemurs and has not been previously associated with pneumonia or death in these animals.

Case Study - Deep Cutaneous Mass Excision Reveals an Unusual Finding

Case presentation of a 62-year-old male who presented to the emergency department complaining of a mass in his right hand which began 14 days prior to evaluation. The mass was located in the proximity of the multiple neurovascular structures; therefore, surgical excision in the operating room was required. The patient’s pathological findings revealed a thick-walled, smooth surfaced cyst consistent with a bot fly larva (Dermatobia hominis) enclosed in an exoskeleton casing, rendering the diagnosis furuncular myiasis. Because areas of cutaneous myiasis are frequently misdiagnosed as pyogenic infection, it is important that the clinician maintains bot fly larvae in their differential diagnosis for a boil-type lesion in a patient that has visited the American tropics. It is imperative that providers consider surgical consultation in cases of suspected cutaneous myiasis due to the likelihood of complex anatomical structural involvement or unforeseen difficulty in removal when the larva is located subdermally with fascial encasement.

North American Deer Mouse, &lt;em&gt;Peromyscus maniculatus&lt;/em&gt;, Consuming a Parasitizing Botfly Larva, Diptera: Cuterebridae

During a laboratory study in Algonquin Provincial Park, Ontario, Canada, I videotaped a female North American Deer Mouse, Peromyscus maniculatus gracilis, consuming a botfly larva, Family Cuterebridae, that had just emerged from her chest. Although botfly parasitism has been widely studied in several species of small mammals, there are no prior reports of the host consuming the emerged botfly parasite.