Bot fly parasitism in mantled howler monkeys (Alouatta palliata): General patterns and climate influences.

Parasitism is a strong selective pressure, and its study is crucial for predicting the persistence of host species. Mantled howler monkeys are infected by the larvae of the bot fly Cuterebra baeri. This parasitosis produces myiasis and may have negative impacts on host health, although systematic information on the dynamics of this host-parasite relationship is very limited. Currently, all available information on infection patterns of C. baeri comes from a single mantled howler monkey population (Barro Colorado Island, Panama). Therefore, in this study we describe temporal variation in infection patterns for a newly mantled howler monkey population and analyze the relationship between climate and infection likelihood. We assessed the presence of C. baeri nodules in 17 adult individuals in Los Tuxtlas for 10 months through direct observation and compiled data on ambient temperature and rainfall. Most subjects had nodules during the study and there were no differences between sexes in the number of nodules. Nodules were usually located in the neck. Prevalence and abundance of nodules peaked thrice during the study (February, April, and September), a pattern that was very similar to that of parasitism intensity (February, April, and August). Incidence closely tracked these peaks, increasing before and decreasing after them. The likelihood of nodule appearance increased when both mean and minimum temperature decreased in the 24-21 prior days to nodule appearance. It also increased with decreased rainfall in the 5-2 prior days to nodule appearance. Although only three of the eight analyzed climate variables had a significant effect on parasitosis, these results suggest that climate may affect pupal development and the access of larvae to hosts. Besides contributing data on C. baeri parasitism for a new mantled howler monkey population, our study provides novel information on the influence of environmental factors on the dynamics of host-parasite systems.

CUTANEOUS MYIASIS AND ITS RELATIONSHIP TO WELLNESS IN EASTERN BOX TURTLES (TERRAPENE CAROLINA CAROLINA) IN CAPE COD, MASSACHUSETTS.

Eastern box turtles (Terrapene carolina carolina) face a variety of anthropogenic, infectious, and environmental threats and have been affected by high morbidity and mortality disease events. Wellness parameters in free-ranging eastern box turtles with a high prevalence of myiasis on Cape Cod, MA, were documented to identify epidemiologic trends or associations with several health parameters. There were 109 samples collected from 59 individual box turtles over the course of 4 mon. Six turtles died over the course of this study. Fly larvae infestations varied in severity and were observed in the cutaneous and subcutaneous tissue (n = 18; 30.5%). Animals with myiasis had fewer plastron abnormalities than those without (P = 0.034), and all turtles found in bogs had evidence of fly larvae infections (P < 0.0001). Individuals with myiasis also had lower body condition index (P = 0.014), lower total white blood cells (P = 0.031), lower PCV (P < 0.0001), lower total solids (P < 0.0001), higher erythrocyte sedimentation rate (P < 0.0001), lower calcium (P = 0.018), and lower phosphorus (P = 0.017). Three turtles tested positive for terrapene herpesvirus 1, but presence was not associated with myiasis. Heavy metal analysis revealed no significant differences between turtles with and without myiasis. This study examined the health of a population of eastern box turtles, and continued health assessments will be beneficial in determining the impact of myiasis on future conservation plans.

Pedicle myiasis by Lucilia caesar (Diptera, Calliphoridae): An emerging disease in roe deer from north-western Spain.

A total of 35 male roe deer (Capreolus capreolus) from Lugo province (north-western Spain) were examined for pedicle myiasis between 2020 and 2022. All these animals had died by different causes and were examined or preserved just after their death to avoid post-mortem infestations. After external and internal head inspection, five animals were diagnosed with severe myiasis at the basis of the antlers (14.29%; 95% confidence interval = 5.38-31.04). All the affected bucks presented a cutaneous wound (1.5-15 cm in diameter) around the pedicles with extensive tissue destruction, exposition of frontal and parietal bones, and massive infestation by dipteran larvae (2-12 mm long). Four of five roe deer showed whitish egg clusters adhered to the basis of the antlers. Moreover, in one animal, six larvae had penetrated the cranial cavity, and in two of them larvae were also found in the nasopharyngeal cavity. All the cases were recorded in summer (May-August). Morphological identification and subsequent molecular confirmation revealed that all animals were infested by different larval stages of Lucilia caesar (Diptera: Calliphoridae). This study represents the first report of pedicle myiasis in Spain. Since this disease is reported sporadically, the detection of five cases in a short period of time suggests an increase in the incidence of this myiasis.

Prevalence of Oestrus ovis in small ruminants from the eastern Iberian Peninsula. A long-term study.

Oestrus ovis is an obligate parasite that causes myiasis in domestic ruminants, being commonly found in the Mediterranean area. From 2009 to 2019 a total of 3476 heads of culling sheep and goats from the Mediterranean coast of Spain were examined for the presence of O. ovis. The total prevalence was 56.3%, significantly higher in sheep than in goats (61.2% and 43%, respectively). Differences were found in the mean annual prevalence, with the highest value being registered in 2018 (61.7%) and the lowest in 2012 (50.3%). Autumn, for sheep, and winter, for goats, were the seasons with the highest number of infested specimens. Temperature, but not rainfall, was found to be associated with prevalence (p < 0.05). Most L1 were found in the anatomic region I (septum, meatus, and ventral conchae), while L2 and L3 were mainly located in regions II (nasopharynx, ethmoid labyrinth, and dorsal conchae), and III (sinuses). The overall intensity was 12.8 larvae per head, significantly higher in sheep (13.3) than in goats (3.5). Our results confirm the high prevalence of O. ovis in sheep and goats in this geographic area over the last decade, with the trend increasing in recent years in association with higher mean temperatures.

Prevalence and pathology of Cephalopina titillator infestation in Camelus bactrianus from Xinjiang, China.

BACKGROUND: In camels, nasopharyngeal myiasis is caused by the larvae of Cephalopina titillator, which parasitize the tissues of nasal and paranasal sinuses, pharynx, and larynx. C. titillator infestation adversely affects the health of camels and decreases milk and meat production and even death. However, the C. titillator infestation in Bactrian camels has not been widely studied. METHODS: The present study was conducted to determine the prevalence and risk factors of C. titillator in Bactrian camels of northwestern Xinjiang. Suspected larvae recovered from infested camels were evaluated for C. titillator by microscopy and polymerase chain reaction. Nucleotide sequences of the partial mitochondrial cytochrome c oxidase subunit I (COX1) and cytochrome b (CYTB) genes from the C. titillator of camels were aligned from the NCBI database. Furthermore, the gross and histopathological alterations associated with C. titillator infestation were evaluated via pathological examination. RESULTS: Of 1263 camels examined 685 (54.2%) camels were infested with suspected C. titillator larvae. Different larval stages were topically detected in the nasal passages and pharynx of the camel heads. Microscopy analysis of the pharyngeal mucosa tissue revealed necrotic tissue debris and some inflammatory cells. Molecular detection of the larval COX1 and CYTB genes indicated that pathogen collected in Bactrian camels was C. titillator. The epidemiological study demonstrated that the prevalence rate of C.titillator infestation was significantly higher in camels of Bestierek Town Pasture (67.2%) and Karamagai Town Pasture (63.6%) compared to Kitagel Town Pasture (38.7%) and Qibal Town Pasture (35.8%) (P < 0.05). No significant difference was observed between the prevalence rates in male (52.6%) and female (54.6%) camels (P > 0.05). The prevalence was higher in warm (64.2%) than that in cold (48.4%) seasons (P < 0.001). The prevalence in camels with non-nomadic method (67.2%) was significantly higher than in animals with nomadic method (47.5%) (P < 0.001). The prevalence of C.titillator infestation was significantly higher in animals of aged 5-10 (60.1%) and aged > 10 (61.1%) years old compared to those of aged < 5 (31.7%) years old camels (P < 0.001). CONCLUSION: Our results confirm that there is a high prevalence of C. titillator in Bactrian camels from Xinjiang, closely related to age, season, pasture environment, and husbandry methods. Developing prevention, diagnosis, and control programs to prevent transmission is necessary.

Traumatic myiasis by Wohlfahrtia magnifica in sheep flocks from southeastern Spain: prevalence and risk factors.

Wohlfahrtia magnifica (Diptera: Sarcophagidae) is an obligate myiasis-causing fly of livestock that is widely distributed throughout the Mediterranean basin. A total of 73 683 sheep from 122 flocks in Albacete Province (southeastern [SE] Spain) were examined to detect active traumatic myiasis. The influence of several individual and flock factors on the prevalence was also assessed. The overall flock prevalence of traumatic myiasis was 95.9%, with an individual prevalence of 7.1%. Wohlfahrtia magnifica was identified in all of the positive animals except one that was infested by Lucilia sericata (Diptera: Calliphoridae). Adults of both genders showed a higher risk of infestation than juveniles, whereas males of all ages displayed an increased risk of infestation than females of all ages; the existence of a lambing building on the farm, poor husbandry facilities and the location area were also identified as risk factors. Prevalence was highest in the summer, and the fly season lasted from March to November. Genitalia were the main location of infestation in males (94.4%) and females (76.3%). Our results reveal that traumatic myiasis by W. magnifica is widespread in southeastern Spain, hence preventive measures minimizing the attractiveness of sheep to gravid flies are necessary to avoid health and welfare problems and significant production losses in sheep flocks.

Prevalence of tracheopulmonary myiasis amidst humans.

Myiasis is a parasitic infestation of live vertebrates with the dipteran larvae that grow within the host while feeding on its living or dead tissue. Human myiasis is prevalent among individuals in close association of domestic animals and those inhabiting the unhygienic conditions. Open neglected suppurative wounds are the favourable sites that attract and stimulate the gravid female flies for oviposition. However, the poor personal hygiene, ignorance and the mental illness further add to it. Tracheopulmonary myiasis involves the infestation of foul smelling nasal and oral orifices or neglected wounds like tracheostomal incisions with the parasitic dipteran larvae which may extend up to the trachea, bronchi and lungs leading to serious health complications. Despite the incidence of human tracheopulmonary infestation is rare, the severe medical impediments and heterogeneous worldwide distribution signify the medical importance of this condition. The present manuscript reviews and summarizes the worldwide reported cases of human tracheopulmonary myiasis and the predisposing risk factors for onset of the same, as future reference for parasitologists and medical professionals.

Human ophthalmomyiasis caused by Oestrus ovis-first report from Croatia and review on cases from Mediterranean countries.

Oestrus ovis is the most common cause of human ophthalmomyiasis. So far, majority of ophthalmomyiasis cases have been reported from Mediterranean countries, but not from Croatia. In current study, we present first two cases of human ophthalmomyiasis in Croatia, caused by O. ovis larvae. Reviewing a PubMed database, additional 259 cases of human ophthalmomyiasis in countries of Mediterranean basin have been reported. A total of 260 (99.62%) cases had external, while 1 (0.38%) had internal form of ocular myiasis. In all cases, O. ovis larvae were identified as the causative agent. O. ovis infestation is usually reported in shepherds and farmers although there is a high prevalence of infection in urban areas as well. Various climatic factors influence O. ovis larvipositional activity. Air temperature is the most important factor affecting O. ovis larviposition, while humidity, wind speed, and time of the day play only a moderate role. Most common symptoms of ophthalmomyiasis are irritation and redness, and in more than half of cases infestation is multiple. Ophthalmomyiasis interna is eye-compromising condition. Since there is reduced awareness among patients and medical professionals, the real number of ophthalmomyiasis cases is probably significantly higher than published. Global warming predisposes future increase of O. ovis prevalence in humans, which emphasizes the need for mandatory reporting and surveillance of disease.

High morbidity cutaneous enzootic myiasis by Dermatobia hominis (Diptera: Oestridae) in sambar deer (Rusa unicolor).

This study describes the first known occurrence and treatment of enzootic cutaneous myiasis by Dermatobia hominis in a herd of sambar deer (Rusa unicolor). Sambar deer are clinically affected by enzootic cutaneous myiasis during the spring and summer in Rio de Janeiro, Brazil. Through direct inspection and clinicopathological evaluation in the herd with 80 R. unicolor, it was observed that infestation by D. hominis caused 100% morbidity. At histological exam, skin had eosinophilic and granulomatous chronic active severe necrohemorrhagic dermatitis associated with botfly and moderate surrounding fibroplasia. The systemic treatment with oral ivermectin at 0.08% was effective in 93.7% of deer with enzootic cutaneous myiasis after fourteen days. After treatment, the skin deer had eosinophilic and granulomatous chronic severe dermatitis associated with degenerated botfly and severe fibroplasia. Notable differences in leukocyte profile were observed between groups pre- and post-treatment. Decrease of relative values of neutrophils and eosinophils were significant in the treated deer group. An increase of relative values of monocytes was also confirmed in the treated group. Sambar deer was the only species affected by D. hominis, even though several other wild herbivores were kept in the same area. More studies are needed to elucidate the susceptibility of R. unicolor to D. hominis cutaneous infestations.

The impact of botfly parasitism on the health of the gracile mouse opossum (Gracilinanus agilis).

Fragmented habitats generally harbour small populations that are potentially more prone to local extinctions caused by biotic factors such as parasites. We evaluated the effects of botflies (Cuterebra apicalis) on naturally fragmented populations of the gracile mouse opossum (Gracilinanus agilis). We examined how sex, food supplementation experiment, season and daily climatic variables affected body condition and haemoglobin concentration in animals that were parasitized or not by botflies. Although parasitism did not affect body condition, haemoglobin concentrations were lower in parasitized animals. Among the non-parasitized individuals, haemoglobin concentration increased with the increase of maximum temperature and the decrease of relative humidity, a climatic pattern found at the peak of the dry season. However, among parasitized animals, the opposite relationship between haemoglobin concentration and relative humidity occurred, as a consequence of parasite-induced anaemia interacting with dehydration as an additional stressor. We conclude that it is critical to assess how climate affects animal health (through blood parameters) to understand the population consequences of parasitism on the survival of individuals and hence of small population viability.

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.

Molecular identification and detection of Wohlfahrtia magnifica in ovine vulvar myiasis in Gansu, China.

Traumatic myiasis causes substantial economic losses to farmers worldwide. In the present study, six flocks of sheep (2261 sheep) were investigated in Gansu, China, and 207 of 552 larvae were genetically characterized based on three genes, including cyt b, EF-1α, and white gene, by polymerase chain reaction and sequence analysis. A survey of sheep in China revealed that the prevalence of vulvar myiasis of six sheep flocks was 5.00% (11/220, Flock1), 4.85% (10/206, Flock2), 4.50% (9/200, Flock3), 5.00% (15/300, Flock4), 4.68% (15/320, Flock5), 0% (0/1015, Flock6), respectively. The sequence and phylogenetic analysis showed that only Wohlfahrtia magnifica was detected in the field samples. This is the first report of ovine vulvar myiasis caused by W. magnifica in Gansu, China. Some prophylactic measures are strongly recommended to reduce the risk of sheep acquiring traumatic myiasis in Gansu, China.

Prevalence and husbandry-related risk factors of myiasis in domestic cavies in the western highlands of Cameroon.

The presence of parasites on the farm can be a cause of losses in animal production, and often a threat to public health. A cross-sectional study was carried out in rural areas of the western highlands of Cameroon to determine the prevalence and husbandry-related risk factors associated with Cordylobia anthropophaga infestations in domestic cavies. The overall prevalence of myiasis in animals was 2·80% [95% confidence interval (CI) 1·50-5·10]; myiasis was found in 2% and 4·30% animals in Menoua and Bamboutos divisions, respectively. Eleven farms (8·95%) in total were infested with C. anthropophaga, with 6·41% and 13·34% of farms in the Menoua and Bamboutos divisions, respectively. The relative risk of infestation within each factor showed that the risk of myiasis in animals kept in kitchen compartments without litter was 6·16 times higher (95% CI 1·71-22·29, P = 0·04) than in animals kept in kitchens and house floors. Despite the low prevalence, the burden of cordylobiasis needs to be assessed. It is assumed that the risk of humans acquiring the disease is higher in farmers keeping cavies in kitchen compartments without litter. Farmers need to be educated on control measures to reduce the risk of infestation, which include both sanitation and medical (larvae extraction) measures.

Chrysomya bezziana (Diptera: Calliphoridae) infestation: case report of three dogs in Malaysia treated with spinosad/milbemycin.

BACKGROUND: Infestation of wounds with the larvae of Callophorid flies is relatively common in countries where these parasites are found. The most common species associated with infections in Southeast Asia is Chrysomya bezziana (Ch. bezziana), the Old World screw worm. Treatment consists of either subcutaneous injection of ivermectin or oral administration of nitenpyram combined with aggressive tissue debridement under general anaesthesia. OBJECTIVES: To describe the treatment of cutaneous myiasis in three dogs caused by the larvae of Ch. bezziana in Malaysia and their treatment with spinosad plus milbemycin. RESULTS: In all dogs, a single oral dose of spinosad plus milbemycin at the recommended dosage of 31-62 mg/kg and 0.5-1.0 mg/kg, respectively, was able to kill all larvae within 8 h. Most dead larvae fell off the host and those remaining on the host were dead and easily removed with simple saline flushing and gentle debridement. Neither general anaesthesia nor aggressive mechanical debridement were needed in any patient. CONCLUSIONS AND CLINICAL IMPORTANCE: Oral spinosad plus milbemycin is a safe, licensed and effective treatment at the recommended dose for the rapid elimination of Ch. bezziana myiasis, with no need for sedation or anaesthesia.

DERMAL MYIASIS CAUSED BY THE FLESH FLY, PARASARCOPHAGA (LIOSARCOPHAGA) DUX (THOMSON, 1869) (DIPTERA: SARCOPHAGIDAE) AT THE SITE OF A MALIGNANT MELANOMA: A CASE REPORT.

Dermal myiasis due to the flesh fly has not been commonly reported in Thailand. A 64-year-old man came to the hospital with a 6-month history of a black tumor on the dorsum of the right great toe. The tumor was biopsied and determined to be a malignant melanoma. Second instar larvae were also seen in the wound and one larva was reared until the adult stage wherein it was identified as the flesh fly, Parasarcophaga (Liosarcophaga) dux (Thomson, 1869) (Diptera: Sarcophagidae). This case shows myiasis due to synanthropic sarcophagid flies occurs in Thailand and can occur in a malignant melanoma.

Traumatic Myiasis: A Neglected Disease in a Changing World.

Traumatic myiasis, the parasitic infestation by fly larvae in traumatic lesions of the tissues of living vertebrates, is a serious medical condition in humans and a welfare and economic issue in domestic animals. New molecular studies are providing insights into its evolution and epidemiology. Nevertheless, its incidence in humans is generally underreported, particularly in tropical and subtropical regions. Myiasis in domestic animals has been studied more extensively, but continuous management is difficult and expensive. A key concern is the inadvertent introduction and global spread of agents of myiasis into nonendemic areas, facilitated by climate change and global transport. The incursion of the New World screwworm fly (Cochliomyia hominivorax) into Libya is the most notable of many such range shifts and demonstrates the potential risks of these parasites and the costs of removing them once established in a geographic area. Nevertheless, the insect agents of myiasis can be of societal benefit to forensic science and in medicine as an aid to wound treatment (larval therapy).

Galápagos mockingbirds tolerate introduced parasites that affect Darwin's finches.

Introduced parasites threaten native host species that lack effective defenses. Such parasites increase the risk of extinction, particularly in small host populations like those on islands. If some host species are tolerant to introduced parasites, this could amplify the risk of the parasite to vulnerable host species. Recently, the introduced parasitic nest fly Philornis downsi has been implicated in the decline of Darwin's finch populations in the Galápagos Islands. In some years, 100% of finch nests fail due to P. downsi; however, other common host species nesting near Darwin's finches, such as the endemic Galápagos mockingbird (Mimus parvulus), appear to be less affected by P. downsi. We compared effects of P. downsi on mockingbirds and medium ground finches (Geospiza fortis) on Santa Cruz Island in the Galápagos. We experimentally manipulated the abundance of P. downsi in nests of mockingbirds and finches to measure the direct effect of the parasite on the reproductive success of each species of host. We also compared immunological and behavioral responses by each species of host to the fly. Although nests of the two host species had similar parasite densities, flies decreased the fitness of finches but not mockingbirds. Neither host species had a significant antibody-mediated immune response to P. downsi. Moreover, finches showed no significant increase in begging, parental provisioning, or plasma glucose levels in response to the flies. In contrast, parasitized mockingbird nestlings begged more than nonparasitized mockingbird nestlings. Greater begging was correlated with increased parental provisioning behavior, which appeared to compensate for parasite damage. The results of our study suggest that finches are negatively affected by P. downsi because they do not have such behavioral mechanisms for energy compensation. In contrast, mockingbirds are capable of compensation, making them tolerant hosts, and a possible indirect threat to Darwin's finches.

Cephenemyiosis, an emergent myiasis in roe deer (Capreolus capreolus) from northwestern Spain.

Cephenemyia stimulator larvae cause a specific myiasis in roe deer, which is widely distributed in Europe. In Spain, this parasite was detected by the first time in 2005, coinciding with a high mortality of this ruminant especially in northwest of the country. The aim of this study was to analyse the results obtained by necropsy and ELISA to elucidate when the first infestation by C. stimulator in roe deer from northwestern Spain occurred, as well as to determine the influence of some intrinsic factors on the prevalence and intensity of infestation. During 1994-2000, none seropositive roe deer was observed by ELISA. However, from 2007 to 2014, 38 % of animals were seropositive. The results of the necropsy pointed that prevalence and intensity of infestation had increased over the years. There was a positive and significant correlation between the number of animals harbouring C. stimulator larvae and seroprevalence values. This significant correlation was also observed between the seroprevalence and mean intensity of infestation. Adult roe deer showed higher prevalence and intensity of infestation than younger reaching statistical significance. It is also detected that the prevalence of infestation was significantly higher in males than in females although the mean number of larvae found in females were higher than in males. The combined use of direct and indirect techniques demonstrated a high prevalence of C. stimulator infestation in roe deer in the northwest of Spain, which certainly highlights the importance of this myiasis during the last years.

Origins of Wohlfahrtia magnifica in Italy based on the identification of mitochondrial cytochrome b gene haplotypes.

To identify the geographical origins of larvae of Wohlfahrtia magnifica (Diptera: Sarcophagidae) causing myiasis of sheep in Italy, comparative DNA sequence analysis of the mitochondrial cytochrome b gene was performed, based on gene fragments amplified by PCR from genomic DNA isolated from individual specimens. DNA extractions of 19 larvae from Lazio, Molise, Puglia, and Sicilia generated 17 readable sequences homologous to 2 haplotypes, either CB_magn01 or CB_magn02; DNA extracts from 4 adult flies from Calabria (reared from larvae) produced 4 readable sequences belonging to the haplotype CB_magn01. The two haplotypes found represent both the East and West phylogenetic lineages of W. magnifica, which is consistent with the species' arrival from central/southeast Europe (East lineage) and/or from southwest Europe/northwest Africa (West lineage). This is the first report of the sympatric occurrence of the two lineages, which could have resulted from natural or human-assisted dispersal. Polymorphic nuclear loci will have to be characterized in order to explain the origins and lack of mitochondrial haplotype diversity of this pest in Italy, where it poses increasing veterinary problems.