Temperature is a common climatic descriptor of lachryphagous activity period in Phortica variegata (Diptera: Drosophilidae) from multiple geographical locations.
ABSTRACT: BACKGROUND:The drosophilid Phortica variegata is known as vector of Thelazia callipaeda, the oriental eyeworm native to Asia that has become an emergent zoonotic agent in several European regions. Unlike almost all other arthropod vectors of pathogens, only P. variegata males feed of lachrymal secretions of animals, ingesting first-stage larvae (L1) of the worm living in the orbital cavities of the host, and allowing with the same behaviour the introduction of infective L3. Despite the increased detection of T. callipaeda in many European countries, information about the length of the lachryphagous activity period of P. variegata and a deep knowledge of the environmental and climatic variables involved are still limited. METHODS:We herein present the results of a multicentre study involving five sites from four different countries (Italy, Spain, UK and USA) where canine thelaziosis is endemic and/or where it has already been ascertained the presence of P. variegata. Field data have been obtained on a fortnightly basis from mid-April to the end of November 2018 from a contemporary standardized sampling (same sampling effort and time of collection in all sites) of lachryphagous flies collected around the eyes of a human bait using an entomological net. These data have been associated to data collection of local climatic variables (day length, temperature, wind speed, barometric pressure and relative humidity). RESULTS:Overall, a total of 4862 P. variegata flies (4637 males and 224 females) were collected, with high differences in densities among the different sampling sites. Significant positive correlations were found between P. variegata male density and temperature and wind speed, while negative correlations were observed for barometric pressure and relative humidity. However, the above significant differences are confirmed in each sampling site separately only for the temperature. CONCLUSIONS:This multicentre study highlights that temperature is the major common environmental driver in describing the lachryphagous activity of P. variegata in Europe and USA and, therefore, the transmission risk of thelaziosis.
Project description:BACKGROUND:The fruit fly Phortica variegata (Drosophilidae: Steganinae) feeds on the ocular secretions of animals and humans, and has been described as an intermediate host of the eye worm Thelazia callipaeda (Spirurida: Thelaziidae) in Italy. Despite the increased detection of T. callipaeda in many European countries, information about its vector role in natural conditions is still limited. In the Iberian Peninsula, thelaziosis caused by T. callipaeda has been reported in dogs, cats, red foxes, wild rabbits and humans. METHODS:In the last seven years, we have detected increased numbers of cases of canine thelaziosis at three locations in mainland Spain: Site 1, La Vera region (Cáceres Province, central-western Spain; 51 cases); Site 2, El Escorial municipality (Madrid Community, central Spain; 23 cases); and Site 3, Miraflores de la Sierra municipality (Madrid Community, central Spain; 41 cases). Site 1 is considered endemic for T. callipaeda while the other two sites have been recently recognised as risk zones for T. callipaeda infection. RESULTS:From June 2016 to September 2017, 2162 flies were collected and morphologically identified as Phortica spp. (Site 1, n = 395; Site 2, n = 1544; and Site 3, n = 223). Upon dissection, third-stage T. callipaeda larvae were found in two out of 155 flies examined from Site 1, and both these larvae tested molecularly positive for the eye worm. Of the 395 flies collected from Site 1, 371 were molecularly processed for arthropod species identification and T. callipaeda detection. All 371 flies were identified as P. variegata and 28 (7.5%; 95% CI: 4.8-10%) tested positive for T. callipaeda DNA haplotype 1. CONCLUSIONS:Our findings indicate that T. callipaeda circulates among dogs and P. variegata in Spain, where zoonotic cases have been also reported. The co-existence of canine thelaziosis and Phortica spp. in geographical areas previously considered free of the eye worm indicates a risk of infection for both animals and humans living in this region.
Project description:Thelazia callipaeda is a zoonotic nematode that affects the eyes of domestic and wild animals, including dogs, cats and red foxes. This parasitic eye worm is transmitted by Phortica variegata, which is a zoophilic fruit fly spread in Europe. Two wild European rabbits (Oryctolagus cuniculus) found dead in north-eastern Portugal were submitted to necropsy.Both animals presented gross lesions compatible with haemorrhagic viral disease. Eye examination revealed the presence of six worms (three in each animal, on both eyes). Out of the six nematodes, five females and one male were morphologically and molecularly identified as T. callipaeda.This is the first report of T. callipaeda in wild rabbits from Portugal, which reveals a new host for this parasite in southern Europe and emphasizes the importance of including thelaziosis in the differential diagnosis of ocular alterations in both animals and humans from areas where the eye worm is endemic.
Project description:The observational data described here was collected between 28 February 2011 and 30 November 2015. The data analysis and interpretation were published in the article "Surface radiation balance and weather conditions on a non-glaciated coastal area in the Antarctic region" . An instrumented tower located on the non-glaciated coastal area of the of the Brazilian Antarctic Comandante Ferraz Station, at King George Island, Antarctic Peninsula was used. It was collected data of air temperature and relative humidity, wind speed and direction, barometric pressure, incident and reflected shortwave radiation, longwave radiation emitted by atmosphere and by surface, and net radiation with a sampling frequency of 0.1 Hz. The data was stored as 5-min averages and automatically transmitted to the Air-Sea Interaction Laboratory, at the University of São Paulo, Brazil. The dataset is hosted in the Mendeley repository.
Project description:<h4>Background</h4>Thelazia callipaeda is a zoonotic parasitic nematode of the family Thelaziidae, with Phortica okadai as its intermediate host and only confirmed vector in China. China has the largest number of human cases of thelaziosis in the world. It is generally believed that infected domestic animals (dogs and cats) are the most important reservoir hosts of T. callipaeda, and thus pose a direct threat to humans. At present, there is little research or attention focused on the role of wildlife in the transmission cycle of thelaziosis in nature reserves.<h4>Methods</h4>We selected locations in four national nature reserves across China to monitor P. okadai and wildlife. We used a fly-trap method to monitor P. okadai density. Morphological analysis of the parasites collected from the conjunctival sac of the infected wildlife was undertaken as the first step in species identification, and polymerase chain reaction (PCR) was used for species confirmation.<h4>Results</h4>In 2019, the density of P. okadai in Foping National Nature Reserve in China increased sharply, and infected P. okadai were newly found in the reserve. Giant panda, wild boar, leopard cat, and black bear were found to be newly infected with T. callipaeda (one individual of each species). A total of four worms were collected, one from each species of wildlife. The four worms were identified as T. callipaeda by their morphological characteristics; species identification was confirmed by PCR amplification.<h4>Conclusions</h4>To the best of our knowledge, this is the first report of T. callipaeda infection in P. okadai as well as in a variety of wildlife, including giant panda, in nature reserves in China. These results indicate that there is a transmission cycle of T. callipaeda among wildlife in these nature reserves. The increasing number of case reports of thelaziosis in wildlife suggest a likely risk of T. callipaeda infection for the inhabitants of villages situated around nature reserves.
Project description:BACKGROUND: Thelazia callipaeda (Spirurida, Thelaziidae), eyeworms, are known as the causative agents of thelaziosis, initially described in Asia and, later on, over the last decade, also in some European countries (e.g., Italy, France, Germany and Switzerland). In June 2010, the first case of canine thelaziosis was observed in central western Spain (La Vera region, Cáceres) and subsequent epidemiological investigation is reported in the present study. RESULTS: This study describes the first autochthonous cases of infection by T. callipaeda in dogs from central western Spain where the first case of eyeworm infection was reported.A total of 456 dogs was examined in this geographical area. Thelazia callipaeda eyeworms were observed in 182 (39.9%) animals, of which 28 showed apparent clinical signs (i.e., conjunctivitis, oedema, epiphora and petechiae). A total of 762 adult nematodes (214 males, 548 females; mean infection rate of 4.18; SD 4.74) were collected with cotton swabs or by flushing of the conjunctival sac of infected animals using physiological saline solution. Nematodes were identified as T. callipaeda according to the morphological keys and molecular analysis of sequences of a portion of the mitochondrial cytochrome c oxidase subunit 1 (cox 1) gene. The sequences were identical to those representing T. callipaeda haplotype 1, previously reported in Europe. CONCLUSIONS: The high infection rate of canine thelaziosis herein reported suggests that practitioners should include this eye infection amongst differential diagnoses of ocular diseases in dogs from this area of Spain or those moving across this area of Spain. Based on the high infection prevalence recorded, the potential public health risk to humans from this region is also discussed.
Project description:The spirurid nematode Thelazia callipaeda, also called the "Oriental eyeworm", is the causative agent of canine and human ocular thelaziosis. In the past few years it has started to spread across central Europe and new endemic areas have been established. The present study reports on the first four autochthonous cases of canine ocular thelaziosis in the territory of Slovakia, Central Europe.All cases were recorded in dogs living in eastern Slovakia, near the border with the Ukraine. All worms collected were investigated morphologically and their identification further confirmed at the molecular level by PCR amplification and direct sequencing. Nucleotide sequences of partial T. callipaeda cox1 and 28S rDNA gene fragments isolated from Slovak dogs were submitted to the GenBank database under accession numbers KY476400 and KY476401, respectively.Considering that all four cases were diagnosed in animals that had never travelled abroad, there is clear evidence of an autochthonous occurrence and thereby the further spread of T. callipaeda across Europe. Moreover, at latitude of 48°N, these cases might be considered as the northernmost recorded cases of autochthonous in western and Central Europe.
Project description:Globally, since the end of December 2019, coronavirus disease (COVID-19) has been recognized as a severe infectious disease. Therefore, this study has been attempted to examine the linkage between climatic variables and COVID-19 particularly in National Capital Territory of Delhi (NCT of Delhi), India. For this, daily data of COVID-19 has been used for the period March 14 to June 11, 2020, (90 days). Eight climatic variables such as maximum, minimum and mean temperature (°C), relative humidity (%), bright sunshine hours, wind speed (km/h), evaporation (mm), and rainfall (mm) have been analyzed in relation to COVID-19. To study the relationship among different climatic variables and COVID-19 spread, Karl Pearson’s correlation analysis has been performed. The Mann–Kendall method and Sen’s slope estimator have been used to detect the direction and magnitude of COVID-19 trends, respectively. The results have shown that out of eight selected climatic variables, six variables, viz. maximum temperature, minimum temperature, mean temperature, relative humidity, evaporation, and wind speed are positively associated with coronavirus disease cases (statistically significant at 95 and 99% confidence levels). No association of coronavirus disease has been found with bright sunshine hours and rainfall. Besides, COVID-19 cases and deaths have shown increasing trends, significant at 99% confidence level. The results of this study suggest that climatic conditions in NCT of Delhi are favorable for COVID-19 and the disease may spread further with the increasing temperature, relative humidity, evaporation and wind speed. This is the only study which has presented the analysis of COVID-19 spread in relation to several climatic variables for the most densely populated and rapidly growing city of India. Thus, considering the results obtained, effective policies and actions are necessary especially by identifying the areas where the spread rate is increasing rapidly in this megacity. The prevention and protection measures should be adopted aiming at to reduce the further transmission of disease in the city.
Project description:BACKGROUND:In Europe, the first Thelazia callipaeda infections were found in the eyes of some dogs in Italy three decades ago. Since that time, this vector-borne nematode species has been diagnosed in domestic and wild carnivores and humans in some western European countries. During the last few years, autochthonous thelaziosis of dogs, red foxes, cats and humans has also been reported from eastern Europe. The first cases of ocular infections caused by T. callipaeda have been described in dogs living in the eastern and southern part of Slovakia and Hungary. METHODS:Whitish parasites found in the conjuctival sac and/or under the third eyelid of one or both eyes of animals were removed and morphologically identified according to species and sex. To confirm the morphological identification with molecular analysis a single step conventional PCR was carried out. RESULTS:A total of 116 adult worms (1-37 per dog, median: 7, IQR: 14.5 and 7 from a cat) were collected from the eyes of 11 animals. Nematodes were identified as T. callipaeda according to the morphological keys and molecular analysis. The sequences of a portion of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene were identical to those representing T. callipaeda haplotype 1, previously reported in neighbouring and other European countries. Since the infected cat and dogs had never travelled abroad, all of the cases were autochthonous thelaziosis. CONCLUSIONS:The present study reports the first case of thelaziosis in a cat and new cases in 10 dogs found in the southern and northern region of Hungary, respectively. Further studies are needed to clarify whether wild carnivores (e.g. red foxes, golden jackals) may act as reservoirs of this eyeworm species in the country.
Project description:Seasonal and diurnal flight patterns of the invasive walnut twig beetle, Pityophthorus juglandis, were assessed between 2011 and 2014 in northern California, USA in the context of the effects of ambient temperature, light intensity, wind speed, and barometric pressure. Pityophthorus juglandis generally initiated flight in late January and continued until late November. This seasonal flight could be divided approximately into three phases (emergence: January-March; primary flight: May-July; and secondary flight: September-October). The seasonal flight response to the male-produced aggregation pheromone was consistently female-biased (mean of 58.9% females). Diurnal flight followed a bimodal pattern with a minor peak in mid-morning and a major peak at dusk (76.4% caught between 1800 and 2200 h). The primarily crepuscular flight activity had a Gaussian relationship with ambient temperature and barometric pressure but a negative exponential relationship with increasing light intensity and wind speed. A model selection procedure indicated that the four abiotic factors collectively and interactively governed P. juglandis diurnal flight. For both sexes, flight peaked under the following second-order interactions among the factors when: 1) temperature between was 25 and 30 °C and light intensity was less than 2000 lux; 2) temperature was between 25 and 35 °C and barometric pressure was between 752 and 762 mba (and declined otherwise); 3) barometric pressure was between 755 and 761 mba and light intensity was less than 2000 lux (and declined otherwise); and 4) temperature was ca. 30 °C and wind speed was ca. 2 km/h. Thus, crepuscular flight activity of this insect can be best explained by the coincidence of moderately high temperature, low light intensity, moderate wind speed, and low to moderate barometric pressure. The new knowledge provides physical and temporal guidelines for the application of semiochemical-based control techniques as part of an IPM program for this invasive pest.
Project description:BACKGROUND:Countries of eastern Europe are considered, due to several risk factors, more vulnerable to infections with newly (re)emerging pathogens. During the last decade, in several European countries, reports of autochthonous cases of ocular thelaziosis due to Thelazia callipaeda have been published, posing a great concern from both veterinary and public health perspective. However, in the Republic of Moldova only limited epidemiological data are available regarding zoonotic vector-borne pathogens and, until now, no data exist on the zoonotic nematode T. callipaeda. METHODS:In September 2018, an 11-year-old dog, mixed-breed, intact male was referred to a private veterinary clinic from Chișinău, Republic of Moldova, with a history of 2 weeks of an ocular condition affecting the right eye. The ophthalmological exam revealed the presence of nematode parasites in the conjunctival sac and under the third eyelid. The collected parasites were identified by morphological techniques and molecular analysis. RESULTS:A total of 7 nematodes were collected, and 5 females and 2 males of T. callipaeda were identified morphologically. The BLAST analysis confirmed the low genetic variability of this parasite in Europe. The travel history of the patient allowed us to confirm the autochthonous character of the case. CONCLUSIONS:To the best of our knowledge, this is the first report of thelaziosis in dogs from the Republic of Moldova, which confirms the spreading trend of T. callipaeda and the existence of an autochthonous transmission cycle of this zoonotic parasite in the country.