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1.
West Nile Virus (WNV)1 is an emerging pathogen in Cyprus, with the first human case of infection reported in 2016, and another documented in 2018. A cluster of cases in humans was then reported in 2019. However, little is known regarding which avian species might bring WNV to Cyprus. Here, we investigated seroprevalence of WNV antibodies in migratory and resident birds, captured across Cyprus to assess to what extent human populations might be exposed to WNV. We used Enzyme-Linked Immunosorbent Assay (ELISA)2 to test for the presence of WNV antibodies in 836 avian blood samples of 44 species captured between 2015 and 2020. A seropositivity rate of 1.3 % was found. The majority of seropositive wild birds belonged to the migratory species Sylvia atricapilla, a common and widespread migrant, implying a high risk of WNV being introduced throughout Cyprus.  相似文献   

2.
于2005年从飞抵上海的12种候鸟和4种留鸟中采集208份血清样品,采用酶联荧光测定(ELFA)法和酶联免疫吸附试验(ELISA),分别对伯氏疏螺旋体和西尼罗病毒的感染状况进行了血清抗体调查,结果受检野鸟样品的检测结果均为阴性。  相似文献   

3.
A regional survey was conducted in Nepal for antibody to Japanese encephalitis virus (JEV) in domestic animals. Sera from pigs, and limited numbers of ducks and horses were collected from 16 districts in 2002-2003 and subjected to three serological tests. Of 270 porcine sera tested by C-ELISA, 55% were found positive for the presence of antibodies against Japanese encephalitis virus. Additional testing for IgM antibody to JEV revealed less than 2% of C-ELISA positive sera had evidence of recent JEV infection. Plaque reduction neutralisation tests (PRNT) using JEV, Murray Valley encephalitis (MVEV) and Kunjin (KUNV) viruses implicated JEV as the flavivirus associated with the observed antibody response in most sero-positive pigs. However, eight porcine sera with predominant neutralising antibody for KUNV (an Australasian subtype of West Nile Virus) provided evidence for the circulation of West Nile virus in Nepal.  相似文献   

4.
Prevalence and risk factors for feline coccidia and Giardia species infections were estimated for cats visiting 434 Banfield hospitals in 40 states in 2003-2004. Evaluated were 631,021 cats making 1,456,712 office visits (encounters) and having 211,105 fecal examinations. The overall fecal prevalences of coccidia and Giardia species were 1.4% and 0.58%, respectively. Cats at increased risk of coccidia infection were under 4 years of age, intact, and seen during the summer, fall, and spring months compared to winter. Cats at increased risk of Giardia species infection were under 4 years of age. Those at decreased risk were mixed breed and seen during the summer, fall, and spring. The highest regional risk of coccidia and Giardia species infection was for cats in the East South Central region and Mountain region, respectively, compared to the South Pacific region.  相似文献   

5.
The circulation of West Nile virus in Portugal was assessed by serological surveys conducted during 2004-2010 in horses and birds. The detection of WNV antibodies in both species in all the years covered by the study as well as the presence of anti-WNV IgM in symptomatic horses that had not traveled outside the country, support the notion that WNV circulates in Portugal.  相似文献   

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8.
《African Zoology》2013,48(2):239-245
The effects of timing, frequency and duration of mouth opening and marine overwash events on fish assemblages in two, adjacent temporarily open/closed estuaries were investigated. Sampling was conducted biannually over two years during summer and winter, using selective sampling gear to target estuarine-associated marine species. During this period the East Kleinemonde Estuary opened more frequently than the West Kleinemonde Estuary and it also experienced a greater number of bar overwash events when larval recruitment can occur. The timing of mouth opening and the frequency of marine overwash events did not influence species richness of marine-spawning species but had a pronounced effect on abundances (catch-per-unit-effort) of species. The species composition of both estuaries was similar, but the catch-per-unit-effort in the East Kleinemonde Estuary was more than three times greater than that of the West Kleinemonde Estuary. The East Kleinemonde also supported a greater proportion of immature individuals of Rhabdosargus holubi and Monodactylus falciformis, and the length frequency distributions of both these species differed significantly between the two estuaries. The larger fish sizes in the West Kleinemonde Estuary were attributed to the prolonged mouth closure that resulted in the trapping of larger juveniles and mature fish within the estuary.  相似文献   

9.
West African Dwarf Sheep inoculated sequentially with two flaviviruses: yellow fever and Dakar bat or West Nile and yellow fever viruses, developed neutralizing (N) and haemagglutination inhibiting (HI) antibodies to several flaviviruses; dengue type 1, dengue type 2, yellow fever, West Nile and Wesselsbron viruses. Experimental infection of these animals with the indigenous strain of Wesselsbron virus resulted in the modification of the clinical disease. The disease was reduced in severity and there was complete absence of, or marked reduction in the level and duration of circulating virus and fever. Seronegative animals infected with the same strain of Wesselsbron virus developed the classical disease characterized by a high fever, anorexia, leucopenia and a high level of viraemia. The absence of clinical reports of Wesselsbron disease and lack of other isolations of the virus from Nigeria could possibly be explained by the presence of the flavivirus group antibodies in domestic animal sera.  相似文献   

10.
The prevalence of heterophyid (Digenea: Heterophyidae) encysted metacercariae (EMC) in its second intermediate host, the fish Mugil spp. and Tilapia spp. was studied in a subtropical permanent Lake in northeastern Egypt. Seasonal changes in the occurrence of the EMC in different fish hosts were monitored in a longitudinal field survey lasting 12 months from June 2006 to May 2007. This study tested two hypotheses; (i) prevalence and intensity of heterophyid EMC fluctuate seasonally throughout the year and (ii) variation in the prevalence and intensity of heterophyid EMC is host-dependent. A total of 832 fish specimens comprising 5 species collected from Manzala Lake, northeastern Egypt were examined by artificial gastric juice digestion for EMC. All five species of brackish water fish examined were found to harbor the EMC of the family Heterophyidae in their muscles. The overall infection prevalence of EMC over 12 months was 23.2%. The adult flukes recovered from puppies experimentally infected with morphologically different metacercariae from different fish species were compatible with six species belong to five genera of Heterophyidae, namely, Heterophyes heterophyes, Heterophyes aequalis, Pygidiopsis genata, Phagicola sp., Haplorchis sp. and Stictodora sp. EMC of H. heterophyes were most abundant, detected in 56% of the total fish examined. P. genata was ranked second, followed by Phagicola sp., H. aequalis, Haplorchis sp., and Stictodora sp., respectively. Seasonal differences in infection were observed for all heterophyid species studied in all fish species examined. Heterophyid infections reached peak prevalences during the summer season 38.2% followed by spring 26.6% and autumn 19.3% seasons, whereas the lowest prevalence was recorded in the winter 8.7%. Intensity of heterophyid EMC followed the same seasonal pattern, being high during summer months and low in winter months. All fish species were infected with all the heterophyid digeneans, but with different prevalence. Possible reasons for these findings are discussed with reference to host, climatic and biotic factors.  相似文献   

11.
The emergence of West Nile virus (WNV) was expected in Austria since the initial discovery of the infection in neighbouring Hungary in 2003/2004. In 2008 six cases of West Nile disease were diagnosed at the Institute for Veterinary Disease Control M?dling, Austrian Agency for Health and Food Safety (AGES), involving five goshawks (Accipiter gentilis) and one gyrfalcon (Falco rusticolus), which were found dead in the eastern Austrian federal states of Lower Austria, Vienna and Styria, respectively. Pathomorphological and immunohistochemical findings suggested a WNV infection. Virus was isolated in embryonated specific pathogen free chicken eggs and propagated in mouse neuroblastoma cells (NA), in which a cytopathic effect occurred. The virus was identified and characterised by electron microscopic examination and molecular detection using RT-PCR, sequencing, and phylogenetic analysis. The Austrian WNV sequences exhibited nucleotide identities of 99.9% to the lineage 2 WNV sequences described in Hungary since 2004. In addition, 71 sera of 14 different bird species were screened for the presence of WNV antibodies using a commercial ELISA: 43.7% of the tested samples showed antibody titers. Selected positive sera were also subjected to WNV neutralisation tests, in which the ELISA results were verified in 66%. The results of this study confirm unambiguously the presence of a lineage 2 WNV infection in birds of prey in the eastern part of Austria.  相似文献   

12.
Nile tilapia Oreochromis niloticus, summer flounder Paralichthys dentatus, and walleyes Sander vitreus were treated with Romet-30 (PHARMAQ AS, Oslo, Norway) via a medicated ration at 50 mg Romet-30 kg fish body weight(- 1) d(-1) for 10 d to compare the elimination kinetics of the test substance. This study was part of a larger effort to develop a species grouping concept for the labeling of therapeutic compounds for cultured fishes. The fish tests were conducted at the ideal water temperature for each species and at 5 degrees C lower than the ideal temperature except for summer flounder, which would not feed at the lower temperature of 15 degrees C. Test temperatures were 30 degrees C and 25 degrees C for Nile tilapia, 20 degrees C and 17 degrees C for summer flounder, and 25 degrees C and 20 degrees C for walleyes. Neither component of Romet-30 (sulfadimethoxine and ormetoprim) could be detected in samples of the edible portion of walleyes (muscle plus skin) collected at day 10 posttreatment or thereafter. In studies with summer flounder, only one fish had a detectable concentration of either component on day 21 or thereafter. Elimination of Romet-30 by Nile tilapia was extremely rapid. The limited number of Nile tilapia with detectable sulfadimethoxine or ormetoprim during the posttreatment period prevented the determination of elimination half-life or elimination in this species.  相似文献   

13.
Crows have been the centerpiece of avian West Nile virus (WNV) surveillance and research in North America. This work has demonstrated variation in susceptibility to WNV infection between American (Cor vus brachyrhynchos) andFish Crows (Corvus ossifragus). The higher WNV-associated mortality rate in American Crows compared with Fish Crows suggests that WNV antibody prevalence would be greater in the Fish Crow population. The objectives of this study were to 1) determine whether Fish Crows had higher WNV antibody prevalencethan American Crows, 2 ) determine th e persistence o f antibodies to WNV in naturally infected Fish Crows, and 3) develop a technique to distinguish Fish Crows from American Crows on the basis of sequence analysis and restriction enzyme digestion of a mitochondrial DNA fragment. West Nile virus antibody prevalence was 16.5% (n = 97) in Fish Crows and 5.7% in American Crows (n = 53) collected from Georgia between 2004 and 2006. Antibodies persisted at high titers for 12 mo in Fish Crows. This is the first report of WNV antibody persistence in a crow species. A polymerase chain reaction technique paired with restriction enzyme digestion easily distinguished American Crows from Fish Crows on the basis of a mitochondrial DNA fragment.  相似文献   

14.
The prevalence and extent of respiratory tract lesions were measured in 1425 pigs from 27 randomly selected herds in the summer of 1982 and winter of 1983. About 75% of pigs had lesions of enzootic pneumonia, approximately 60% had atrophic rhinitis and approximately 11% had pleuropneumonia and/or pleuritis. Individual pig growth rate was recorded on two of the farms, and it was found that the correlations between growth rate and severity of enzootic pneumonia lesions were positive on one farm and negative on the other. Negative correlations between severity of turbinate atrophy and growth rate existed in one of the two herds. Extent of pneumonia and severity of turbinate atrophy were poorly related in individual pigs but herd averages were moderately and positively correlated. Prevalence of diffuse pleuritis and of pleuropneumonia were positively related, as were the extent of pneumonia and prevalence of localized pleuritis. Prevalence of pleuropneumonia was strongly correlated with increased days-to-market. A method of estimating the average days-to-market using weekly herd data (inventory) was developed.  相似文献   

15.
The seasonal pattern of Dictyocaulus filaria infection in four flocks of sheep under field conditions was studied by faecal examination for larvae. The prevalence of infection in lambs was low in spring and summer but increased in late autumn or winter, then fell again to a low level by May. However, most lambs became infected at some time during their first year of life. In ewes the prevalence of infection was generally low, but rose during winter and spring. Seasonal pattern and intensity of infection were influenced by weather conditions and the persistence of infection from the previous year, moist summer conditions giving rise to a higher level of infection in autumn and winter than a dry summer. The source of infection may be the ewes or yearlings, or infective larvae surviving over the winter on pasture. Autoinfection occurred, some lambs becoming infected with at least three generations of the parasite, but at the levels of infection recorded clinical disease was rare.  相似文献   

16.
West Nile Virus (WNV) infection manifests itself clinically a nd pathologically differently in various species of birds. The clinicopathologic findings and WNV antigen tissue distribution of six great gray owls (Strix nebulosa) and two barred owls (Strix varia) with WNV infection are described in this report. Great gray owls usually live in northern Canada, whereas the phylogenetically related barred owls are native to the midwestern and eastern United States and southern Canada. Naturally acquired WNV infection caused death essentially without previous signs of disease in the six great gray owls during a mortality event. Lesions of WNV infection we re dominated by hepatic and splenic necrosis, with evidence o f disseminatedintravascular coagulation in the great gray owls. WNV antigen was widely distributed in th e organs of the great gray owls and appeared totarget endothelial cells, macrophages, and hepatocytes. The barred owls represented two sporadic cases. They had neurologic disease with mental dullness that led to euthanasia. These birds had mild to moderate lymphoplasmacytic encephalitis with glial nodules and lymphoplasmacytic pectenitis. WNV antigen was sparse in barred owls and only present in a few brain neurons and renaltubular epithelial cells. The cause of the different manifestations of WNV disease in these fairly closely related owl species is uncertain.  相似文献   

17.
Urbanization of natural areas can change abiotic factors, providing artificial sources of humidity in summer and decreasing variation of temperatures in winter. Our study aimed at document risk factors of infection in mammal reservoirs of pathogenic Leptospira in the human/wildlife interface of a large metropolitan area. We hypothesize that survival of Leptospira and thus their prevalence in animal reservoirs should be higher in residential areas than in natural habitats, especially after the hot, dry Mediterranean summers. We established the prevalence of Leptospira spp. and identified the serovars in 353 urine samples from micromammals (chiefly the wood mouse Apodemus sylvaticus, n = 266) using direct immunofluorescence and PCR. Animals were captured in spring and autumn, 2011–2012, in two natural parks and two adjacent residential areas in periurban Barcelona (NE Spain). Overall observed prevalence of infection was 11%, ranking between 8% and 13% in the better represented host species. We observed marked differences between seasons; the probability of finding a micromammal infected in spring was three times greater than in autumn (almost four times for wood mouse). Prevalence was not related with type of habitat, micromammal relative abundance or sex of the animal. Three Leptospira species were confirmed: Leptospira interrogans (47% of cases), Leptospira borgpetersenii (41%) and Leptospira kirschneri (12%). The serovars most commonly detected were those typically hosted by rodents, and serovars Ballum and Icterohemorrhagiae were the only ones found in autumn. People living in periurban Barcelona and those visiting the natural areas of the metropolitan area face hazard of infection with rodent‐borne Leptospira, especially during spring.  相似文献   

18.
The accidental introduction of West Nile Virus into New York City from the Old World in 1999 resulted in an epidemic in humans, horses, and birds that swept to the west coast in just 3 years. The virus is transmitted by infective mosquitoes among susceptible native birds, which serve as amplifying hosts. Clinical disease occurs in humans and horses, but not enough virus is produced in their blood to infect other mosquitoes; therefore, humans and horses are considered dead-end hosts. Humans can best protect themselves by remaining indoors during periods of high mosquito activity and/or by using recommended repellents. Effective vaccines are available for horses.  相似文献   

19.
A survey for West Nile Virus (WNV) haemagglutination-inhibition (HI) antibody was carried out in humans and domestic animals. Human sera were collected from Ibadan, while the animal sera were collected from both Ibadan and Maiduguri. Out of 304 human sera tested, 123 were positive (40%). There was a higher prevalence of HI antibody in adults than children. Sex distribution of positive sera showed that 37% of males and 43% of females had WNV HI antibody. There was no significant difference in the prevalence of HI antibody in both sexes. On the 123 WNV HI positive sera tested, 104 (85%) and 78 (75%) had yellow fever and Potiskum HI antibody respectively. Monotypic WNV virus reactions were frequently found in children while polytypic reactions were frequently found in adults. A total of 200 animal sera were examined, 50 camels, 50 goats, 49 cattle and 51 sheep. The highest prevalence of HI antibody was found in camels (26%), followed by sheep (20%). Percentage of positive sera in other species were: goat (18%) and cattle (6%). Of the 35 WNV HI positive animal sera, 26 and 20% reacted with Yellow fever and Potiskum virus antigens respectively.  相似文献   

20.
Bird migration has long been hypothesized as the main mechanism for long‐distance dispersal of flaviviruses, but the role of migratory birds in flaviviruses spillover is not well documented. In this study, we investigated the eco‐epidemiology of West Nile virus (WNV) and Usutu virus (USUV) in trans‐Saharan passerines during their spring stopover in southern Tunisian oases. To do, we combined oral swab analysis and serological tools to assess whether migratory birds could be reaching these stopover sites while infectious or have been previously exposed to viruses. All sampled birds tested negative for oral swab analysis. However, anti‐WNV and anti‐USUV antibodies were detected in 32% and 1% of tested birds, respectively. Among WNV‐seropositive species, the Golden oriole (Oriolus oriolus) showed the highest anti‐WNV occurrence probability. In this species, anti‐WNV occurrence was twice larger in males than females. Inter‐specific and intraspecific morphological, physiological and behavioural differences could explain these results. Although our findings did not show evidence for passerines migrating while infectious, they did not exclude an existing enzootic WNV transmission cycle in Tunisian oases. Further investigations including larger samples of migratory birds are needed for a better understanding of this issue.  相似文献   

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