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1.
Swimmer's itch is caused by the penetration of free‐swimming larvae of trematodes of the family Schistosomatidae in human skin. It is usually reported in people engaged in recreational water activities in freshwater bodies and in most of cases, it is provoked by bird schistosomes of the genus Trichobilharzia. In the summer 2017, many cases of dermatitis were recorded in people bathing in the waters of the Albano Lake (Rome, Italy) and a parasitological investigation was carried out in order to ascertain the causative agent of these cases. Snails of the family Lymnaeidae, natural intermediate hosts of bird schistosomes, were collected from lake shallow waters to detect the presence of trematodes of the genus Trichobilharzia. Pools of maximum 10 snails were placed in Petri dishes, and cercarial emergence was stimulated exposing snails to strong artificial light intensity at 25°C. Three hundred and thirty‐seven snails were collected and screened for the shedding of cercariae. Furcocercariae of the family Schistosomatidae, with a morphology overlapping that of the genus Trichobilharzia, were detected in seven Petri dishes. Assuming that in each positive Petri dish just one snail was shedding furcocercariae, the minimum infectious rate was 2.1%. Molecular analysis of furcocercariae allowed ascribing them to the species Trichobilharzia franki. Snails of the species Radix auricularia were identified as intermediate hosts of the parasite. This is the second record of T. franki causing cercarial dermatitis in Central Italy, the third in Italy. The 2017 was in Italy exceptionally warm and dry. Trematodes are sensitive to changes in temperature, being cercarial production and emission rates temperature dependent. Small increases in water temperature would speed up parasite development and transmission, leading to a manifold increase in cercarial emergence. Moreover, high temperatures raise chances to acquire the infection, due to increased time spent in water by people.  相似文献   

2.
目的了解鸭血吸虫病在湖北省荆州太湖港地区的流行状况。方法用病原学检查方法调查鸭血吸虫感染率和螺类毛蚴感染率,用询诊法了解人群尾蚴性皮炎的患病情况。结果该地区鸭血吸虫感染率分别为湖滩放养鸭为4.52%,湖泊河流放养鸭为2.25%,螺类毛蚴感染率:湖滩椎实螺类为5.30%;湖区和坝区人群尾蚴性皮炎阳性率分别为8.89%和6.02%。结论该地区鸭血吸虫病流行仍较为严重,且对下水作业人员造成一定危害,是一个重要的公共卫生问题。  相似文献   

3.
The eggs of three species of avian schistosomes were recovered from indigenous South African birds. Gigantobilharzia sp. was recorded from the kelp gull, Larus dominicanus and the gannet, Morus capensis; Austrobilharzia sp. from L. dominicanus, and Trichobilharzia sp. from the spurwing goose, Plectropterus gambensis, the Egyptian goose, Alopochen aegyptiacus and L. dominicanus. The morphology of these eggs is compared to that of described species of avian schistosomes.  相似文献   

4.
As part of the USA's National Strategy for Pandemic Influenza, an Interagency Strategic Plan for the Early Detection of Highly Pathogenic H5N1 Avian Influenza in Wild Migratory Birds was developed and implemented. From 1 April 2006 through 31 March 2009, 261 946 samples from wild birds and 101 457 wild bird fecal samples were collected in the USA; no highly pathogenic avian influenza was detected. The United States Department of Agriculture, and state and tribal cooperators accounted for 213 115 (81%) of the wild bird samples collected; 31, 27, 21 and 21% of the samples were collected from the Atlantic, Pacific, Central and Mississippi flyways, respectively. More than 250 species of wild birds in all 50 states were sampled. The majority of wild birds (86%) were dabbling ducks, geese, swans and shorebirds. The apparent prevalence of low pathogenic avian influenza viruses during biological years 2007 and 2008 was 9.7 and 11.0%, respectively. The apparent prevalence of H5 and H7 subtypes across all species sampled were 0.5 and 0.06%, respectively. The pooled fecal samples (n= 101 539) positive for low pathogenic avian influenza were 4.0, 6.7 and 4.7% for biological years 2006, 2007 and 2008, respectively. The highly pathogenic early detection system for wild birds developed and implemented in the USA represents the largest coordinated wildlife disease surveillance system ever conducted. This effort provided evidence that wild birds in the USA were free of highly pathogenic avian influenza virus (given the expected minimum prevalence of 0.001%) at the 99.9% confidence level during the surveillance period.  相似文献   

5.
1. Disposition kinetics of florfenicol were studied in Pasteurella-free (control) and Pasturella-infected Muscovy ducks following intravenous and/or intramuscular injection in a single dose of 30 mg/kg body weight. In addition, the tissue distribution and residual pattern of the drug were determined in diseased ducks. 2. The maximum serum concentration of florfenicol in control healthy and infected ducks was reached 1 hour after intramuscular injection but the peak concentration in control ducks was higher than in infected birds. 3. The volume of distribution, total body clearance and systemic bioavailability were higher in infected ducks than in control birds 5.15 l/kg, 10.24 ml/kg/min and 73.03% respectively. Data relating to intravenous injection were analysed using a 2 compartment open model curve fit. 4. Florfenicol was not detected in the serum of infected ducks on the 7th day following intramuscular administration of 30 mg/kg body weight twice daily for 5 successive days but was detected in kidney, bile and liver.  相似文献   

6.
C L Mo  E C Burgess 《Avian diseases》1987,31(1):197-201
Mallards (Anas platyrhynchos platyrhynchos) and white pekin ducks (Anas platyrhynchos domesticus) were infected with duck plague virus and challenged with LD20's of Pasteurella multocida and P. anatipestifer. There was no difference between mortality rates of duck plague-infected ducks and controls, suggesting that these organisms do not act synergistically under the conditions of our experiments. There was a difference of about 500-fold between the LD20 of P. multocida for mallards and that for white pekin ducks, indicating that mallards are much more susceptible to avian cholera than white pekin ducks.  相似文献   

7.
1. The aim of this work was to determine the frequency of occurrence of Toxoplasma gondii and genetically analyse isolates from a number of avian hosts in the southwest of Iran (Khuzestan province). The frequency of T. gondii was determined in free-range chickens (Gallus domesticus), sparrows (Passer domesticus), pigeons (Columba livia) and starlings (Sturnus vulgaris).

2. Isolates obtained from Toxoplasma-infected birds were subjected to molecular typing by PCR-restriction fragment length polymorphism (RFLP) with sequence analysis of the GRA6 gene.

3. The results showed that 41 (16·5%) of 241 samples of avian tissue were infected with T. gondii. Sparrows were most frequently infected (17 out of 64).

4. Analysis of the GRA6 gene by PCR-RFLP and DNA sequencing revealed Type II and III T. gondii were the predominant lineage, accounting for 19·5% and 80·5% of the isolates, respectively.

5. It was concluded that the use of this PCR test facilitated the diagnosis of T. gondii in avian hosts and the GRA6 PCR-RFLP method clearly differentiated between the three different T. gondii lineages. This study showed a higher prevalence of type III compared with type II T. gondii in infected avian hosts in southwestern Iran.  相似文献   


8.

Over the last two decades, the highly pathogenic avian influenza H5N1 virus has gained a lot of attention due to its zoonotic and mutative nature. Iran is among the countries significantly affected by the virus as it hosts migratory birds during seasonal migration. In this study, the molecular characterizations of hemagglutinin (HA) and neuraminidase (NA) genes and proteins of H5N1 strain A/chicken/Iran/8/2015 detected in backyard poultry, Mazandaran province, were investigated. Phylogenetic analysis classified this virus as a member of subclade 2.3.2.1c, with the cleavage site motif of “PQRERRRK-R/GLF”. HA carried a few mutations altering affinity to mammalian cells; however, the virus was categorized as avian. NA protein had the 20-amino acid deletion at aa position 49–69 similar to those isolated since 2000. Mutations of H253Y and H274Y contributing to antiviral resistance were present in NA. From this analysis, it can be concluded that the wild migratory birds flying from Western Asia to Eastern Africa are probably the main carriers of seasonal H5N1 in the country.

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9.
The complex life cycles of most trematode parasites include three hosts. The first intermediate host is a snail, the second is normally a teleost fish and a piscivorous bird serves as the definitive host. Lymnaeid snails are most likely to be responsible for cercarial shedding, which infect exposed fish and in turn are eaten by piscivorous birds. From 2008 to 2010 fish in the Okavango and Orange-Vaal River Systems were collected and dissected in order to determine the prevalence and intensity of larval trematode infections in the eyes and brains. This paper discusses the possible ecological factors which can influence the probability of certain fish species becoming infected with diplostomid cercariae and hence metacercariae. The feeding strategies and sizes of piscivorous birds, which could act as definitive hosts for the adult worms, are summarized and discussed. Information on the snail species responsible for furcocercous cercarial shedding in the two study sites is also included.  相似文献   

10.
Infections by Cryptosporidium were detected in association with clinical disease in 11 humans (Homo sapiens), 19 calves (Bos taurus), nine common quail (Coturnix coturnix), six mallard ducks (Anas platyrhynchos), five ring-necked pheasant (Phasianus colchicus) and a single budgerigar (Melopsittacus undulatus). Infections in mammals were accompanied by transient diarrhoea and anorexia, whereas infected birds exhibited clinical signs of respiratory distress. Repeated cross-transmission studies revealed apparent strain differences or differences in the host specificity of several mammalian and avian isolates for homologous vertebrate classes only. Oocysts from humans and calves were infective to mice, pigs or lambs, but not to chickens, whereas oocysts from quail and pheasant were infective to chickens, but not to mice.  相似文献   

11.
Duck rearing is an important component of sustainable living in poor rural communities, especially as a source of subsistence. A study was conducted on 118 households (N = 1,373 Jinding ducks, Anas platyrhynchus) from December 2002 to February 2004 on Hatia Island in Bangladesh with the aim of identifying the factors that limit the health and production of Jinding ducks. Overall duck mortality was 29.3%, with disease (19.7%) being a more significant factor than predation (9.6%; p = 0.001). Duck mortality also varied significantly among study zones (p < 0.001). Common diseases were duck plague (21.1%) and duck cholera (32.1%). Helminth infection was prevalent, with endemic trematode (Prosthogonimus spp., Trichobilharzia spp., Echinostoma spp.) and nematode (Cyathostoma bronchialis, Amidostomum anseris, Heterakis gallinarum, Capillaria spp., and Echinuria spp.) infections and epidemic cestode infections due to Hymenolepsis setigera. The median egg production rate per duck per household was 93 for a 6-month laying period. The odds of diminished egg production (average ≤ 93 eggs per duck per household for a 6-month laying period) was 25.4 times higher in ducks that were kept in traditional duck houses (p < 0.001) and 14.2 times higher in ducks that experienced delays in the onset of sexual maturity (days 191 and 280; p < 0.001). Ducks that were provided snails for a shorter period of time over the laying period were 18.2 times more likely to produce fewer eggs than their longer fed peers (p = 0.002). In conclusion, duck mortalities due to diseases and predation and parasitic infections appear to be common constraints on household duck production on Hatia Island. Additionally, improving duck housing and providing longer nutritional supplementation with snails increased the production capabilities of household-raised Jinding ducks on Hatia Island.  相似文献   

12.
A survey of gastrointestinal parasitic infection as determined by faecal examination was conducted among domestic and wild birds in Bangladesh. Birds were sampled from households, wet markets and wetlands in Chittagong and Greater Sylhet districts during April 2012 to February 2013. Mist nets were used to catch resident wild and migratory birds. The overall prevalence of parasitic infection ranged among locations from 25 to 55% in indigenous domestic ducks (live bird samples = 304), 20% in resident wild birds (environmental faecal samples = 40) and 40% in migratory birds (live bird samples = 35). The prevalence of parasitic infection was significantly higher in indigenous domestic ducks collected during summer (39%) than winter (22%) (p = 0.04). In domestic indigenous ducks and Muscovy ducks, both single and multiple types of parasitic infections were found. However, other domestic birds and wild birds often had a single type of parasitic infection. Ascaridia spp. with an average egg load of 50–900, was commonly detected in faecal samples of domestic and wild birds in this study. Other identified parasites were Capillaria spp. and Heterakis spp. both in domestic and wild birds. Improvement of biosecurity measures for household duck farms through educating and motivating household farmers could help mitigate the effects of parasitic infection on production.  相似文献   

13.
This study aimed to assess which method of wild waterbird surveillance had the greatest probability of detecting highly pathogenic avian influenza (HPAI) H5N1 during a period of surveillance activity, the cost of each method was also considered. Lake Constance is a major wintering centre for migratory waterbirds and in 2006 it was the site of an HPAI H5N1 epidemic in wild birds. Avian influenza surveillance was conducted using harmonised approaches in the three countries around the lake, Austria, Germany and Switzerland, from 2006–2009. The surveillance consisted of testing birds sampled by the following methods: live birds caught in traps, birds killed by hunters, birds caught in fishing nets, dead birds found by the public and catching live Mute Swans (Cygnus olor); sentinel flocks of Mallards (Anas platyrhynchos) were also used. Scenario tree analysis was performed including sensitivity analysis, followed by assessment of cost-effectiveness. Results indicated that if HPAI H5N1 was present at 1% prevalence and assuming HPAI resulted in bird mortality, sampling dead birds found by the public and sentinel surveillance were the most sensitive approaches despite residual uncertainty over some parameters. The uncertainty over the mortality of infected birds was an influential factor. Sampling birds found dead was most cost-effective, but strongly dependent on mortality and awareness of the public. Trapping live birds was least cost-effective. Based on our results, we recommend that future HPAI H5N1 surveillance around Lake Constance should prioritise sentinel surveillance and, if high mortality is expected, the testing of birds found dead.  相似文献   

14.
The ecology of avian influenza (AI) viruses in wild aquatic birds of Asia is poorly understood, especially for the H5N1 high pathogenicity AI (HPAI) viruses. From March 2006 through November 2008, 20 AI viruses were isolated in the Crimea region of Ukraine with an overall frequency of virus recovery of 3.3%. All the viruses were isolated from three species of dabbling ducks: mallard (Anas platyrhynchos), wigeon (Anas penelope), and garganey (Anas querquedula), making the frequency of virus recovery for dabbling ducks 6.3%. The viruses were predominantly isolated during the fall sampling period. All viruses were genetically and antigenically characterized. No H5N1 HPAI viruses were isolated, but other HA and NA subtypes were identified including H3N1 (2), H3N6 (3), H3N8 (4), H4N6 (6), H5N2 (3), H7N8 (1), and H10N6 (1) subtypes. All isolates were of low pathogenicity, as determined by the intravenous pathogenicity index of 0.00. For H5N2 and H7N8 isolates, the HA gene was sequenced and the phylogenetic analysis revealed possible ecologic connections of the Crimea region with AI viruses from Siberia and Europe. No influenza A isolates were recovered from other Anseriformes (diving ducks [two species of pochards] and graylag geese), Columbiformes (collared doves), Gruiformes (coot), and Galliformes (gray partridges).  相似文献   

15.
Cloacal and tracheal swabs were collected from 1389 hunter-killed ducks in Cameron Parish, Louisiana, during the 1986 and 1987 waterfowl seasons. Twenty-eight avian influenza viruses (AIVs) were isolated from 605 blue-winged teal (Anas discors), 75 mottled ducks (A. fulvigula), 375 gadwalls (A. stepera) and 334 green-winged teal (A. crecca). Prevalence estimates of AIV in ducks sampled during September, November, and December through January were 3.1%, 2.0%, and 0.4%, respectively. Differences in prevalence were detected by season (P = 0.044) and age class (P = 0.036). Two isolations from resident mottled ducks document transmission of AIV on these wintering areas. Much subtype diversity was present, with nine of 13 hemagglutinin (HA) and nine of nine neuraminidase (NA) subtypes recovered. Predominant HA and NA subtypes were typical of AIVs commonly associated with waterfowl. Results indicate that AIVs are transmitted in the wintering areas, and, although prevalence is low, these viruses continue to circulate within these duck populations during winter.  相似文献   

16.
Blastocystis is a common intestinal parasite among humans and animals such as non-human primates, pigs, cattle, birds, amphibians, and less frequently, rats, reptiles and insects. Since Blastocystis is a widely transmissible parasite between humans and mammals or birds, it is prominent to determine whether newly secluded non-human isolates are zoonotic. There are no comprehensive studies in Iran assessing the prevalence and molecular identification of Blastocystis infection in birds, especially in pigeons and crows. So, the aim of this study was to identify Blastocystis subtypes (STs) in crows and pigeons in Tehran province, Iran, using Nested PCR-RFLP and sequencing. Overall, 300 Blastocystis isolates from birds (156 pigeons and 144 crows) were subtyped by PCR, and the homology among isolates was then confirmed by RFLP analysis of the 18S rRNA gene. The prevalence of Blastocystis infection was detected 42.9% in pigeons and 44.4% in crows. All positive pigeons were owned by ST13 (100%). Among crows, 46 samples (71.8%) like pigeons were ST13, and 13 samples (20.3%) were ST14. Five samples (7.9%) remained unknown. This study was the first report of ST13 and ST14 of Blastocystis from birds. In the present study, our data revealed a high prevalence of Blastocystis sp. in pigeon’s and crow’s samples and the isolates from these birds were classified into two genetically distinct STs. Therefore, birds appear to be infected with various STs. It is important to determine the phylogenetic relationships between unknown STs from these birds and the multiple STs of Blastocystis.  相似文献   

17.
H5N1 highly pathogenic avian influenza (HPAI) viruses continue to be a threat to poultry in many regions of the world. Domestic ducks have been recognized as one of the primary factors in the spread of H5N1 HPAI. In this study we examined the pathogenicity of H5N1 HPAI viruses in different species and breeds of domestic ducks and the effect of route of virus inoculation on the outcome of infection. We determined that the pathogenicity of H5N1 HPAI viruses varies between the two common farmed duck species, with Muscovy ducks (Cairina moschata) presenting more severe disease than various breeds of Anas platyrhynchos var. domestica ducks including Pekin, Mallard-type, Black Runners, Rouen, and Khaki Campbell ducks. We also found that Pekin and Muscovy ducks inoculated with two H5N1 HPAI viruses of different virulence, given by any one of three routes (intranasal, intracloacal, or intraocular), became infected with the viruses. Regardless of the route of inoculation, the outcome of infection was similar for each species but depended on the virulence of the virus used. Muscovy ducks showed more severe clinical signs and higher mortality than the Pekin ducks. In conclusion, domestic ducks are susceptible to H5N1 HPAI virus infection by different routes of exposure, but the presentation of the disease varied by virus strain and duck species. This information helps support the planning and implementation of H5N1 HPAI surveillance and control measures in countries with large domestic duck populations.  相似文献   

18.
Repeated epizootics of highly pathogenic avian influenza (HPAI) virus subtype H5N1 were reported from 2003 to 2005 among poultry in Vietnam. More than 200 million birds were killed to control the spread of the disease. Human cases of H5N1 infection have been sporadically reported in an area where repeated H5N1 outbreaks among birds had occurred. Subtype H5N1 strains are established as endemic among poultry in Vietnam, however, insights into how avian influenza viruses including the H5N1 subtype are maintained in endemic areas is not clear. In order to determine the prevalence of different avian influenza viruses (AIVs), including H5N1 circulating among poultry in northern Vietnam, surveillance was conducted during the years 2006-2009. A subtype H5N1 strain was isolated from an apparently healthy duck reared on a farm in northern Vietnam in 2008 and was identified as an HPAI. Although only one H5N1 virus was isolated, it supports the view that healthy domestic ducks play a pivotal role in maintaining and transmitting H5N1 viruses which cause disease outbreaks in northern Vietnam. In addition, a total of 26 AIVs with low pathogenicity were isolated from poultry and phylogenetic analysis of all the eight gene segments revealed their diverse genetical backgrounds, implying that reassortments have occurred frequently among strains in northern Vietnam. It is, therefore, important to monitor the prevalence of influenza viruses among healthy poultry between epidemics in an area where AIVs are endemic.  相似文献   

19.
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20.
Fasciolosis is an important disease in veterinary medicine worldwide, and is a cause of great economic loss in livestock husbandry in Iran. This study was aimed to determine prevalence of Fasciola gigantica infection in field-collected snails of Radix gedrosiana in northwestern Iran. The snails were collected from 28 perennial and seasonal freshwater habitats from May to December 2010 and identified. A fragment of 618bp of 28s rRNA gene was amplified by polymerase chain reaction (PCR). The PCR products were subjected to restriction fragment length polymorphism (RFLP) using DraII and AvaII enzymes. PCR-RFLP patterns revealed that 3.12% of the snails were infected with F. gigantica. It was also found that the infected snails had a limited distribution over the water bodies located in the central part of the region. It was concluded that PCR-RFLP was a reliable approach to detect Fasciola infection in pond snails and may be useful to establish control measures for livestock and humans' fasciolosis in the region.  相似文献   

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