Prevalence of Toxoplasma gondii antibodies in stray cats in Sari, northern Iran

Cats are important in the epidemiology of Toxoplasma gondii because they are the only hosts that can excrete environmentally resistant oocysts. T.gondii is a major zoonotic agent which infects up to one-third of the world population. Toxoplasmosis in neonates and immunocompromised patients can lead to severe disease and death. A cross- sectional parasitological and serological survey with latex agglutination test (LAT) to detect anti-T. gondii antibodies was conducted on 100 serum samples collected from stray cats in five urban areas of Sari, Northern Iran, from April to November 2004. Classification by age, sex, weight, season and region was made. Results analyzed according to specific variables. The overall prevalence of T. gondii IgG antibodies (LAT titre ≥1:1) were found in 40 of 100(40%) of stray cats, with regional variations. Overall 16 of 100(16%) of stray cats had diagnostically significant antibody titres (LAT ≥ 1:64). Prevalence was significantly higher in adult cats (1.5–3.0 kg, 54.5% of 66) than in juvenile cats and kittens (≤1.4 kg, 11.8% of 34) and higher in female stray cats (44.4% of 72) than in male stray cats (28.6% of 28). Toxoplasma seroprevalence was highest in the season of spring (22.4%). There was a significant difference in the prevalence of infection relative to host age and weight (P < 0.05). No significant difference was found between the prevalence of infection relative to host gender, urban sites and season (P > 0.05). Prevalence of T. gondii oocyst was also analyzed by a routine coprological method in 100 cats. T. gondii oocysts were not found in any faecal samples analyzed. Only 2 out of 100 smear preparations of intestinal mucosa showed trophozoites of T. gondii.     

Toxoplasma gondii in Ireland: Seroprevalence and Novel Molecular Detection Method in Sheep,Pigs, Deer and Chickens

Toxoplasma gondii is among the most studied parasites worldwide but there is not much information about it published in Ireland. The objectives of this study were to determine the seroprevalence of T. gondii in sheep, pigs, deer and chickens and the molecular detection of T. gondii DNA in muscle tissue. Serum samples were collected from these species at the time of slaughter at Irish abattoirs during 2007 and tested for anti‐T. gondii antibodies using a commercial semi‐quantitative latex agglutination test. Antibodies (titre ≥1 : 64) were found in 36% (105/292) sheep, 4.7% (15/317) pigs and 6.6% (23/348) deer. In chickens, 18% (65/364) had antibody titres, ranging between 1 : 5 and 1 : 1024. Significant (P ≤ 0.05) age‐related differences in seroprevalence were found in adult sheep (58.1%) and pigs (23.1%). Significant gender differences in seroprevalence was also found in sheep with more females (43%) than males (22.4%) being positive. However, when adjusted for age through logistic regression gender was no longer significant. Seroprevalence was also evaluated on farm locations grouped to NUTS level 3, but the prevalence was too low to draw any statistical conclusions. Using a nested PCR, the presence of T. gondii DNA was detected in diaphragm samples from 3.6% (3/83) sheep, 13.0% (3/23) pig and 4.2% (3/71) deer. Meat digestion liquids from a Trichinella spp. survey in pigs were also used for the first time to detect T. gondii. Toxoplasma gondii DNA was detected in 50% (10/20) of pooled samples. This is the first in depth study of T. gondii seroprevalence in animals in Ireland and a novel method, using digestion liquid from pooled diaphragm samples, for PCR detection in pigs is described.     

Toxoplasma gondii and Chlamydophila abortus in Caprine Abortions in Tobago: a Sero‐Epidemiological Study

A sero‐epidemiological study was conducted on a goat farm that experienced an abortion epidemic in the 2005 breeding season in Tobago. Serum samples of goats (aborting and non‐aborting) and cats were collected, in addition to the use of stored sera from the farm sampled in 2003 and 2004. Farm records on the reproductive and mortality rates for year 2003, 2004 and 2005 were also reviewed. The sera were screened for Toxoplasma gondii antibodies using the latex agglutination test (LAT), Chlamydophila abortus with an enzyme‐linked immunosorbent assay (ELISA) and Brucella abortus using the buffered plate agglutination test (BPAT). Farm records revealed that for the period 2003–2005, the average kid per doe rate decreased from 2.1 to 1.5, the mortality rate increased from 6.3% in 2002 to 19.4% in 2004 and the fertility rate decreased from 98–99% (2002–2004) to 89% (2005). There was a dramatic increase in the abortion rate from <1% (2002, 2003 and 2004) to 29.2% (2005). Of a total of 161 sera tested comprising 12 from 2003, 89 from 2004 and 70 from 2005, 0 (0.0%), 21 (23.6%) and 45 (64.3%) were positive for T. gondii agglutinins (i.e. titres ≥1 : 64) and the differences were statistically significant (P < 0.05; χ²). Of all serum samples tested, only 1 (1.1%) of 89 from 2004 was positive for C. abortus while all the sera tested were negative for B. abortus. Amongst the 24 does which aborted in 2005 and were available for testing in mid‐2005, 15 (62.5%) had reciprocal titres of ≥1 : 2048, three (12.5%) each had titres of 1 : 1024, 1 : 256 and ≤1 : 16 i.e. negative. The seroprevalence and titres of does that aborted, 20 (87.0%) of 23, all with titres ≥1 : 256 suggesting current infection, were statistically significantly (P < 0.05; χ²) higher than was detected amongst does that delivered normal kids, 25 (53.25) of 47 with 22 (48.8%) having titres of ≥1 : 256. One (50.0%) of two cats caught and tested was seropositive with a reciprocal titre of 128. This is considered the first documentation of T. gondii agglutinins in caprine abortion as well the detection of C. abortus antibodies from livestock in Trinidad. It is concluded that of the three zoonotic abortifacient pathogens tested for, T. gondii appeared to have played some aetiological role in the abortion epidemic investigated.     

Comparison of Different Commercial Serological Tests for the Detection of Toxoplasma gondii Antibodies in Serum of Naturally Exposed Pigs

Toxoplasma gondii is the aetiological agent of the zoonotic disease toxoplasmosis and transmitted among other ways by chemically and physically untreated, that is, raw pork to humans. The detection of Toxoplasma gondii is impossible by currently practiced meat inspection, but serological tests can be used to detect Toxoplasma gondii antibodies in pig herds and can consequently be helpful to identify potentially contaminated pork. Therefore, appropriate serological tests are required. In this study, serum samples of 1368 naturally exposed slaughter pigs from 73 Austrian farms were collected. Serum samples of at least 16 slaughter pigs per farm were tested. The prevalence of Toxoplasma gondii antibodies in serum was measured by a commercial available modified agglutination test (MAT) and compared to three different commercial available enzyme‐linked immunosorbent assays (ELISA). The MAT detected 6.5%, ELISA I 6.7%, ELISA II 4.8% and ELISA III 4.3% of the pigs as Toxoplasma gondii antibody positive. The agreement, according to the kappa coefficient (κ), was substantial between the MAT and ELISA I (κ = 0.62), II (κ = 0.64) and III (κ = 0.67). A better agreement was determined between ELISA I and II (κ = 0.715), ELISA I and III (κ = 0.747) and ELISA II and III (κ = 0.865). At least one pig per farm was detected Toxoplasma gondii antibody positive in 17 (23.3%) farms by the MAT, 26 (35.6%) farms by ELISA I, 16 (21.9%) farms by ELISA II and 11 (15.1%) farms by ELISA III. Pig farms with a high number of Toxoplasma gondii antibody‐positive pigs or high antibody titres were identified by all of the four used serological tests. Concerning the occurrence of Toxoplasma gondii antibodies in Austrian pig farms, a monitoring and surveillance programme would be reasonable to find high‐risk farms.     

Evidence of Toxoplasma gondii Exposure in Boer Goat Herds in Missouri,USA

Limited data currently exist on the prevalence of Toxoplasma infections in goats in the USA. The objective of this pilot investigation was to determine the prevalence of Toxoplasma gondii antibodies in Boer goats raised in Missouri. Sera collected from 367 Boer goats in 24 herds were tested using a commercial latex agglutination assay. Evidence of T. gondii antibodies was present in 25 of the 367 goats, with titres of 1 : 32 in 4, 1 : 64 in 11, 1 : 128 in 5, 1 : 256 in 3 and 1 : 1024 in 2. Estimates for the apparent animal‐level and between‐herd prevalence were 6.8% (95% CI = 4.7–9.9%) and 41.7% (95% CI = 24.5–61.2%). These results confirm that Boer goats in Missouri are exposed to T. gondii and may constitute a public health risks.     

First identification of Sarcocystis tenella (Railliet, 1886) Moulé, 1886 (Protozoa: Apicomplexa) by PCR in naturally infected sheep from Brazil

Sarcocystis tenella is a dog–sheep protozoan parasite, causing a widespread enzootic muscle parasitosis and neurological disease mainly in lambs. This parasite is pathogenic to sheep and important to the economical production of sheep. The present study was initially aimed to determine Toxoplasma gondii infection and the occurrence of co-infection with other Apicomplexa parasites in 602 Brazilian sheep. Twenty of these sheep were positive with antibodies to T. gondii by MAT and IFAT-IgG tests, positive with PCR-RFLP genotyping at multiple loci, and parasites were isolated from mice infected with sheep tissue samples. Two additional sheep born in Brazil, a 2-year-old female Polwarth (Ideal) sheep, a breed originated from Australia (#1), and a 1-year-old male Corriedale sheep, a breed originated from New Zealand and Australia (#2) were positive to T. gondii antibodies by serum tests, and PCR, but negative for bioassay in mice. In genotyping at 12 loci, sheep #1 sample and #2 presented positive results only for some markers. PCR-RFLP of 18S ribosomal RNA (18S rRNA) was performed in all 22 animals to identify the possibility of co-infection of T. gondii with other Apicomplexa parasites, such as S. tenella, Neospora caninum and Hammondia hammondi, resulting in a T. gondii profile for the first 20 animals and a unique genotyping profile for sheep #1 and #2, identical to S. tenella. The 18S rRNA PCR products (310 bp) were sequenced and blasted to GenBank database at NCBI. Both samples were identical to S. tenella 18S rRNA gene (GenBank accession number L24383-1). These results suggest the existence of co-infection of S. tenella with T. gondii in ewes from Brazil.     

A serologic study on Toxoplasma gondii infection in slaughtered sheep and goats in Qazvin Province,Iran

Background

Toxoplasma gondii is a common protozoan parasite among all mammals, in particular small ruminants, worldwide. Traditional husbandry can be a major risk factor for infection of sheep and goats with this parasite.

Objectives

The present study aimed to determine the current status of the prevalence for T. gondii in livestock of Qazvin Province.

Methods

In this cross-sectional study, the sera of 455 sheep and 375 goats were examined to detect anti-Toxoplasma IgG antibodies by using in-house indirect ELISA.

Results

Overall, 33.62% (153/455) of sheep and 36.41% (130/375) of goats were positive for anti-Toxoplasma IgG antibodies with no statistically significant difference. The prevalence rate of T. gondii among the sheep of Qazvin County was significantly higher than in Abyek and Abhar counties (p < 0.001).

Conclusions

The results of the present study indicate that the prevalence of T. gondii in sheep and goats of the study area is high. Therefore, the meat of the animals reared in this area can be a potential source of human infections by this parasite.

     

Prevalence of Neospora antibodies in beef cattle in New Zealand

dAim:To estimate the prevalence of Neospora infection in a sample of New Zealand beef cattle.

dMethods: The prevalence of Neospora caninum infection in New Zealand beef cattle was estimated by collecting blood at slaughter from 499 beef cattle from 40 different farms at 2 slaughter plants in the North Island and 1 in the lower South Island. Sera were tested using an ELISA against Neospora tachyzoite antigen.

dResults: The prevalence of seropositive cattle was 2.5% (n=120), 3.6% (n=166) and 2.3% (n=213) at the plants surveyed, the overall prevalence being 2.8%. The serologically positive cattle came from 9 farms, 3 of which had more than 1 positive animal. The highest prevalence recorded amongst animals from 1 farm was 4/13 (31%), in a group of young steers.

dConclusion: Neosporosis appears to be present at a lower level in the New Zealand beef cattle population than in the New Zealand dairy cattle population. Nevertheless, from the high seroprevalence evident amongst young cattle on 1 farm, we suggest that Neospora may be a cause of infertility in beef cattle in this country.     

Serological Survey of Toxoplasma gondii Infection in the Domestic Goose (Anser domestica) in Southern China

In the present study, the antibodies to Toxoplasma gondii in 191 farm‐bred and 83 house‐bred geese (Anser domestica) were assessed for the prevalence of T. gondii infection in southern China with the modified agglutination test. Antibodies to T. gondii (MAT ≥ 1 : 5) were found in 27 (14.14%) of farm‐bred geese and 14 (16.87%) of house‐bred geese. Geese infected with T. gondii may be a source of T. gondii infection for humans and cats.     

Seroprevalence of Toxoplasma gondii infection in sheep and alpacas (Llama pacos) in Chile

Serum samples from 408 sheep from different regions of Chile and 447 alpacas (Llama pacos) from the north of the country were tested for Toxoplasma gondii antibodies. The indirect haemagglutination test (IHAT) was used in both species and the indirect immunofluorescence test (IIFT) was also used on the sheep samples in order to compare the performance of the tests in that species. In both tests, titers ≥1:16 were considered diagnostically significant. Sera from 49 sheep (12%) were positive to T. gondii antibodies by the IHAT. When using the IIFT, 114 sheep sera (28%) were positive. The different results obtained in sheep sera between the tests were significant (p<0.0001). No differences were observed between geographical locations or sex of the sampled sheep regarding serological detection of T. gondii antibodies in sheep. As expected, adult sheep showed higher T. gondii reactivity than young sheep (p=0.0008). The corrected prevalence of toxoplasmosis in alpaca was 16.3% (32 positive out of 447). The rather low prevalence in alpacas may be associated with their extensive management as well as the extreme climatic conditions of The Andes which apparently would not be favorable for the transmission of the parasite.     

First detection of Chlamydia psittaci from a wild native passerine bird in New Zealand

AIMS: To undertake disease surveillance for Chlamydia psittaci in native birds as part of a pilot study to examine pathogen diversity on Hauturu-o-Toi/Little Barrier Island. To retrospectively review the Massey University post-mortem database to determine previous cases of avian chlamydiosis in New Zealand.

METHODS:Mistnetting of forest birds was conducted across an elevational gradient on Hauturu-o-Toi/Little Barrier Island. Minitip culture swabs were used to collect cloacal samples from native birds. These swabs were screened for Chlamydia family DNA using two PCR methods. Positive results were sequenced. A retrospective review of the Massey University post-mortem database of all avian cases from 1990 to 2011 was conducted.

RESULTS:Ten native birds including four bellbirds (Anthornis melanura), three rifleman (Acanthisitta chloris), two hihi (Notiomyces cincta), and one whitehead (Mohoua albicilla) were sampled and one otherwise healthy female hihi was positive by both PCR screening methods for Chlamydophila. Sequencing confirmed 99–100% genetic similarity to C. psittaci. A retrospective review of the Massey University post-mortem database revealed no previous diagnoses of avian chlamydiosis in wild native New Zealand birds although it has been detected in captive parrots, and wild and captive exotic pigeons.

CONCLUSIONS:This is the first report of the detection of C. psittaci from a wild native bird in New Zealand. The bird was a Passeriforme from an endangered species that was captured free-living on Little Barrier Island. The incidence of avian chlamydiosis in native birds in New Zealand appears to be very low, based on the retrospective review of the post-mortem database.

CLINICAL RELEVANCE: It is unlikely that avian chlamydiosis is a significant problem for hihi population health. The detection of this organism has greater significance for other more susceptible species on Little Barrier Island and for human health, particularly for conservation workers involved in wildlife translocations. It further suggests that passerine birds may be a reservoir for C. psittaci in New Zealand ecosystems.     

Investigation of the index case herd and identification of the genotypes of Theileria orientalis associated with outbreaks of bovine anaemia in New Zealand in 2012

CASE HISTORY AND CLINICAL FINDINGS: On 7 September 2012 the Ministry for Primary Industries was notified of a dairy cow with regenerative anaemia (haematocrit (HCT) 0.08?L/L) in a herd of 465 Jersey-Friesian cross cows (index case herd) in the Northland region of New Zealand. Organisms consistent with Theileria spp. were present in red blood cells on a blood smear. No other causes of anaemia were detected following examination of affected cows. Blood samples collected from 29 randomly selected cows on 26 September 2012 showed that 24 (83%) were anaemic (HCT≤0.24 L/L) and therefore fitted the case definition for bovine anaemia associated with Theileria orientalis infection.

LABORATORY FINDINGS: Using a T. orientalis type-specific PCR assay that targeted the single subunit rRNA gene, all of six animals tested were positive for T. orientalis type Ikeda. Blood samples collected from clinically affected cattle in 11 subsequent outbreaks from throughout the North Island showed that T. orientalis Ikeda type was a common finding, but mixed infections with Chitose type were also identified. In addition, using a PCR assay that targeted the major piroplasm surface gene, T. orientalis type 5 was detected in one cow from the Waikato region.

DIAGNOSIS: The presence of T. orientalis type Ikeda, as well as type 5, was confirmed in cattle from outbreaks of bovine anaemia in herds throughout the North Island of New Zealand.

CLINICAL RELEVANCE: Two new types of T. orientalis were identified in this investigation, that were associated with a sudden rise in cases of bovine anaemia. The body of evidence showed that the Ikeda type was implicated as the cause of disease observed in this epidemic.     

Prevalence of Candidatus Mycoplasma haemolamae,bovine viral diarrhoea virus,and gastrointestinal parasitism in a sample of adult New Zealand alpaca (Vicugna pacos)

AIM: To determine the prevalence of infection with Candidatus Mycoplasma haemolamae (Mhl), antibodies to bovine viral diarrhoea virus (BVDV), and BVDV antigen, and the prevalence of animals with elevated faecal nematode egg counts (FEC) in a sample of adult New Zealand alpaca (Vicugna pacos).

METHODS: Blood samples were obtained from 175 alpaca, collected from 15 farms around New Zealand, and from 31 samples sent to a diagnostic laboratory for routine haematology. Blood smears (n=170) were examined microscopically for the presence of haemoplasma, and DNA was extracted from whole blood (n=206) for real-time PCR testing for Mhl. Packed cell volume (PCV) was determined for 193 samples. Serum samples (n=195) were tested for BVDV antibody using ELISA, and for BVDV antigen using a real-time PCR assay. Faecal samples were collected from 143 animals; FEC were measured, and samples pooled for larval culture.

RESULTS: No haemoplasma organisms were present on blood smear examination. Of the 206 blood samples, two (from the same farm) were positive for Mhl by real-time PCR testing, giving a prevalence of infection with Mhl of 0.97%. Of the 195 serum samples tested, four (2.1%) were positive for antibodies to BVDV; animals with BVDV antibodies were from 3/15 (20%) farms, none of which farmed cattle. None of the serum samples were positive by PCR for BVDV antigen. The median FEC was 50?epg (min 0, max 4,700), with 55/143 (38.5%) samples having 0?epg, and 33/143 (23.1%) having ≥250?epg. Haemonchus spp. were the most common nematodes present in faecal larval cultures from the North Island. Log₁₀ FEC was negatively associated with PCV (p=0.02), and was higher in males than females (p<0.001), and in animals that were positive compared with negative for Mhl (p=0.022).

CONCLUSIONS AND CLINICAL RELEVANCE: The number of alpaca infected with Mhl was low, as was the seroprevalence of BVDV. Gastrointestinal parasitism was, however, a common finding in this sample of New Zealand alpaca.     

Occurrence of anti-<Emphasis Type="Italic">Toxoplasma gondii</Emphasis> antibodies in female cattle in south-west of Iran

Toxoplasmosis, caused by Toxoplasma gondii, is a significant disease in livestock and humans. In Iran, studies shows that T. gondii infection in humans is relatively high and prevalence is associated mainly with consumption of undercooked meat or meat products. We have examined 450 serum samples from female cattle distributed over all Ahvaz, the center of Khouzestan province, south-west of Iran. IgG antibodies to T. gondii were assayed by the modified agglutination test using whole tachyzoites of T. gondii, and found in 71 (15.77%) of 450 cattle with titers of 1:25 in 38, 1:50 in 18, 1:100 in 11, 1:200 in three and 1:400 in one. Titers of antibodies were decreased in cattle over 2 years old. These results indicate that T. gondii infection in cattle of Khouzestan is relatively considerable, but not very high and consumption of beef may be a source of infection for humans in south-west of Iran.     

Seroprevalence of <Emphasis Type="Italic">Toxoplasma gondii</Emphasis> antibodies from slaughter pigs in Chongqing,China

Toxoplasmosis is a disease caused by the protozoan Toxoplasma gondii which infects most genera of warm-blooded animals, including humans. The objective of this investigation is to evaluate the seroprevalence of toxoplasmosis in pigs in Chongqing Municipality, southwest China. Slaughterhouse pigs’ serum samples collected from six different regions in Chongqing were assayed for T. gondii antibodies by an indirect hemagglutination test. The average seroprevalence of T. gondii were found in 30.6% (278/908) in slaughter pigs, ranging from 21.6% to 40.9% among different sampling sites. The results indicated that toxoplasmosis in swine of Chongqing Municipality was relatively serious, and the pork may be an important source for human infection with T. gondii. Comprehensive measures are needed to strengthen further prevention and control of the disease in Chongqing.     

Protozoa1 encephalomyelitis of dogs involving Neosporum caninum and Toxoplasma gondii in New Zealand

In a retrospective study of 15 cases of encephalomyelitis in dogs, three cases of Neospora caninum and two cases of Toxoplasma gondii infection were identified using immunohistochemical staining of central nervous system sections. All cases of neosporosis showed ataxia and progressive hind limb paralysis due to multifocal non-suppurative meningoencephalomyelitis which was most severe in the spinal cord and base of the brain stem. Neospora tissue cysts could not be distinguished morphologically from those of T. gondii using light microscopy, but electron microscopy confirmed their characteristic features. Although Neospora abortion in cattle has only recently been recognised in New Zealand, this study has shown that neosporosis has been present in dogs since at least 1972.     

Prevalence of Toxoplasma gondii in common moles (Talpa europaea)

Background

The prevalence of Toxoplasma gondii in common moles, Talpa europaea, was investigated in order to determine whether moles can serve as an indicator species for T. gondii infections in livestock.

Findings

In total, 86 moles were caught from 25 different sites in the Netherlands. Five different trapping habitats were distinguished: pasture, garden, forest, roadside, and recreation area. No positive samples (brain cysts) were found during microscopic detection (n = 70). Using the Latex Agglutination Test (LAT), sera of 70 moles were examined, whereby no sample reacted with T. gondii antigen. Real Time-PCR tests on brain tissue showed 2 positive samples (2.3%).

Conclusions

Because of the low number of positives in our study, the use of the common mole as an indicator species for livestock infections is currently not recommended.

Electronic supplementary material

The online version of this article (doi:10.1186/s13028-014-0048-0) contains supplementary material, which is available to authorized users.     

Endoparasites of brushtail possums (Trichosurus vulpecula) from the South Island,New Zealand

As part of a study to assess whether endoparasites could assist in the biological control of brushtail possums in New Zealand, we investigated the composition and distribution of possum endoparasites in the South Island. Possums were collected near five of the original release areas in the South Island: Banks Peninsula, Hokitika, Nelson, Dunedin and Invercargill.

Among the nematodes, those most frequently encountered were Trichostrongylus spp., which were present in possums from all five study areas. Trichostrongylus species from possums in the Invercargill area comprised 4.5% T. colubriformis, 0.9% T. vitrinus and 11.3% T. retortaeformis. Paraustrostrongylus trichosuri and Parastrongyloides trichosuri were found only in the Invercargill area, where they infected 1.4% and 14% of possums respectively. The cestode Bertiella trichosuri was present in possums from all locations except Dunedin. The protozoan Eimeria spp. occurred in all areas.

These are the first records of Parastrongyloides trichosuri, Paraustrostrongylus trichosuri, T. vitrinus, T. retortaeformis and Eimeria spp. in South Island possums.

The prevalence of endoparasites and the intensity of infection was very low compared to the lower North Island of New Zealand. Endoparasites at the existing levels in the South Island probably have very little effect on possum populations.     

Detection of Toxoplasma gondii DNA in Fresh and Frozen Semen from Rams in Brazil

The aim of this study was to estimate the prevalence of genomic DNA of Toxoplasma gondii in semen samples from commercial rams in artificial insemination centres in Brazil, as well as in fresh semen from rams in the northeast of Brazil. In total, 108 semen samples were obtained from artificial insemination centres, and genomic DNA of T. gondii was detected in 24 of 108 (22.2%). The prevalence of antibodies anti‐Toxoplasma gondii among sheep on rural properties was 9.2% (10/109), and 100% of the semen samples of these animals were positive in the PCR for T. gondii DNA. The molecular identity was confirmed through sequencing, which indicated 99.9% similarity with the T. gondii DNA sequences stored in the GenBank. This study reports the first occurrence of T. gondii DNA in the semen of rams, which came from artificial insemination centres in Brazil, as well as the occurrence of T. gondii DNA in the fresh semen of naturally infected rams in the northeast of Brazil.     

Serological survey of exposure to Erysipelothrix rhusiopathiae in poultryin New Zealand

Abstract

AIMS: To estimate the seroprevalence of antibodies to Erysipelothrix rhusiopathiae in chickens in New Zealand, and to estimate the effect of housing type, geographical location and age on seroprevalence.

METHODS: A cross-sectional serological survey of a convenience sample of 545 broiler, breeder, and layer chickens in 55 flocks was conducted in 2010–2011. Birds were aged 5–83 weeks; housing types were free-range, shed, caged, and unknown; and flocks were located in the Auckland, Manawatu, North Canterbury, Otago, Taranaki, Waikato, and Wairarapa regions of New Zealand. An ELISA was used to measure antibodies to E. rhusiopathiae. Samples with an optical density reading ≥1.50 were considered to be positive. Logistic regression analysis was used to model the effect of housing type, geographical location and flock age on the prevalence of samples positive for antibodies to E. rhusiopathiae.

RESULTS: The overall prevalence of samples with antibodies to E. rhusiopathiae was 39.8 (95% CI=35.68–44.06)% for the 545 samples, and 46/55 (84%) farms that were tested had at least one positive sample. Mean seroprevalence for types of housing was 44.2 (95% CI=37.79–50.70)% for free-range (n=240 birds), 23.7 (95% CI=17.83–30.38)% for shed (n=190), 73 (95% CI=56–86)% for caged (n=37) and 50 (95% CI=38–62)% for unknown (n=78). The disease was present in all seven geographical locations from which samples were obtained for this study. Seroprevalence increased with increasing age of birds (p<0.001); for birds ≤12 weeks of age it was 2 (95% CI=0.3–8)% (n=91), 13–24 weeks 29.1 (95% CI=23.34–35.46)% (n=230), 25–36 weeks 47 (95% CI=32–64)% (n=40), 37–48 weeks 75 (95% CI=51–91)% (n=20), >48 weeks 63.8 (95% CI=54.78–72.12)% (n=127). Neither housing type nor geographical location had a significant effect on the likelihood of samples being positive for antibodies to E. rhusiopathiae.

CONCLUSIONS: The results of this study suggest the prevalence of erysipelas under New Zealand field conditions may be higher than expected and that the disease is significantly associated with increasing age. Housing type and geographical location appear to be unrelated to seroprevalence.

CLINICAL RELEVANCE: Further study of the epidemiology of E. rhusiopathiae in chickens in New Zealand should be considered in order to minimise the extent of birds' exposure to the organism. These findings will assist in the design of further studies.