Detection of <Emphasis Type="Italic">Toxoplasma gondii</Emphasis> oocysts in environmental soil samples using molecular methods

Infections caused by Toxoplasma gondii are prevalent in humans and animals throughout the world. So far, there is no sufficient information concerning T. gondii oocysts prevalence in the environment, especially in soil. Therefore, the aim of this study was to estimate occurrence of T. gondii oocysts in soil and determine the genotype of detected parasites. A total of 101 soil samples were taken from different sites (sand-pits, “farming ground”, areas around rubbish dumps) located in the Tri-City (Poland). Oocysts were recovered using the flotation method. Then, PCR reactions targeting the B1 gene were performed for specific T. gondii detection. The positive samples were further confirmed by PCR amplification of a repetitive element (REP) sequence [GenBank accession number AF146527]. Toxoplasma DNA was found in 18 samples. Among them, seven samples were successfully genotyped at the SAG2 locus. They were classified as SAG2 type I (5 samples) and SAG2 type II (2 samples). This is one of the first investigations describing T. gondii oocyst detection in environmental soil samples with rapid molecular detection methods and genotyping. The results of our findings showed that soil contaminated with T. gondii oocysts may play a role in the epidemiology of human toxoplasmosis in Poland.     

The first detection of Toxoplasma gondii DNA in environmental fruits and vegetables samples

Toxoplasma gondii infections are prevalent in humans and animals all over the world. The aim of the study was to estimate the occurrence of T. gondii oocysts in fruits and vegetables and determine the genotype of the parasites. A total number of 216 fruits and vegetables samples were taken from shops and home gardens located in the area of northern Poland. Oocysts were recovered with the flocculation method. Then, real-time polymerase chain reaction (PCR) targeting the B1 gene was used for specific T. gondii detection and quantification. Toxoplasma DNA was found in 21 samples. Genotyping at the SAG2 locus showed SAG2 type I and SAG2 type II. This is the first investigation describing T. gondii DNA identification in a large number of fruits and vegetables samples with rapid molecular detection methods. The results showed that fruits and vegetables contaminated with T. gondii may play a role in the prevalence of toxoplasmosis in Poland.     

Occurrence of <Emphasis Type="BoldItalic">Cryptosporidium</Emphasis> spp. in red foxes and brown bear in the Slovak Republic

Wild animals can be involved in epidemiology of many important diseases and often act as reservoirs of pathogens which cause disease in domestic animals and humans. This paper aims the role of red fox (Vulpes vulpes) and brown bear (Ursus arctos) in the circulation of coccidian parasites from the genus Cryptosporidium. Cryptosporidiosis is known as an important enteric pathogen, clinical symptoms in particular in immune-compromised individuals range from mild to severe diarrhoea and dehydration, which could be fatal. Fecal samples from 62 red foxes shot during September 2010 to February 2011 and 63 brown bears collected during June 2010 to March 2011 in central and eastern Slovakia were examined for the qualitative determination of Cryptosporidium spp. antigens in faeces by sandwich ELISA kit. Overall, 38.7% (24/62) of faecal samples of red foxes and 55.6% (35/63) of faecal samples of brown bear were positive. Our preliminary results emphasize prevalence of Cryptosporidium spp. amongst brown bears and red foxes in Slovakia and highlight the potential risk for transmission of cryptosporidiosis to humans using the countryside for professional or recreational purposes.     

Occurrence of Echinococcus multilocularis in red foxes from the Carpathian regions of Slovakia and Poland

The extensive distribution of Echinococcus multilocularis cestode from endemic alpine areas to the parts of Central Europe has been recorded in recent years. The first confirmed finding of E. multilocularis in Slovakia was recorded in 1999 in the area adjacent to the Polish border. At present, this serious zoonosis occurs almost across the whole territory of Slovakia. The occurrence of these tapeworms in red foxes (Vulpes vulpes) at the border regions of Slovakia and Poland has been monitored. In these districts, out of 152 faecal samples examined, 36.2% were positive for the coproantigen-ELISA. With the sedimentation and counting technique the prevalence of E. multilocularis in red foxes was up to 38.8%. The examination of foxes from neighbouring districts revealed worm burden ranging from 1–15,000 specimens, but the majority of animals harboured medium number of tapeworms. In the Small Carpathian and Sub-Carpathian regions of Poland, out of 65 samples examined, 13.8% were coproantigen positive. Using the small intestine scraping method only 6.1% prevalence of E. multilocularis in red foxes was determined, mostly with a high worm burdens over 1,000 specimens. The results suggest possible transborder transmission of E. multilocularis, the causative agent of serious alveolar echinococcosis.     

Parasites and vector-borne pathogens of southern plains woodrats (<Emphasis Type="Italic">Neotoma micropus</Emphasis>) from southern Texas

From 2008 to 2010, southern plains woodrats (Neotoma micropus) from southern Texas, were examined for parasites and selected pathogens. Eight helminth species were recovered from 97 woodrats including, Trichuris neotomae from 78 (prevalence = 80%), Ascarops sp. from 42 (43%), Nematodirus neotoma from 31 (32%), Raillietina sp. from nine (9%), Taenia taeniaeformis larvae from eight (8%), and an unidentified spiurid, a Scaphiostomum sp. and a Zonorchis sp. each from a single woodrat. Besnotia neotomofelis was detected in three (3%) woodrats and microfilaria were detected in seven (7%). Polymerase chain reaction (PCR) testing of blood samples from 104 woodrats detected a novel Babesia sp. in one (1%) and Hepatozoon sp. in 17 (16%) woodrats. Partial 18S rRNA gene sequence of the Babesia was 94% similar to B. conradae. Histologic examination of tissues detected intestinal coccidia in seven of 104 (7%), Sarcocystis neotomafelis in 26 (25%), Hepatozoon sp. in 21 (20%), and Dunnifilaria meningica in four (4%) woodrats. Three woodrats (5%) were seropositive for Toxoplasma gondii. Ectoparasites recovered included fleas (Orchopeas sexdentatus and O. neotomae), ticks (Ixodes woodi and Ornithodoros turicata), mites (Trombicula sp. and Ornithonyssus (Bdellonyssus) bacoti) and bot flies (Cuterebra sp.). The only difference in prevalence related to gender was for N. neotoma (males > females, p = 0.029). Prevalence of T. neotomae and all intestinal parasites combined was significantly higher in adults compared with juveniles (p = 0.0068 and p = 0.0004), respectively. Lesions or clinical signs were associated with Cuterebra and B. neotomofelis. Collectively, these data indicate that woodrats from southern Texas harbor several parasites of veterinary and/or medical importance.     

Toxoplasma gondii in Capybara (Hydrochaeris hydrochaeris) antibodies and DNA detected by IFAT and PCR

Toxoplasmosis is considered nowadays as one of the most important foodborne diseases in the world. One of the emerging risks in acquiring infection with Toxoplasma gondii is the increasing popularity of wild animals and game meat. Capybara (Hydrochaeris hydrochaeris) is the world’s largest extant rodent and is used for human consumption in many areas of South America, and in case it carries T. gondii cysts, it may act as a source of infection. In the present study, we detected infection with T. gondii in capybaras from the south of Brazil. Antibodies to T. gondii were assayed in the serum of capybaras using the indirect fluorescent antibody test (IFAT ≥ 1:16). Blood, liver, heart, lymph nodes, and spleen tissues were collected and tested by polymerase chain reaction (PCR) for B1 gene and ITS1 region. The results showed that 61.5% (16/26) capybaras were seropositive to T. gondii. Titers of specific antibodies to T. gondii ranged from 1:16 to 1:512. Among the feral rodents studied, 7.7% (2/26) were PCR positive for B1 gene assay and 11.5% (3/26) were positive for ITS1 PCR assay; for both test, the prevalence was 15.4%. Liver, heart, and blood tissues were those which tested positive for the apicomplexan. Our findings show a high percentage of infection with T. gondii in asymptomatic capybaras. Based on those data, we hypothesize that the consumption of raw or undercooked capybara meat could be a source of infection for humans.     

Dynamic development of parasitophorous vacuole of <Emphasis Type="Italic">Eimeria tenella</Emphasis> transfected with the yellow fluorescent protein gene fused to different signal sequences from apicomplexan parasites

Intracellular stages of Eimeria tenella reside within a membrane-bound parasitophorous vacuole (PV). PVs of apicomplexan parasites like E. tenella play important roles in nutrient acquisition, multiplication, and evasion of host immune responses. Different signal sequences from apicomplexan parasites were investigated in the transfected E. tenella for their functions in targeting yellow fluorescent protein (YFP) to subcompartments and the dynamic development of the PV of E. tenella was studied. Two 5′ terminal signal sequences derived from Toxoplasma gondii GRA8 protein and Plasmodium falciparum repetitive interspersed family protein, respectively, were confirmed to target YFP to the PVs of the transfected E. tenella, suggesting that signal sequences are functionally conserved among Apicomplexa. Three structurally different types of PVs were observed during the endogenous development of the transfected E. tenella in vitro. In addition, three subcompartments in the PV, namely, membranous extensions into the host cell cytosol, membranous extensions into the vacuolar lumen, and particle-like bodies, were detected during schizogony of the parasite.     

Specific detection of Echinococcus spp. from the Tibetan fox (Vulpes ferrilata) and the red fox (V. vulpes) using copro-DNA PCR analysis

There are three Echinococcus species, Echinococcus granulosus, E. multilocularis, and E. shiquicus, which are distributed on the vast area of pastureland on the eastern Tibetan plateau in China. Tibetan foxes (Vulpes ferrilata) have been determined to be the main wild definitive host of E. multilocularis and E. shiquicus, but little information is available on the prevalence of these two parasites in Tibetan foxes. Consequently, the copro-prevalence of these parasites in foxes from the eastern Tibetan plateau was evaluated in this study. For each copro-DNA sample extracted from fox feces, a 133-bp segment of EgG1 Hae III was used to screen for infection with E. granulosus. Multiplex nested polymerase chain reaction (PCR) analysis was used to target an 874-bp segment of the mitochondrial COI gene to distinguish E. multilocularis and E. shiquicus. Among 184 fecal samples, 120 were from Tibetan foxes and six from red foxes (Vulpes vulpes). Of the fecal samples from Tibetan foxes, 74 (giving a copro-prevalence of 62?%) showed the presence of Echinococcus spp.: 23 (19?%) were found to contain E. multilocularis, 32 (27?%) E. shiquicus, and 19 (16?%) showed mixed infection with both E. multilocularis and E. shiquicus. Two fecal samples from red foxes were found to be infected with E. multilocularis. No fox feces were found to be infected with E. granulosus. Tests on zinc finger protein genes and a 105-bp fragment of the Sry gene found no significant difference in the prevalence of the two parasites between sexes. The efficiency of our multiplex nested PCR methods were compared with previous polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP) methods and some problems associated with the copro-PCR were discussed.     

Investigation of Neospora caninum, Hammondia sp., and Toxoplasma gondii in tissues from slaughtered beef cattle in Bahia, Brazil

Neospora caninum, Hammondia sp., and Toxoplasma gondii are parasites with morphological and genetic similarities. N. caninum and T. gondii are important abortive agents of cattle and sheep, respectively, and may infect numerous animal species. Hammondia sp. is not known to induce disease in animals, but may cause confusion in the identification of closely related coccidia. The aim of this study was to investigate infection rates caused by N. caninum, Hammondia sp., and T. gondii in beef cattle using a nested PCR for Toxoplasmatinae rDNA, followed by sequencing of the PCR products. Antibodies to N. caninum and T. gondii were also investigated in the tested animals. Brains and hearts were obtained from 100 beef cattle in a slaughterhouse in Bahia. Seven samples from brain tested positive for Toxoplasmatinae DNA. No positive reactions were found in heart tissues. After sequencing of the PCR products from all positive tissues, five sequences matched with N. caninum and two matched with T. gondii. Antibodies to N. caninum and T. gondii were found in 20% and 26% of the animals, respectively. The confirmation of N. caninum and the absence of Hammondia heydorni in the tested animals is suggestive that cattle are not efficient intermediate hosts of H. heydorni; however further studies need to be performed using a greater variety of tissues and a higher sample size. The detection of T. gondii DNA in bovine tissues reinforces the potential risk of transmission of this parasite to humans and other animals through the consumption of bovine meat.     

Molecular identification of Trichinella britovi in martens (Martes martes) and badgers (Meles meles); new host records in Poland

Trichinella larvae were detected in a marten (Martes martes) and a badger (Meles meles) in Poland. The animals were found dead following car accidents. All examined animals derived from the Mazurian Lake district, north-east Poland, near the village Kosewo Górne where Trichinella infection were earlier confirmed in wildlife; red foxes and wild boars. The muscle samples were examined by artificial pepsin-HCl digestion method. The parasites were identified as Trichinella britovi by multiplex polymerase chain reaction method. Larvae were found in two out of three martens and one out of seven examined badgers. This is the first report of the identification of Trichinella britovi larvae from martens and badgers in Poland.     

Trichinella sp. in red foxes (Vulpes vulpes) from Catalonia, NE Spain

European legislation allows the official recognition of Trichinella-free pig holdings, provided Trichinella sp. infection is absent from humans and prevalence of Trichinella sp. infection in red foxes (Vulpes vulpes) is below 0.1% in the area, region or country. Tibialis anterior muscle samples from 1,319 red foxes captured in Catalonia (NE Spain) between 1998 and 2007 were analyzed for Trichinella sp. using the digestion method. Four foxes resulted positive (one in 1999, one in 2002 and two in 2006), accounting for a low prevalence (0.3%). However, this prevalence was concentrated in mountain or rural areas with a low sample size, reaching high local prevalences. The two positive samples in 2006 were characterized as Trichinella britovi, and a sylvatic cycle of trichinellosis seems to occur, at least in the rural insufficiently sampled regions of Catalonia. Overall, the results obtained do not currently allow the establishment of Trichinella-free pig holdings in the study area, but further research is needed to better know the prevalence and cycle of Trichinella sp. in Catalonia.     

Detection of<Emphasis Type="Italic"> Echinococcus multilocularis</Emphasis> antigens in faeces by ELISA

Faecal samples deriving from 391 animals belonging to nine species (polecats, badgers, martens, weasels, rats, dogs, cats, red foxes, raccoon-dogs) were examined by capture ELISA for the presence of the Echinococcus multilocularis coproantigen. The main claim of our studies is the reliable detection of E. multilocularis coproantigens, mainly in the faeces of foxes, dogs and cats. For the first time in coproantigen detection we used a double-sandwich ELISA. The main advantage of this method is the higher specificity and better differentiation of positive and negative faecal samples, in comparison with sandwich ELISA. The overall specificity of double-sandwich ELISA was 95.1% with only 16 of 327 E. multilocularis-free animals giving false-positive results. The E. multilocularis coproantigen was detected by double-sandwich ELISA in 37.5% of examined red foxes and in 8.0% of examined raccoon-dogs, compared with a prevalence of just 29.8% in red foxes and 8.0% in raccoon-dogs, as determined by parasitological techniques.     

Liver stage antigen 3 isolated from a cDNA library of <Emphasis Type="Italic">Plasmodium falciparum</Emphasis> erythrocytic stages

Toxoplasma gondii is one of the most prevalent protozoan parasites in Iran. This study was aimed to isolate T. gondii from a variety of hosts and to genetically analyze the parasite isolates. The prevalence of T. gondii in different animal hosts was assessed in two provinces of Iran, Tehran and Mazandaran in the central and northern parts, respectively. The latex agglutination (LA) test was carried out, and antibodies were found in 24 out of 105 sheep, 5 out of 35 goats, 23 out of 45 free-ranging chickens (Gallus domesticus), 2 out of 13 ducks (Anas spp.), and two of four stray cats (Felis domesticus). T. gondii was isolated by bioassay in mice from four sheep, six chickens, one duck, two cats, and three human samples. Genotyping of these 16 isolates was performed using Multiplex PCR for five microsatellite markers and GRA6 gene sequence analysis. The results indicated that the studied isolates consisted of only two genotypes, II and III, with no evidence of type 1 or mixed genotypes.     

Infections with cardiopulmonary and intestinal helminths and sarcoptic mange in red foxes from two different localities in Denmark

Monitoring parasitic infections in the red fox is essential for obtaining baseline knowledge on the spread of diseases of veterinary and medical importance. In this study, screening for cardiopulmonary and intestinal helminths and sarcoptic mange (Sarcoptes scabiei) was done on 118 foxes originating from two distinct localities in Denmark, (Copenhagen) greater area and southern Jutland. Fifteen parasite species were recorded in 116 foxes (98.3%), nine parasitic species are of zoonotic potential. Parasite diversity was greater in foxes of Copenhagen in terms of overall parasite species richness and species richness of all helminth groups individually: trematodes; cestodes; and nematodes. Six parasite species were recovered from foxes of Copenhagen, but not from foxes of Southern Jutland: Echinochasmus perfoliatus; Echinostoma sp.; Pseudamphistomum truncatum; Dipylidium caninum; Angiostrongylus vasorum; and Sarcoptes scabiei, but Toxascaris leonina was only recorded in foxes of southern Jutland. A high prevalence and abundance of A. vasorum in foxes of Copenhagen was observed. The prevalence of four nematode species; Eucoleus (Capillaria) aerophilus, Uncinaria stenocephala, Toxocara canis, and Crenosoma vulpis, in foxes of both localities were comparable and ranging from 22.9% to 89%. The prevalence of Mesocestoides sp. was significantly higher in foxes of Copenhagen. Taenia spp. were detected using morphological and molecular analysis, which revealed the dominance of T. polyacantha in foxes of both localities. Infections with sarcoptic mange were evident only among foxes of Copenhagen (44.9%), which significantly affected the average weight of the infected animals. Further remarks on the zoonotic and veterinary implications of the parasites recovered are given.     

The prevalence of Echinococcus multilocularis in red foxes in Poland—current results (2009–2013)

The aim of the study was to determine the prevalence of Echinococcus multilocularis in red foxes (Vulpes vulpes) in Poland. Overall, 1,546 intestinal samples from 15 of the 16 provinces in Poland were examined by the sedimentation and counting technique (SCT). The mean prevalence of E. multilocularis in Poland was 16.5 % and was found in 14 of the 15 examined provinces. The mean intensity of infection was 2,807 tapeworms per intestine. Distinct differences in prevalence were observed between regions. In some provinces of eastern and southern Poland, the level of prevalence was 50.0 % (Warmińsko-Mazurskie), 47.2 % (Podkarpackie), 30.4 % (Podlaskie) and 28.6 % (Ma?opolskie), while in other provinces (west and south-west), only a few percent was found: 2.0 % (Dolno?l?skie), 2.5 % (Wielkopolskie) and 0.0 % (in Opolskie). The border between areas with higher and lower prevalence seems to coincide with a north–south line running through the middle of Poland, with prevalence from 17.5 to 50.0 % in the eastern half and from 0.0 to 11.8 % in the western half. The dynamic situation observed in the prevalence of this tapeworm indicated the necessity of continuing to monitor the situation concerning E. multilocularis in red foxes in Poland.     

Divergence within the marker region of the <Emphasis Type="Italic">groESL</Emphasis> operon in <Emphasis Type="Italic">Anaplasma phagocytophilum</Emphasis>

Anaplasma phagocytophilum is an obligate intracellular bacterial parasite in human and animal granulocytes. In Europe, A. phagocytophilum is transmitted by Ixodes ticks; Ixodes ricinus is the vector of the parasite in Poland. In terms of epidemiology, the identification of pathogens in ticks increasingly relies on molecular techniques. Polymerase chain reaction (PCR) with species-specific primers is a tool that allows the quick and accurate detection of pathogens in ticks, humans, or animals. DNA was extracted from the blood of Capreolus capreolus and Cervus elaphus, and amplified using the primers HS1/HS6 (external) and HS43/HSVR (internal). For sequencing, six samples from roe deer and two samples from red deer were selected, and the resulting sequences were submitted to GenBank (accession numbers DQ779568, DQ779567, EU157919, EU157920, EU157921, EU157922). These nucleotide sequences were compared with each other and five variants were distinguished in roe deer and one in red deer. A comparison of the sequences of the author’s database revealed 45 polymorphic sites of substitution character (76% transitions and 24% transversions). The homology tree revealed two groups, one with sequences only from roe deer, while the second with sequences isolated mainly from red deer, livestock animals, and humans. These strains of A. phagocytophilum are also present in Poland.     

Diagnosis of pulmonary infection with Toxoplasma gondii in immunocompromised HIV-positive patients by real-time PCR

The aim of the study presented here was to evaluate the use of PCR for improving the diagnosis of Toxoplasma gondii infection in immunocompromised hosts. Three hundred thirty-two bronchoalveolar lavage (BAL) fluid samples were analyzed by real-time PCR targeting a 529 bp element of T. gondii. In positive samples, the genotype of the parasite was determined by sequence analysis of the GRA6 gene. Positive results were achieved for 2% (7/332) of the samples tested. Genotyping was possible in two samples and revealed GRA6 type II T. gondii. PCR for detecting T. gondii in BAL samples should be performed in all immunosuppressed HIV-positive patients with symptoms of a systemic infection of unknown etiology. Trimethoprim-sulfamethoxazole prophylaxis does not exclude concomitant infection with T. gondii.     

Prevalence of Toxoplasma gondii infection in HIV-infected patients and food animals and direct genotyping of T. gondii isolates,Southern Ghana

Toxoplasma gondii is of public health and veterinary importance causing severe diseases in immunocompromised individuals including HIV/AIDS patients and in congenital cases and animals. There is limited information on the epidemiology of T. gondii infection in humans, particularly HIV patients and food animals and the parasite genotypes in Ghana. A total of 394 HIV-infected patients from three hospitals were screened for T. gondii anti-IgG and IgM using ELISA. DNAs from blood samples of seropositve participants and 95 brain tissues of food animals were PCR assayed to detect Toxoplasma gra6. DNA positive samples were genotyped using multilocus nested polymerase chain reaction restriction fragment length polymorphism at 10 loci: sag1, alt.sag2, sag3, btub, gra6, l358, c22-8, c29-2, pk1, and apico. The overall seroprevalence was 74.37% (293/394). Toxoplasma DNAs were detected in 3.07% of the seropositive participants and 9.47% of the animals. Six of the human DNA positive samples were partly typed at sag3: 33.33, 50, and 16.67% isolates had type I, II, and III alleles, respectively. All nine isolates from food animals typed at nine loci except apico were atypical: six isolates were identical to ToxoDB #41 and #145, and one was identical to TgCkBrRj2 all identified in Brazil. The genotype of two isolates has not been reported previously and was named as TgCtGh1. T. gondii seroprevalence is high among the HIV-infected individuals with T. gondii circulating in Ghana being genetically diverse.

     

Detection of toxoplasmosis in patients with end-stage renal disease by enzyme-linked immunosorbent assay and polymerase chain reaction methods

Toxoplasmosis caused by Toxoplasma gondii is an opportunistic infection. In healthy individuals, the infection is largely asymptomatic, but in immunocompromised people the parasite can become widely disseminated, causing severe toxoplasmosis. In patients undergoing haemodialysis, the phagocytic process shows a highly significant impairment. Therefore, this study aimed to investigate toxoplasmosis in patients with end-stage renal disease (ESRD) undergoing haemodialysis in Ahvaz hospitals, southwest of Iran. A total of 280 patients and 100 healthy subjects participated in this study. The presence of serum IgM and IgG antibodies against T. gondii was detected by ELISA and the presence of Toxoplasma parasites in whole blood was evaluated by GRA6 PCR. Anti-T. gondii IgG antibodies were detected in 82 (29.3 %) haemodialysis patients and 26 (26 %) controls. In addition, anti-T. gondii IgM antibodies were detected in 7.9 % of patients and in 4 % of controls. For both the antibodies, the differences were statistically significant (P?<?0.05). PCR was performed with DNA extracted from blood samples of all patients and controls. PCR gave positive results with four of the 280 blood samples from patients but none for the control blood samples. The results revealed a high percentage of positivity for Toxoplasma antibodies in patients with ESRD undergoing haemodialysis and also confirmed the parasite in whole blood, indicating disseminated infection in these patients. Patients undergoing dialysis have a higher rate of active infection with Toxoplasma likely due to reactivation of a chronic infection. Thus, parasitological examinations of ESRD patients should be periodically carried out for monitoring and evaluating the possible dissemination of toxoplasmosis during haemodialysis.     

Prevalence of <Emphasis Type="Italic">Toxoplasma gondii</Emphasis> indirect fluorescent antibodies in naturally- and experimentally-infected chickens (<Emphasis Type="Italic">Gallus domesticus</Emphasis>) in Thailand

Toxoplasma gondii infections in free-range (FR) chickens (Gallus domesticus) are potential public health risks. Antibodies for T. gondii were found in 194 out of 303 serum samples (64.03%) from FR chickens in Thailand tested by the indirect fluorescent antibody test (IFAT, 1:16). To verify the validity of serologic data in this survey, sera from chickens experimentally infected with the RH strain of T. gondii were tested by the IFAT. Antibodies against T. gondii were detected as early as 7 days p.i., peaked at 2 weeks, and then declined by 10 weeks p.i.