Epidemiological Aspects of Visceral Leishmaniasis in Baft District,Kerman Province,Southeast of Iran

Background

Visceral leishmaniasis (kala-azar) is an endemic disease in some areas of Iran. A cross- sectional study was conducted for sero-epidemiological survey of visceral leishmaniasis (VL) in Baft district from Kerman Province, southeast of Iran.

Methods

Blood samples were collected from children up to 12 years old and 10% of adult population from Baft villages with a multi-stage randomized cluster sampling. In addition, blood samples were collected from 30 domestic dogs from the same areas. All the collected blood samples were tested by direct agglutination test (DAT) for the detection of anti-Leishmania antibodies in both human and dog using the cut-off value of ≥1:3200 and ≥1:320, respectively. Parasitological, molecular, and pathological were performed on infected dogs. Chi-square and Fisher exact tests were used to compare sero-prevalence values.

Results

From 1476 collected human serum samples, 23 (1.55%) showed anti-Leishmania antibodies at titers of 1:800 and 1:1600 whereas 14 (0.95%) showed anti-Leishmania infantum antibodies at titers of ≥1:3200. No statistically significant difference was found between male (1.18%) and female (0.69%) sero-prevalence (P=0.330). Children of 5-8 years showed the highest sero-prevalence rate (3.22%). Seven out of 30 domestic dogs (23%) showed anti-Leishmania antibodies at titers ≥1:320. Leishmania infantum was identified in five infected dogs by nested – PCR assay.

Conclusion

It seems that visceral leishmaniasis is being endemic in southern villages of Baft district, southeast of Iran.     

Canine Visceral Leishmaniasis in Boyer Ahmad District,Kohgiluyeh & Boyer Ahmad Province,Southwest of Iran

Background

Mediterranean type of visceral leishmaniasis (VL) is present in different parts of Iran. Several studies have identified dogs as the main reservoirs of the VL caused by Leishmania infantum in Iran and other Mediterranean regions. This study aimed to determine the seroprevalence of canine visceral leishmaniasis as animal reservoir host for human visceral leishmaniasis in Boyer Ahmad district in southwest of Iran.

Methods

A seroepidemiological study was carried out to determine the seroprevalence of canine visceral leishmaniasis (CVL) among ownership dogs by using direct agglutination test (DAT) in 23 of 182 villages of Boyer Ahmad district, during August 2009 to August 2010. One hundred and seventy serum samples from ownership dogs were selected by multi-stage cluster sampling in villages of Boyer Ahmad district. All samples were tested by DAT and anti-Leishmania antibodies titers at ≥ 1:320 was considered as positive.

Results

Of the 170 serum samples, 10% were positive by DAT at titers of 1:320 and higher. No statistical significant difference was found between male (10.7%) and female (8.3%) seroprevalence. The highest seroprevalence rate (15.1%) was observed among the ownership dogs of four to seven years age. Altogether, seventeen (25.4%) of the seropositive dogs had clinical signs and symptoms.

Conclusion

It seems that Boyer Ahmad district is an endemic area for canine visceral leishmaniasis in Iran.     

Molecular and Seroepidemiological Survey of Visceral Leishmaniasis among Humans and Domestic Dogs in Mazandaran Province,North of Iran

Background

New cases of visceral leishmaniasis (VL) have been reported recently in some parts of Mazandaran Province, north of Iran where the first human case of VL was reported in 1949. This study aimed to determine the present status of Leishmania infantum infection among humans and domestic dogs using serological and molecular methods in central parts of Mazandaran Province.

Methods

In this cross-sectional study, blood samples were randomly collected from 402 humans and forty-nine domestic dogs throughout 2009 and 2010 in the central part of Mazandaran Province including Semeskadeh and Kiakola districts where recent cases of human visceral leishmaniasis had been reported there. All the collected samples were tested by direct agglutination test (DAT) for the detection of anti-Leishmania infantum antibodies as well as convenience PCR assay on whole blood samples for detection of leishmanial infection and identification of Leishmania species.

Results

None of 402 collected human (402) and dog (49) blood samples showed anti Leishmania infantum antibodies at titers 1:3200 and 1:320 as cut-off values of DAT, respectively but only 2 of domestic dogs (4.1%) were found PCR-positive corresponding to L.infantum.

Conclusion

This study confirms the circulation of L. infantum at least among domestic dogs and highlights the sporadic pattern of VL in the studied areas. Further investigations regarding to sand flies fauna and wild canines as reservoir hosts of the disease, are recommended.     

Endoparasites of Stray Dogs in Mashhad,Khorasan Razavi Province,Northeast Iran with Special Reference to Zoonotic Parasites

Background

To find out different species of helminthes and blood/tissue protozoan parasites of stray dogs and their potential role for transmission of zoonotic species to human in Mashhad, Khorasan Razavi Province, northeast Iran, during 2008-2009.

Methods

Totally, 100 stray dogs were selected among Mashhad municipal collection from different sites of the city. Internal organs were examined for any parasites. Helminthes were identified based on morphological characteristics. Smears prepared from peripheral blood as well as liver, spleen and any skin lesion were stained by Giemsa and examined microscopically. Samples obtained from spleen were aseptically cultured in three culture media including NNN, Schneider''s Drosophila (HIMEDIA) and RPMI1640 (GIBCO) for isolation of Leishmania spp. The titer of anti-Leishmania and anti-Toxoplasma antibodies were measured by direct agglutination test (DAT) and indirect fluorescent antibody test (IFAT), respectively.

Results

84% of dogs were infected at least with one species of intestinal helminthes. The species of parasites and rate of infection were as follows: Taenia hydatigena (61%), Dipylidium caninum (46%), Mesocestoides lineatus (19%), Echinococcus granulosus (10%), Toxascaris leonina (53%) and Toxocara canis (7%). Anti-Leishmania antibodies were detected by DAT in 8 dogs (8%) at 1:320 titers and higher. Forty seven dogs (47%) showed anti-Toxoplasma titer at 1:10 and 17 (17%) showed titer of ≥1:100. No blood parasites were found in prepared blood smears.

Conclusion

The high rate of parasitic infection and presence of zoonotic species especially E. granulosus and T. canis emphasizes the risk of diseases spread in urban areas by stray dogs     

Human Visceral Leishmaniasis in Kermanshah Province,Western Iran,During 2011-2012

Background

Visceral leishmaniasis (VL) or kala-azar is a parasitic disease caused by the species of Leishmania donovani complex. It is endemic in some parts of provinces of Iran. According to the reported cases of VL in Kermanshah Province in recent years, this study was conducted to determine the seroprevalence of VL in high risk villages of the province.

Methods

Totally, 1622 serum samples obtained from children under 15 years old and 178 from adults in 22 villages of studied areas. Serum samples were examined by direct agglutination test (DAT) for the detection of anti-Leishmania antibodies. Data were analyzed using SPSS software ver.11.5.

Results

Only 6 serum samples (0.33%) showed anti-Leishmania antibodies against L.infantum at titers ≥ 1/3200. Four of the seropositive cases had a history of kala-azar and Leishman bodies were seen in their bone marrows. The highest (0.5%) and lowest (0.29%) seroprevalence was seen in the age groups of 5-9 and 10-14 years old, respectively. None of the adults were seropositive. There were not any significant differences between the rate of seropositivity in males (0.36%) and females (0.31%). 66.7% of seropositive individuals showed clinical manifestations. The most important symptoms in Kala-azar patients were fever, hepato-spleenomegally and anemia.

Conclusion

Kala-azar is occurred sporadically in Kermanshah Province. But presence of significant number of positive sera confirms the necessity for attention of people and clinicians to kala-azar.     

Canine Heartworm in Southeastern of Iran with Review of disease distribution

Background

Heartworm (Dirofilaria immitis) is mosquito-borne filarial nematode capable of causing serious cardiopulmonary disease in canines and felines, and pulmonary dirofilariasis in man. This research was conducted with the objectives of determining the incidence and assessing possible risk factors of canine heartworm in the southeast of Iran.

Methods

From October 2012 to September 2013, blood samples from 87 dogs from Zabol area in Sistan and Baluchestan and 33 dogs from Bam area in Kerman Province were examined for detection of Dirofilaria immitis using modified knott test and serology.

Results

Out of 120 dogs, 29 (24.2%; 95%CI: 16.6-31.8%) were positive, serologically. The overall seroprevalence of D. immitis in dog in Zabol and Bam was 27.5% (95% CI: 24.7-32.5%) and 15.15% (95% CI: 12.3-20.7%), respectively. 28.8% of stray dogs and 20.6% of housed dogs in the study areas were seropositive. Seroprevalence of D. immitis was not significantly different between stray and housed dogs (P = 0.295). Investigation of seasonal dynamic of infection with D. immitis in stray and housed dog showed that the proportion of infected dog in spring and summer was greater than colder season (autumn and winter) which was not significant. The prevalence of infection with D. immitis in >5 years old stray dogs (53.8%) was greater than other age categories while in housed dogs infection rate was greater in 3-5 years old (27.3%).

Conclusion

It is important to point out the increased incidence of canine heatrworm in Iran. In order to stop the spread of canine heartworm, preventive measures must be taken now.     

Leishmaniasis in Turkey: Determination of Leishmania Species by Matrix-Assisted Laser Desorption Ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF MS)

Background

Cutaneous leishmaniasis (CL) is endemic in Southeastern Anatolia, mainly in Sanliurfa and Hatay provinces, and the causative agents are mostly Leishmania tropica and less frequently L. infantum. Here, we report the first MALDI-TOF analyses of Leishmania promastigotes obtained from the cultures of two CL cases from Osmaniye and Hatay provinces who were initially diagnosed by microscopy, culture and identified as L. infantum with Real-Time PCR (RT-PCR).

Methods

Samples obtained from the skin lesions of patients were initially stained with Giemsa and cultivated in NNN medium. Examination of the smears and cultures revealed Leishmania amastigotes and promastigotes, respectively. The promastigotes (MHOM/TR/2012/CBU15 and MHOM/TR/2012/MK05) obtained from the cultures of both patients were used for RT-PCR targeting the ITS-1 region in the SSU of rRNA. The reference strains of four Leishmania species (L. infantum, L. donovani, L. tropica and L. major) were initially assessed with MALDI-TOF and their data were added to MALDI-TOF Biotyper Library.

Results

Both RT-PCR and MALDI-TOF analyses indicated that the causative agent in both patient samples was L. infantum.

Conclusion

Despite disadvantages such as requirement of culture fluid with nothing but promastigotes and high cost, MALDI-TOF analysis may be a fast, sensitive and specific diagnostic tool in especially large-scale research studies, where the cost declines, relatively.     

Clinical Features and Laboratory Findings of Visceral Leishmaniasis in Children Referred To Children Medical Center Hospital,Tehran, Iran during 2004-2011

Background

Visceral leishmaniasis (VL) is one of the most important parasitic diseases endemic in northwestern and southern areas of Iran. The aim of the present study was to review the records of children hospitalized with VL in order to characterize the clinical features of children as well as laboratory finding in Children Medical Center Hospital, Tehran, Iran.

Methods

The medical records of all children with a final diagnosis of VL were reviewed from 2004 to 2011. Demographic, clinical information, laboratory finding and treatment were considered.

Results

A total number of 34 children with confirmed VL through 2004-2011 were included in the study. The most prevalent sign and symptoms were fever (97.1%), pallor and weakness (97.1%), appetite loss (61.8%), splenomegaly (97.1%) and hepatomegaly (88.2%). The most frequent laboratory abnormalities were hematological including anemia (97.1%), thrombocytopenia (91.2%) and leukopenia (67.6%). Direct agglutination test (DAT) was performed in 23 cases and all of them showed anti-Leishmania antibodies with titers of ≥ 1: 3200. In addition, 90% of patients had positive rK39 results. Identification of Leishmania in the aspirates of the bone marrow was found in 83.3% of patients.

Conclusion

Regional surveillance system in order to monitoring of leishmaniasis trends as well as detection of new emerging foci is recommended.     

Assessment of the Effects of a Novel Herbal Immunomodulator Drug (IMOD) on Cytokine Profiles in Experimental Canine Visceral Leishmaniasis: a Preliminary Survey

Background

Cytokines play a fundamental role in the regulation of immune responses in remission and/or relapsing of leishmaniasis. Therefore, immunotherapy for the treatment of canine visceral leishmaniasis (CVL) has represented a principle approach in control of the infection. The present research aimed to evaluating the immunotherapeutic potential of a novel herbal immunomodulator drug (IMOD) on CVL.

Methods

Twelve mongrel dogs were intravenously infected with Iranian strain of L. infantum and randomly divided into three groups; 1: negative control (non-infected), 2: immunotherapy with IMOD and 3: positive control (non-treated). Cell proliferation and Th1-/Th2-type cytokines were measured in peripheral blood mononuclear cell (PBMC) by cell proliferation kit I (MTT) and enzyme-linked immunospot (ELISpot) assays, respectively.

Results

At the 60 days follow-up assessment, no adverse effects were observed in treated interventional group. Cellular proliferation assay indicated that PBMCs of IMOD group had higher stimulation index (SI) than positive control group (p < 0.05). Enhancement of CD4+T cells such as IL-2, IL-4 & IL-10 were detected in negative control group due to in vitro IMOD stimulation 30 days post-treatment. In accordance to decreasing trends of Th1 & Th2 cytokines in positive control group, the mean number of IFN-γ IL-2, IL-4 and IL-10 spot forming cells (SFCs) down regulated for IMOD group during the study.

Conclusion

These data indicate that IMOD had immunomodulatory potential but is not sufficient for total parasitic cure due to balance of Th1/Th2 cytokines. This is a preliminary study and we propose to undertake a series of experiments to evaluate the CVL due to in vitro modulatory effects of IMOD.     

Seroepidemiological Survey of Human Visceral Leishmaniasis in Ilam Province,West of Iran In 2013

Background:

Visceral leishmaniasis (VL) as one of the most important human parasitic disease is endemic in some parts of Iran. Several cases of VL have been reported recently in the Ilam Province. The current study aimed to assess the present status of human VL in the region.

Methods:

A random cluster sampling method was used to collect 456 serums samples from the children up to 12 years of age and 10% of adults living in urban and rural areas of the province. All the collected serum samples were tested by direct agglutination test (DAT) to detect anti- Leishmania infantum antibodies.

Results:

Of the examined 456 serum samples with direct agglutination test (DAT), only 21 (0.43%) sera showed anti- Leishmania antibodies at titers 1:400 and higher. Distribution of anti- Leishmania antibodies titers were: 1:400(n=4), 1:800(n=11), 1:1600(n=3), 1:3200(n=1), and 1:6400(n=1). Individuals with titers ≥1:3200 showed clinical signs and symptoms such as fever and splenomegaly. The highest and lowest seropositivity were observed in the age groups of 5–9 and >15 years old, respectively. There were no significant difference between the rate of seropositivity in males and females.

Conclusion:

VL with a low prevalence circulates in some parts of Ilam province, particularly in the southern parts. Complementary studies should be needed to find animal reservoir hosts and vectors. Furthermore, health systems and physicians should pay particular attention to the disease.     

A Preliminary Parasitological Survey of Hepatozoon Spp. Infection in Dogs in Mashhad,Iran

Background

We attempted to determine the prevalence of Hepatozoon spp. infection in Mashhad, northeast of Iran, via blood smear parasitology.

Methods

The prevalence was investigated by examination of blood smear parasitology, using blood samples collected from 254 dogs (51 strays and 203 privately owned-dogs).

Results

Two stray dogs (2/51; 3.92%) and two privately-owned dogs (2/203; 0.98%) were infected with Hepatozoon spp. Therefore, as per blood smear parasitology, the prevalence of Hepatozoon spp. infection was 1.57% (4/254). Sixteen out of 254 dogs (6.29%) were infested with ticks; all of which were Rhipicephalus sanguineus. One of the dogs infected with Hepatozoon spp. exhibited ticks at the time of examination. Concurrent infection with Ehrlichia canis and Leishmania infantum was not detected in the four Hepatozoon spp. infected dogs.

Conclusion

This is the first epidemiological study on the prevalence of Hepatozoon spp. infection in dogs in Iran.     

Development and Assessment of Loop-Mediated Isothermal Amplification (LAMP) Assay for the Diagnosis of Human Visceral Leishmaniasis in Iran

Background

Parasitological methods for the diagnosis of Visceral leishmaniasis (VL) require invasive procedures, so serological and molecular approaches have been developed but are not generally applicable in the field. We evaluated a loop mediated isothermal amplification (LAMP) assay using blood from VL patients and compared it to nested PCR.

Methods

Forty-seven subjects with clinical features (fever, hepatosplenomegaly and anemia) were confirmed positive for VL by the direct agglutination test (DAT) at titers >3200. Forty DAT negative individuals from non-endemic areas with no clinical signs or symptoms of VL served as controls. A LAMP assay was performed using a set of six primers targeting Leishmania infantum kinetoplast DNA (kDNA) minicircle gene under isothermal (64 °C) conditions. For nested PCR we used primers targeting the kDNA minicircle gene.

Results

The LAMP assay provided a detection limit of 1 parasite in 1 ml of peripheral blood and detected L. infantum DNA in 44 of 47 DAT-confirmed VL cases, with diagnostic sensitivity of 93.6% (95% CI). No L. infantum DNA was amplified in controls, indicating a specificity of 100%. The nested PCR yielded sensitivity of 96% (95% CI) and a specificity of 100% (95% CI).

Conclusion

The LAMP assay gave results similar to those of nested PCR but in a shorter time. The LAMP method is simple; requires no sophisticated equipment; has a short reaction time; and results, indicated by turbidity of the reaction mixture, are observable with the naked eye.     

In Vitro Inhibitory Effect of Berberis vulgaris (Berberidaceae) and Its Main Component,Berberine against Different Leishmania Species

Background

Leishmaniasis has been identified as a major public health problem in tropical and sub-tropical countries. The present study was aimed to investigate antileishmanial effects of various extracts of Berberis vulgaris also its active compoenent, berberine against Leishmania tropica and L. infantum species on in vitro experiments.

Methods

In this study in vitro antileishmanial activity of various extracts of B. vulgaris also its active compoenent, berberine against promastigote and amastigote stages of L. tropica and L. infantum was evaluated, using MTT assay and in a macrophage model, respectively. Furthermore, infectivity rate and cytotoxicity effects of B. vulgaris and berberine in murine macrophage cells were investigated.

Results

The findings of optical density (OD) and IC₅₀ indicated that B. vulgaris particulary berberine significantly (P<0.05) inhibited the growth rate of promastigote stage of L.tropica and L.infantum in comparison to meglumine antimoniate (MA). In addition, B. vulgaris and berberine significantly (P<0.05) decreased the mean number of amastigotes in each macrophage as compared with positive control. In the evaluation of cytotoxicity effects, it could be observed that berberine as compared with B. vulgaris exhibited more cytotoxicity against murine macrophages. Results also showed that when parasites were pre-incubated with B. vulgaris their ability to infect murine macrophages was significantly decreased.

Conclusion

B.vulgaris particularly berberine exhibited potent in vitro leishmanicidal effects against L. tropica and L.infantum. Further works are required to evaluate the antileishmanial effects of B.vulgaris on Leishmania species using clinical settings.     

Molecular and Serological Detection of Acute and Latent Toxoplasmosis Using Real-Time PCR and ELISA Techniques in Blood Donors of Rafsanjan City,Iran, 2013

Background

The differentiation between acute and latent forms of the Toxoplasma gondii (T. gondii) infection is still considered as a complicated issue. This study was aimed to elucidate the status of infection in the blood donors and the probable importance of blood transfusion in the transmission of the infection through detecting both immunological and genetic markers of acute and latent infection.

Methods

Totally 235 blood samples from blood donors were collected. The levels of anti-T. gondii IgG and IgM antibodies were examined by specific ELISA kits. cDNA were synthesized from total extracted mRNA molecules from the serum samples and SAG1 gene, specific for tachyzoite form, were amplified using Real-Time PCR technique. Demographic information of study subjects including their gender, age, job, and habitat were recorded.

Results

Out of 235 serum samples, 80 (34.04%) and 4 (1.71%) were positive regarding anti-T. gondii IgG and IgM antibodies, respectively. Real-Time PCR results showed that 14 out of 200 (6.97%) of blood donor had mRNA molecules of SAG1 gene. The positive results of Real-Time PCR of SAG1 in female gender and housekeepers were significantly higher than those of male gender and other job categories.

Conclusion

The prevalence of chronic and acute infection is high in Iranian blood donors. Additionally, evaluation of antibodies could not be reliable, because several donors negative for anti-T. gondii IgM antibodies had detectable SAG1 mRNA molecules. Hence, it seems that molecular diagnostic tests are essential to detect acute infections.     

Anti-Toxoplasma gondii Antibody Levels in Blood Supply of Shiraz Blood Transfusion Institute,Iran

Background

The prevalence of Toxoplasma gondii infection in the blood donors has been poorly studied. The aim of this study was to assess the prevalence of acute and chronic toxoplasmosis in blood products.

Methods

A total of 250 blood products (112 fresh frozen plasma and 138 packed cells) in the Blood Transfusion Institute, Shiraz, Iran were tested for specific T. gondii antibodies (IgG and IgM) by ELISA method in 2013. Positive IgG anti-T. gondii samples were further tested for IgM anti-T. gondii antibody. A positive IgG test with the negative and positive IgM test was interpreted as a chronic and acute toxoplasmosis, respectively. The relationship of jobs, blood types, sex, marital status and residency of participants with chronic toxoplasmosis prevalence were statistically analyzed by χ².

Results

Of 250 samples, 58 (23.2%) and one were positive for IgG anti-T. T. gondii (chronic) and IgM anti-T. T. gondii (acute) antibodies levels, respectively. Twenty nine (25.9%) of fresh frozen plasma (FFP) samples were positive for IgG anti-T. gondiiiand 1(0.89%) of them was positive for IgM anti-T. gondiii antibody. Thirty (21.74%) of packed cell samples were positive for IgG anti-T. gondii antibody. The prevalence of chronic toxoplasmosis was significantly higher in workers, farmers, house wives, unemployed and free jobs (P=0.007), people with low education levels (P=0.035) and B type of blood ABO system (P=0.0001). However, there were no significant differences regarding to age, sex, marital status, residency and type of blood products.

Conclusions

There were chronic and acute toxoplasmosis in blood products and the prevalence of toxoplasmosis especially chronic form was high. Therefore screening of blood for T. gondii antibodies may be considered.     

Trichinella Infection in Wildlife of Northeast of Iran

Background

The objective of this investigation was to detect the presence of Trichinella in some carnivores of Mashhad in northeast of Iran and to identify Trichinella species circulating in this area.

Methods

The present study was carried out using muscle tissue collected from 120 stray dogs, 26 wild boars, 25 rodents, two foxes and two hyenas captured in Mashhad City, province of Khorasan Razavi, Iran.

Results

Trichinella larvae were detected in three stray dogs by artificial digestion and compression. All larvae were identified as T. britovi using multiplex PCR.

Conclusion

This is the first report of identification of T. britovi in stray dog in Iran.     

P-glycoprotein A Gene Expression in Glucantime-Resistant and Sensitive Leishmania major (MRHO/IR/75/ER)

Background

Leishmaniasis is a parasitic disease caused by different species of Leishmania parasites with a wide range of clinical manifestations. Antimonial compounds such as meglumine antimoniate (glucantime) are the first line drugs for the treatment of leishmaniasis. However, according to reports of the drug resistance of parasites, the efficacy of antimonial compounds is low. The ATP-binding cassette (ABC) proteins are present in all organisms and mediate the transport of vital elements through biological membranes. One of the important mechanisms of resistance in Leishmania parasites is the overexpression of ABC efflux pumps. P-glycoprotein A (pgpA) is a related gene for ABC transporter in Leishmania species. The aim of this study was to compare the pgpA expression in laboratory-induced resistant L. major (MRHO/IR/75/ER) and sensitive parasites.

Methods

RNA extraction of promastigotes of sensitive and resistant clones was performed and total RNA was reverse transcribed. The real-time quantitative polymerase chain reaction (PCR) was used to assess RNA expression profiles and the expression levels were calculated using 2^-ΔCt method.

Results

The mean expression level of pgpA mRNA was 2.70 ± 0.51 in in sensitive Leishmania clone and 6.08 ± 1.50 in resistant Leishmania clone (P = 0.021).

Conclusion

The expression of pgpA gene in resistant strains of L. major was almost fivefold higher than those in susceptible strains. Therefore, this can be used in field isolates, i.e. overexpression of the gene can prove resistance in wild type field isolates.     

Seroprevalence of Toxoplasma gondii Infection in Dogs in Tehran,Iran

Background

Toxoplasma gondii infects a wide range of animals; felines are definitive hosts and other animals including the dogs are intermediate hosts. The aim of this study was to determine the seroprevalence of T. gondii infection in dogs in Tehran, capital of Iran and to investigate possible associated risk factors.

Methods

Three hundreds ninety six serum samples were collected during 2007–8 from the dogs. Collected samples were tested using an indirect fluorescent antibody test (IFAT) in dilutions of 1:16 and more. All procedures were carried out in Shahrekord University, Iran. All the data were analyzed using SPSS software, qui square test with confidence interval of 0.95.

Results

From evaluated samples, 89 (22.47%) were positive in titers of at least 1:16. further evaluations in other dilutions showed positive results in dilutions of maximum 1:16, 1:32, 1:64, 1:128 and 1:256 in 38, 29, 15, 2 and 5 dogs respectively. Investigation of the role of risk factors showed no sex predisposition while infection rate was significantly higher in dogs older than one year old. Living places were of significant importance; infection rate was significantly higher in stray or guard dogs in compare with household dogs (P<0.05).

Conclusion

Relatively high seroprevalence of T. gondii infection in dogs in Tehran shows high environmental contamination. It is recommended that the dogs with suspected clinical signs be tested for T. gondii infection.