Trend of toxocariasis in Iran: a review on human and animal dimensions.

One of the neglected soil and/or food-borne diseases with international public health importance is toxocariasis. Human cases are being increasingly reported from Asian, African, Oceania, European and the American countries. Hence, human toxocariasis (HT) is now considered as a major zoonosis with global and regional importance. In Iran, human and animal toxocariasis is an endemic disease with clinical and epidemiologic health problem aspects. Doubtless, understanding the epidemiology and the trend of this important parasitic disease and its affecting factors will provide the establishment of effective prevention and control programs. To better understand the trend of toxocariasis researches in Iran, this study was performed to analyze different aspects of this zoonotic disease including history, life cycle, species, human animals and environmental studies, diagnostic aspects and treatments to find out the gaps, including different aspects of clinical sings in human patients, new and specific recombinant antigens based on the native antigens, new diagnostic tools, especially rapid diagnostic tests, paratenic hosts status and new treatment procedures which is necessary to be investigated in the future studies on this important zoonotic disease.

The occurrence of Toxocara species in naturally infected broiler chickens revealed by molecular approaches.

Consuming raw and undercooked meat is known to enhance the risk of human toxocariasis because Toxocara species have a wide range of paratenic hosts, including chickens. The aim of this study was to identify species of Toxocara in naturally infected broiler chickens using molecular approaches. A polymerase chain reaction (PCR) method was used for the differentiation of Toxocara canis and Toxocara cati larvae recovered from tissues and organs, and identified by microscopic observations. Thirty-three 35- to 47-day-old broiler chickens were used for examination of Toxocara larvae. The duodenum, liver, lungs, heart, kidneys, skeletal muscles and brain of each chicken were examined using the pepsin method, and DNA from each tissue was extracted as the template for PCR assay. The findings revealed that 5 of 33 (15.2%) broiler chickens were infected with Toxocara larvae. Larvae were recovered from the liver (n = 19), duodenum (n = 8), skeletal muscles (n = 8) and brain (n = 2) of broiler chickens naturally infected with Toxocara spp. The results showed that the frequencies of the species in the chickens were T. canis larvae (n = 5, 83.3%) and T. cati larvae (n = 1, 16.7%). Our data from the present study demonstrated the importance of broiler chickens as a paratenic host for the parasite's life cycle in the environment. The implementation of DNA amplification as a routine diagnostic technique is a specific and alternative method for identification of Toxocara larvae, and allowed the observation of specific species under field conditions within the locations where broiler chickens are typically raised and exposed to Toxocara spp. eggs or larvae.

Leucocytozoonosis in domestic birds in southwestern iran: an ultrastructural study.

BACKGROUND: Leucocytozoonosis is a disease of birds caused by obligate intracellular protozoa of the genus Leucocytozoon. We determined the prevalence of Leucocytozoon spp. using light and transmission electron microscopy in domestic birds in southwest of Iran. METHODS: A total of 825 blood smears from 275 birds were examined for presence of infection. The structure morphology of Leucocytozoon spp. was studied using light and electron microscopy. RESULTS: Forty-four (16.0%) of the birds were positives for Leucocytozoon. The detected parasite were found in 14 chickens (5.1%), 12 geese (4.3%), 10 ducks (3.6%), and 8 turkeys (2.9%). The majority of the records were from the northeastern regions. CONCLUSION: Leucocytozoonosis are distributed in the Lorestan province bird population and electron microscopy can resolve the problem to distinguish between similar species of Leucocytozoon.

The serological study of cystic echinococcosis and assessment of surgical cases during 5 years (2007-2011) in Khorram Abad, Iran.

BACKGROUND: Echinococcus granulosus is a cestode whose larval stage causes cystic echinococcosis in wild animals, livestock, and human. OBJECTIVE: The aim of this study is to highlight the seroepidemiology of E. granulosus infection and surgical cases in the general population of Khorram Abad district, southwest of Iran. MATERIALS AND METHODS: Anti-E. granulosus antibodies were tested in 617 inhabitants in Khorram Abad by enzyme-linked immunoassay and antigen B. The surgical cases of cystic echinococcosis were investigated in Shohaday-e-Ashayer Hospital of Khorram Abad (as a referral center) from 2007 to 2011. RESULTS: In total, 95 (15.4%) of the 617 participants (mean age 39.6 ± 17.6 years) had anti-E. granulosus antibodies. Prevalence of infection was more in males (60%) than females (40%), and showed statistical significance (P < 0.001). High-titer antibodies were most prevalent among the subjects aged 20-29 years. There was significant association between the presence of Echinococcus antibodies and the sector of residence, education of volunteers, and occupation (P < 0.05). According to hospital records, 58 cystic echinococcosis cases were referred to the hospital during the 5 years. Among the cases, 28 (48.3%) were men and 30 (51.7%) were women. They were between 4 and 74 years of age (36.6 ± 18.9 years). The liver was the organ where most of the hydatid cysts (51.7%) were located, followed by lungs (20.7%). CONCLUSION: This is the first report of the seroprevalence and contributing factors for E. granulosus infection in the general population in Khorram Abad. The findings confirm the importance of diagnosing human cystic echinococcosis in these regions, given the prevalence rates of surgical cases during the last 5 years, and need further evaluation of the risk factors present.

Prevalence of oral Entamoeba gingivalis and Trichomonas tenax in patients with periodontal disease and healthy population in Shiraz, southern Iran.

BACKGROUND: It was shown that two parasites of Entamoeba gingivalis (E. gingivalis) and Trichomonas tenax (T. tenax) may be responsible for oral parasitic infection. This study was designed to evaluate the prevalence of these parasites in oral cavity of patients with periodontal disease and in healthy population in Shiraz, Southern Iran. MATERIALS AND METHODS: A total of 50 patients with periodontal disease (case group) and 50 subjects with healthy gingiva (control group) entered in the present study. A questionnaire recorded general health, smoking habits, and any history of antibiotic consumption during the last six months for each patient. In the case group, saliva was collected by sterile swab and the gingival crevicular fluid by the paper point. The plaque and calculi were collected by sterile curette and scaler. In the control group, saliva and gingival crevicular fluid were collected and sent to laboratory for further studies. RESULTS: In the case group, nine patients were infected, six with E. gingivalis and three with T. tenax. Seven patients had mobility of the teeth, one patient was smoker and five had previous history of antibiotic consumption. In the control group, only one subject was infected with E. gingivalis without any history of smoking and antibiotic consumption. CONCLUSION: Parasitic infections are relatively common in patients with periodontal disease. It seems that follow-up of instructions are essential in control of parasitic infection in Southern Iran.

Soil contamination with Toxocara spp. eggs in the public parks from three areas of Khorram Abad, Iran.

Toxocariasis is a parasitic zoonose caused by the infection of larval nematode Toxocara species. A total of 285 soil samples from January to March 2009 in 18 public parks were collected to test for soil contamination with Toxocara eggs. Soil samples were investigated for the present of Toxocara eggs using sucrose flotation method. Distribution of Toxocara spp. eggs in samples collected from public parks was 63.3%. The highest number of eggs recovered from 200 g of soil was 128. A total 304 eggs were recovered and 42.1% fully developed to embryonated egg stages. The contamination rate in second region in the studied areas was higher than the other regions. A similar tendency was observed in parks size, so that parks higher than 10,000 m2 were more highly contaminated. The present investigation clearly shows that public parks have been contaminated with Toxocara eggs in Khorram Abad, suggesting that care should be taken when using public parks.

Histopathologic changes and larval recovery of Toxocara cati in experimentally infected chickens.

This study was made to determine the distribution pattern of Toxocara cati larvae in chickens as a paratenic host and its potential zoonotic risk by consuming infected chickens. Two groups of chickens were fed with 1,000 and 3,000 embryonated eggs of T. cati. The chickens were necropsied 3, 7, 14, and 21 days postinfection. The liver, lungs, kidneys, spleen, small intestine, and half of all the striated muscles were digested for larval recovery. Squash method was used for brain. Larvae were recovered from the liver and brain of infected chickens with 1,000 embryonated eggs. Samples of these tissues were prepared for histopathologic studies. Experimental chickens exhibited hemorrhages in the liver, lungs, and kidneys on all days postinfections (dpi). White spots on the liver surfaces that showed necrotic foci, infiltration of eosinophils, and a few lymphocytes around necrotic areas were seen on 14 and 21 dpi. Remains of larvae were present in the liver on 14 dpi. Pathologic findings showed that larvae migrated in different organs of chickens. We suggest that chickens could be paratenic hosts, and human infection with T. cati might occur after consumption of raw or undercooked meat of infected chicken with T. cati.