Iranian Journal of Parasitology
Volume:6 Issue: 1, Jan-Mar 2011

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

The aim of this study was to assess the performance of Antigen B (AgB) isolated from different Echinococcus granulosus intermediate hosts and from different cyst locations for immu­nodiagnosis of human cystic echinococcosis (CE). Hydatid cyst fluids were collected from lung and liver cysts of sheep, liver cysts of goats, lung cysts of camels and cattle, and liver cysts of human. AgB was purified from each of these hydatid cysts fluids. Serum samples obtained from 47 pathologically confirmed cases of CE along with 30 sera samples from non-CE patients and 40 sera from healthy individuals were tested by ELISA using AgB prepared from different hosts or cyst locations. The highest sensitivity (97.8%) for diagnosis of CE was seen with AgB prepared from hu­man liver cysts. This maximal sensitivity was followed by AgB isolated from those of sheep liver and lung cysts. The least sensitivity was found with AgB prepared from bovine lung cysts. The highest specificities (97.1%) were observed with AgB isolated from human liver cysts fol­lowed by those of sheep and goat liver cysts while the lowest specificity was seen with AgB iso­lated from bovine lung cysts. In view of the specificities and sensitivities of the different AgB, the best validity was found for AgB prepared from human liver cysts while the least validity was found with AgB prepared from bovine lung cysts. For any AgB-based tests, obtaining of the antigen from one of these sources will signifi­cantly increase the diagnostic sensitivity and specificity of the assay.

The aim of this study was to detect and characterize Cryptosporidium spp. in water sam­ples collected from recreational ponds of Chaharmahal va Bakhtiyari Province of Iran. Meth­ods: Thirty water samples were collected from November 2009 to May 2010. Each sample con­tained 10 liters of water. We used the SSU rRNA-based PCR-RFLP technique. Out of thirty samples examined, 6 (20%) were positive for different Cryptosporidium spp. Restriction pattern analysis showed that C. parvum has been the most prevalent genotype, fol­lowed by C. hominis and C. canis, respectively. In this area, the higher prevalence of C. par­vum compared with other genotypes is consistent with the distribution of cattle. Farm animals, particularly cattle are the main source of cryptosporidial contamina­tion for recreational waters in this area.

Toxoplasmosis is a worldwide endemic disease. In congenitally infected infants and AIDS patients, toxoplasmosis causes high rates of morbidity and mortality. In these cases antibody detection is difficult; so detection of parasite or its components could be useful tool for early detection and following treatment of the infection. Sixty-three BALB/c mice were injected intra-peritoneal with 5×103 tachyzoites of Toxoplasma gondii RH strain, nine mice were sacrificed daily for 7 days. Fourteen mice were in­jected with phosphate buffer saline as control group. Dot-ELISA was performed for detection of T.gondii antigen in mice sera and capture - ELISA was done as golden standard assay too. Toxoplasma gondii antigen was detected from day 2 in mice sera; 22% of mice sera on day 2, 33% on day 3,77% on day 4 and 100% on day 5 till their death on day 7 had shown antigene­mia by dot - ELISA, no positive result was detected in control mice by dot- ELISA. Dot-ELISA is a sensitive method for diagnosis of T. gondii infection in the animal model; also, this technique is more rapid and easy to perform method in comparison with cap­ture-ELISA.

Immunological response of host and parasite play a key role in developing vaccina­tion and immunization. The present study deals with the immune response and effecter mechanism, which was confirmed by migration inhibition factor (MIF). The present work was conducted in Parasitological Lab of Postgraduate Department of Zool­ogy, Government Holkar Science College, Indore (M.P.) during 2006-2007. For MIF assay, lymphocytes were separated from heparinized blood of experimental and control mice. Aliquots of cell suspension were placed in four wells cut in a preparation of agarose in a Petri dish. Two wells were filled with soluble test antigen, while rest two wells were filled with medium (control wells). Petri dish was incubated overnight at 37 °C in a humidified environment at 5% CO2 in air. Cells migrated under the agarose in a circle were fixed and stained. Diameters of the migration areas were measured with ocular micrometer. MIF reaction was maximum (44.2%) in the group IVEgESAg5 and minimum (10.8%) in the group IVASoAg1. The maximum MIF reaction was shown by eggs ES antigen and least by adult worm somatic antigen. The interesting observation was that migration inhibition increases as dose increased or we could say the reaction was dose dependent Increased value of MIF response in vaccinated mice suggested the involvement of lymphocytes in cell-mediated immunity. This study also proves that excretory-secretory (ES) anti­gen of eggs from Trichuris muris was more effective in imparting immunity in mice.

Echinococcosis/hydatidosis is considered endemic in Mauritania. The aim of this study is to present an epidemiological study on the echinococcosis in man and animals in the Nouakchott region. The internal organs from livestock carcasses were inspected for research of hydatid cysts. The hydatid fluid was examined for research of the protoscoleces. Dogs were necropsied for the collect of Echinococcus granulosus. In the Nouakchott Hospital, 24 surgical operation of human hydatid cysts have been per­formed, out of which 50% were localised in the lung, 33% in the liver and 17% elsewhere. Then, the incidence rate would be of 1.2% per 100 000 inhabitants in Mauritania. In the dog, the prevalence rate is 14%. The average number of E. granulosus on the whole dogs is 172 and 1227 on the positive dogs. Concerning the livestock, hydatid cysts found in 30.1% of the dromedary, 5.5% of the cattle and 6.5 of the sheep. The fertility rate of hydatid cysts in humans (75%) and camels (76%) was significantly higher than that of sheep (24%) and cattle (23%) (P<0.0001). Hydatid infestation is characterized globally by the dominance of pulmonary localiza­tions in hu­mans (50%) and camels (72.7%) and in the liver in sheep (76.1%) and cattle (82.3%). The differences between prevalence rates, the fertility of hydatid cysts and diversity sites localization observed in humans and camels of one hand and the sheep and cattle on the other hand, depends possibly the strain(s) diversity of E. granulosus.

The aim of this study was to investigate the ‘acaricidal effect' of Zataria multiflora and Ar­temisia annua essential oils on Rhipicephalus (Boophilus) annulatus. This study was carried out in 2009 in the Laboratory of Parasitology of the Faculty of Veteri­nary Medicine of Shahrekord University, west central Iran. Six dilutions (5, 10, 20, 40, 60 and 80 µL/cm3) of both essential oils were used against engorged female R. (Boophilus) annula­tus ticks using an in vitro immersion method. The mortality rates for each treatment were re­corded 6, 15 and 24 hours post inoculation (hpi). Mortality rate was analyzed using Repeated Meas­ures Analysis of Variance, and compari­son of means was carried out using General Linear Models Procedure. The mortality rate caused by different dilutions of Z. multiflora essential oil ranged from 26.6% (using 10 µL/cm3) to 100% (using 40 µL/cm3) and for A. annua essential oil it was 33.2 to 100% (using 20 and 80 µL/cm3, respectively) by the end of the experiment (36 hpi). No mortality was recorded for the non-treated control group or for dilutions less than 5 and 10 µL/cm3 using Zataria and Artemisia essential oils, respectively. For Z. multiflora mortality peaked at 15 hpi for all concentrations other than 20 µL/cm3 and took 24 h to achieve its maximum effect while for A. an­nua the two highest concentrations needed 24 hpi to reach their full effect. In addition, essen­tial oils applied at more than 20 and 60 µL/cm3 caused 100% egg-laying failure in engorged fe­male ticks by Zataria and Artemisia, respectively while no failure was observed for the non-treated control group. The mortality rate in both botanical acaricides was dose-dependent. Both these medicinal plants have high potential acaricidal effects on the engorged stage of R. (Boophilus) annulatus in vitro.

We used the PCR technique based on the abovementioned primer pair and sequenc­ing to demonstrate the Theileria infection in the sheep samples collected from Sultanate of Oman. According to the frame work of "integrated control of ticks and tick borne diseases in global­ized world managed by EU-ICTTD-3 project, the samples from blood, liver, spleen, lymph node and lung were sent to the laboratory of Iranian Research Center for Ticks and Tick-borne Diseases (IRCTTD). Sam­ples from blood smear and impression smears from liver, spleen, lymph node, and lung were analyzed by Geimsa staining. The DNA was extracted from the abovemen­tioned samples and analyzed by PCR tech­nique using specific primers derived from the nucleo­tide sequences of 18S rRNA gene of T. lestoquardi, which can amplify the common region in other Theileria and Babesia spp. Subsequently the amplified DNA was sequenced. The analysis of blood smears of the sheep was negative for piroplasmosis performed through the Giemsa staining. The impression smears prepared from liver, spleen, lymph node, and lung showed suspi­cious structures mimicking Theileria schizonts in some cells. The results showed an expected PCR prod­uct of 428 bp in length, which is specific for Theileria spp. The PCR products were subsequently se­quenced. The corresponding nucleotide sequence is registered under accession number JF309152 in Gen­Bank. The sequence alignment in GenBank showed that the PCR products had 99% homology to the known T. lestoquardi registered under accession number AF081135 in the GenBank. Oman sheep are highly susceptible for Theileria infection and the infected sheep mostly die before the microschizonts or erythrocytic form of Theileria appears in the nucleated or ery­trocytic cells respectively.

Dirofilaria immitis is an important parasite in dog and other carnivores. Our objec­tive was study on incidence and periodicity of heartworm in north of Iran and using other meth­ods for its diagnosis in addition to Parasitology exam. This survey spanned two years, between 2006 and 2008. Blood samples were collected from 431 stray dogs distributed along north of Iran, the coastal areas of the Caspian Sea. The Knott's modified test was used for diagnosis of D. immitis and other filariae. Meanwhile, the periodic­ity of microfilaria in peripheral blood circulation was calculated and the imaging diagno­sis techniques of four dogs that had positive results were done. Diagnostic parasitology results indicated that 16.01% of stray dogs were microfilaremic. Two different microfilariae were diagnosed: D. immitis in 13.69%, Dipetalonema reconditum in 1.86% and in 0.46% both of them. There was no statistically significant between infection to fiariae with sex and age of dogs. Also study on the periodicity of the presence of microfilaria in peripheral circulation showed that the highest rate of those was at 1 am and the lowest rate at 12 pm. Radiographic study showed distinctive signs with varied degrees of severity included: Tortu­ous and enlargement of main and lobar pulmonary artery, pulmonary parenchymal lesions and Right side heart enlargement that confirmed in electrocardiography. Also in echocardiographic images observed short parallel-sided images with the appearance of equal signs that indicated the pres­ence of the heartworm. These results showed that to obtain a reliable diagnosis of heartworm infection, imag­ing tests could support parasitological exams.

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. 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. 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). 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.

In this study the haemolymph components of infected and none infected Lymnaea gedrosiana with xiphidiocercaria larvae was compared. Five hundred Fifty Lymnaea snails were collected from Ilam and Mazandaran prov­inces, Iran, during 2008-2009. The snails were transported to the lab at Tehran University of Medi­cal Sciences and their cercarial sheddings were studied. Haemolmyphs of snails were ex­tracted and cells were counted using haemocytometer and cell-surface carbohydrate were recog­nized by conjugated lectin (Lentil). Haemolymph protein concentrations were measured by Brad­ford protein assay method and soluble protein compositions were determined on sodium dodecyl sulphate polyacrilamide gel electrophoresis (SDS-PAGE). From the 550 examined Lymnaea snails for cercariae, 27 snails were infected with xiphidiocer­cariae. Mean of haemolymph cells (haemocyte) number were obtained 93480±2.43 (cells/ml) for none infected snails (25 snail) and 124560±2800 (cells/ml) for infected snails (25 snail). Mannose carbohydrate was recognized on haemocyte of none infected and infected snails. Mean of protein concentration of haemolymph plasma was obtained as 1354 ± 160 μg/ml (1.4 mg/ml) for none infected snails (25 snails) and 1802±138 μg/ml (1.8 mg/ml) for infected snail (25 snails). Comparing to none infected snails, the SDS-PAGE results of haemolymph plasma of infected snails, showed an extra protein band (70 kDa). The results showed a significant differ­ence between the amounts and the kinds of proteins in haemolymph of infected and none infected snails. This information might be useful to understand of parasite detection, adhesion, engulf­ment and antigen agglutination by snail.

The presence of Visceral Larva Migrans (VLM) in a patient is reported. A 57-year- old woman suffering from right upper abdominal and suprapubic pain referred into a clinic in Khorramabad, Lorestan Province, Iran. A cystoscopy was performed and biopsy was taken. The light micro­scopic study showed a couple of larvae as well as mononuclear inflammatory cell- infiltration. Because occurrence of VLM is potentially problem in rural areas, it is recommended that an educa­tional program to be initiated to prevent and control VLM infection in both rural and urban people. Clinicians also should consider the clinical features of visceral larva migrans.