Iranian Journal of Parasitology
Volume:4 Issue: 2, Apr-Jun 2009

Cystic echinococcosis caused by Echinococcus spp. is considered endemic in Iran. To clarify the pre­sent status of hydatidosis in Iran the present review article is presented. Authentic databases and search engines from 1996 onwards were utilized to enquire the situation of the disease in Iran. Human hydati­dosis is responsible for approximately 1% of admission to surgical wards and the rate of human infec­tion is 0.6-1.2/100000. The usual order of involvement, i.e. liver, lung, and other organs, respectively is documented here as well. Risk factors include contact with dog, eating vegetable, geophagy and con­tact with sheep. Dogs play a critical role in transition the hydatidosis. The rate of infec­tion with E. granulo­sus in stray dogs shows a prevalence of 5% to 49% in different parts of Iran. Followed by sheep with 88% fertilized cysts, camel with 70%, and cattle with 19% have been considered as the most important and the weakest intermediate host of E. granulosus, respectively. Molecular analyses clearly indicate that the camel/dog strain (G6 genotype) of E. granulosus as well as the cosmopolitan, common sheep strain (G1 genotype) occurs in Iran. A wide variety of livestock including sheep, cattle, goat, camel and buffalo also harbor the disease. E. multilocularis another agent of human hydatidosis (alveolar cyst) is reported here as well and from 1946 to 1993, 37 cases of human alveo­lar echinococcosis were reported from northwestern Iran. Hydatidosis must be consid­ered as a dilemma in Iran because of its endemicity in the country.

The erythrocyte binding antigen 175 kDa (EBA-175) gene is located on chromosome 7. It encodes protein that binds to specific receptor glycophorin A on the erythrocyte surface during inva­sion. It has a dimorphic nature (FCR3 and CAMP). This study was designed to determine the distribu­tion of EBA-175 alleles of Plasmodium falciparum in the southeast of Iran We used the nested PCR method with specific primers, which improves the two fragments of the EBA-175 gene. Sixty eight microscopically positive blood samples were collected from the in­fected falciparum malaria subjects in the southeast of Iran. In this study which marks the first one in Iran, CAMP strains (714 bp) and FCR-3 strains (795 bp) were found in 14 (37.8%) and 23 (62.2%) in the originally Iranian subjects and in 10 (32.3%) and 19 (61.3%) Pakistani infected migrants respectively. Two migrant cases (6.4%) had mix CAMP/FCR-3 infection. The two fragments of dimorphic EBA-175 gene were observed and the FCR-3 allele was more prevalent in Iran. There was no significant correlation between one of the EBA-175 alleles and the subject group in the mentioned region. This distributional pattern should be considered in design­ing to control P. falciparum malaria in the region.

Miltefosine is a new drug of choice for the treatment of visceral leishmaniasis. Numerous experi­mental studies have shown miltefosine is effective on Leishmania donovani, however, effectiveness of miltefos­ine in treatment of L. infantum is not fully understood. The aims of the present study were to evaluate cytotoxic effects of miltefosine on Iranian strain of L. infantum, and to determine its 50% inhibitory concentration (IC50) as well as lethal dose. Anti-L. infantum activity of miltefosine was studied by treatment of cultured promastigotes with vari­ous concentration of miltefosine. MTT assay was used to determine L. infantum viability and the results were expressed as IC50. Annexin-V FLUOS staining was performed to study apoptotic properties of this drug by us­ing FACS flow cytometry. Miltefosine led to dose-dependent death of L. infantum with features compatible with apoptosis includ­ing cell shrinkage, DNA laddering, and externalization of phosphatidylserine with preservation of integrity of plasma membrane. The 100% effect was achieved at 22 µM and IC50 after 48 hours of incubation was 7 μM. Miltefosine exerts cytotoxic effect on Iranian strain of L. infantum via an apoptosis-related mecha­nism.

Mixed infection with amphistomes seems common in native cattle of Iran. The aim of this study was to determine diagnostic antigens in cattle mixed amphistomiasis. Specific antigens of Cotylophoron cotylophorum, Gastrothylax crumenifer and Paramphisto­mum cervi (mixed infection), the most common species, were collected from cattle was deter­mined. Adult trematodes were collected from the rumen of naturally infected cattle at meat inspec­tion. After their homogenization and centrifugation, somatic antigens were prepared and ana­lyzed by SDS-PAGE. Specific antigens were determinated by western blot with homologous and heterolo­gous sera. SDS-PAGE of whole worms extract was performed at different concentrations and subse­quent gels staining. Immunoblotting analysis using sera from cattle naturally infected with am­phistomes, Dicrocoelium dendriticum, Fasciola spp. and hydatid cyst was performed. Electrophorese analysis of somatic antigens revealed the presence of 10 and 21 protein bands at 4 µgr/ml and 8 µgr/ml with molecular weights ranging from 25-120 and 25-150 kDa, respectively. The best result was taken at 8 mg/ml concentration. Although western blot of these proteins demon­strate 5 major antigenic polypeptides ranging from 50 to 100 kDa which were recognized by serum of cat­tle naturally infected with mixed amphistomes.

The aim was to compare three different methods (direct examination, culture and PCR meth­ods) for the diagnosis of Acanthamoeba keratitis (AK) in corneal scrapes. Twenty eight corneal scrapes and contact lenses were collected from keratitis patients and re­ferred to the De­partment of Medical Parasitology and Mycology, School of Public Health, Tehran Univer­sity of Medical Sci­ences. Corneal scrapes were divided in three parts for direct examination, culture on non-nutrient agar and PCR analysis. PCR analysis was also performed using a 18S rRNA gene primer pair (DF3 region). DF3 (Diagnostic frag­ment 3) is a region of the nuclear small subunit ribosomal RNA gene which is specific for detecting Acan­thamoeba strains. Acanthamoeba was the causative agent of keratitis in 50% of the patients. Direct smear of all pre­pared corneal scrapes in AK patients was negative and culture was positive in only 14.3% of the isolates. PCR analysis was positive in 71.4% of AK patients. These three methods were negative in corneal scrapes of non-AK patients. The sensitivity and specificity of PCR technique for the detection of Acanthamoeba sp. were calculated as 71.4% and 100%, respectively. According to high sensitivity and specificity of PCR-based method, this study confirmed that PCR using 18S rRNA gene primers (DF3 region) is more useful for detecting AK cases compare to culture and direct microscopy methods.

For a long time, intestinal parasite infections are among the major problems of public health in Iran. Our aim was epidemiological studies on the frequency of intestinal parasites in patients re­ferred to three hospitals in Tehran during 2007-2008. During 2007-2008, by simple random selection, 1000 stool samples were collected from Mi­lad, Hazrat-e-Rasoul and Shahid Fahmideh hospitals in Tehran, Iran. We examined the samples using di­rect smear, formol-ethyl acetate concentration, Agar-plate culture and Ziehl-Neelsen staining tech­nique. The frequency of intestinal parasites were: Blastocystis hominis 12.8%, Giardia lamblia 2.5%, En­tamoeba coli 4.8%, Iodamoeba butschlli 0.9%, unknown 4 nuclei cysts 0.4%, Endolimax nana 3.2%, Chilomastix mesnili 0.4%, Strongyloides stercoralis 0.1%, Hymenolepis nana 0.2% and Taenia sagi­nata 0.2%. Coccidian parasites were not found. Results show that infection with intestinal parasites does not statistically significant according to sex and age. The intestinal parasites, especially helminthic infections have been decreased during re­cent years.

Pediculus capitis or head louse infestation affects millions of children worldwide, especially those in the 5-11 years age group. This study aimed to determine the prevalence of head pediculosis among school children in ur­ban and rural areas of Fars Province, southern Iran. All school children of age 6-11 yr from both genders in all urban and rural areas of the province were screened for head louse infestation by examination of their hair and scalps. Parents of all infested children were also exam­ined. The study was repeated in different seasons in the same areas. Moreover, infested children were treated with 5% permethrin shampoo and re-examined one week later for any relapse. The general prevalence of head louse infestation in primary school students was 0.49% in autumn, 0.37% in win­ter and 0.20% in spring. In the mentioned seasons, the prevalence of P. capitis was higher among females and in ru­ral areas (P=0.001). Although treatment with permethrin shampoo failed in females, it was successful in all infected males from both regions in autumn and spring and in males from urban areas in winter. Head louse infestation is uncommon among Fars Province school children in rural and urban areas and should not be considered a public health priority. However, due to the higher prevalence of pediculosis in low socioeco­nomic group and rural area in our region, it seems that health promotion, particularly early detection and effec­tive management strategies should target this group in the province.

Cystic hydatid disease is an important zoonosis, affecting humans and animals and is a significant public health and economic problem throughout the world and Iran. Since extraction of DNA from the parasite is a primary and crucial step which has a principal effect on PCR results, in the current study five simple methods for DNA extraction from protoscoleces of Echinococcus granulosus were ap­plied and compared with each other. After collecting hydatid cysts from an abattoir, DNA samples were extracted from two cyst isolates from sheep, two from goats and two from camels using five different methods involving the use of glass beads, mechanical grinder, freeze-thaw, boiling and crushing. For all DNA samples ex­tracted, one PCR assay based on amplifying rDNA-ITS1 region was performed and amplicons re­solved on 1.5% agarose gels. The methods were compared regarding to DNA and PCR bands, time and cost effectiveness and laborious amount. The target DNA was successfully amplified from all samples using all methods produced an expected band size. All methods showed some advantages and disadvantages in PCR gels. The boiling method, which was the most time and cost effectiveness method, achieved the thick­est bands in the PCR following grinder, crushing, freeze-thaw and glass beads. Boiling and crushing methods were the most suitable methods regarding their amplicon quality, easiness, quickness and cost effectiveness.

Central nervous system involvement arising from schistosomiasis is uncommon. It may be produced most fre­quently by Schistosoma japonicum infection, but reports of S. mansoni presenting as an intracerebral mass lesion are particularly rare. The authors describe the case of a 35-year-old woman with a 3-month history of partial epilep­tic seizures and head­aches. She immigrated to Egypt 4 years ago and had worked in Iraq for 2 years after the immigration. The patient''s gen­eral physical and neurological examinations were unremarkable. Magnetic resonance (MR) imaging revealed an enhanc­ing lesion with surrounding edema and mild mass effect in the left frontal lobe. A stereotactic brain biopsy demonstrated intraparenchymal granulomas surrounding S. mansoni eggs. S. mansoni was identified by stool examination. Prednisone (1 mg/kg per day for 1 week, with gradual with­drawal during the following 3 weeks) and praziquantel (2 doses at 20 mg/kg per day) therapy was initiated. The patient''s symptoms resolved following medical treatment and the follow-up MR imaging yielded normal findings. This case is the rare imported case of cerebral schistosomiasis in China and the neuroschistosomiasis should be considered as the patient lived in a region in which this disease is endemic.

This case report states a 25-year-old woman, residing in the city of Dezfool, Khuzestan Province, south of Iran with the diagnosis of cutaneous leishmaniasis in June 2008. Her skin lesion had de­veloped from 8 months earlier as a nodule on her left arm, 1×3 cm in diameter. Because of sever­ity of the lesion, we prescribed meglumine antimoniate intralesionally with giving up her breast feeding. After 6 months follow-up, no recurrence was seen.