Iranian Journal of Parasitology
Volume:7 Issue: 1, Jan-Mar 2012

Toxoplasmosis is one of the most common parasitic diseases worldwide. Although estimated that one third of the world's population are infected with Toxoplasma gondii, but the most common form of the disease is latent (asymptomatic). On the other hand, recent findings indicated that la­tent toxoplasmosis is not only unsafe for human, but also may play various roles in the etiol­ogy of different mental disorders. This paper reviews new findings about importance of latent toxop­lasmosis (except in immunocompromised patients) in alterations of behavioral parameters and also its role in the etiology of schizophrenia and depressive disorders, obsessive-compulsive disorder, Alzheimer's diseases and Parkinson's disease, epilepsy, headache and or migraine, men­tal retardation and intelligence quotients, suicide attempt, risk of traffic accidents, sex ratio and some possible mechanisms of T. gondii that could contribute in the etiology of these alterations.

In this study the level of IL-23 and IL-27 produced by macrophages derived from peri­pheral blood mononuclear cell culture collected from patients with healing or non-healing form of cutane­ous leishmaniasis lesion were compared before and after treatment with live Leishmania to explore whether IL-23 or IL-27 plays any role in healing process of cutaneous lesions induced by L. major. Twenty patients resident in Isfahan Province, with healing or non-healing form of cutaneous leishmaniasis lesion caused by Leishmania major participated in this study. In vitro productions of IL-23 and IL-27 by peripheral blood derived macrophages, before and after stimulation with live L. major (MRHO/IR/75/ER) promastigotes were evaluated using ELISA method. Patient with healing form of le­sion received no treatment and patient with non-healing form of lesion received at least 2 courses of glucan­time. The mean production of IL-23 and IL-27 from macrophages of patients with healing form of lesion was significantly higher than patients with non-healing form of lesion. The levels of IL-23 and IL-27 in culture supernatants before and after stimulation in healing form of CL was significantly higher than non- healing form of CL (P < 0.001). IL-23 and IL-27 might play a role in human leishmaniasis and further studies are needed to understand the role of IL-23 and IL-27 in leishmaniasis.

Plasmodium vivax is responsible for approximately 80 million malaria cases in the world. Apical membrane antigen1 (AMA-1) is a type I integral membrane protein present in all Plasmo­dium species. AMA-1 interferes in critical steps of invasion of human hepatocytes by sporo­zoites and red blood cells by merozoites and is one of the most immunodominant antigens for elicit­ing a protective immune response in human. It is considered as a promising antigen for inclusion in a vaccine against P. vivax. Since more knowledge is needed to lighten the scope of such antigen we com­pared genetic variation in P. vivax AMA-1from an Iranian isolate with those reported from some of the other malarious countries so far. P. vivax genomic DNA was extracted from the whole blood of an Iranian patient with pa­tent P. vivax infection. The nucleotide sequence for 446 amino acid (AA) residues (42-488 of PvAMA-1) was amplified by PCR and cloned in pUC19 vector for sequencing. Sequence analysis of the antigen showed a high degree of identity (99%) with strong homol­ogy to the PvAMA-1 gene of P. vivax S3 and SKO814 isolates from India and Korea (Asian isolates) respectively, and 96% similarity with P. vivax Sal-1 AMA-1 gene from El Salvador. We cloned and characterized three domains of PvAMA-1 gene from an Iranian patient. Predicted protein sequence of this gene showed some discrepancies in corresponding protein in compar­ing with similar genes reported from other malarious countries.

Knowledge about the amphistomid fauna in Iranian domestic ruminants depends on the studies conducted almost 30 years ago. The last situation in cattle is introduced here in the provinces in south coast of Caspian Sea. Amphistomid species were collected from cattle at slaughter houses of the provinces Gilan and Mazanderan in 2010. Median sagittal sections were prepared by the conventional me­thod. Species were identified by the histomorphological pecularities of the muscular argans. Five amphistomid species, Paramphistomum cevri, P. gotoi, Calicophoron calicopho­rum, Carmyerius spatiosus and Gastrothylax compressus, recovered. Calicophoron calicopho­rum is a new species for Iran. Criteria used in identification of the species were illustrated. Iran has a rich amphistomid fauna and mostly under the influence of oriental condi­tions.

A successful malaria elimination program calls for enough attention to parasite carri­ers, especially asymptomatic malaria, as well as the diagnosis and treatment of clinical cases. Asymptomatic malaria is an infection that patients do not show any symptom; thus, these patients play critical role in the concept of an elimination program. The current investigation was con­ducted to evaluate the presence of these cases in Bashagard District, formerly a high malaria transmis­sion area in Hormozgan Province, Iran. Blood samples (n=500) were collected from symptomless individuals residing in Basha­gard to evaluate Plasmodium infection by using microscopic, serological and nested-PCR techniques. Regarding the microscopic and nested-PCR analysis, no asymptomatic infection was detected among studied individuals. Totally, 1% of the studied population (5 of 500) had anti PvMSP-119-specific IgG antibody; however, only 0.2% (1 of 500) of the individuals was seroposi­tive to recombinant PfMSP-119, using ELISA. This study showed no asymptomatic malaria infection in the studied population; hence malaria elimination is feasible and can be successfully carried out in this region.

Cutaneous leishmaniasis constitutes a major public health problem in many parts of the world including Iran. The primary objective of this study was to identify Leishmania spe­cies in endemic districts of Kerman Province, south-eastern Iran. This study was conducted by random sampling as cross- sectional descriptive between 2008 and 2010. Overall, 203 skin scraping smears were taken from the patients. Nested -PCR was performed to amplify variable minicircle fragments of Leishmania kDNA. Bam was the most infected district (71.1%), followed by Kerman (14.7%), Jiroft (5.4%), Baft (2.7%), Sirjan (1.6%), Shahr-e Babak (1.5%) and others (3.0%). L. tropica was the most common species identified (194 cases, 95.6%), while L. major was found in only 9 cases (4.4%). Of 203 identified patients, all species in Bam (l07 cases), Kerman (32 cases), Jiroft (l6 cases) and Shahr-e- Babak (l1 cases) were detected as L. tropica, whereas infected subjects in Baft and Sir­jan showed L. tropica or L. major. Characterization of Leishmania species resulted in generation of 750 bp and 560 bp fragments, corresponding to those of L. tropica and L. major, respectively. L. tropica is the main species (95.6%) caused ACL in endemic areas of Kerman Prov­ince; however L. major is present in low level (4.4%).

Cryptosporidium spp. is a coccidian parasite infected humans and animals. Prevalence rate of Cryptosporidium spp. infection associated with is some parameters such as sampling, age, season, country and contact to domestic animals. This study aimed to determine Cryptosporidium spp. Infection in humans and some animals in rural areas of Shushtar district from Khuzestan Province, south- west of Iran. In this study, Stool specimens were randomly collected from 45 cattle, 8 buffalos, 35 calves, 22 turkeys, 3 sheep, 2 geese as well as 62 humans in different seasons selected from rural areas of Shushtar district located in Khuzestan in the south- west of Iran from August 2009 to April 2011. The collected stool samples were examined by modified Ziehl-Neelsen staining method. Altogether, 68/115 (59.1%) domestic animals and 9/62 (14.5%) of humans were showed Cryptosporidium spp. infection in the study areas. In this study we found the high frequency of Cryptosporidium spp. infection in the studied areas.

Echinococcus granulosus, a zoonotic cestode parasite, causative agent of hydatid cyst is endemic in many parts of the world including the Middle East. Study on different aspects of this parasite is very important and valuable. However, working with adult worms which their habitat situated in the small intestine of canids, is dangerous and risky. Achieving such risky situa­tion needs a controlled condition which is cultivation of the organisms in the laboratory. In this regard, cultivation of E. granulosus protoscoleces leading to adult worms was established in the laboratory for the first time in Iran. Under aseptic conditions a number of protoscoleces were cultivated in diphasic S.10E.H medium using CO2 incubator to produce adult worms. Different forms of parasites including pre-segmentation stages (PS1 - PS4) and segmenta­tion stages (S5-S8) and developing stages in segmented worms (S10-S11) were ob­served and evaluated in these medium. Finally adult worms contained four proglottids with a large and distinct genital pore were observed 50-55 days post cultivation. These parasites do not produce fertile eggs and conclusively do not have risk of hydatid disease transmission to the research­ers. The mentioned method for producing E. granulosus adult worms can open a new window for researches and facilitate working on different aspects of hydatidosis especially for diagnosis, protection and treatment studies.

A parasitological survey of Schistosoma haematobium and S. intercalatum infection among primary schoolchildren in capital area of Democratic Republic of São Tomé and Príncipe (DRSTP) was undertaken. Subjects with positive infection were confirmed by the detection of S. haematobium ova in the urine or S. intercalatum ova in the stool by using centrifugation concentration or merthiolate-iodine-forma­lin concentration method. Totally, 252 urine and stool samples, respectively, were obtained from apparently healthy schoolchildren, of which 121 from boys (9.8 ± 1.4 yr) and 131 from girls (9.7 ± 1.3 yr). None of participating schoolchildren were found having S. haematobium ova in the urinary speci­men. While, among 4 primary schools studied, only schoolchildren from Saint Marçal were detected with S. intercalatum ova in the fecal specimen, making the overall prevalence of S. intercalatum infection among schoolchildren was 2.4% (6/252) and girls had insignificantly higher prevalence (3.1%, 4/131) than that (1.7%, 2/121) in boys (χ2 = 0.5, P = 0.5). Water control and sanitation as well as snails eliminated by molluscicides are urgently needed to reduce S. intercalatum infection in DRSTP inhabitants.

The aim of this study was to detect the occurrence of parasites in fish in Armand River, Chaharmahal va Bakhtyari Province regarding the importance of native fish population in the river. The occurrence of parasites was investigated in 6 native fish (Capoeta capoeta, C. damas­cina, C. aculeta, Barbus barbulus, B. grypus and Glyptothorax silviae) collected from the current main channel of the river from autumn 2009 to summer 2010. 63.7 % of the studied fishes were infected with 19 parasite spe­cies including Ichthyophthirius multifiliis, Myxobolus musayevi, Dactylogyrus lenkorani, D. graci­lis, D. pulcher, D. chramuli, D. akaraicus, D. skrjabiensis, two species of Gyrodactylus, Para­diplozoon sp., Lamproglena compacta, Copepodid of Lernaea cyprinacea, Ergasilus sp., Allocreadium isoporum, Allocreadium pseudaspii, Kawia sp., Bothriocephalus gowkongensis and Rhabdochona denudata. The infection rate was significantly higher (P<0.05) in C.aculeata while the maximum parasite diversity was found in C.damascina. The infection rate was also signifi­cantly different in four seasons (P<0.05) but no significant differences were found among fishes with different weight and length. High prevalence of Ichthyophthirius multifiliis and Rhabdochona denudata may af­fect native fish population. Monogenean parasites Dactylogyrus akaraicus and D. skrjabiensis collected from B. barbulus and C. capoeta are reported for the first time in Iran. B. barbulus is also reported as a new host for aforementioned parasites.

Although infection of dromedary camels with Cryptosporidium spp. is rare in Iran, it is considered a zoonotic threat to the keepers and herders of camels. Thus we investigated the prevalence of Cryptosporidium in these two hosts in Yazd Province, a semi-arid region in center of Iran. This study was conducted during 4 seasons (winter 2008, summer 2009, winter 2009 and summer 2010). Fecal samples (n=200) were collected from live camels. Also, 100 abomasal mucosa and related fecal samples of the slaughtered camels were investigated. Stool samples from 100 individuals who were in persistent contact with camels were also obtained. After staining by modified Ziehl-Neelsen method, the prepared specimens were studied microscopically. Re­sults were analyzed using SPSS 16. The rate of infection in feces and abomasal mucosa of camels were 20.33% and 12%, respectively. In addition, simultaneous fecal and mucosal infection was detected in 3 cases in winter. Statistical analyses showed no significant relation between infection and age of camels, as well as their sex and the season. Cryptosporidiosis in people who were in long-term contact with camels was also investi­gated microscopically by obtaining stool samples of 100 individuals (50 in summers, 50 in winters), 24 of them being infected with Cryptosporidium spp. The rate of infection was higher in winter than summer (16/50 compared with 8/50). The prevalence of Cryptosporidium spp. in camels and involved humans in Yazd Prov­ince is relatively considerable and of public health importance.

Pediculosis (head lice) is considered as one of the most common health problems of the students in primary schools. The purpose of this study was to survey the prevalence rate of the infesta­tion in the schools of Gonabad City (south of Khorasan-e-Razavi Province) to prevent its out­break by on-time planning. In this retrospective-descriptive study, data were collected from the files of recorded health examinations of 55,997 female and male students of Gonabad City. We surveyed the in­fested cases to Pediculus capitis and P. corporis during 2006-2010. We used schools health unit of the city health center and review reports of infestation to head lice and body lice in cumulative centers. The reports showed 398 cases of P. capitis and 3 P. corporis infestations, which 91.5% were female (P <0.05). Generally 46.4% were from rural and 63.6% were from urban areas (P <0.05). 71.3% of the infestation to head lice was from the last month and the rest had recently been infested. The most age group being infested were students of 6-10 years old and the lowest were >17 yr. Pediculosis infestation has become a major health problem in primary school stu­dents in south of Khorasan-e-Razavi.

Development of new natural agents for parasitic diseases treatment has unexpec­tedly increased to overcome effectively against emergence and re-emergence of parasitic diseases, the appearance of drug resistant organisms and toxic side effects of current agents. The aim of the study was to evaluate antiprotozoal activities of chitosan biomolecule on trophozoites of Trichomo­nas gallinae. The antitrichomonal activity of various low molecular weight chitosan concentrations including 125, 250, 500 and 1250 μg ml-1 against T. gallinae trophozoites cultured in trypticase-yeast extract-maltose medium supplemented with heat-inactivated cold horse serum was eva­luated in vitro. Samples containing medium without chitosan were also assayed as controls. The mortality rates at 0, 3 and 6 h post treatment with all concentrations were signifi­cantly different from control group (P<0.05). Treated trophozoites showed more susceptibility to the highest concentration reaching mortality rate of 100% at 3h post inoculation. However, at this time, results for 125, 250 and 500 μg ml-1 were 93%, 95% and 96.7%, respectively. The results demonstrate that the application of chitosan biomolecule is a promising option for treatment of trichomoniasis in pigeons.

A number of methods for detecting diversity in Entamoeba have been described over the years. In the present study the genetic polymorphism of noncoding locus A-L was ana­lyzed using PCR and sequencing in order to clarify the genotypic differences among E. dispar isolates. A total of 28 E. dispar from patients with gastrointestinal symptoms were determined and the genomic DNA was extracted directly from stool. For genotype analysis; Locus A-L was amplified by PCR and PCR products were sequenced. The sequences obtained were edited ma­nually and aligned using Gene Runner software. With sequencing of PCR products a reliable genetic diversity in size, number and posi­tion of the repeat units were observed among the Iranian E. dispar isolates in locus A-L gene. Se­quences showed variation in length from 448bp to 507bp and seven distinct types were identified. The genetic diversity of loci like A-L shows them to be suitable for epidemiological studies such as the characterization of the routes of transmission of these parasites in Iran.

We report a case of human nasal nosocomial myiasis in a 69-year-old rural man with numerous live maggots in nostrils. The patient was admitted in Emergency Ward due to dyspnea. After 72 hours the companion of patient discovered larva. The presence of the third instar larva indicated that the infestation was not more than three days. The collected instars were cleared, fixed and morphological studies then were carried out precisely and the larva was identified as Lucilia sericata.