Clinical and haematological characteristics of human trichostrongyliasis.

Trichostrongylus spp. are primarily parasites of ruminants, but humans can become infected as accidental hosts. Information about the clinical aspects of human trichostrongyliasis is limited. This study investigated the clinical and haematological characteristics of a large number of trichostrongyliasis patients. In the Fouman district of Guilan Province in northern Iran, during 2015-2016, 60 patients were identified as positive for Trichostrongylus spp., using stool examination methods. The clinical manifestations and demographic data of all patients were recorded and further analysed. Twenty-three patients (38.3%) were male and 37 (61.7%) were female. Among the individuals infected only with Trichostrongylus, only nine patients (16.4%) were asymptomatic. Forty-six patients (83.6%) presented with gastrointestinal (76.3%), pulmonary (30.9%) and cutaneous (12.7%) symptoms. No statistically significant relationship was found between clinical manifestations and sex or age groups. Ten patients (18.1%) revealed eosinophilia and five (9.1%) presented with hypochromic microcytic anaemia. The relationship between eosinophilia and age group, sex and clinical manifestations showed no statistical significance. Our study indicated that trichostrongyliasis may be a major parasitic aetiology for gastrointestinal symptoms and eosinophilia in rural residents of endemic areas.

Molecular analysis of isolates of the cestode Rodentolepis nana from the great gerbil, Rhombomys opimus.

Rodentolepis nana (syn. Hymenolepis nana) is a cyclophyllidean zoonotic enteric parasite with worldwide distribution. In humans, it is more prevalent in children, especially in temperate zones. A morphologically similar species of R. nana occurs in different rodents, including gerbils. In the present study molecular characterization of five isolates of R. nana from Rhombomys opimus in the Golestan Province (n= 2) and Razavi Khorasan Province (n= 3), both in north-eastern Iran, were analysed. After DNA extraction, the internal transcribed spacer 2 (ITS2) region of the R. nana isolates was amplified and sequenced, and genetic variation was analysed. Accordingly, two isolates from the Razavi Khorasan Province showed ITS2 signatures that differed from the isolates from the Golestan Province. The third isolate from Razavi Khorasan did not reveal these specific signatures, but exhibited sparse nucleotide polymorphisms in the ITS2 sequence. The ITS gene is conserved, and variation in this fragment could be an interesting subject for further inspection of existing variation in the genome of R. nana, among different domestic and wildlife host species and from different areas.

Sequence variation in mitochondrial cox1 and nad1 genes of ascaridoid nematodes in cats and dogs from Iran.

The study was conducted to determine the sequence variation in two mitochondrial genes, namely cytochrome c oxidase 1 (pcox1) and NADH dehydrogenase 1 (pnad1) within and among isolates of Toxocara cati, Toxocara canis and Toxascaris leonina. Genomic DNA was extracted from 32 isolates of T. cati, 9 isolates of T. canis and 19 isolates of T. leonina collected from cats and dogs in different geographical areas of Iran. Mitochondrial genes were amplified by polymerase chain reaction (PCR) and sequenced. Sequence data were aligned using the BioEdit software and compared with published sequences in GenBank. Phylogenetic analysis was performed using Bayesian inference and maximum likelihood methods. Based on pairwise comparison, intra-species genetic diversity within Iranian isolates of T. cati, T. canis and T. leonina amounted to 0-2.3%, 0-1.3% and 0-1.0% for pcox1 and 0-2.0%, 0-1.7% and 0-2.6% for pnad1, respectively. Inter-species sequence variation among the three ascaridoid nematodes was significantly higher, being 9.5-16.6% for pcox1 and 11.9-26.7% for pnad1. Sequence and phylogenetic analysis of the pcox1 and pnad1 genes indicated that there is significant genetic diversity within and among isolates of T. cati, T. canis and T. leonina from different areas of Iran, and these genes can be used for studying genetic variation of ascaridoid nematodes.

Trichinella britovi in the jackal Canis aureus from south-west Iran.

Trichinellosis is an important helminthic food-borne zoonosis, which is caused by nematodes of the genus Trichinella. Although, Trichinella spp. has been detected frequently in Iranian wildlife, this parasitic infection is not considered a major public health problem. This is largely because Islamic codes forbid consumption of pork meat in this country. However, knowledge about this zoonotic pathogen is important because human trichinellosis has been documented in countries where most of the population is Muslim. The aims of the present work were to investigate whether Trichinella spp. was still circulating in wildlife of the Khuzestan Province (south-west Iran) about 30 years after the first investigation, to identify the aetiological agent at the species level by molecular analyses, and to review the literature on Trichinella spp. in animals of Iran. During the winter 2009-2010, muscle samples from 32 road-killed animals (14 dogs and 18 jackals, Canis aureus) were collected. Muscle samples were digested and Trichinella sp. larvae were isolated from two jackals. The Trichinella sp. larvae have been identified as Trichinella britovi by molecular analyses. These results confirm that T. britovi is the prevalent species circulating in wild animals of Iran.

Evidence that the Echinococcus granulosus G6 genotype has an affinity for the brain in humans.

The present study investigates the molecular characteristics of cerebral Echinococcus cysts. A total of 10 specimens of cerebral Echinococcus cysts, including six formalin-fixed paraffin blocks and four intact cerebral cysts, were used for this study. The target DNA was successfully amplified from eight samples and sequenced. BLAST analysis indicated that sequenced isolates belong to the Echinococcus granulosus (G6) genotype. All of the eight sampled brain cysts belonged to the G6 genotype, while all of the eight liver cysts belonged to G1. This is a strong indication that G6 has a higher affinity for the human brain than G1.

Comparison of six simple methods for extracting ribosomal and mitochondrial DNA from Toxocara and Toxascaris nematodes.

Six simple methods for extraction of ribosomal and mitochondrial DNA from Toxocara canis, Toxocara cati and Toxascaris leonina were compared by evaluating the presence, appearance and intensity of PCR products visualized on agarose gels and amplified from DNA extracted by each of the methods. For each species, two isolates were obtained from the intestines of their respective hosts: T. canis and T. leonina from dogs, and T. cati from cats. For all isolates, total DNA was extracted using six different methods, including grinding, boiling, crushing, beating, freeze-thawing and the use of a commercial kit. To evaluate the efficacy of each method, the internal transcribed spacer (ITS) region and the cytochrome c oxidase subunit 1 (cox1) gene were chosen as representative markers for ribosomal and mitochondrial DNA, respectively. Among the six DNA extraction methods, the beating method was the most cost effective for all three species, followed by the commercial kit. Both methods produced high intensity bands on agarose gels and were characterized by no or minimal smear formation, depending on gene target; however, beating was less expensive. We therefore recommend the beating method for studies where costs need to be kept at low levels.

Occurrence of Clinostomum complanatum in Aphanius dispar (Actinoptrygii: Cyprinodontidae) collected from Mehran River, Hormuzgan Province, South of Iran.

OBJECTIVE: To investigate the possibility of Aphanius dispar (A.dispar) acting as intermediate host for Clinostomum complanatum (C. complanatum), from Mehran River, Hormuzgan Province of Iran. METHODS: During a biological study of A. dispar in Mehran River, Hormuzgan Province, South of Iran, a total of 97 fish specimens were collected in 24 January 2006. RESULTS: 4 specimens (4.12%) including 1 male and 3 female were found infected with C. complanatum metacercaria. These metacercaria were coiled in the epiderm on the body surface of infected fishes. The infection is known as yellow spot disease. The parasite abundance, intensity and prevalence were 0.05%, 1.25% and 4.12%, respectively. The infection was higher in females than males. CONCLUSIONS: To the best of our knowledge, this is the first report on occurrence of C. complanatum metacercaria in A. dispar in Iran.

Prevalence of bovine cysticercosis in slaughtered cattle in Iran.

Bovine cysticercosis is an important food safety issue and can cause economic loss. A cross sectional study on Taenia saginata cysticercosis was carried out in slaughtered cattle in Iran in order to determine the infection rate during a three-years period, from 2005 to 2007. A total of 4,534,105 cattle were examined by routine meat inspection. The results showed that 11,410 cattle (0.25 %) were infected with Cysticercus bovis; among those 1,041 carcasses (0.02%) were condemned. In such carcasses the metacestodes caused extensive damage in the vicinity of cysts in infected cattle. The rejected carcasses had an average of 410 thousands USD loss annually.

The first occurrence of Trichinella murrelli in wild boar in Iran and a review of Iranian trichinellosis.

Trichinella larvae isolated from the thigh muscle of a wild boar, Sus scrofa, captured from Gilan Province, northern Iran, was processed for DNA analysis. Polymerase chain reaction (PCR) for amplification of the 5S rDNA fragment demonstrated a 700 bp band on agarose gel. Analysis of DNA sequencing by BLAST confirmed the isolate as T. murrelli. This report constitutes the first recorded occurrence of T. murrelli in Asia, and also the first occurrence in a wild boar host.

The occurrence of severe infections with Rhabditis axei in AIDS patients in Iran.

During an investigation on strongyloidiasis in AIDS patients from Iran, direct smears of stools revealed many eggs and larvae of Rhabditis axei, which were subcultured to confirm identification.

Strongyloides stercoralis hyper-infection syndrome in HIV+/AIDS patients in Iran.

Strongyloides stercoralis is an intestinal nematode in humans, distributed through tropical and subtropical regions of the world. In most individuals, the infection has a chronic nature due to auto-infection at the low level. Accelerated auto-infection, mainly after an alteration in immune status, can cause a syndrome of severe hyper-infection or potentially fatal disseminated strongyloidiasis. Due to the increasing numbers of immunocompromised patients in Iran, strongyloidiasis is an emerging public health concern in the country. In the current study, which was carried out between 2003 and 2005, for the investigation on strongyloidiasis in HIV(+)/AIDS patients, a total of 781 patients were examined by agar plate culture, formalin ether concentration, and direct smear preparation of stool samples. According to the results, 2 out of 781 HIV( + )/AIDS patients were found infected with S. stercoralis, but both patients were at the progressive stage of AIDS and showing severe hyper-infection syndrome. In both cases, numerous rhabditiform and filariform larvae were found in fresh stool direct smears, and rapid and intensive development of parasite in agar plate cultures. In conclusion, in the progressive stages of AIDS, as a result of immunosuppression conditions or in the context of chemotherapy, S. stercoralis is capable of inducing overwhelming infection.

Helminth eggs in raw and treated wastewater in the Islamic Republic of Iran.

To assess the type and load of helminths in wastewater and the quality of treatment, we examined the raw and treated wastewater of 8 wastewater treatment plants (WTP) in Tehran and 2 in Isfahan for the presence of helminth eggs during 2002-2003. Wastewater samples obtained from both inlet and effluent of each treatment plant were examined on several occasions using the modified Bailenger method. Untreated entry wastewater in Tehran WTPs contained a larger variety of helminth eggs than those of Isfahan, as well as higher total egg counts. The helminths identified in the influent of Tehran included Ascaris lumbricoides, hookworms, Enterobius vermicularis, Trichostrongylus spp., Taenia spp., Hymenolepis nana and Dicrocoelium dendriticum, while in Isfahan only A. lumbricoides, Trichostriogylus and H. nana were isolated. After treatment, the number of eggs/L fell to < or = 1 egg/L.

Helminth eggs in raw and treated wastewater in the Islamic Republic of Iran

To assess the type and load of helminths in wastewater and the quality of treatment, we examined the raw and treated wastewater of 8 wastewater treatment plants [WTP] in Tehran and 2 in Isfahan for the presence of helminth eggs during 2002-2003. Wastewater samples obtained from both inlet and effluent of each treatment plant were examined on several occasions using the modified Bailenger method. Untreated entry wastewater in Tehran WTPs contained a larger variety of helminth eggs than those of Isfahan, as well as higher total egg counts. The helminths identified in the influent of Tehran included Ascaris lumbricoides, hookworms, Enterobius vermicularis, Trichostrongylus spp., Taenia spp., Hymenolepis nana and Dicrocoelium dendriticum, while in Isfahan only A. lumbricoides, Trichostriogylus and H. nana were isolated. After treatment, the number of eggs/L fell to </= 1 egg/L

Natural infection of the gerbil Meriones lybicus with the metacestode of Taenia endothoracicus in Arak, central Iran.

Polycephalic larvae of Taenia endothoracicus were found from naturally infected gerbils Meriones lybicus in a rural area of Arak, central Iran. A large cyst containing 19 protoscolices was located in the peritoneum, attached to the large omentum. The characteristics of the protoscolices and rostellar hooks confirmed the identification of these larvae as T. endothoracicus.

Frenkelia parasites in a small mammal community. Dynamics of infection and effect on the host.

A community of small mammals, Clethrionomys glareolus, Arvicola terrestris, Microtus arvalis, M. agrestis, M. subterraneus, Apodemus spp. and Sorex spp., was studied as hosts of Frenkelia glareoli and F. microti in Fronche-Comté (France). They were monitored in spring, summer and autumn on an area of about 1,350 ha comprising open field, hedgerow network and forest. Among 1,714 small mammals examined between July 1992 and October 1993, 47% (178/376) of C. glareolus, 9.9% (14/139) of A. terrestris and 1.3% (4/311) of Apodemus spp. were infected by F. glareoli. The prevalence of infection with F. microti was 9.2% (66/716) in M. arvalis and 8.2% (6/73) in M. agrestis. M. subterraneus and Sorex spp. were not infected. The maintenance of each parasite in a rural landscape is assured both by a forest and a grassland host. Multiple logistic regression showed that prevalence was highly age-dependent, with an apparent seasonal pattern. Prevalence varied between 30% in summer and 60% in early spring for F. glareoli in C. glareolus and between 3% in autumn to 30% in early spring for F. microti in M. arvalis. The year, habitat, host sex, relative density had no impact on prevalence. In M. arvalis only, sexually active voles were preferentially uninfected, indicating a possible impact of this parasitism on fertility.