Copro-PCR prevalence of Echinococcus granulosus infection in dogs in Kerman, south-eastern Iran.

The main objective of this study was to determine the prevalence of taeniid parasites and the specific detection of Echinococcus granulosus using copro-DNA polymerase chain reaction (PCR) analysis in the stray dogs of Kerman, south-eastern Iran. From September 2013 to May 2014, faecal samples of stray dogs were collected from different parts of the city of Kerman and its suburbs. Faecal samples from dogs were collected randomly within 24 h of defecation. All samples were transferred to the research lab and coprological examinations were conducted by the formalin-ether concentration method. In the microscopically positive samples, mitochondrial cytochrome c oxidase subunit 1 (cox1) specific primers were used to determine the taeniid identity of the infection. In addition, another set of primers was used for the specific diagnosis of E. granulosus sensu lato. In total, 307 faecal samples from stray dogs were examined for the presence of the parasites. Taeniidae eggs were detected in 34 dogs (11.07%). All 34 taeniid-positive specimens were PCR positive for cox1 (444 bp). Of all taeniid-positive specimens, 21 samples (6.8% of all dog specimens) were positive according to primers specific for E. granulosus. The findings of the present study revealed that canine echinococcosis is prevalent in the stray dogs in Kerman. The findings of the present study have important implications for hydatid control programmes in the area.

Global Distribution of Alveolar and Cystic Echinococcosis.

Alveolar echinococcosis (AE) and cystic echinococcosis (CE) are severe helminthic zoonoses. Echinococcus multilocularis (causative agent of AE) is widely distributed in the northern hemisphere where it is typically maintained in a wild animal cycle including canids as definitive hosts and rodents as intermediate hosts. The species Echinococcus granulosus, Echinococcus ortleppi, Echinococcus canadensis and Echinococcus intermedius are the causative agents of CE with a worldwide distribution and a highly variable human disease burden in the different endemic areas depending upon human behavioural risk factors, the diversity and ecology of animal host assemblages and the genetic diversity within Echinococcus species which differ in their zoonotic potential and pathogenicity. Both AE and CE are regarded as neglected zoonoses, with a higher overall burden of disease for CE due to its global distribution and high regional prevalence, but a higher pathogenicity and case fatality rate for AE, especially in Asia. Over the past two decades, numerous studies have addressed the epidemiology and distribution of these Echinococcus species worldwide, resulting in better-defined boundaries of the endemic areas. This chapter presents the global distribution of Echinococcus species and human AE and CE in maps and summarizes the global data on host assemblages, transmission, prevalence in animal definitive hosts, incidence in people and molecular epidemiology.

Molecular and morphological characterization of the tapeworm Taenia hydatigena (Pallas, 1766) in sheep from Iran.

Although Taenia hydatigena is one of the most prevalent taeniid species of livestock, very little molecular genetic information exists for this parasite. Up to 100 sheep isolates of T. hydatigena were collected from 19 abattoirs located in the provinces of Tehran, Alborz and Kerman. A calibrated microscope was used to measure the larval rostellar hook lengths. Following DNA extraction, fragments of cytochrome c oxidase 1 (CO1) and 12S rRNA genes were amplified by the polymerase chain reaction method and the amplicons were subjected to sequencing. The mean total length of large and small hooks was 203.4 µm and 135.9 µm, respectively. Forty CO1 and 39 12S rRNA sequence haplotypes were obtained in the study. The levels of pairwise nucleotide variation between individual haplotypes of CO1 and 12S rRNA genes were determined to be between 0.3-3.4% and 0.2-2.1%, respectively. The overall nucleotide variation among all the CO1 haplotypes was 9.7%, and for all the 12S rRNA haplotypes it was 10.1%. A significant difference was observed between rostellar hook morphometry and both CO1 and 12S rRNA sequence variability. A significantly high level of genetic variation was observed in the present study. The results showed that the 12S rRNA gene is more variable than CO1.

Genetic characterization of Echinococcus granulosus in camels, cattle and sheep from the south-east of Iran indicates the presence of the G3 genotype.

Echinococcus granulosus, the aetiologic agent of cystic echinococcosis (CE), is one of the most important zoonotic helminthes worldwide. Isolates of the parasite show considerable genetic variation in different intermediate hosts. Several genotypes and species are described in different eco-epidemiological settings. This study investigated E. granulosus genotypes existing in livestock and humans from the province of Kerman, located in south-eastern Iran, using sequencing data of cox1 and nad1 mitochondrial genes. Fifty-eight E. granulosus isolates, including 35 from sheep, 11 from cattle, 9 from camels and 3 from goats, were collected from slaughterhouses throughout Kerman. One human isolate was obtained from a surgical case of CE. Mitochondrial cox1 and nad1 regions were amplified using polymerase chain reaction (PCR) and 38 isolates were sequenced. Genotypes G1 (73.7%), G3 (13.2%) and G6 (13.1%) were identified from the isolates. G1 was the most common genotype from sheep (86.7%), cattle (80%), camels (44.4%) and goats (100%). Sheep, cattle and camels were also found to be infected with the G3 genotype (buffalo strain). The human isolate was identified as the G6 genotype. Results showed that the G3 genotype occurred in different animal hosts in addition to G1 and G6 genotypes.

Sonographical and serological survey of human cystic echinococcosis and analysis of risk factors associated with seroconversion in rural communities of Kerman, Iran.

Cystic echinococcosis (CE) caused by larval stage of Echinococcus granulosus, is an endemic zoonosis in Iran particularly in rural regions. The objective of this study was to determine the prevalence of CE among rural communities in Kerman using ultrasonography (US) and serology. Kerman Province, in southeastern Iran, is the largest province, with 2.9 million inhabitants. A sample of 1140 individuals (200 males and 940 females) was selected by randomized cluster sampling in 2006-2008. After acquiring informed consent for each participant a questionnaire was filled, complete abdominal US in supine position was carried out and 5 ml blood was collected for ELISA test. Two hydatid cases (0.2%) were detected by ultrasound. Serological results showed 7.3% seropositivity, and females (8.3%) were significantly more positive than males (2.1%). There were significant difference between CE seropositivity and sex, age and occupation. Residents of desert regions (Shahdad, Andouhjerd and Golbaf) were 2.5 times more likely to be seropositive than mountainous regions with better socioeconomic status (OR = 2.5; 95% CI = 1.09-5.95). Dog ownership does not appear to be a significant risk factor for CE in the region. Only about 10% of households own dogs, usually only one dog. However, the stray dog population of Kerman province is estimated at 145 000-480 000 (3.5-11.5 times the owned dog population). Infection in humans and animals would appear to come mostly from infected stray dogs. Management of stray dog population could make major progress in control of hydatid disease. In addition, proper washing of vegetables decreased probability of infection by 53% (OR = 0.47; 95% CI = 0.26-0.84). The serological study showed that many people, especially women, had been exposed to Echinococcus eggs and had seroconverted but were not infected.