The role of chewing lice (Phthiraptera: Philopteridae) as intermediate hosts in the transmission of Hymenolepis microps (Cestoda: Cyclophyllidea) from the willow ptarmigan Lagopus lagopus (Aves: Tetraonidae).

The cestode Hymenolepis microps is an intestinal parasite of tetraonid birds, including the willow ptarmigan (Lagopus lagopus). This parasite is able to maintain a high prevalence and intensity throughout the year, even in a subarctic environment in bird populations with relatively low host densities, indicating effective transmission routes. Willow ptarmigan consume mainly vegetal material and active consumption of invertebrates is confined to the first two or three weeks of life. Ptarmigan are infected by different species of ectoparasites, of which two species of feather lice, Lagopoecus affinis and Goniodes lagopi, are the most abundant. In this study, we explored the hypothesis that feather lice may be suitable intermediate hosts for H. microps. We applied histological techniques and light microscopy to investigate lice for the presence of larval cestode stages (cysticercoids). We found 12 cysticercoid-like structures inside chewing lice collected on L. lagopus hosts harbouring H. microps. In addition, a polymerase chain reaction (PCR) screening of Ischnocera lice DNA, targeting the 18S rRNA gene of the cestode, showed positive results for two different short fragments of the 18S rRNA gene of H. microps which were sequenced from lice collected on birds. Both independent lines of evidence support the hypothesis that Ischnocera lice might be suitable intermediate hosts in the life cycle of H. microps in L. lagopus.

Prevalence of Hymenolepis nana and H. diminuta from Brown Rats (Rattus norvegicus) in Heilongjiang Province, China.

Hymenolepis nana and Hymenolepis diminuta are globally widespread zoonotic cestodes. Rodents are the main reservoir host of these cestodes. Brown rats (Rattus norvegicus) are the best known and most common rats, and usually live wherever humans live, especially in less than desirable hygiene conditions. Due to the little information of the 2 hymenolepidid species in brown rats in China, the aim of this study was to understand the prevalence and genetic characterization of H. nana and H. diminuta in brown rats in Heilongjiang Province, China. Total 114 fecal samples were collected from brown rats in Heilongjiang Province. All the samples were subjected to morphological examinations by microscopy and genetic analysis by PCR amplification of the mitochondrial cytochrome c oxidase subunit 1 (COX1) gene and the internal transcribed spacer 2 (ITS2) region of the nuclear ribosomal RNA gene. In total, 6.1% (7/114) and 14.9% (17/114) of samples were positive for H. nana and H. diminuta, respectively. Among them, 7 and 3 H. nana isolates were successfully amplified and sequenced at the COX1 and ITS2 loci, respectively. No nucleotide variations were found among H. nana isolates at either of the 2 loci. Seventeen H. diminuta isolates produced 2 different COX1 sequences while 7 ITS2 sequences obtained were identical to each other. The present results of H. nana and H. diminuta infections in brown rats implied the risk of zoonotic transmission of hymenolepiasis in China. These molecular data will be helpful to deeply study intra-specific variations within Hymenolepis cestodes in the future.

Senna leaf extracts induced Ca(+2) homeostasis in a zoonotic tapeworm Hymenolepis diminuta.

Context Plants and plant products have been used in traditional medicine as anthelmintic agents in human and veterinary medicine. Three species of Senna plant, S. alata (L), S. alexandrina (M) and S. occidentalis (L.) Link (Fabaceae) have been shown to have a vermicidal/vermifugal effect on a zoonotic tapeworm Hymenolepis diminuta (Rudolphi) (Cyclophyllidean). Objective The present study validates the mode of action of these Senna plants on the parasite. The alcoholic leaf extract was determined to obtain information on the intracellular free calcium concentration level. Materials and methods Hymenolepis diminuta was maintained in Sprague-Dawley rat model for 2 months. Live parasites collected from infected rat intestine were exposed to 40 mg/mL concentration of each plant extracts prepared in phosphate buffer saline at 37 °C, till parasite gets paralyzed. The rate of efflux of calcium from the parasite tissue to the medium and the level of intracellular Ca(2+ )concentration were determined by an atomic absorption spectroscopy. Results This study revealed that exposure of the worms to the plant extract leads to disruption in intracellular calcium homeostasis. A significant increase (44.6% and 25%) of efflux in Ca(2+ )from the tissue to the incubated medium was observed. Senna alata showed high rate of efflux (5.32 mg/g) followed by S. alexandria and S. occidentalis (both 4.6 mg/g) compared with control (3.68 mg/g). Discussion and conclusion These results suggest that leaf extracts caused membrane permeability to Ca(2+ )after vacuolization of the tegument under stress and the extracts may contain compound that can be used as a chemotherapeutic agent.

The complete mitochondrial genome of the dwarf tapeworm Hymenolepis nana--a neglected zoonotic helminth.

Hymenolepis nana, commonly known as the dwarf tapeworm, is one of the most common tapeworms of humans and rodents and can cause hymenolepiasis. Although this zoonotic tapeworm is of socio-economic significance in many countries of the world, its genetics, systematics, epidemiology, and biology are poorly understood. In the present study, we sequenced and characterized the complete mitochondrial (mt) genome of H. nana. The mt genome is 13,764 bp in size and encodes 36 genes, including 12 protein-coding genes, 2 ribosomal RNA, and 22 transfer RNA genes. All genes are transcribed in the same direction. The gene order and genome content are completely identical with their congener Hymenolepis diminuta. Phylogenetic analyses based on concatenated amino acid sequences of 12 protein-coding genes by Bayesian inference, Maximum likelihood, and Maximum parsimony showed the division of class Cestoda into two orders, supported the monophylies of both the orders Cyclophyllidea and Pseudophyllidea. Analyses of mt genome sequences also support the monophylies of the three families Taeniidae, Hymenolepididae, and Diphyllobothriidae. This novel mt genome provides a useful genetic marker for studying the molecular epidemiology, systematics, and population genetics of the dwarf tapeworm and should have implications for the diagnosis, prevention, and control of hymenolepiasis in humans.

[A rare case of Hymenolepis diminuta infection in a small child]. / Nadir bir olgu olarak küçük bir çocukta Hymenolepis diminuta enfeksiyonu.

Unlike Hymenolepis nana that transmits directly from person to person, the transmission of Hymenolepis diminuta to human is via accidentally ingesting of arthropods carrying cysticercoid larvae as intermediate host. In places with poor hygienic conditions, this cestod may cause seldom infections especially in children. Studies carried out on various populations have reported the prevalence rate of H.diminuta between 0.001% and 5.5%. Although the reported cases are mostly children, the disease can be seen in every age group. In this report, a pediatric case of H.diminuta infection is presented. A twenty one-month-old male patient with the symptoms of vomiting 3-4 times a day along with mud-like diarrhea continuing for a week was admitted to the pediatric outpatient clinic. According to the history, it was learned that the house where he lived was above a barn and there was a history of insect swallowing. Laboratory findings revealed iron-deficiency anemia. The macroscopic appearance of the stool was in a pale clay-like form, and by direct microscopic examination with lugol solution, 70-75 µm in diameter, thick-shelled and six central hookleted eggs that are characteristic for H.diminuta were identified. A six-day course of oral niclosamide was administered to the patient beginning with 500 mg on the first day and 250 mg on the following five days, together with the treatment for the iron deficiency anemia. After fifteen days, the oral niclosamide treatment was repeated. No H.diminuta eggs were detected in the parasitological examination performed one month after completion of the second round of treatment. This case has been presented to call attention to the importance of patient anamnesis and microscopic examination in the diagnosis of H.diminuta infection which is a rarely seen parasitosis.

[Parasitological monitoring as part of epidemiological surveillance of helminthiasis in the Russian Federation].

The paper presents data on the prevalence of helminthiasis in Russia on the basis of the State Reports on the sanitary and epidemiological situation in the Russian Federation. It comparatively characterizes morbidity rates in 2010-2012. Morbidity analysis has revealed the main reasons for the prevalence of parasitic diseases and the possible ways of their elimination.

[Intestinal parasitosis and environmental pollution: 1343 pediatric cases in Beni-Mellal, Morocco]. / Parasitoses intestinales et pollution de l'environnement: cas de 1343 enfants à Beni-Mellal--Maroc.

This study was undertaken to determine the possible health risk associated with raw wastewater use in agricultural purposes, particularly, the transmission of parasite infections among children of five regions in Beni-Mellal, Morocco. In a randomly-selected sample of 1343 children, 740 of them were from five regions using raw wastewater for agriculture, and 603 were from 4 control regions that do not practice wastewater irrigation. One or more parasite infections were identified in 50.8% of the children living in the wastewater re-use regions and in 8.2% only of the others. The seven parasites identified were Entamoeba histolytica, Giardia intestinalis, Ascaris lumbricoides, Trichuris trichiura, Enterobius vermicularis, Hymenolepis nana, Taenia saginata, which infected 34.3%, 5.1%, 20.5%, 0.4%, 5.2%, 7.2%, 0.5% in the exposed population and 4.3%, 0.3%, 3.8%, 0.3%, 1.0%, 0.6% and 0.0% in the control population respectively. In conclusion, raw wastewater use in Beni-Mellal lead to a high risk of parasite infections. Adequate treatment of wastewater is highly recommended.

Predation of beetles (Tenebrio molitor) infected with tapeworms (Hymenolepis diminuta): a note of caution for the manipulation hypothesis.

Previous laboratory studies have indicated that tenebrionid beetles infected with Hymenolepis diminuta display behavioural alterations. These are assumed to increase the likelihood of this intermediate host being predated by the Rattus sp. definitive host, and hence provide support for the Manipulation Hypothesis. We tested this hypothesis by both assessing beetle behaviour and predation rates in semi-naturalistic environments. Behavioural assays showed that infected beetles were more often exposed (not concealed under boxes) than uninfected beetles. However, there were no differences in predation rates between infected and uninfected beetles. We discuss this in terms of the historical and evolutionary contexts under which such altered behaviours could evolve and their implications for the Manipulation Hypothesis.

[An analysis of the results of clinical trials of praziquantel analogs in intestinal cestode and trematode infections. 1. The treatment of intestinal cestode infections (diphyllobothriasis, taeniasis, hymenolepiasis)]. / Analiz rezul'tatov klinicheskikh ispytanii analogov prazikvantelia pri kishechnykh tsestodozakh i trematodozakh. 1. Lechenie kishechnykh tsestodozov (difillobrotrioz, teniidozy, gimenolepidoz).

The studies have demonstrated a high efficacy of prasiquantel in therapy of enteric cestodiases. No differences in the efficacy and tolerance of prasiquantel analogs manufactured by various pharmaceutic firms (azinox, CIS; pikiton, China; biltricide, Bayer, India; cesol, Merk, India; cisticide, Merk India) were detected. Prasiquantel single dose (15 mg/kg) efficacies in diphyllobothriasis, taeniarhynchiasis, and taeniasis made up 91.4, 98.5, and 100%, respectively. In hymenolepiasis the efficacy of a total dose (40 and 50 mg/kg given twice with a 10-day interval) was 88.9%.

[Parasitoses of food origin in Tunisia]. / Les parasitoses d'origine alimentaire en Tunisie.

About diet parasitosis, the author distincts three origins of contamination: telluric, proteinic, and both. The telluric parasitosis are the most frequent, intestinal (by helminths or protozoairs) as visceral (hydatidosis). The frequence of these parasitosis is subjected to changes in the different areas, in intensity, but also in the nature of identified parasite. Toxoplasmosis, transmitted by the two mods occurs in Tunisia. The population average percentage protection is however no sufficient to prevent the risk of contamination during pregnancy.

Observations on coprophagy and the transmission of Hymenolepis nana infections in mice.

Young, previously uninfected white mice became infected with Hymenolepis nana when exposed in small cages to parasite eggs which had been sprinkled in suspension onto the floor of their cage, or to faeces from mice with patent infections. The mean daily probabilities of infection for individual eggs under these two conditions were 2-9 X 10(-6) and 5-4 X 10(-6) respectively. If the mice were starved for 24 h prior to exposure to faeces, then the mean daily probability of infection increased to 2-6 X 10(-4). These differences in transmission are interpreted as being due to differences in the extent of coprophagy; they are not due to any effect of starvation on the hatchability of eggs.