High prevalence of Nova hantavirus infection in the European mole (Talpa europaea) in France.

SUMMARY: Recent discovery of genetically distinct hantaviruses in shrews and moles (order Soricomorpha, family Soricidae and Talpidae) has challenged the conventional view that rodents serve as the principal reservoir hosts. Nova virus (NVAV), previously identified in archival liver tissue of a single European mole (Talpa europaea) from Hungary, represents one of the most highly divergent hantaviruses identified to date. To ascertain the spatial distribution and genetic diversity of NVAV, we employed RT-PCR to analyse lungs from 94 moles, captured in two locations in France, during October 2012 to March 2013. NVAV was detected in more than 60% of moles at each location, suggesting efficient enzootic virus transmission and confirming that this mole species serves as the reservoir host. Although the pathogenic potential of NVAV is unknown, the widespread geographical distribution of the European mole might pose a hantavirus exposure risk for humans.

CARD15 mutations in Blau syndrome.

We have identified three missense mutations in the nucleotide-binding domain (NBD) of CARD15/NOD2 in four French and German families with Blau syndrome. Our findings indicate that, in addition to Crohn disease, CARD15 is involved in the susceptibility to a second granulomatous disorder.

Treatments for pediatric achalasia: Heller myotomy or pneumatic dilatation?

AIM: The treatment of achalasia consists of reducing distal esophageal obstruction by either Heller myotomy surgery or endoscopic pneumatic dilatation. The aim of the present study was to evaluate the short- and middle-term results of these procedures in children. METHODOLOGY: For technical reasons, children under six years old (n=8) were treated by surgery only, whereas patients over six years old (n=14) were treated by either Heller myotomy or pneumatic dilatation. RESULTS: Of the children aged under six years, 75% were symptom-free at six months and 83% at 24 months of follow-up. Of the patients aged over six years, complete remission was achieved by Heller myotomy in 44.5% vs. 55.5% by pneumatic dilatation after six months, and in 40% vs. 65%, respectively, after 24 months. Both pneumatic dilatation and Heller myotomy showed significant rates of failure. CONCLUSION: These results suggest that pneumatic dilatation may be considered a primary treatment in children over six years old. Also, where necessary, Heller myotomy and pneumatic dilatation may be used as complementary treatments.

TNFSF15 polymorphisms are associated with susceptibility to inflammatory bowel disease in a new European cohort.

OBJECTIVES: Inflammatory bowel disease (IBD), e.g., Crohn's disease (CD) and ulcerative colitis (UC), is a complex genetic disorder. Tumor necrosis factor (ligand) superfamily, member 15 (TNFSF15) has been previously identified as a susceptibility gene for CD in Japanese and UK cohorts. This replication study was designed in order to confirm and further validate the role of TNFSF15 in IBD. METHODS: A total of 666 IBD families (corresponding to 2,982 relatives) with European ancestry were genotyped for the rs6478108 and rs7869487 polymorphisms, which define the main TNFSF15 haplotypes previously associated with CD. An association between the main haplotypes and CD, UC and IBD was tested using the Genehunter TDT and Unphased statistics. Caspase recruitment domain 15 (CARD15)/TNFSF15 interaction and genotype/phenotype correlations were also studied. RESULTS: The previously reported "high-risk" haplotype (A) was associated with IBD (P=0.001) (OR=1.25 (1.05-1.50)) and CD (P=0.02) (OR=1.31 (1.03-1.67)) whereas the "protective" (B) haplotype was significantly less transmitted to IBD and CD patients. No interaction between CARD15 and TNFSF15 was detected. We also failed to define a clinical subgroup of CD patients specifically associated with TNFSF15 haplotype A. CONCLUSIONS: This study confirms that TNFSF15 or a closely linked gene is involved in the genetic predisposition to CD.

Inflammatory Bowel Diseases: the genetic revolution.

The genetic component of Inflammatory Bowel Diseases is among the best known for complex genetic disorders. If the functional candidate gene approach was rarely fruitful in the past, genome-wide scans allowed finding several susceptibility genes for Crohn disease including NOD2, IL23R, ATG16L1, IRGM, TNFSF15, a region close to PTGER4, PTPN2, PTPN22, NKX2-3 and many others. Only one gene, ECM1, has been reported for ulcerative colitis alone. We now need to further explore these new genes before to understand their biological role. However they clearly demonstrate the importance of innate immunity and autophagy for Crohn's disease and of the TH-17 differentiation for ulcerative colitis, Crohn's disease and other inflammatory disorders.

[Hemorrhagic ascites revealing duodenal duplication]. / Une ascite hémorragique révélant une duplication duodénale.

Duodenal duplication is a rare congenital disorder of the gastrointestinal tract. The presentation is highly variable. We report a case of duodenal duplication presenting with hemorrhagic ascites in a 3-month-old girl. The diagnosis of duodenal duplication can be made preoperatively by resonance magnetic imaging. Surgical resection of the duplication was performed. Microscopic examination of the specimen confirmed the duodenal duplication. To our knowledge, this is the 1st reported case of hemorrhagic ascites caused by duodenal duplication and demonstrated by resonance magnetic imaging.

Long-term outcome, growth and digestive function in children 2 to 18 years after intestinal transplantation.

OBJECTIVE: Small bowel (SB) transplantation (Tx), long considered a rescue therapy for patients with intestinal failure, is now a well recognised alternative treatment strategy to parental nutrition (PN). In this retrospective study, we analysed graft functions in 31 children after SBTx with a follow-up of 2-18 years (median 7 years). PATIENTS: Twelve children had isolated SBTx, 19 had combined liver-SBTx and 17 received an additional colon graft. Growth, nutritional markers, stool balance studies, endoscopy and graft histology were recorded every 2-3 years post-Tx. RESULTS: All children were weaned from PN after Tx and 26 children remained PN-free. Enteral nutrition was required for 14/31 (45%) patients at 2 years post-Tx. All children had high dietary energy intakes. The degree of steatorrhoea was fairly constant, with fat and energy absorption rates of 84-89%. Growth parameters revealed at transplantation a mean height Z-score of -1.17. After Tx, two-thirds of children had normal growth, whereas in one-third, Z-scores remained lower than -2, concomitant to a delayed puberty. Adult height was normal in 5/6. Endoscopy and histology analyses were normal in asymptomatic patients. Chronic rejection occurred only in non-compliant patients. Five intestinal grafts were removed 2.5-8 years post-Tx for acute or chronic rejection. CONCLUSIONS: This series indicates that long-term intestinal autonomy for up to 18 years is possible in the majority of patients after SBTx. Subnormal energy absorption and moderate steatorrhoea were often compensated for by hyperphagia, allowing normal growth and attainment of adult height. Long-term compliance is an important pre-requisite for long-term graft function.

Molecular detection of divergent trypanosomes among rodents of Thailand.

Herpetosoma is a homogenous subgenus of several dozen named species that are often described as morphologically indistinguishable T. lewisi-like parasites. These trypanosomes normally infect rodents and utilize fleas as vectors. Although this trypanosome subgenus is considered non-pathogenic to normal hosts, some of them are on rare occasion reported in association with human disease. Recently, a T. lewisi-like infection was detected in a sick Thai infant, thus the objective of this study was to investigate the prevalence of T. lewisi infections among different rodents indigenous to Thailand in order to identify possible sources of human cases. Blood was collected from a total of 276 rodents trapped from urban and rural areas of three Thai provinces between 2006 and 2007. These samples were processed for DNA isolation and tested with a PCR assay universal for the genus Trypanosoma, followed by internal transcribed spacer 1 (ITS-1) sequence analysis to identify infections in positive samples. Herpetosoma known as T. lewisi-like trypanosomes were present among Rattus (14.3%) and Bandicota (18.0%) rodent species and salivarian trypanosomes closely related to T. evansi were detected in Leopoldamys (20%) and Rattus (2.0%) species. Herpetosoma were prevalent among rodents associated with both human and sylvatic habitats, while three of the four salivaria-positive rodents were from a forest biotope. A Herpetosoma ITS-1 sequence amplified from one of these samples was 97.9% identical to that reported for T. lewisi in an experimentally infected rat and 96.4% identical to the sequence amplified from blood from a Thai infant. Habitats where rodents were collected significantly affect rodent infection, at least for T. lewisi, suggesting that the degree of anthropization may influence the transmission of Trypanosoma spp. These results suggest that multiple Herpetosoma species or strains are enzootic to Thailand, and that Rattus and Bandicota species are possible sources of human exposure to these parasites.

Is intestinal transplantation the future of children with definitive intestinal insufficiency?

UNLABELLED: Intestinal transplantation (IT) is the newest and most difficult of organ transplantations. The first ever (1987) and the longest surviving (1989) IT were performed in our institution. However, IT still has to demonstrate its benefit to children on long-term parenteral nutrition (PN). We tried to clarify this aspect by looking back at our 13 years' experience. PATIENTS: From 1994 to December 2007, 74 IT were performed in 69 children, 39 with an isolated small bowel (IT), 35 combined with a liver transplant (LITx). The indications were: short bowel syndrome (n = 25), congenital mucosal diseases (n = 22), and motility disorders (n = 22). Median age at transplantation was 5 years (1 - 17 years). Follow-up was 1 to 12 years (median 5 years). RESULTS: Thirty-one children have a functioning graft (42 %), 15/39 IT, 16/35 LITx. They are at home without PN, with a good quality of life. One child is PN-dependent 1.5 years post IT. Post IT, 16 children were detransplanted: 12 early on (1 for mechanical complications, 11 because of resistant rejection; 3 less than 3 years, one 9 years post SBT (chronic rejection). In 2 noncompliant teenagers, PN was reintroduced (one was detransplanted later on). Several years post LITx, 2 children underwent bowel detransplantation due to an acute viral infection complicated with rejection. Twenty-two children died (32 %, 8 IT, 14 LITx), 18 early on from infectious or surgical complications, 4 more than 1 year post IT, 3 after retransplantation (1 in another unit). Bad prognostic factors are multiple previous surgeries, an older age (> 7 y), and chronic intestinal pseudo-obstruction. DISCUSSION: Complications post IT are frequent and life-threatening, especially early on: rejection (IT), infections (LITx). Later on, the rate of complications decreases but remains significant, especially in noncompliant patients. However we describe here a 13-year learning curve; the recent results are encouraging with regard to control of rejection and viral infections. CONCLUSION: Intestinal transplantation is indicated only in selected patients in whom long-term PN cannot be performed safely any more. In every child with intestinal insufficiency, the therapeutic strategy must be discussed early on in order to perform IT at the right time under optimal conditions. IT should evolve from being a "rescue" procedure to becoming a true therapeutic option.

[Medication in infectious acute diarrhea in children]. / Traitement médicamenteux des diarrhées aiguëis du nourrisson et de l'enfant.

Acute infectious diarrhea in children remain still a frequent cause of morbidity. 50 % of them are due to rotavirus. Oral rehydration therapy and early realimentation have drastically reduced their mortality and morbidity. Beside oral or eventually IV rehydration therapy no medication has proven its efficacy based on the main HMO criteria (reduction of over 30 % of the stool output) except racecadotril and loperamide which is contre-indicated for the last one in children less than 2 years old. Other medications such as silicates or some probiotics have shown efficacy on diarrhea duration or stool consistency but not on stool output. They have so no formal indication in infectious diarrhea and should be considered as "comfort" treatment. Antibiotics, beside their indication in shigella, cholera and amibiasis could be used in invasive diarrhea in some debilating conditions or infants less than 3 months.

Factors influencing outcome after intestinal transplantation in children.

We evaluated 131 patients (6 months-14 years) who experienced 21 deaths before listing, 11 continuing on the waiting list, 38 well on home parenteral nutrition, 6 off parenteral nutrition and 59 transplanted (20 girls) aged 2.5 to 15 years, (18 >7 years). They received cadaveric isolated intestine (ITx, n = 31) or liver-small bowel (LITx, n = 32), including right colon (n = 43; 23 LITx) for short bowel (n = 19), enteropathy (n = 20), Hirschsprung (n = 14), or pseudo-obstruction (n = 6). Treatment included tacrolimus, steroids, azathioprine, or interleukin-2 blockers. After 6 months to 10.5 years, the patient and graft survivals were 75% and 54%. Sixteen patients (10 LITx) died within 3 months from surgery (n = 3), bacterial (n = 5) or fungal (n = 6) sepsis, or posttransplant lymphoproliferative disorder (n = 2). Rejection occurred in 27 patients, including 10 steroid-resistant episodes requiring antilymphoglobulins. The grafts were removed due to uncontrolled rejection in seven ITx recipients. Surgical complications were observed in 38 recipients (25 LSBTx) within 2 months, including bacterial (n = 22) or fungal (n = 11) sepsis, cytomegalovirus disease (n=12), adenovirus (n = 11), or posttransplant lymphoproliferative disorder (n = 12). Forty-two children (19 LSBTx) are alive. Weaning from parenteral nutrition was achieved after 42 days (median). Factors related to death or graft loss were pre-Tx surgery (P < .01), pseudo-obstruction (P < .01), age over 7 years (P < .03), fungal sepsis (P < .03), steroid resistant rejection (P < .05), hospitalized versus home patient (P < .01), and retransplantation (P < .05). Colon transplant did not affect the outcome. Interleukin-2 blockers improved isolated ITx (P < .05). Early referral and close monitoring of intestinal failure and related disorders are mandatory to achieve successful ITx.

Crohn's disease in children. Preliminary experience with a laparoscopic approach.

BACKGROUND: Laparoscopic surgery in patients with Crohn's disease (CD) has been demonstrated to have advantages over a conventional approach in children. The aim of this study was to review the children treated for CD with a laparoscopic approach, to report our indications, the surgical procedure, the complications, and to compare the children with pancolitis or ileocaecal (segmental) Crohn's disease. PATIENTS AND METHOD: We reviewed the files of 11 children treated for CD in a single institution between 1999 and 2004 for a retrospective study of clinical and surgical data. Mann-Whitney U-test was used for statistical analysis of nonparametric data. RESULTS: Eleven children were operated. The average age when initial clinical symptoms became apparent was 12.1 years (range 6.6 - 15), and surgery was performed after an average of 3.4 years of disease (range 1 - 7.6). The surgical indications were stenosis in 6 cases, failure to thrive in 1 case (segmental CD, SCD group) and pancolitis refractory to medical treatment in 4 cases (pancolitis group, PCD group). Mean operative time was 207 minutes (range 140 - 270) for the SCD group and 285 minutes (range 260 - 300) for the PCD group (p < 0.05). Three cases needed a conversion to open surgery (2 in PCD group, one in SCD group), mainly in relation to anastomosis performed with an EEA stapler. The average length of surgical unit stay was 6.5 days (range 4 - 8) for the PCD group and 6.4 days (range 4 - 8) for the SCD group; average follow-up was 16 months (range 3 - 38). Two patients had a relapse of CD (stenosis of the anastomosis in one, skin fistula in the other). CONCLUSION: A laparoscopic approach for ileocolic resection in Crohn's disease is a feasible procedure, even in cases of pancolitis. We recommend an extra-corporeal anastomosis because, in relation to the inflammatory bowel, the mechanical anastomosis is not a safe procedure in cases of pancolitis.

Molecular cloning and characterization of a rat intestinal sucrase-isomaltase cDNA. Regulation of sucrase-isomaltase gene expression by sucrose feeding.

To investigate the regulation of expression of intestinal sucrase-isomaltase (SI) complex in response to sucrose feeding, we isolated a cDNA (RPSI1) encoding partially the pro-SI of rat intestinal mucosa. The clone consists of 1929 mRNA-derived nucleotides, which covered the region including the C-terminal part of the isomaltase and the N-terminal part of the sucrase in the final SI complex. Nucleotide and amino-acid sequences of RPSI1 were compared with their corresponding regions in rabbit pro-SI. A greater similarity was found in sucrase parts than in isomaltase parts of the two species. Northern blot analysis revealed that the mRNA levels of SI increased rapidly after sucrose force feeding, while those of rats fed a carbohydrate-free diet did not. These changes in mRNA levels correlated with the corresponding enzyme activities. The results demonstrate that the induction of SI activities is directly associated with an increase in SI mRNA levels. Our results also suggest that circadian modulation of SI transcription may occur in basic SI gene expression.

Sizing up human health through remote sensing: uses and misuses.

Following the launch of new satellites, remote sensing (RS) has been increasingly implicated in human health research for thirty years, providing a growing availability of images with higher resolution and spectral ranges. However, the scope of applications, beyond theoretical large potentialities, appears limited both by their technical nature and the models developed. An exhaustive review of RS applications in human health highlights the real implication thus far regarding the diversity and range of health issues, remotely sensed data, processes and interpretations. The place of RS is far under its expected potential, revealing fundamental barriers in its implementation for health applications. The selection of images is done by practical considerations as trivial as price and availability, which are often not relevant to addressing health questions requiring suitable resolutions and spatio-temporal range. The relationships of environmental variables from RS, geospatial data from other sources for health investigations are poorly addressed and usually simplified. A discussion covering the potential of RS for human health is developed here to assist health scientists deal with spatial and temporal dynamics of health, by finding the most relevant data and analysis procedures.

Genetic refinement and physical mapping of a chromosome 16q candidate region for inflammatory bowel disease.

Crohn's disease (CD) is a complex genetic disorder for which a susceptibility gene, IBD1, has been mapped within the pericentromeric region of chromosome 16. In order to refine the location of IBD1, 77 multiplex CD families were genotyped for 26 microsatellite markers evenly spaced by approximately 1 cM. Nonparametric linkage analyses exhibited a maximum NPL score of 3.49 (P=2.37x10(-4)) in a region centred by markers D16S3136, D16S3117 and D16S770. Simulation studies showed that the probability for IBD1 to be located in a 5 cM region around these markers was 70%. A 2.5 Mb YAC and BAC contig map spanning this genetic region on chromosome band 16q12 was built. TDT analyses demonstrated suggestive association between the 207 bp allele of D16S3136 (P<0.05) and a new biallellic marker hb27g11f-end (P=0.01). These markers were located in the hb27g11 and hb87b10 BAC clones from the contig. Taken together, the present results provide a crucial preliminary step before an exhaustive linkage disequilibrium mapping of putatively transcribed regions to identify IBD1.

Host-parasite coevolution: comparative evidence for covariation of life history traits in primates and oxyurid parasites.

The environmental factors that drive the evolution of parasite life histories are mostly unknown. Given that hosts provide the principal environmental features parasites have to deal with, and given that these features (such as resource availability and immune responses) are well characterized by the life history of the host, we may expect natural selection to result in covariation between parasite and host life histories. Moreover, some parasites show a high degree of host specificity, and cladistic analyses have shown that host and parasite phylogenies can be highly congruent. These considerations suggest that parasite and host life histories may covary. The central argument in the theory of life history evolution concerns the existence of trade-offs between traits. For parasitic nematodes it has been shown that larger body sizes induce higher fecundity, but this is achieved at the expense of delayed maturity. As high adult mortality would select for reduced age at maturity, the selective benefit of increased fecundity is expressed only if adult mortality is low. Parasite adult mortality may depend on a number of factors, including host longevity. Here we tested the hypothesis concerning the positive covariation between parasite body size (which reflects parasite longevity) and host longevity. To achieve this goal, we used the association between the pinworms (Oxyuridae, Nematoda) and their primate hosts. Oxyurids are highly host specific and are supposed to be involved in a coevolutionary process with their hosts. We found that female parasite body length was positively correlated with host longevity after correcting for phylogeny and host body mass. Conversely, male parasite body length and host longevity were not correlated. These results confirm that host longevity may represent a constraint on the evolution of body size in oxyurids, at least in females. The discrepancy between female and male oxyurids is likely to depend on the particular mode of reproduction of this taxon (haplodiploidy), which should result in weak (or even null) selection pressures to an increase of body size in males.

Morphology and morphometrics of three oxyurids parasitic in primates with a description of Lemuricola microcebi n. sp.

Classical and morphometric analyses were conducted on several samples of oxyurid nematodes parasitic in strepsirrhine primates: Cheirogaleus major, Galago senegalensis, and Microcebus murinus. A diagnosis of Lemuricola contagiosus Chabaud & Petter, 1959 from C. major is given using syntypes, from which a lectotype is selected. The rest of the specimens were compared to L. contagiosus. From measurements taken from each sex, an initial Principal Component Analysis (PCA) was performed on log-transformed data and a second PCA was performed on log-shape ratios after elimination of the isometric differences. The parasites collected from M. murinus, which can be differentiated from the closely related L. contagiosus by both standard morphological characters and morphometric variables, are described as Lemuricola microcebi n. sp. The parasites collected from Galago are morphologically very similar to L. microcebi n. sp. The most probable explanation for this resemblance is considered to be a transfer from Microcebus to Galago but, due to the small numbers of individuals in our samples, it is impossible to eliminate the possibility that the parasites of Galago belong to an undescribed species. Until more material or information can be obtained, it is proposed to refer to the parasites from Galago as Lemuricola sp.

The Enterobiinae subfam. Nov. (Nematoda, Oxyurida) pinworm parasites of primates and rodents.

Recent redescriptions of most members of the Oxyuridae Cobbold, 1864 parasitic in primates revealed that they share following derived characters: sexual dimorphism of lateral alae (single-crested in the males, double-crested in the females); in males a second pair of genital papillae always surrounded by strongly cuticularized rings; in females, uterine tube divided into 2 parts by a cellular wall forming a diaphragm. These characters are interpreted as synapomorphies, providing evidence that these taxa represent a monophyletic group, and we propose to classify them in a new subfamily of the Oxyuridae: the Enterobiinae subfam.nov. The Enterobiinae as recognized herein occurs in both Old World and New World Primates and rodents of the family Sciuridae (tribe Sciurini in the Holarctic region and tribe Xerini in the Ethiopian region). The new subfamily includes the following genera: Enterobius Leach, 1853; Colobenterobius Quentin, Betterton & Krishnasamy, 1979; Rodentoxyuris Quentin & Tenora 1974; Xeroxyuris Hugot, 1995; Lemuricola Chabaud & Petter, 1959; Protenterobius Inglis, 1961; Madoxyuris Chabaud, Brygoo & Petter, 1965; Trypanoxyuris Vevers, 1923; Hapaloxyuris Inglis & Cosgrove, 1965 and Paraoxyuronema Artigas, 1936. The genus Paraoxyuronema is revalidated as a subgenus of Trypanoxyuris due to its specialized buccal structures. This genus groups all pinworm nematodes specific for primates of the family Atelidae, including: P. brachytelesi Artigas, 1937 occurring in Brachyteles arachnoides; P. atelis (Cameron, 1929) occurring in Ateles spp., and P. duplicidens (Buckley, 1931) and P. lagothricis (Buckley, 1931), which are parasites of Lagothrix spp. Inglisoxyuris inglisi Chabaud, Petter & Golvan, 1961, included in the monospecific genus Inglisoxyuris and previously classified as a subgenus of the Lemuricola, does not share the characters of the new subfamily and, until its precise classification can be considered with more information, it is proposed to refer to this species as an Oxyuridae sensu lato. A diagnosis and a key of the genera included in the new subfamily are given.

A cladistic analysis of the Trichostrongyloidea (Nematoda).

A morphologically based cladistic analysis of 40 genera included within the Trichostrongyloidea (Amidostomatidae, Dromaeostrongylidae and Trichostrongylidae) is proposed. Two genera were used as outgroups, one from the Strongylina and the other from the Ancylostomatina. Seven genera do not appear in the matrix because some significant morphological characters remain unknown for these genera. Nonetheless, except for Moguranema which is excluded as incertae sedis, a likely systematic position could be assigned to them based on the morphological characters that are known. The classification which best fits the consensus tree is composed of three families. In adding the genera not included in the tree, we obtain: (i) Trichostrongylidae with three sub-families, Amidostomatinae (four genera), Filarinematinae (three genera) and Trichostrongylinae (five genera); (ii) Haemonchidae with two sub-families: Ostertagiinae (eight genera) and Haemonchinae (five genera); (iii) Cooperiidae with three sub-families: Libyostrongylinae (five genera), Obeliscoidinae n. subfam. (five genera) and Cooperiinae (ten genera). Dromaeostrongylus and Ortleppstrongylus, whose females have a caudal spine, are excluded from the Trichostrongyloidea and are placed in the Molineoidea. The hypotheses relating to the evolutionary history of the Trichostrongyloidea are: the origin of the superfamily could have occurred during the upper Cretaceous period. The two most ancient sub-families (Amidostomatinae and Filarinematinae) would be of Gwondwanan origin and evolved during the Paleocene period within Neotropical aquatic birds and within the Australian marsupials. The Trichostrongylinae would have arisen during the Eocene period within birds and then adapted to diverse archaic mammals in the Neotropical region on one hand and in the Nearctic region, on the other hand and lastly adapted to the Lagomorpha and subsequently to the Ruminantia. In both families originating from the Trichostrongylidae, the adaptation to the Lagomorpha may have taken place during the Oligocene but in a different way. In the Haemonchidae, the Ostertagiinae may have passed directly from the Neartic region to Europe. In the Cooperiidae, the adaptation to Lagomorpha may have occurred either within the Libyostrongylinae which may have remained in the Ethiopian region since the Paleocene, or, more likely, by the passage of the Obeliscoidinae from the Nearctic region to the Asian, through the Bering strait. In all cases, the adaptation of the Trichostrongyloidea of Lagomorpha to Ruminants apparently took place during the Miocene, mainly in the Palearctic and the Ethiopian regions.

Evolution of the Old World Arenaviridae and their rodent hosts: generalized host-transfer or association by descent?

Ten scenarios optimizing the number of cospeciation events between the phylogenies of the Old World Arenaviridae (OWA) and their murine hosts are tested while attempting to answer the following questions. Does the coevolutionary model explain their respective distribution? What kind of evolutionary events could have most frequently contributed to the horizontal and/or vertical transmission of the OWA? How to define secondary hosts and to interpret their existence in the evolutionary process? Where are the geographical origins of the OWA? All scenarios support the "diffuse coevolution" hypothesis previously proposed for the OWA, in which parallel phylogeny and/or host switches on closely related hosts can be considered as the most common mechanisms of transmission. The scenarios allow defining more precisely the concepts of principal and secondary hosts. Such scenarios also suggest that the diversity of the viruses and their rodent hosts could be higher than currently expected and that cophylogeny could have been underestimated. The "diffuse coevolution" hypothesis permits to interpret the transfer of the viruses to distant hosts as a result of a disturbance in their regular mode of dispersion, which could match with the periods of emergence as human parasites. The comparison of the viral phylogeny with the host cladogram also suggests that the viruses parasitized the Murinae before several lineages became distinct and spread in Africa. This supposes that the origin of the arenaviruses has to be found out of Africa.