Study on the role of the sylvatic cycle of African swine fever in Senegal

It is generally believed that African swine fever (ASF) virus in Sub-Saharan Africa is maintained in nature by warthogs (Phacochoerus africanus) and soft ticks from the genus Ornithodoros (Penrith et al., 2004). In Senegal, warthogs are present in some nature reserves and the presence of an argasid tick (O. sonrai) has been described (Vial et al., 2007). In order to verify the presence of such a sylvatic cycle in Senegal, 74 warthog sera from different locations were analysed for ASF antibodies by Blocking Elisa and Algenex anti rp-30 ELISA. Moreover, 48 warthog burrows were inspected in the Sine Saloum National Park. Equally, 132 sera from free-ranging pigs reared in central and South Senegal and 74 warthogs sera were analyzed for the presence of antibodies against Ornithodoros erraticus (Canals et al, 1990). All the warthog sera were negative against ASF antibodies and anti-tick antibodies. Equally, no presence of soft ticks were detected in the 48 warthog burrows inspected despite O. sonrai was found in neighbouring rodent burrows. Among the 132 pig sera tested against tick antibodies, 8.5% (n=12) showed positive titres. There was a strong correlation between the later sera and those sampled in the area of distribution of O. sonrai (OR=7.1; p="0.028)." In addition, among those sera, 36% (n=4) showed also positive titres to ASF virus. The absence of antibodies against ASF in warthog sera confirms the lack of circulation of ASFV among warthog populations in Senegal, even in areas where the tick is present. The absence of antibodies against soft ticks in warthogs from different regions confirms that contacts between warthogs and O. sonrai are inexistent. The detection of antibodies against O. sonrai in pig sera confirms that contacts between both species occur. Moreover, it seems to confirm that O. sonrai and O. erraticus are antigenically related and that this diagnostic method could be useful to determine the distribution of O. sonrai in Senegal and other countries. Finally, these results prove the absence of warthog involvement in the cycle of ASF virus and confirm a potential role of O. sonrai as a reservoir host for the virus in Senegal. (Texte intégral

Human otoacariasis: a common outbreak in rubber growing belt of Karnataka.

Background/Objective: Soft tick in the ear is a very common acute painful and distressing condition in the flowering months of October to March. It’s a common condition in the rubber growing belt of Sullia.The mouthparts of the tick grips firmly the skin of the external auditory canal or the tympanic membrane and sucks blood and swells up. Otoscopy and removal of the tick from the ear can be done in outpatients in adults and difficult in a frightened irritable child.Materials and methods: 312 cases of intra-aural ticks presenting to the opd and casualty which included 131 males and 181 females were included in the study.Results: Out of the 312 cases of intra-aural ticks, 170 cases were treated in the outpatient and 140 cases under short general anesthesia with oto-microscopy.Conclusion: Intra-aural tick infestation is an acute painful condition which needs prompt management by an experienced otolaryngologist. Proper visualization and instrumentation is necessary to avoid complications.

Hard tick species of livestock and their bioecology in Golestan Province, North of Iran

Background: A survey on tick species composition was carried out in Golestan Province Iran during year 2010- 2011.The aim was to determine tick species parasitizing domestic ruminants and their seasonal population dynamics. Methods: A total of 124 sheep, 92 goats, 84 cattle, 74 camels and 12 horses in several villages were inspected for tick infestation. The collected ticks preserved in 70% alcohol and then were identified. Results: The overall 1059 ticks (453 female, 606 male) were collected. The ticks occur on sheep, goats, cattle, camels and horses as 72.1%, 77.3%, 75.8%, 69.3%, and 50% respectively. The frequency of ticks in spring was more than other seasons and the least was observed in winter. In the spring and summer, infestation rate in domestic ruminants were calculated as 100%. Six genus and fourteen hard and soft tick species were identified including Rhipicephalus sanguineus, R. bursa, Ixodes ricinus, Haemaphysalis punctata, H. sulcata, H. erinacei, H. inermis, Hyalomma marginatum, Hy. asiaticum, Hy. dromedarii, Hy. excavatum, Hy. anatolicum, Hy. detritum, Boophilus annulatus and Argas persicus. Rhipicephalus sanguineus was the most abundant species in the study area. The largest number of ticks was collected from animal ears and tails. Haemaphysalis, Hyalomma, Rhipicephalus and Boophilus occurred in mountainous, forest and plateau areas of Golestan Province but Ixodes occurred only in mountainous and forest areas, whereas Rhipicephalus and Hyalomma were present in coastal areas of Golestan Province. Conclusion: The result of this study is a survey on tick species from domestic animals in Iran and implication of possible prevention measures for diseases transmitted by ticks

Portuguese hosts for Ornithodoros erraticus ticks

The hematophagous soft tick Ornithodoros erraticus feeds nocturnally on multiple warm-blooded vertebrate hosts. This tick is often found living buried in the soil of traditional pigpens. O. erraticus is an important infectious disease vector both for humans and animals. In the Iberian Peninsula, this tick serves as the vector of human tick-borne relapsing fever caused by the spirochete Borrelia hispanica. The natural ecosystems maintaining this spirochete are not well understood, with details of competent vertebrate reservoirs and tick–host interactions poorly understood. Investigation of arthropod blood meal composition provides evidence linking the vector to specific hosts, providing insights into possible disease reservoirs. Ticks collected from two pigpens located in southern Portugal were subjected to blood meal analysis. PCR amplification of vertebrate cytochrome b was used to disclose the original host from which 349 ticks had derived their previous blood meal. Host origins for blood meal analysis from 79 of 349 ticks revealed that 46.8% had previously fed from pigs, 35.4% human, 13.9% bovine, 5.1% sheep, 1.3% rodent, and 1.3% from birds. Three samples revealed mixed blood meals, namely, human–pig (1.3%), sheep–pig (1.3%), and bovine–pig (1.3%). The major role of pigs as hosts is consistent with fieldwork observations and underlines the importance of pigs for maintaining O. erraticus tick populations. Humans serve as accidental hosts, frequently confirmed by reports from both producers and veterinarians. Other livestock species and wildlife prevalent in the region appear only to have a minor role in maintaining this tick. The results demonstrate the importance of blood meal analysis to determine tick hosts providing a tool for investigation of sylvatic cycle for Borrelia hispanica

Ornithodoros quilinensis sp. nov. (Acari, Argasidae), a new tick species from the Chacoan region in Argentina

Ornithodoros quilinensis sp. nov. (Acari: Argasidae) is described from larvae collected on the small rodents Graomys centralis (Cricetidae: Sigmodontinae) in Argentina. The diagnostic characters for this new species are a combination of small size (520-540 μm), a dorsal plate oval in shape with a length of approximately 200 μm, 14 pairs of dorsal setae, hypostome short and narrower at the base (length from Ph1 to apex 133 μm (120-141)) with dental formula 2/2 and apex blunt, and the capsule of the Haller's organ irregular in shape and without reticulations. The analysis of the 16S rDNA sequences available for the genus Ornithodoros indicate that, phylogenetically, O. quilinensis represents an independent lineage only related to a Bolivian tick species of the genus Ornithodoros yet not formally described.Fil: Venzal, José M.. Universidad de la Republica, Salto; UruguayFil: Nava, Santiago. Instituto Nacional de Tecnología Agropecuaria Eea, Rafaela; ArgentinaFil: Mangold, Atilio Jose. Instituto Nacional de Tecnología Agropecuaria Eea, Rafaela; ArgentinaFil: Mastropaolo, Mariano. Instituto Nacional de Tecnología Agropecuaria Eea, Rafaela; ArgentinaFil: Casás, Gustavo. UNIVERSIDAD DE LA REPUBLICA (UDELAR); . Universidad de la República; UruguayFil: Guglielmone, Alberto Alejandro. Instituto Nacional de Tecnología Agropecuaria Eea, Rafaela; Argentin

Can the Gram-negative bacterium Escherichia coli colonize the gut of Lone Star Tick (Amblyomma americanum)?

Ticks are obligate blood feeding ectoparasites and vectors of several mammalian pathogens (Williams-Newkirk et al, 2014). In addition to pathogens they also carry a bacterial community with commensal and symbiotic relationships (Bonnet et al, 2017). Using a culture-dependent approach we previously reported a high prevalence of Gram-positive bacteria in the gut of field collected lone star ticks (Amblyomma americanum). These results suggested that epithelial immunity functions to control Gram-negative bacteria in A. americanum. In this study, we used a culturing and non-culturing approach to measure the outcome of E.coli (Gram-negative) when fed to female adult lone star ticks (n=16). Results showed a significant reduction of E.coli at Days 1, 3 and 7 post bacterial feeding. qPCR of 16S rDNA confirmed reduction of bacterial rDNA when compared to water fed ticks (n=16). Our results suggest that there is a midgut epithelial immune response in place, which mainly targets Gram-negative bacteria

Assessing the impact of climate change on vector-borne viruses in the EU through the elicitation of expert opinion

Expert opinion was elicited to undertake a qualitative risk assessment to estimate the current and future risks to the European Union (EU) from five vector-borne viruses listed by the World Organization for Animal Health. It was predicted that climate change will increase the risk of incursions of African horse sickness virus (AHSV), Crimean-Congo haemorrhagic fever virus (CCHFV) and Rift Valley fever virus (RVFV) into the EU from other parts of the world, with African swine fever virus (ASFV) and West Nile virus (WNV) being less affected. Currently the predicted risks of incursion were lowest for RVFV and highest for ASFV. Risks of incursion were considered for six routes of entry (namely vectors, livestock, meat products, wildlife, pets and people). Climate change was predicted to increase the risk of incursion from entry of vectors for all five viruses to some degree, the strongest effects being predicted for AHSV, CCHFV and WNV. This work will facilitate identification of appropriate risk management options in relation to adaptations to climate change