Feline leukemia virus in owned cats in Southeast Asia and Taiwan.

Feline leukaemia virus (FeLV) is a retrovirus associated with fatal disease in cats with infection in its progressive form. Although there are numerous reports on the occurrence of FeLV in the feline population worldwide, there is a paucity of data in Asia. In this study, we assessed the circulation of FeLV by ELISA and nested PCR in cats from different countries in Southeast Asia (i.e., Thailand, Malaysia, Singapore, Philippines, Indonesia and Vietnam) and Taiwan during 2017-2018. Forty-seven cats were positive to FeLV by antigen or provirus detection, but 32 samples were considered truly positive on the basis of positive molecular testing. Frequency of occurrence of FeLV proviral DNA ranged from 0% (0/43 positive samples) in Indonesia to 18.5% (22/119 positive samples) in Thailand. A statistically significant association (p < 0.05) was found between country of cats origin, age, lifestyle, abnormal oral mucosa, and FeLV molecular positive results. In-depth studies are needed in other countries in Southeast Asia to elucidate the mosaic of knowledge about FeLV epidemiology.

Endosymbionts carried by ticks feeding on dogs in Spain.

Studies on tick microbial communities historically focused on tick-borne pathogens. However, there is an increasing interest in capturing relationships among non-pathogenic endosymbionts and exploring their relevance for tick biology. The present study included a total of 1600 adult ticks collected from domestic dogs in 4 different biogeographical regions of Spain. Each pool formed by 1 to 10 halves of individuals representing one specific ticks species was examined by PCR for the presence of Coxiellaceae, Rickettsia spp., Rickettsiales, Wolbachia spp., and other bacterial DNA. Of the pools analyzed, 92% tested positive for endosymbiont-derived DNA. Coxiella spp. endosymbionts were the most prevalent microorganisms, being always present in Rhipicephalus sanguineus sensu lato (s.l.) pools. Rickettsia spp. DNA was detected in 60% of Dermacentor reticulatus pools and 40% of R. sanguineus s.l. pools, with a higher diversity of Rickettsia species in R. sanguineus s.l. pools. Our study reveals a negative relationship of Rickettsia massiliae with the presence of tick-borne pathogens in the same pool of ticks. An additional endosymbiont, 'Candidatus Rickettsiella isopodorum', was only detected in D. reticulatus pools. Data from this study indicate that dogs in Spain are exposed to several endosymbionts. Due to the importance of tick-borne pathogens, characterizing the role of endosymbionts for tick physiology and prevalence, may lead to novel control strategies.

Defining the concept of 'tick repellency' in veterinary medicine.

Although widely used, the term repellency needs to be employed with care when applied to ticks and other periodic or permanent ectoparasites. Repellency has classically been used to describe the effects of a substance that causes a flying arthropod to make oriented movements away from its source. However, for crawling arthropods such as ticks, the term commonly subsumes a range of effects that include arthropod irritation and consequent avoiding or leaving the host, failing to attach, to bite, or to feed. The objective of the present article is to highlight the need for clarity, to propose consensus descriptions and methods for the evaluation of various effects on ticks caused by chemical substances.

Toxoplasma gondii in wild and domestic animals from New Caledonia.

Samples (serum or meat juice) collected from 205 animals in New Caledonia in April 2009 were tested for antibodies against Toxoplasma gondii by ELISA using the multi-species ID Screen® Toxoplasmosis Indirect kit (IDVET, Montpellier). Antibodies to T. gondii were detected in 2% (1/49) of the pigs, in 3.3% (1/30) of the cattle, in 13.8% (4/29) of Rusa deers, in 16% (4/25) of the horses, in 32.8% (21/64) of the dogs, and in 50% (4/8) of cats. Statistically, no significant difference was observed between T. gondii seroprevalence and age or sex. No survey on the prevalence of T. gondii in animals has ever been conducted in New Caledonia and this is the first serological evidence of T. gondii in Rusa deer (Cervus timorensis russa). These results indicate an important circulation of T. gondii exists in the animal populations of New Caledonia. In view of humans being exposed, it is advisable to insist on sanitary education and on respect for good hygienic and food practice.

A review of trends in the distribution of vector-borne diseases: is international trade contributing to their spread?

It is difficult to determine the part that international trade has played in the expansion of vector-borne diseases, because of the multitude of factors that affect the transformation of habitats and the interfaces between vectors and hosts. The introduction of pathogens through trade in live animals or products of animal origin, as well as the arrival of arthropod vectors, is probably quite frequent but the establishment of an efficient transmission system that develops into a disease outbreak remains the exception. In this paper, based on well-documented examples, the authors review the ecological and epidemiological characteristics of vector-borne diseases that may have been affected in their spread and change of distribution by international trade. In addition, they provide a detailed analysis of the risks associated with specific trade routes and recent expansions of vector populations. Finally, the authors highlight the importance, as well as the challenges, of preventive surveillance and regulation. The need for improved monitoring of vector populations and a readiness to face unpredictable epidemiological events are also emphasised, since this will require rapid reaction, not least in the regulatory context.

Seroprevalence and factors associated with Toxoplasma gondii infection in wild boar ( Sus scrofa) in a Mediterranean island.

Knowledge of the factors affecting the presence of Toxoplasma gondii in wildlife is limited. Here we analyse which local landscape characteristics are associated with the presence of toxoplasmosis in wild boar, Sus scrofa, on the island of Corsica, France. Meat juice samples from 1399 wild boars collected during two hunting seasons were tested for T. gondii antibodies using the modified agglutination test (titre 1:4). The overall seroprevalence was 0.55 (95% CI 0.50-0.59) for the first year and 0.33 (95% CI 0.29-0.35) for the second year. Seroprevalence varied according to age and county. At the county level, seropositivity in adults was related to farm density during year 1, and to habitat fragmentation, farm density and altitude during year 2. The exposure of wild boar to T. gondii is thus variable according to landscape characteristics and probably results in a variable risk of transmission of toxoplasmosis to humans.

[Toxoplasmosis: a survey on meat products in Côte d'Ivoire]. / Toxoplasmose: à propos d'une enquête sur la viande en Côte d'Ivoire.

Toxoplasmosis is a worldwide parasitic zoonosis that can cause severe problems under certain circumstances. Before the advent of the last-generation anti-retroviral drugs, estimation predicted that 50% of HIV-infected patients would develop toxoplasmosis (mainly central nervous system forms). It is the first clinical manifestation of AIDS in 20% of patients. This report describes an epidemiological survey on the seroprevalence of Toxoplasma antibodies in bushmeat and pork in the Côte d'Ivoire. The purpose was to determine how the parasite circulates among wild and domestic animals and to evaluate the risk of transmission to humans after ingestion of these meats. Fifteen samples of bushmeat were purchased on markets in 6 different cities. A total of 91 single samples of fresh pork raised at three different modern breeding facilities were collected from a slaughterhouse in Abidjan. Serological testing was performed on muscle fluid using an ELISA test (Pourquier Toxoplasma kit). No bushmeat sample was positive. Global seroprevalence in pork samples was 8.8% [range, 8.2-9.37]. The seroprevalence of toxoplasmosis measured in pork samples produced at modern livestock breeding facilities was lower than values reported in samples produced by traditional breeding in Africa. This finding suggests that the use of modern techniques excluding rodents (good hygiene) can reduce animal contamination. Curing (heat and smoking) may account for the absence of Toxoplasma antibodies in bushmeat. Public information campaigns concerning the risk of consuming meat containing cysts as well as raw vegetables contaminated with oocysts are needed to prevent transmission of toxoplasmosis.

Molecular divergences of the Ornithodoros sonrai soft tick species, a vector of human relapsing fever in West Africa.

The soft tick Ornithodoros sonrai is recognized as the only vector of Borrelia crocidurae causing human relapsing fever in West Africa. Its determination has been exclusively based on morphological features, geographical distribution and vector competence. Some ambiguities persist in its systematics and may cause misunderstanding about West African human relapsing fevers epidemiology. By amplifying and aligning 16S and 18S rDNA genes in O. sonrai specimens collected from 14 distinct sites in Senegal and Mauritania, we showed the existence of four genetically different subgroups that were morphologically and ecologically identified as belonging to the same species. Within O. sonrai, intraspecific polymorphism was high (pairwise divergence from 0.2% to 16.4%). In all cases, these four subgroups formed a monophyletic clade sharing a common ancestor with East African soft ticks that transmit Borrelia duttoni human relapsing fever. From amplification of the flagellin gene of B. crocidurae we verified that all subgroups of O. sonrai were infected by B. crocidurae and may constitute vectors for this pathogen. All flagellin sequences were identical, refuting the hypothesis suggesting parallel evolution between O. sonrai and B. crocidurae. However, differences in infection rates were significant, suggesting different vector competences between subgroups of O. sonrai.

Effects of cow age and pregnancy on Bartonella infection in a herd of dairy cattle.

Bartonella spp. are small hemotropic bacteria infecting mammals. Four Bartonella species have been recently described in cattle and wild ruminants. To date, the biology and possible pathogenic role of Bartonella species isolated from ruminants are poorly understood. Therefore, a dairy herd of 448 cows and heifers was surveyed in order to establish the prevalence of Bartonella bovis and B. chomelii infections, the level of bacteremia, and the relationship between bacteremia and age or pregnancy status. The putative impact of Bartonella infection on production performance (individual milk cell count, milk yield) and reproductive status (success of artificial insemination [AI], placental retention, embryonic death, and abortion) was also assessed. The overall mean prevalence of B. bovis bacteremia was 59%, with the highest prevalence in heifers (92.5%). No B. chomelii was isolated, and 95% (114/120) of the B. bovis strains isolated and tested by PCR-restriction fragment length polymorphism belonged to type I. The level of bacteremia was higher in pregnant cows than in nonpregnant cows (P = 0.05), and the level of bacteremia rose during the last two-thirds of gestation (P < 0.001). There was no correlation between bacteremia and milk yield, individual milk cell count, success of first AI, interval between two calvings, or incidence of abortion and embryonic death. The interval from calving to first AI was shorter and the incidence of placental retention was lower in bacteremic animals than in nonbacteremic ones (P = 0.03 and P = 0.01, respectively).

Identification of Bartonella strains isolated from wild and domestic ruminants by a single-step PCR analysis of the 16S-23S intergenic spacer region.

Of the 20 species or subspecies of Bartonella currently known, 7 cause various diseases in humans with many being zoonotic. However, some Bartonella species appear only to cause asymptomatic bacteraemia in their hosts. In ruminants, three Bartonella species (B. bovis, B. capreoli and B. schoenbuchensis) have recently been described. However, limited or no information has yet been published concerning their mode of transmission and their possible pathogenicity for domestic cattle. The phylogenetic relationship of these species with other bacteria of the Bartonella genus has only been recently investigated. It is therefore necessary to develop appropriate tools that will easily allow identification of these ruminant strains for epidemiological and clinical studies. A single-step PCR assay, based on the amplification of a fragment of the 16S-23S rRNA intergenic spacer (ITS), was evaluated for identification of Bartonella isolated from domestic cattle and from free-ranging or captive cervids. For each Bartonella species tested, the PCR assay led to a product that was unique either for its length or its sequence. All ruminant isolates tested could be easily differentiated among themselves and from the other Bartonella species. Furthermore, sequence analysis of the PCR products revealed a close relationship between all ruminant Bartonella strains. Therefore, ITS PCR testing appears to be a convenient tool for a quick diagnosis of ruminant Bartonella species.

Evaluation of the dermatophyte test medium RapidVet-D.

The performance of the dermatophyte test medium (DTM) RapidVet-D was assessed using hair samples collected from experimentally infected guinea pigs. Three dermatophyte species were included in the study: Microsporum canis, Trichophyton mentagrophytes and Trichophyton equinum. DTM substrates were inoculated with infected hairs and scales, incubated at 18, 21, 24, 27 or 37 degrees C and examined daily for 15 days. The rapidity of colour change was clearly related to the incubation temperature and to the number of infected hairs deposited on the reactive substrates. With the optimum incubation temperature 27 degrees C, a systematic colour change could be observed only a few days post-inoculation: 3 days with M. canis infected hairs, 4 days with T. equinum and 5 days with T. mentagrophytes.