Luís Tavares

Survey of infectious and parasitic diseases in stray cats at the Lisbon Metropolitan Area, Portugal

A survey of infectious and parasitic diseases of stray cats was carried out using biological samples collected from animals captured during a catch-neuter-release programme in four counties of the Lisbon Metropolitan Area. The main objective was to investigate the potential threat of stray cats for animal and public health. Samples of blood, stool, hair and auricular swabs were collected from 231 cats in 27 colonies. Anti-Toxoplasma gondii antibodies were detected in 47/194 samples (24.2%); anti-Leishmania infantum antibodies in 1/180 cats (0.6%); intestinal parasites in 23/74 samples (Toxocara cati, Isospora felis, Ancylostoma tubaeforme, Dipylidium caninum, Uncinaria stenocephala, Toxascaris leonina) and Otodectes cynotis in 4/182 cats (2.2%); dermatophyte fungi were isolated in 40/136 samples (29.4%); feline immunodeficiency virus antibodies were detected in 23/226 samples (10.2%); feline leukaemia virus antigen in 14/198 samples (7.1%); and feline coronavirus RNA in 9/127 samples (7.1%). Our results revealed that zoonotic agents, namely dermatophyte fungi and Toxocara cati were present in stray cat colonies in the investigated counties. Overall the low frequency of major pathogens suggests a balanced relationship between host and agents.

Serologic Survey for Canine Distemper Virus and Canine Parvovirus in Free-ranging Wild Carnivores from Portugal

A serologic survey for Canine distemper virus (CDV) and canine parvovirus (CPV) was performed on serum and lung extract from an opportunistic sample of 120 free-ranging wild carnivores (13 species) from Portugal, collected from 1995 to 2006. Antibodies to CDV were detected in wolf (Canis lupus; 3/27) and red fox (Vulpes vulpes; 2/22). Antibodies to CPV were detected in wolf (9/28), red fox (2/14), wildcat (Felis silvestris;1/8), genet (Genetta genetta; 17/18), and stone marten (Martes foina; 3/17). Antibodies to CPV were detected throughout the study, whereas for CDV antibodies were detected in 3 of 10 yr and only during winter. The extremely high CPV antibody prevalence in genets is unprecedented. Although based on a limited sample, these data suggest widespread exposure of free-ranging Iberian carnivores to CDV and CPV.

Natural infection of synathropic rodent species Mus musculus and Rattus norvegicus by Leishmania infantum in Sesimbra and Sintra – Portugal

BackgroundCanine leishmaniosis caused by Leishmania infantum is a parasitic zoonotic disease transmitted by phlebotomine sandflies (Diptera: Psychodidae). Genus Phlebotomus is the biological vector in the Old World and Lutzomyia in the New World. The dog is the domestic reservoir host but other animals like the fox (Vulpes vulpes) and rodents are known to maintain the infection in both sylvatic and domestic cycles.MethodsTo identify the role of synanthropic rodents Mus musculus and Rattus norvegicus as reservoir hosts for Leishmania infantum natural infection, 30 rodents were captured under a trap rodent control program in two private dog shelters from Sintra and Sesimbra, located in the Lisbon Metropolitan Area, known to be endemic for canine leishmaniosis in Portugal. Tissue samples were screened for the presence of Leishmania amastigotes by qPCR and parasitological analysis.ResultsA total of 33.3% (9/27) of Mus musculus rodents revealed the presence of Leishmania spp. DNA while 29.6% (8/27) were positive in the parasitological analysis. Concerning Rattus norvegicus (n=3), one animal revealed infection only by parasitological analysis.ConclusionsOur results identified for the first time in Portugal the presence of Leishmania infection in both rodent species. As susceptible hosts, infected Mus musculus and Rattus norvegicus may increase the risk for dog and human infection in households and surrounding areas, enhancing the need for efficient rodent control measures in shelters and risk zones to prevent transmission of the infection.

Relevance of feline interferon omega for clinical improvement and reduction of concurrent viral excretion in retrovirus infected cats from a rescue shelter.

Abstract Feline Immnunodeficiency (FIV) and Feline Leukemia (FeLV) viruses are common infectious agents in stray cats and shelter environments. Recombinant feline interferon-ω (rFeIFNω) has shown an antiviral action not only against FIV and FeLV but also against herpesvirus (FHV-1) and calicivirus (FCV). Sixteen naturally infected FIV/FeLV cats were followed during rFeIFNω therapy in order to monitor clinical signs and to correlate with excretion of concomitant viruses (FCV, FHV-1, feline coronavirus (FCoV) and parvovirus (FPV)). Cats were submitted to clinical evaluations and concomitant virus excretion assessement. Comparing D0–D65, 10/16 cats improved clinical scores. Of the 10 cats positive for FHV-1 on D0, 4 were negative and 6 reduced viral loads. Of the 11 FCoV positive cats, 9 reduced viral loads. The 13 FCV positive cats and the FPV positive cat were negative on D65. In conclusion, rFeIFNω improves clinical signs and reduces concurrent viral excretion in naturally infected retroviral cats.

Global phylogeography and evolution of chelonid fibropapilloma-associated herpesvirus.

A global phylogeny for chelonid fibropapilloma-associated herpesvirus (CFPHV), the most likely aetiological agent of fibropapillomatosis (FP) in sea turtles, was inferred, using dated sequences, through Bayesian Markov chain Monte Carlo analysis and used to estimate the virus evolutionary rate independent of the evolution of the host, and to resolve the phylogenetic positions of new haplotypes from Puerto Rico and the Gulf of Guinea. Four phylogeographical groups were identified: eastern Pacific, western Atlantic/eastern Caribbean, mid-west Pacific and Atlantic. The latter comprises the Gulf of Guinea and Puerto Rico, suggesting recent virus gene flow between these two regions. One virus haplotype from Florida remained elusive, representing either an independent lineage sharing a common ancestor with all other identified virus variants or an Atlantic representative of the lineage giving rise to the eastern Pacific group. The virus evolutionary rate ranged from 1.62×10(-4) to 2.22×10(-4) substitutions per site per year, which is much faster than what is expected for a herpesvirus. The mean time for the most recent common ancestor of the modern virus variants was estimated at 192.90-429.71 years ago, which, although more recent than previous estimates, still supports an interpretation that the global FP pandemic is not the result of a recent acquisition of a virulence mutation(s). The phylogeographical pattern obtained seems partially to reflect sea turtle movements, whereas altered environments appear to be implicated in current FP outbreaks and in the modern evolutionary history of CFPHV.

Virological Survey in free-ranging wildcats (Felis silvestris) and feral domestic cats in Portugal.

Abstract To determine the presence of viral pathogens in natural areas a survey was conducted on an opportunistic sample of fifty eight wild (Felis silvestris silvestris) and feral cats (F. s. catus). The biological materials included serum, lung tissue extract and stool. Feline leukemia virus p27 antigen was detected in 13/50 serum/lung tissue extract samples (26%), canine distemper virus antibodies were detected in 2/26 serum/lung tissue extract samples (7.7%), feline coronavirus RNA was present in 6/29 stool samples (20.7%) and feline parvovirus DNA in 2/29 stool samples (6.9%). Canine distemper virus RNA was not detected. Feline immunodeficiency virus and feline coronavirus antibodies were not detected. Evidence of exposure to feline leukemia virus, canine distemper virus, feline coronavirus and feline parvovirus was found in wild and feral cats raising the importance of performing a comprehensive survey to correctly evaluate the potential threat of infectious diseases to endangered species, namely to the wildcat and to the Iberian lynx, which is meant to be reintroduced after 2012 in Portugal.

Molecular detection of haemotropic Mycoplasma species in urban and rural cats from Portugal

Objectives The aim of the present study was to evaluate the prevalence of haemoplasma infection in cats in Portugal and to assess risk factors for infection. Methods Real-time polymerase chain reaction techniques were used to assess 236 urban and rural cats from central and southern Portugal. Results The overall prevalence of haemoplasma in the target population was 27.1% (64/236), with individual species’ prevalences as follows: 17.8% (42/236) ‘Candidatus Mycoplasma haemominutum’ (CMhm), 14.4% (34/236) Mycoplasma haemofelis (Mhf) and only 5.9% (14/236) ‘Candidatus Mycoplasma turicensis’ (CMt). Multiple infections were detected in 8.1% (19/236) of the samples, with triple and double infections with Mhf and CMhm being most commonly detected (5.9% [14/236] of cats). Haemoplasma infection was significantly higher in shelter cats (P = 0.015) than in cats with other lifestyles (eg, free-roaming/house pet/blood donors). Haemoplasma prevalence was also higher in cats with feline immunodeficiency virus infection (FIV; P = 0.011). Although sex was not significantly associated with haemoplasma infection (P = 0.050), CMt was predominantly found in males (P = 0.032). Also, the presence of haemoplasma multiple infections was statistically associated with being in a shelter (P = 0.021), male (P = 0.057) and with FIV co-infection (P = 0.004). No evidence of an association between haemoplasma infection and geographical location, age or feline leukaemia virus co-infection was found. Conclusions and relevance The results obtained in our study are consistent with the documented worldwide prevalence of feline haemoplasma infections, suggesting that the three main feline haemoplasma species are common in Portugal.

Oral Recombinant Feline Interferon-Omega as an alternative immune modulation therapy in FIV positive cats : clinical and laboratory evaluation

Abstract Recombinant-Feline Interferon-Omega (rFeIFN-ω) is an immune-modulator licensed for use subcutaneously in Feline Immunodeficiency virus (FIV) therapy. Despite oral protocols have been suggested, little is known about such use in FIV-infected cats. This study aimed to evaluate the clinical improvement, laboratory findings, concurrent viral excretion and acute phase proteins (APPs) in naturally FIV-infected cats under oral rFeIFN-ω therapy (0.1MU/cat rFeIFN-ω PO, SID, 90days). 11 FIV-positive cats were treated with oral rFeIFN-ω (PO Group). Results were compared to previous data from 7 FIV-positive cats treated with the subcutaneous licensed protocol (SC Group). Initial clinical scores were similar in both groups. Independently of the protocol, rFeIFN-ω induced a significant clinical improvement of treated cats. Concurrent viral excretion and APP’s variation were not significant in the PO Group. Oral rFeIFN-ω can be an effective alternative therapy for FIV-infected cats, being also an option for treatment follow-up in cats submitted to the licensed protocol.

Evaluation of viremia, proviral load and cytokine profile in naturally feline immunodeficiency virus infected cats treated with two different protocols of recombinant feline interferon omega.

Abstract This study assesses viremia, provirus and blood cytokine profile in naturally FIV-infected cats treated with two distinct protocols of interferon omega (rFeIFN-ω). Samples from FIV-cats previously submitted to two single-arm studies were used: 7/18 received the licensed/subcutaneous protocol (SC) while 11/18 were treated orally (PO). Viremia, provirus and blood mRNA expression of interleukin (IL)-1, IL-4, IL-6, IL-10, IL-12p40, Interferon-γ and Tumor Necrosis Factor-α were monitored by Real-Time qPCR. Concurrent plasma levels of IL-6, IL-12p40 and IL-4 were assessed by ELISA. IL-6 plasma levels decreased in the SC group (p = 0.031). IL-6 mRNA expression (p = 0.037) decreased in the PO group, albeit not sufficiently to change concurrent plasma levels. Neither viremia nor other measured cytokines changed with therapy. Proviral load increased in the SC group (p = 0.031), which can be justified by a clinically irrelevant increase of lymphocyte count. Independently of the protocol, rFeIFN-ω seems to act on innate immunity by reducing pro-inflammatory stimulus.

Detection and quantification of bovine papillomavirus type 2 in urinary bladders and lymph nodes in cases of Bovine Enzootic Hematuria from the endemic region of Azores.

Bovine Enzootic Hematuria (BEH) is a disease with a severe impact on production indexes and characterized by the development of bovine urinary bladder tumors, particularly in the Azores archipelago. The purpose of this study was to investigate and quantify BPV2 tissue distribution in bovine urinary bladder tumors, normal bladders, and iliac lymph nodes of cattle from the Azores. A real-time PCR system targeting the L1 gene was developed and allowed for the specific detection of the virus. BPV2 DNA was detected in a large proportion of the samples tested, both from neoplastic and healthy tissues, indicating that this virus is very prevalent in the bovine population of the Azores. Moreover, all types of tissues tested were positive, confirming a wide viral distribution within the infected animal. Bovine cutaneous papillomas sampled from Portuguese mainland dairy cattle were used as controls. Viral load ranged between 2.2×10(4) copies/cell in the skin papillomas, and 0.0002 copies/cell in the urinary bladders tumors from the Azores. This is the first report presenting quantitative data on BPV2 infection in bovine urinary bladder lesions from the Azores. This approach will provide a useful tool to evaluate the role of BPV2 not only in the pathogenesis BEH but also in cell transformation mechanisms.