Trypanosomiasis caused by Trypanosoma vivax has increased the reports in Brazil in the last decade. An outbreak is herein first reported in the state of Goiás, from May 2016 to January 2017. The outbreak start occurred in the city of Ipameri (Goiás) after the introduction of 18 auctioned cows from the state of Minas Gerais. Direct parasitological test (blood smears) and polymerase chain reactions targeting the catL genes diagnosed T. vivax infection. Fifty six cows from a herd of 161 were infected; 12 died during the outbreak and 44 animals persistently positive (by blood smears) even after chemical treatment were discarded. After this first case, five other cases were detected in state of Goiás. The spread of this disease can be linked to the commercialization of animals carrying T. vivax, allied to the iatrogenic transmission practice, using a single needle and syringe for all cows, during oxytocin administration before each milking.Keywords: Bovines, lactating cows, oxytocin, PCR, Trypanosomiasis, T. vivax. ResumoTripanossomíase causada por Trypanosoma vivax tem sido reportada em várias regiões do Brasil na última década. Um surto é aqui reportado no Estado de Goiás, de maio de 2016 a janeiro de 2017. O início do referido surto ocorreu na cidade de Ipameri (Goiás) depois da introdução de 18 vacas Girolando, provenientes do Estado de Minas Gerais. Pelo exame parasitológico direto (esfregaço sanguíneo) e pela reação em cadeia pela polimerase, identificou-se a infecção por T. vivax nos animais. Cinquenta e uma vacas de um rebanho de 161 foram infectadas; 12 morreram durante o surto e 44 animais permaneceram positivos (pelo esfregaço sanguíneo) mesmo recebendo tratamento químico (diminazene), e foram descartadas. Após esse primeiro caso, foram detectados outros cinco casos no Estado de Goiás. A disseminação dessa doença pode estar ligada à comercialização de animais portadores de T. vivax, aliada à prática de transmissão iatrogênica, utilizando-se uma única agulha e seringa para, todas as vacas, durante a administração da oxitocina antes de cada ordenha.Palavras-chave: Bovinos, vacas em lactação, oxitocina, PCR, Tripanossomíase, T. vivax.

Bovine trypanosomosis has been spreading in Brazil. In the present study, we evaluated the spatial distribution, prevalence and risk factors of this disease in the state of Goiás, Brazil, and performed both molecular and phylogenetical analyses of Trypanosoma vivax. A total of 4049 blood samples were collected from cattle for a period of 2 years. The parasitological diagnosis was performed using the Woo method and a questionnaire was administered to the farmers to document risk factors associated with the disease in the herd. Positive samples were DNA sequenced and compared to GenBank codes. The prevalence of T. vivax was 8.84%, occurring on 24 ranches only in dairy cattle and mainly in the central and southern portions of the state. The acquisition of new animals infected with T. vivax and the administration of exogenous oxytocin to cows using the same syringe and needle were the main associated factors (P ≤ 0.05). After an outbreak, milk production decreased by 39.62%. The presence of biting flies (tabanids, Haematobia irritans and Stomoxys calcitrans) was not a risk factor (P > 0.05) for the occurrence of T. vivax. The epidemiological data demonstrate the importance of restricting the practice of auctions as well as eliminating the use of exogenous oxytocin in animals during milking. The samples tested by polymerase chain reaction were positive for T. vivax and were genetically homologous with T. vivax found in different states of Brazil and west Africa based on the 18S rRNA gene.

Influenza A viruses (IAVs) circulate widely among different mammalian and avian hosts and sometimes give rise to zoonotic infections. Vaccination is a mainstay of IAV prevention and control. However, the efficacy of IAV vaccines is often suboptimal because of insufficient cross-protection among different IAV genotypes and subtypes as well as the inability to keep up with the rapid molecular evolution of IAV strains. Much attention is focused on improving IAV vaccine efficiency using adjuvants, which are substances that can modulate and enhance immune responses to co-administered antigens. The current review is focused on a non-traditional approach of adjuvanting IAV vaccines by therapeutically targeting the immunomodulatory functions of a rare population of innatelike T lymphocytes called invariant natural killer T (iNKT) cells. These cells bridge the innate and adaptive immune systems and are capable of stimulating a wide array of immune cells that enhance vaccine-mediated immune responses. Here we discuss the factors that influence the adjuvant effects of iNKT cells for influenza vaccines as well as the obstacles that must be overcome before this novel adjuvant approach can be considered for human or veterinary use.

Natural killer T (NKT) cells activated with the glycolipid ligand α-galactosylceramide (α-GalCer) stimulate a wide variety of immune cells that enhance vaccine-mediated immune responses. Several studies have used this approach to adjuvant inactivated and subunit influenza A virus (IAV) vaccines, including to enhance cross-protective influenza immunity. However, less is known about whether α-GalCer can enhance live attenuated influenza virus (LAIV) vaccines, which usually induce superior heterologous and heterosubtypic immunity compared to non-replicating influenza vaccines. The current study used the swine influenza challenge model to assess whether α-GalCer can enhance cross-protective immune responses elicited by a recombinant H3N2 LAIV vaccine (TX98ΔNS1) encoding a truncated NS1 protein. In one study, weaning pigs were administered the H3N2 TX98ΔNS1 LAIV vaccine with 0, 10, 50, and 100 μg/kg doses of α-GalCer, and subsequently challenged with a heterologous H3N2 virus. All treatment groups were protected from infection. However, the addition of α-GalCer appeared to suppress nasal shedding of the LAIV vaccine. In another experiment, pigs vaccinated with the H3N2 LAIV, with or without 50 μg/kg of α-GalCer, were challenged with the heterosubtypic pandemic H1N1 virus. Pigs vaccinated with the LAIV alone generated cross-reactive humoral and cellular responses which blocked virus replication in the airways, and significantly decreased virus shedding. On the other hand, combining the vaccine with α-GalCer reduced cross-protective cellular and antibody responses, and resulted in higher virus titers in respiratory tissues. These findings suggest that: (i) high doses of α-GalCer impair the replication and nasal shedding of the LAIV vaccine; and (ii) α-GalCer might interfere with heterosubtypic cross-protective immune responses. This research raise concerns that should be considered before trying to use NKT cell agonists as a possible adjuvant approach for LAIV vaccines.

RESUMO Criptosporidiose é uma parasitose emergente no Brasil e no mundo, classificada como uma das principais causas de diarreia em adultos e crianças. Sua importância deve-se principalmente ao fato de ter uma ampla variedade de hospedeiros e pelo seu potencial zoonótico. Além disto, a forma infectante do agente, Cryptosporidium spp., possui alta resistência ambiental, viabilizando contaminação de alimentos, corpos d'água e solo e possibilitando surtos em alta escala acarretando em prejuízos econômicos e sociais. A subnotificação, falta de tratamento eficaz e baixa utilização de métodos de controle eficientes dificultam a implantação de medidas preventivas, visando diminuir o impacto da doença.