Toxoplasma gondii, Neospora caninum and Leishmania amazonensis antibodies in domestic dogs in the western Brazilian Amazon region

Abstract

Amostras de sangue de 99 cães domiciliados foram coletadas no meio urbano (n = 33) e rural (n = 66) do município de Lábrea, estado do Amazonas, Brasil. Dentre as amostras rurais, 40 foram obtidas em comunidades ribeirinhas e 26 em comunidades indígenas, ambas ao longo do rio Purus. Durante a amostragem foi aplicado um questionário com informações sobre sexo, idade, viver em áreas secas ou alagadiças, acesso ou não às ruas (cães urbanos) e acesso à floresta. A presença de anticorpos contra Toxoplasma gondii, Neospora caninum, Leishmania infantum chagasi e Leishmania amazonensis foi detectada pela reação de imunofluorescência indireta (RIFI) com ponto de corte de, respectivamente, 16, 50, 40 e 40. Associação entre as variáveis qualitativas e a positividade para cada um dos parasitos foi avaliada pelo teste do χ2 (p < 0,05). A ocorrência de animais com anticorpos contra T. gondii, N. caninum e L. amazonensis foi de, respectivamente, 61,6%; 7,1% e 8,1%. Nenhuma amostra foi positiva para L. infantum chagasi. A variável viver em área urbana (p=0,041) apresentou associação com ocorrência de T. gondii e o número de cães positivos a T. gondii aumentou com a idade (p = 0,0006). A variável sexo (machos) apresentou associação com N. caninum (p = 0,018) e nenhuma variável apresentou associação com L. amazonensis. Os títulos de anticorpos contra T. gondii variaram de 64 a 32.768; contra N. caninum de 100 a 800 e contra L. amazonensis de 40 a 640. T. gondii e L. amazonensis são dois agentes de importantes zoonoses e encontram-se ativos na região. O município estudado, especialmente as comunidades ribeirinhas, possuem peculiaridades geográficas, sociais e ecológicas distintas e necessitam maior atenção das autoridades para o controle desses agentes.

Occurrence of Toxoplasma gondii and Neospora caninum antibodies and risk factors in domiciliated dogs of Manaus, Amazonas, Brazil

“…The T. gondii occurrence, found among the dogs in the present study, was lower (12.3%) than the rate of 68% found previously by Ferraroni & Marzochi (1980) in the same city, however very few dogs were examined in their study, and they used a different diagnostic test. In the Amazon region, studies of occurrence of T. gondii antibodies also presented higher rates than the results of the present study, with 61.6% in Lábrea, a city in the south of Amazon state (Basano et al, 2016), 76.5% in Rondônia (Cañón-Franco et al, 2004), and 69.8% and 38% in Pará (Valadas et al, 2010, Paz et al, 2019. However, despite all studies had been made in Amazon region and with the same diagnostic technique, the environmental and the characteristics of the dogs' sampled are not the same.…”

“…Dogs reactive to T. gondii have already been described in practically all Brazilian states (reviewed by Dubey et al, 2012Dubey et al, , 2020 and, in the state of Amazonas (AM), there is a study in the city of Manaus, from 1980, in which the occurrence of antibodies against T. gondii was evaluated in dogs by the hemagglutination test, with a value of 68%, with 13 of the 19 dogs examined being reactive (Ferraroni & Marzochi, 1980). In a more recent study, carried out in the city of Lábrea, AM, 99 dogs were examined for the presence of anti-T. gondii antibodies and 61.6% were reactive (Basano et al, 2016), confirming the occurrence of the parasite in dogs in the region.…”

The triad “dogs, conservation and zoonotic diseases” – An old and still neglected problem in Brazil

“…(leishmaniasis), Leptospira interrogans (leptospirosis), Toxoplasma gondii (toxoplasmosis), Neospora caninum (neosporosis), Dirofilaria immitis (dirofilariasis/heartworm disease), Brucella canis (brucellosis), Sarcoptes scabiei (scabies), Echinococcus spp. (echinococcosis), Rickettsia rickettsii (Brazilian spotted fever), different canine viruses (e.g., distemper virus, adenovirus, coronavirus, herpesvirus, parvovirus), rabies virus, among other pathogens, to both humans and wildlife (Craig et al, 1992;Fiorello et al, 2006Fiorello et al, , 2017Dantas-Torres, 2007;Labruna et al, 2007;Pinter et al, 2008;Piranda et al, 2008;Yabsley et al, 2008;Moraes-Filho et al, 2009;Brunetti et al, 2011;Ogrzewalska et al, 2012;Furtado et al, 2013;Millán et al, 2013;Parrish et al, 2015;Basano et al, 2016;Campos et al, 2016;Curi et al, 2016;Doherty et al, 2017;Lessa et al, 2016;Faccini-Martínez et al, 2017). Importantly, dogs are amplifier hosts of different pathogens (Dantas-Torres, 2007;Piranda et al, 2011;Szabó et al, 2013), which means that they can develop infection at sufficient levels to infect other species, such as vectors, increasing the disease transmission (Kilpatrick and Altizer, 2010;Labruna et al, 2011;Piranda et al, 2011).…”

“…Dogs circulate in forest fragments of protected and nonprotected areas, being registered in the most different environments (Doherty et al, 2017), such as agroforests (Frigeri et al, 2014;Santos et al, 2017), caatinga (Bezerra et al, 2014;Lessa et al, 2016), and the Amazon region (Basano et al, 2016). In Brazil, 53% of native vegetation is located on private properties (Soares-Filho et al, 2014).…”