Spatial and simultaneous representative seroprevalence of anti-Toxoplasma gondii antibodies in owners and their domiciled dogs in a major city of southern Brazil

Abstract

Toxoplasmosis, caused by Toxoplasma gondii, has traditionally been considered an important water and foodborne protozoonosis with important public health considerations. Although felids play a well-established role as definitive hosts, canine epidemiological involvement in the parasite’s life cycle remains questionable and controversial. The increasing closeness of the human-dog bond, particularly seen in urban settings, has been recognized as a historically unprecedented worldwide movement. Sharing daily lives in the same households, dogs may be exposed to similar associated risks of T. gondii infection as their owners. Thus, epidemiological assessment of the intra-domiciled environment, especially among socio-economically different human populations, may provide novel information regarding the actual role of dogs in animal and human toxoplasmosis. Despite spatial approaches being recently used for other water and foodborne diseases, no study has been conducted on the simultaneous spatial seroprevalence of both human and animal IgG anti-T. gondii antibodies in urban areas of major cities. Accordingly, the aim of the present study was to assess the seroprevalence and associated variables of Toxoplasma infection in owners and their domiciled dogs in Londrina, southern Brazil. Human and canine seroprevalence rates and variables associated with seroprevalence were investigated through representative random sampling among 564 households, which included 597 owners and 729 dogs. Overall, statistically significant differences between the seroprevalence of human and dog anti-T. gondii antibodies were found by Immunofluorescence Antibody Testing in 248/597 (41.54%) owners and 119/729 (16.32%) dogs. Through multiple analysis, significant concomitant variables for seropositivity of household individuals (people and dogs) were determined, including public sewer service, yard cleaning frequency, and having a dirty yard. Although no statistically significant multiple logistic model was observed among owners, univariate analysis detected associations with monthly income, soil contact, and occupation. Among dogs, the absence of other dogs and the absence of a dirty yard were concomitant significantly protective associated factors. Age differences between seropositive and seronegative individuals was significant only for human beings, with the median age of negative individuals significantly higher than positive individuals. Although no spatial clusters were identified for humans or residences, a significant cluster was identified for dogs. In conclusion, characteristics of urban toxoplasmosis may include significantly higher owner seroprevalence than their owned dogs, with canine seroprevalence directly associated with having more dogs and a dirty backyard, and spatial differences in both human and dog exposures. Although not a good indicator for human foodborne diseases, dogs may be a reliable sentinel for environmental infection. Moreover, such a holistic approach may provide crucial information for more focused prevention and...

Seroprevalence and incidence of Toxoplasma gondii and Neospora caninum infection in naturally exposed domestic dogs from a rural area of São Paulo state, Brazil

“…Dogs can also act as sentinel animals for human toxoplasmosis, although they are not a good indicator of human foodborne diseases (Benitez et al, 2017b) since some owners feed them homemade food including raw or undercooked meat that can contain parasites (Camossi et al, 2008;Salb et al, 2008). In addition, some dog behaviors, such as rubbing, smelling, or even eating cat feces, increase their role as an indirect vehicle for T. gondii transmission (Frenkel & Parker, 1996).…”

Seroprevalence of Toxoplasma Gondii in Dogs and Cats Domiciled in the West of Santa Catarina, Brazil

“…However, there are authors who did not observe statistical difference in relation to this variable (BRESCIANI et al, 2008;CAÑÓN-FRANCO et al, 2004). A study published by Benitez et al (2017), evaluated the prevalence of humans and their respective dogs and obtained higher statistical seroprevalence in owners (41.54%) compared to their own dogs (16.32%), which can be explained by contamination transmitted by food since the exposure to foods such as raw and undercooked meat to dogs was much lower compared to the guardian.…”

“…The main routes of transmission are: ingestion of contaminated fruits and vegetables or water, raw or uncooked meat, unpasteurized milk and through blood transfusions, organ transplants or congenital form (GARCIA, 1999;SILVA, FIGUEIREDO;FREITAS, 2015). Vegetables can be contaminated directly from the faeces of felines (FERREIRA et al, 2018) or through the source of irrigation water from the garden that can be contaminated by the rainwater flow with fecal pathogens (WELLS et al, 2015).…”

Solid Wastes Provide Breeding Sites, Burrows, and Food for Biological Disease Vectors, and Urban Zoonotic Reservoirs: A Call to Action for Solutions-Based Research

“…One study found no association (119). (126) and can be used as a proxy in the absence of reliable data on rodent distribution in the city (117,126). Presence of rubbish increased risk of scrub typhus (120); Toxoplasma infection in owners and their domiciled dogs was associated with dirty yards (126); and the bubonic plague has historically been associated with solid waste (121,122).…”

“…(126) and can be used as a proxy in the absence of reliable data on rodent distribution in the city (117,126). Presence of rubbish increased risk of scrub typhus (120); Toxoplasma infection in owners and their domiciled dogs was associated with dirty yards (126); and the bubonic plague has historically been associated with solid waste (121,122). For example, Kassir et al (127) conducted an observational study to investigate the risk of rabies and the neighboring Syrian war and the local garbage crisis, finding both were concomitant with a notable increase in the number of dog bites and thus possible rabies exposure.…”