Background Leptospirosis is considered a neglected zoonosis associated with infrastructure problems and low socioeconomic status, particularly slums. Since the disease is mainly transmitted in urban settings by rat urine, this risk factor may be important predictor tool for prompt control and effective prevention at the local level in urban endemic areas. Accordingly, the present study aimed to propose an early spatial predictor tool for human leptospirosis in urban settings, to test the methodology of molecular methods for assessing Leptospira spp. in trapped rats, and report associated environmental data. Methodology/Principal findings Official city records and previous study were used to select risk factors for human leptospirosis in an endemic neighborhood of Curitiba, Brazil. Neighborhood census sectors were divided in high- and low-risk areas using 12 selected factors: flood area, water supply, water course, green coverage, afforestation, sewage network, open sewage, open garbage, garbage collection, dumpster, pavement, and rodent complaints. In addition, rats were captured in pre-determined sites from January through March 2017, euthanized, and individual kidneys samples sent for molecular diagnosis. Human cases were obtained from official city records. In total, 95/112 (84.8%) census sectors were classified as low-risk to human leptospirosis. No significant statistical differences were found in human case frequencies between high and low-risk areas. Kidney samples from 17/25 (68.0%) trapped rats were positive for Leptospira spp. The main risk factors associated with rodent presence included inadequate water supply (p = 0.04), sanitary sewage (p = 0.04), unpaved streets (p = 0.04), and complaint of rodents (p = 0.04). Conclusions/Significance This study offers a new approach to score leptospirosis transmission risk, and to compare small areas and their heterogeneity in the same census sector of endemic areas. Environmental risk factors for Leptospira spp. transmission within the neighborhood were mainly due to differences in infrastructure and basic services. To the author’s knowledge, this is the first study using Leptospira spp. in rats as predictor for human disease in an urban setting of a major city. Although the number of rats trapped was low, this methodology may be used as basis for early and effective interventions, focused on high risk areas for leptospirosis prior to human cases, and potentially reducing morbidity and mortality in low-income areas of urban settings.
Pesq. Vet. Bras. 33(1): 74-79, janeiro 2013 74 RESUMO.-A leptospirose é uma grave zoonose associada às áreas de baixa renda dos centros urbanos. Embora roedores urbanos sejam considerados como principal reservatório para a leptospirose, o cão também pode desenvolver a doença e se tornar carreador assintomático. O objetivo do presente trabalho foi utilizar a metodologia estatística baseada na teoria de processos pontuais espaciais, buscando identificar a forma como se distribuem os cães sororreagentes para a leptospirose e seus determinantes de risco em uma vila na cidade de Curitiba. A análise do modelo possibilitou identificar as regiões de sobre-risco, Leptospirosis is a serious zoonotic disease associated to low income areas of urban settings. Although rodents are considered the main reservoir for urban leptospirosis, dogs may also develop the disease and become asymptomatic carriers. The objective of this study was to apply a statistical method based on the spatial point processes theory for canine leptospirosis to identify how seroreagents dogs are spatially distributed and their risk determinants in a village of Curitiba city. The model analysis allowed the identification of over-risk regions, where seropositivity risk for canine leptospirosis was significantly higher, revealing that not just one, but the combination of animal, owner and environment factors influenced the disease risk within areas with greater spatial effect. Analysis of results clearly identified the highest risk areas in the Pantanal Village, allowing the establishment of more specific preventive actions and focused on risk areas as priority for public health surveillance. onde o risco de soropositividade canina à leptospirose é significativamente maior. A relação significativa do efeito espacial no desenvolvimento da doença, além das variáveis estudadas, revela que não apenas um, mas a ação conjunta dos fatores relacionados ao animal, ao proprietário e ao ambiente influencia o risco maior da doença nos locais de maior efeito espacial. O resultado da análise indica claramente os territórios em maior risco na região da Vila Pantanal, possibilitando o planejamento de ações mais específicas e dirigidas a essas áreas em um contexto de vigilância da saúde. INTRODUÇÃOA leptospirose é uma zoonose reconhecida como um importante problema de saúde pública mundial. A doença se estendeu além das áreas rurais e tornou-se uma das causas de epidemias em comunidades urbanas dos países em desenvolvimento (Pappas et al. 2008). Nesses países, como
Rickettsia spp. bacteria are responsible for tick-borne diseases worldwide, mostly maintained by rickettsial amplifiers capybaras in Brazilian endemic areas. The campus of the University of São Paulo, in southeastern Brazil, is an area endemic for Brazilian spotted fever (BSF), with high density of capybaras and Amblyomma spp., along with confirmed human cases. Besides capybaras, the university has also an in-campus high population of sheltered and free-roaming cats. Accordingly, the aim of this study was to determine the prevalence and characteristics associated with Rickettsia rickettsii, Rickettsia parkeri and Rickettsia felis exposure among cats in a BSF-endemic area. Out of 51 cats sampled, 23/35 shelter (65.7%) and 5/16 free-roaming (31.2%) were positive (titers ≥ 64) for at least one Rickettsia species. Ticks species were present in 3/16 free-roaming cats (18.8%), consisting of Amblyomma spp., nymphs of Amblyomma sculptum and adult Rhipicephalus sanguineus sensu lato. Despite sharing the capybaras environment, the seropositivity among the free-roaming and shelter cats was lower than owned cats in other endemic areas. Whether equally or less exposed to rickettsial infection, compared with owned cats in endemic areas, free-roaming and shelter cats may be used as environmental sentinels for human exposure to rickettsiae in such areas.
Cat infected by a variant of bat rabies virus in a 29-year disease-free urban area of southern Brazil
Despite vulnerability and unsanitary conditions of animal hoarding may predispose environmental contamination and spread of vectors and pathogens, no study to date has focused on their impact on public health and zoonotic diseases. Accordingly, this study aimed to assess the seroprevalence of anti-Toxoplasma gondii antibodies and associated factors in individuals with animal hoarding disorder (AHD) and their dogs in Curitiba, Southern Brazil. Blood samples were obtained from 264 dogs (21 households) and 19 individuals with AHD (11 households). Their blood was tested by indirect fluorescent antibody test (IFAT). Overall, anti-Toxoplasma gondii seropositivity was found in 21/264 dogs (7.95%; 95% CI: 4.69-11.22) with titers ranging from 16 to 4096, and in 7/19 individuals with AHD (36.84%; CI: 15.15-58.53) with titers ranging from 16 to 64. Serological analysis for anti-T. gondii antibodies were considered positive in at least one individual or dog in 9/11 (81.82%; 95% CI: 59.03-100.00) cases that were thoroughly assessed. Surprisingly, the seropositivity of individuals with AHD and their dogs was among the lowest reportedly observed in human and dog populations of Brazil. There was no significant association between positive owners and positive dogs or the presence of cats in the household. Regard epidemiological variables, a significant association was found between dog's seropositivity and the type of dog food. To the authors' knowledge, the present study represents the first investigation of T. gondii seroprevalence in individuals with hoarding disorder and their dogs. In conclusion, despite low sanitary conditions, anti-Toxoplasma gondii antibodies frequency in individuals with AHD and their dogs are lower than the general population likely due to low protozoan load in such isolated households.
Seroprevalence of Toxoplasma gondii has been extensively studied in wild boars worldwide due to the emerging risk for human infection through meat consumption. However, this is the first study that reports toxoplasmosis seroprevalence in wild boars, wild boar hunters and their hunting dogs. The aim of the present study was to evaluate the seroprevalence of anti-T. gondii antibodies in the complex wild boars, hunting dogs and hunters, and to determine the risk factors associated with seropositivity in southern and central-western Brazil. Overall, anti-T. gondii seropositivity was observed in 15/71 (21.1%) wild boars by modified agglutination test (MAT); and 49/157 (31.2%) hunting dogs and 15/49 (32.7%) hunters by indirect immunofluorescent antibody test (IFAT). Seroprevalence of toxoplasmosis in Brazilian wild boars was within the national and international range, posting wild boars as potential environmental sentinels for T. gondii presence. In addition, the findings have comparatively shown that wild boars have been less exposed to infection than hunting dogs or hunters in both Brazilian regions. Seropositivity for T. gondii was statistically higher in 12/14 (85.7%) captured wild boars when compared to 5/57 (7.0%) free-range wild boars (p = 0.000001). Similarly, captured wild boars from anthropized areas were more likely to be seropositive than of natural regions (p = 0.000255). When in multiple regression model, dogs with the habit of wild boar hunting had significant more chance to be positive (adjusted-OR 4.62 CI 95% 1.16–18.42). Despite potential as sentinels of environmental toxoplasmosis, seroprevalence in wild boars alone may provide a biased basis for public health concerns; thus, hunters and hunting dogs should be always be included in such studies. Although hunters should be aware of potential T. gondii infection, wild boars from natural and agricultural areas may present lower protozoa load when compared to wild boars from anthropized areas, likely by the higher presence of domestic cats as definitive hosts.
Occurrences of anti-Toxoplasma AbstractBarbary sheep (Ammotragus lervia) have the potential to act as hosts of important infectious diseases, particularly zoonoses. Blood samples from 17 Barbary sheep at the Curitiba zoo were collected to evaluate occurrences of antiToxoplasma gondii and anti-Neospora caninum antibodies, tested using the indirect immunofluorescence antibody test (IFAT). Anti-T. gondii and anti-N. caninum antibodies were detected in 4/17 (23.5%) and 4/17 (23.5%) samples, respectively. The present study has shown that Barbary sheep at Curitiba zoo were exposed to T. gondii and N. caninum and therefore may act as intermediate hosts, spreading toxoplasmosis and neosporosis within and between species in shared areas.
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