Trypanosoma cruzi in Bats (Chiroptera; Mammalia) from the Brazilian Atlantic Forest, São Paulo State

The causative agent of Chagas disease is Trypanosoma cruzi, which is widely distributed throughout the South American continent and extends into North America. Its occurrence in bats is poorly described and may impact the disease's maintenance and epidemiology. The aim of this study was to detect the agent by PCR assays targeting kDNA and nuclear DNA in the organs of 203 urban bats and rural vampire bats from the Brazilian Atlantic Forest, São Paulo state, during the pandemic period from 2020 to 2022. In total, 6 of the 203 bats (2.97%) were positive for T. cruzi. Infection was detected in 2% (2/101) of Desmodus rotundus, 33% (1/3) of Nyctinomops laticaudatus, 25% (1/4) of Artibeus lituratus, 4% (1/24) of Eumops glaucinus and in 2% (1/41) of Molossus molossus. The gene sequences obtained were assessed for quality and deposited in a public repository. Fruit bats were statistically associated with positivity for T. cruzi. To our knowledge, this study detected T. cruzi for the first time in bats from São Paulo state and in N. laticaudatus and E. glaucinus species.

One Health approach to Coxiella burnetii in Brazilian indigenous communities

Indigenous health has posted complex challenges worldwide, particularly due to historical economic, territorial, social and environmental processes, which may lead to emergence and reemergence of pathogens. In addition to few Coxiella burnetii serosurveys in vulnerable populations, especially in developing tropical countries, no comprehensive One Health approach has focused on human-animal infection along with potential environmental determinants. Accordingly, this study aimed to assess the seroprevalence of anti-C. burnetii antibodies in indigenous populations and their dogs from 10 indigenous communities distributed in southern and southeastern Brazil, along with the correspondent healthcare professionals. In overall, 8/893 (0.90%; 95% CI 0.45-1.76) indigenous and 1/406 (0.25%) dog samples were seropositive, with 7/343 (2.04%) individuals the 1/144 (0.69%) dog from the Ocoy community, located in the city of São Miguel do Iguaçu, bordering Argentina at south, and far 10 km at west from Paraguay. All 84 healthcare professionals tested seronegative.

Serosurvey of Coxiella burnetii in Descendants of Former Black Slaves (Quilombola Communities) of Southern Brazil

Brazilian descendants of former Black-slave (quilombola) communities have been predisposed to several zoonotic diseases due to social vulnerability, characterized by subsistence and close contact with livestock and companion animals. Accordingly, the present study has assessed anti-Coxiella burnetii antibodies in 200 individuals and 20 dogs from four quilombola communities located in Paraná State, southern Brazil. Serum samples were tested by indirect immunofluorescence assay (IFA) using in-house and commercial diagnostic protocols, with analysis of seropositive titers and antibody type. Fisher's exact test was used to compare seropositivity to C. burnetti with binary variables, with variables with three or more possible responses submitted to logistic regression. In total, 44/200 (22%; 95% CI 16.82-28.24) people tested positive, and 4.5% had titers higher than 128, indicating a recent onset of C. burnetii infection. Seropositive individuals were statistically associated with the Limitão community (p = 0.0013), urban workers as occupations (p = 0.0475), consumption of undercooked meat (p = 0.0159), and contact with animal abortion (p = 0.0276). No seropositivity association was found for age, sex, education, habit of entering forest areas, consumption of game meat, consumption of raw milk, flea and tick bites, dog contact, or history of female miscarriage. Only one of 20 dogs was seropositive with a titer of 128, probably related to an acute animal infection. Despite the prevalence here being higher than previous Brazilian reports, including with symptomatic populations, the results were within range for worldwide outbreaks and occupational risk populations. To the reader's knowledge, this is the first human survey of Q fever in southern Brazil and should be considered a warning for C. burnetii in vulnerable populations, particularly Quilombola communities.

One health approach to toxocariasis in quilombola communities of southern Brazil

BACKGROUND

Toxocariasis has been listed among the most neglected parasitic diseases worldwide, with approximately one fifth of the global population exposed, particularly those living under poverty. In Brazil, communities of descendants of enslaved blacks (quilombola) have historically had some of the highest rates of vulnerability and poverty, characterized by lack of health assistance, poor quality of life, and nutritional insecurity.

METHODS

A cross-sectional sampling of quilombola individuals living in four communities of southern Brazil, as well as their dogs and the soil, was carried out from December 2021 to March 2022. Sociodemographic and other information such as water source, alimentary habits, and dog and cat ownership were gathered using a semi-structured questionnaire for assessing toxocariasis risk factors. Human serum samples were tested by ELISA for anti-Toxocara spp. IgG antibody detection was carried out on dog feces and hair, and soil samples were surveyed for presence of Toxocara spp. eggs.

RESULTS

Overall, 172/208 individuals (82.7%, 95% CI = 77.0-87.2) were seropositive, the highest seroprevalence rate to date in Brazil. Male gender (P = 0.029), educational level (P = 0.026), and drinking water source (P = 0.043) were associated with seropositivity by univariate analysis. Final logistic regression revealed increased odds (P = 0.017, OR = 7.6, 95% CI = 1.5-42.7) to have seropositivity in individuals > 50 years old (< 10 years old). As expected, individuals with soil contact were more likely seropositive (P = 0.038, OR = 4.4, 95% CI = 1.1-18.8). Although retrieved in only 5/96 (5.2%) dog feces, Toxocara spp. eggs were found in 18/60 (30.0%) soil samples.

CONCLUSIONS

The high vulnerability and seroprevalence observed in quilombola communities clearly demand a One Health approach for detection, monitoring, and prevention of infection by Toxocara spp. in both human and dog populations.

One health approach to toxocariasis in Brazilian indigenous populations, their dogs, and soil contamination

Introduction

Although socioeconomic vulnerability and lifestyle factors may contribute to the transmission of Toxocara spp., no study has investigated indigenous populations in Brazil using the One Health approach.

Methods

Accordingly, this study assessed anti-Toxocara spp. antibodies in Brazilian indigenous people and healthcare professionals by enzyme-linked immunosorbent assay. Presence of Toxocara spp. eggs (feces and hair) in dogs as definitive hosts and in soil samples of the indigenous communities were also recovered and molecularly investigated.

Results

Overall, 342/463 (73.9%) indigenous individuals and 46/147 (31.3%) non-indigenous healthcare professionals were seropositive for Toxocara spp. In addition, T. canis eggs were retrieved from 9/194 (4.6%) dog fecal samples and 4/204 (2.0%) dog hair samples, mainly from the Paraná State communities (3/42; 7.1%). Soil contamination was observed only in the Paraná State communities (36/90; 40.0%), with the molecular detection of T. canis. River water consumption was also associated with indigenous seropositivity (Odds ratio, 11.4).

Discussion

Indigenous individuals in Paraná State communities were 2.72-fold more likely to be seropositive than those in São Paulo State, likely due to a lack of sanitary infrastructure. In this scenario, a primarily soil-transmitted disease may also have become waterborne, with embryonated eggs probably spread to water supplies by rain. Full-time healthcare professionals in daily contact with indigenous communities were 9.2-fold more likely to be seropositive than professionals who visited sporadically, suggesting exposure to Toxocara spp. during their work and raising health concerns. In addition, the findings herein showed a significantly higher seroprevalence in indigenous people than in healthcare workers (χ2 = 85.5; p < 0.0001), likely due to overtime exposure to Toxocara spp. In conclusion, Brazilian indigenous communities are highly exposed to toxocariasis, with poor infrastructure and contact with contaminated river water as associated risk factors and a higher risk of infection in healthcare professionals working full-time in these communities.

One Health Approach in Serosurvey of Toxoplasma gondii in Former Black Slave (Quilombola) Communities in Southern Brazil and Among Their Dogs

Brazilian quilombos are rural semi-isolated remnant communities of former black slaves and their descendants who traditionally maintained themselves through archaic subsistence livestock and agriculture practices and historically lacked specific public health policies. Although such individuals and their dogs may be exposed to zoonotic pathogens such as Toxoplasma gondii, no study to date has assessed these human-animal populations together. Populations in four different Brazilian quilombos in southern Brazil were evaluated. Overall, 93/208 people (44.7%) and 63/100 dogs (63.0%) were seropositive for IgG anti-T. gondii antibodies by indirect immunofluorescent antibody test (IFAT), 4/208 (1.9%) human samples seropositive for IgM anti-T. gondii antibodies, with a human-dog seropositivity ratio for IgG of 0.71. Quilombola individuals ingesting game meat were 2.43-fold more likely (95% CI: 1.05-5.9) to be seropositive. No risk factors were associated with seropositivity among dogs, thus suggesting that their exposure to T. gondii was random. Surprisingly, our research group had previously found an inverted human-dog ratio for T. gondii seropositivity of 2.54 in the urban area of a nearby major city. Because consumption of raw/undercooked game meat by quilombola individuals may have contributed to higher exposure, higher overall seroprevalence among dogs may have also indicated interaction with wildlife. Although these dogs may hunt wildlife without their owners' awareness, the higher dog seropositivity may also be related to feeding from discarded food in the community or backyard livestock animals and drinking surface water contaminated with oocysts. Thus, wildlife cannot be singled out as the reason, and future studies should consider sampling water, soil, wildlife, and livestock tissues, to fully establish the source of infection in dogs herein.

Cat rabies in Brazil: a growing One Health concern

This review of human and cat rabies from 1986 to 2022 has shown mostly AgV3 variant in human cases with 29/45 (64.4%) reports including 23 from bats, four from cats, and two from unknown species, followed by 8/45 (17.8%) of AgV2 variant (all from dogs), 4/45 from marmoset variant (all from Callithrix jacchus), 2/45 samples compatible with wild canid variant (both from Cerdocyon thous), and one/45 of AgV1 variant from a domestic dog. Only one sample of human rabies was not typified, related to bat aggression. In addition, surveillance conducted in the state of São Paulo confirmed the presence of rabies in 7/23,839 cats (0.031%) and 3/106,637 dogs (0.003%) between 2003 and 2013, with a 10:1 overall cat-to-dog positivity ratio. This 10-fold higher infection rate for cat rabies may be explained by cats' hunting habits and predation. In addition, after 28 years of rabies-free status, a new cat rabies case was reported in the city of São Paulo in 2011. The rabid cat lived, along with other pets, in a household located near the largest downtown city park, whose owners presented animal hoarding behavior. Thus, animal hoarders and rescuers, public health agents, animal health professionals, and the general population with contact need to be aware of the risk of bat-borne rabies followed by spillover from cats to humans. In conclusion, cat rabies cases are becoming increasingly important in Brazil. This poses a One Health concern, given the overlapping of human, bat and cat populations within the same predisposed environment.

Toxoplasma gondii exposure in Brazilian indigenous populations, their dogs, environment, and healthcare professionals

Although Toxoplasma gondii exposure has been reported in indigenous populations worldwide, a One Health approach has not been applied to date. This study concurrently assessed T. gondii exposure in indigenous populations, and their dogs, environment, and indigenous or non-indigenous healthcare professionals (HPs). Human and dog serum samples from 9 indigenous communities in Brazil were assessed by indirect immunofluorescence antibody test for anti-T. gondii antibodies. Soil samples (30 per community) were processed with PCR to amplify T. gondii DNA. Associated risk factors and seroprevalence were analyzed using logistic regression models. Human seropositivity and type of water source were assessed by generalized linear mixed model (GLMM) with binomial error distribution, and game meat consumption with chi-squared test. Overall, 225/463 (49%) indigenous persons were seropositive for anti-T. gondii antibodies. Of all the HPs, 67/168 (40%) were positive, and included 54/147 (37%) positive non-indigenous HPs. Indigenous persons more likely to be seropositive compared with non-indigenous HPs (OR: 1.63; 95% CI: 1.11-2.39). A total of 97/253 (38%) dogs were seropositive and highly associated with seropositive owners (p < 0.001). Based on univariate analysis for indigenous individuals, state location of community (p < 0.001), ethnicity (p < 0.001), consumption of game meat (p < 0.001), type of water source (p < 0.001), and educational level (p = 0.026) were associated with seropositivity. Logistic regression showed that indigenous seropositivity was associated with eating game meat (p = 0.002), drinking water from rivers (p < 0.001), and inversely proportional to the educational level. According to univariate analysis for non-indigenous HP, age (p = 0.005), frequency of visits to the indigenous populations (p < 0.001), consumption of water at the indigenous communities (p < 0.001), and ingestion of raw meat (p = 0.023) were associated with T. gondii seropositivity. Logistic regression revealed living outdoors (p = 0.042), habit of hunting (p = 0.008), and drinking river water (p = 0.007) as risk factors associated to seropositivity in dogs. In addition, indigenous communities lacking water treatment had higher seroprevalence for all groups including indigenous persons (GLMM; z = -7.153; p < 0.001), their dogs (GLMM; z = -2.405; p = 0.0162), and all HPs (GLMM; z = -2.420; p = 0.0155). Human seropositivity was associated with that of their dogs (p < 0.001). A single soil sample, out of 270 (0.37%), was positive for T. gondii by PCR. Our results indicate water source is a risk for human and dog toxoplasmosis in indigenous communities; both share similar exposure. Moreover, quality water access was shown to be crucial to prevent toxoplasmosis in both total and non-indigenous HPs who work in these indigenous communities.

Seroprevalence and associated risk factors of strongyloidiasis in indigenous communities and healthcare professionals from Brazil

Strongyloides stercoralis, a pathogenic roundworm, is considered endemic in several tropical and subtropical areas worldwide. Indigenous populations have the highest soil-transmitted helminthiases-related mortality rates, but the prevalence and risk factors associated with S. stercoralis in Brazilian indigenous populations have not been established. Thus, the present study aimed to assess the seroprevalence and associated risk factors for S. stercoralis in indigenous communities and the healthcare professionals serving them in Brazil. Indigenous populations living in nine communities and healthcare professionals were tested for anti- S. stercoralis antibodies by ELISA. A questionnaire was used to assess socio-epidemiological information. Associated risk factors for seropositivity were tested by chi-square or Fisher's exact tests, using bivariate analyses and multivariate logistic regression. Overall, 174/463 (37.6%; CI 95%: 33.3-42.1) indigenous persons and 77/147 (52.4%; 95% CI: 44.3-60.3) healthcare professionals were seropositive for anti- S. stercoralis antibodies. Seropositivity among the two groups was statistically significant (p = 0.0016; OR = 0.547; 95% CI: 0.376-0.796) and revealed that healthcare professionals were 1.83 times more likely to be seropositive. The multivariate analysis showed that being male or being adult were also risk factors, while having a septic tank as a sanitary facility represented a protective factor for S. stercoralis exposure in indigenous persons. None of the variables evaluated were associated with S. stercoralis exposure in the professional group. The study herein has reported a high seroprevalence to Strongyloides stercoralis in indigenous communities of Brazil and healthcare professionals, warning for potential public health concerns of strongyloidiasis in such populations.

Spatial Owner-Dog Seroprevalence of Leptospira spp. Antibodies in Oceanic Islands and Costal Mainland of Southern Brazil

Leptospirosis has been described as a disease neglected worldwide. Affecting humans and animals, the disease is often related to poor environmental conditions such as lack of sanitation and presence of synanthropic rodents. Despite being considered as a One Health issue, no study has focused on comparing owner-dog seroprevalence between islands and seashore mainland. Accordingly, the present study assessed anti-Leptospira spp. antibodies by applying microscopic agglutination test (MAT) methods to Leptospira and assessing associated risk factors via univariate and multivariate logistic regression analysis of owners and their dogs in islands and seashore mainland of southern Brazil. No anti-Leptospira spp. Seropositivity was found in 330 owner serum samples, while dogs presented an overall seroprevalence of 5.9%. All seropositive dogs reacted to serogroups of Leptospira interrogans, including 66.7% of Pyrogenes, 44.4% Canicola, 22.2% Icterohaemorrhagiae, 16.7% Australis; six reacted to more than one serogroup. No association was found among seropositivity and epidemiological variables, except that neighborhood dogs were less likely to be seropositive. Although no seropositivity was observed in owners, seropositivity in dogs had the potential to indicate such species as being sentinels for environmental exposure and potential human risk of infection.

Leishmania spp. in indigenous populations: A mini-review

Leishmaniasis, considered a neglected vector-borne disease complex of global concern, has a significant impact on indigenous communities due to daily human and animal exposure in periurban, rural, and naturally preserved areas. This mini-review aims to assess and discuss studies of leishmaniasis in these communities of the New World and Old World, particularly those in the Americas and Asia. Such indigenous communities have been mostly built in poor traditional households with no mosquito-net protection, mostly located in environmentally protected areas, favoring vectors and reservoirs. The presence of leishmaniasis cases surrounding such indigenous areas indicated a high risk of infection, which may have been historically underestimated due to a lack of surveillance, even at present. The absence of studies of indigenous populations in recognized endemic areas may reflect insufficient health services. In conclusion, the persistence of this neglectful scenario may impact tragic outcomes and potential outbreaks in indigenous peoples and surroundings populations worldwide.