Detection of Trypanosoma cruzi DNA in lizards: Using non-lethal sampling techniques in a sylvatic species with zoonotic reservoir potential in Chile.

Several reptile species have been described as hosts of Trypanosoma cruzi, the causative agent of Chagas disease, and therefore, they have become vertebrates of epidemiological interest. In recent decades, there has been a growing interest in animal welfare, especially in populations with small numbers where lethal sampling could have catastrophic consequences, and non-lethal methodologies have been developed for detecting zoonotic parasites. In this study, we compared three non-lethal sampling methodologies for detecting T. cruzi DNA in 21 captured specimens of the native lizard Liolaemus monticola, collected from the semiarid Mediterranean ecosystem of Chile. Specimens were subjected to xenodiagnosis (XD), tail clipping, and living syringe sampling procedures to evaluate whether lizards could serve as sentinel species for T. cruzi in endemic regions. To detect the protozoan, real-time PCR (qPCR) was performed on the DNA extracted from the samples (intestinal contents, tail tissues, and blood from living syringes). Trypanosoma cruzi DNA was detected in 12 of 21 lizards, considering all three methodologies. By XD, 12 specimens showed infection (57.1 %), and both living syringe and tail sampling methodologies detected only one infected lizard (4.8 %). Therefore, T. cruzi can be detected in lizards by qPCR using the three methodologies but XD is by far the most effective non-lethal detection methodology. The use of tail and living syringe methodologies showed a large underestimation; however, they might be options for monitoring the presence of T. cruzi in lizard populations when large sample sizes are available.

Assessing leptospirosis and toxoplasmosis seropositivity in wild boars (Sus scrofa): Implications for public and animal health in Southern Brazil.

Leptospirosis and toxoplasmosis are re-emerging zoonosis caused by infection with pathogenic spirochaetes of Leptospira and the protozoa Toxoplasma gondii, respectively. Wild boars (Sus scrofa), an exotic invasive species in Brazil, could play a role in the diseases' epidemiological cycles, but this issue is still unexplored. This study aimed to evaluate the Leptospira spp. and T. gondii seropositivity in wild boars in Rio Grande do Sul state, south Brazil. Of evaluated animals, 16% (13/80) and 85% (52/61) had antibodies to T. gondii and Leptospira spp., respectively. Sex, weight, age, hunt location and season of hunt were evaluated by their association with seropositivity for both pathogens, but none of them had statistical significance. This study revealed that wild boars should be considered as a potential source of Leptospira spp. and T. gondii dissemination for humans and animal species in shared environments in Rio Grande do Sul state.

Helminths of free-ranging dogs and cats in an urban natural reserve in Mexico City and their potential risk as zoonotic agents.

In the Reserva Ecológica del Pedregal of San Ángel, located in the south of Mexico City, Mexico, free-roaming dogs and cats coexist with 148 bird, 33 of mammal, 23 of reptile and seven amphibian species, that represent a remnant of the original fauna of the Mexican Plateau. The negative impact that dogs and cats have on local fauna is unobjectionable, however, the role that these introduced vertebrates play as potential transmitters of infectious diseases for native fauna and humans, is much less understood. Information about parasitic infections in native and introduced animals in this location is scarce. In order to ameliorate this lack of information, the objective of this study is to characterize the helminth fauna of the free-ranging dogs and cats of the ecological reserve. Between 2018 and 2023, 36 Felis silvestris catus and 7 Canis lupus familiaris were studied from the helminthological perspective. Endoparasites were obtained from the digestive tract and were identified to the species level using morphological and molecular evidence. Hosts were parasitized by eight species of helminths: in cats the cestodes Hydatigera taeniaeformis, Mesocestoides sp., Taenia rileyi and the nematode Toxocara cati were recorded, while in dogs, the cestode Taenia pisiformis and the nematodes Ancylostoma caninum, and Uncinaria stenocephala were found. The only species shared between cats and dogs was the cestode Dipylidium caninum. These free-ranging animals act as definitive hosts of 5 species known to have zoonotic potential; their presence in the area may generate a public and animal health problem if programs of dog and cat population control are not continued.

Molecular based confirmation of puma meat sausages implicated in trichinellosis outbreaks in Argentina.

Trichinellosis is a zoonotic disease caused by Trichinella, with the main source of infection being the consumption of pork and pork-derived products. However, it can also be acquired from eating the meat from wild animals targeted for sport hunting. The objectives of this study were: 1) to develop and implement a molecular method for the identification of Sus scrofa (pig and wild boar) and Puma concolor (Puma) meat in sausages eaten raw, which were linked to trichinellosis outbreaks occurring in Córdoba, Buenos Aires and La Pampa provinces, Argentina, in 2010, 2021, and 2022, respectively; and 2) to identify the Trichinella species present in the food. Specific primers were designed for PCR amplification and nucleotide sequencing of a region of the mitochondrial cytochrome b gene from both host species. Samples from the mentioned outbreaks were analysed, and the molecular identification of Trichinella spp. larvae was also performed. Results of the species identification system revealed that sausages from Córdoba and Buenos Aires had a mixed composition of pork and puma meat, while those from La Pampa contained puma meat only. Trichinella spiralis was implicated in all three outbreaks. The species identification system developed and implemented in this study revealed two host species of Trichinella related to human cases, and alerts about the risk of zoonotic transmission to humans through infected puma meat.

Zoonotic Mansonella ozzardi in Raccoons, Costa Rica, 2019-2022.

Mansonella ozzardi, a filarioid parasite, causes human mansonellosis in the Americas. We identified raccoons (Procyon lotor) as wildlife reservoirs of M. ozzardi in Costa Rica. Noting the sympatry of free-ranging raccoons and humans, we conclude that mansonellosis is a considerable public health risk in the region.

Human scabies and sarcoptic mange in northeast Brazil: Results from a rapid assessment method covering an entire state.

Scabies is a neglected tropical disease and has been highlighted as a target for control. Sarcoptic mange affects animals, but mange is also considered a zoonosis. We present rapid assessment data on scabies and sarcoptic mange collected from key informants via a web-based questionnaire in Ceará State (1265 data entries). A total of 181/184 (98.3%) municipalities reported the occurrence of human scabies; 149 (80.9%) current occurrence; 168 (91.3%) severe cases; and 113 (61.4%) severe cases currently. Sarcoptic mange was reported from 149/184 (80.9%) municipalities, and severe mange from 128 (69.9%), most commonly in dogs (117 municipalities), cats (79), pigs (17), cattle (15), horses (15), and goats (2). Respondents from 171 (92.9%) municipalities observed seasonality of occurrence. Scabies and sarcoptic mange are important public health issues in a northeast Brazilian state. The wide distribution of severe cases requires an integrated One Health approach effectively and sustainably to reduce the disease burden.

Zoonotic Ancylostoma ceylanicum Infection in Coyotes from Guanacaste Conservation Area, Costa Rica, 2021.

Ancylostoma ceylanicum is the second most common hookworm infecting humans in the Asia-Pacific region. Recent reports suggest presence of the parasite in the Americas. We report A. ceylanicum infections in coyotes from the Guanacaste Conservation Area, Costa Rica. Our findings call for active surveillance in humans and animals.

Canine leishmaniasis in the Americas: etiology, distribution, and clinical and zoonotic importance.

Canine leishmaniasis is a widespread disease on the American continent, with cases reported from Uruguay to the USA and Canada. While numerous Leishmania spp. have been reported in dogs in this region, Leishmania infantum and Leishmania braziliensis are the most common etiological agents of canine leishmaniasis from a continental perspective. Nonetheless, other species may predominate locally in some countries. The participation of dogs in the transmission cycle of various Leishmania spp. has long been speculated, but evidence indicates that their role as reservoirs of species other than L. infantum is negligible. Various native wildlife (e.g., small rodents, marsupials, sloths, and monkeys) are, in fact, the primary hosts of Leishmania spp. in the Americas. In this review, an updated list of Leishmania spp. infecting dogs in the Americas is presented, along with their distribution and clinical and zoonotic importance.

Chagas Disease and Leishmaniasis, Sympatric Zoonoses Present in Human from Rural Communities of Venezuela.

PURPOSE: Trypanosoma cruzi and Leishmania spp. coexist in several endemic areas, and there are few studies of Chagas disease and leishmaniasis coinfection worldwide; for this reason, the objective of this work was to determine the Chagas disease and leishmaniasis coinfection in several rural communities co-endemic for these diseases. METHODS: A total of 1107 human samples from six co-endemic rural communities of Cojedes state, Venezuela, were analyzed. Serum samples were evaluated by ELISA, indirect hemagglutination, and indirect immunofluorescence for Chagas disease diagnosis, and individuals were evaluated for leishmaniasis by leishmanin skin test (LST). Approximately, 30% of the individuals were also analyzed by PCR (blood clot samples) for T. cruzi and for Leishmania spp. RESULTS: The 14.7% of the individuals were positive to Trypanosoma cruzi infection by serology, and 25.8% were positive to Leishmania spp. current or past infection by LST. Among the group with PCR results, 7.8% were positive for T. cruzi, and 9.4% for Leishmania spp. The coinfection T. cruzi/Leishmania spp. was 6.5%. The T. cruzi DTUs of the positive blood clot samples were TcI, revealed using the molecular markers: (i) intergenic region of the miniexon, (ii) D7 divergent domain of the 24Sα rDNA, (iii) size-variable domain of the 18S rDNA, and (iv) hsp60-PCR-RFLP (EcoRV). The Leishmania species identified were L. (Leishmania) mexicana and L. (Viannia) braziliensis. CONCLUSION: A high prevalence was found for T. cruzi and Leishmania spp. single and coinfections in almost all communities studied, being these results of relevance for the implementation of control programs in co-endemic areas.

Zoonotic Transmission of Hepatic Hydatid Cyst from Domestic Dogs: A Case Report from an Urban-Marginal Area in Ecuador.

BACKGROUND Hepatic hydatidosis, or echinococcosis, is a zoonosis with worldwide prevalence and is potentially lethal in humans. This report presents a case of hydatidosis in a 40-year-old woman that was associated with a zoonotic transmission of Echinococcus granulosus from domestic dogs in an urban-marginal area of the city of Guayaquil, Ecuador. This report shows how early diagnosis and awareness favored the correct treatment of the disease. CASE REPORT A 40-year-old woman from the aforementioned sector presented the following symptoms: malaise, pain in the upper right hypochondrium, palpable mass, jaundice, and fever. Next, the patient's fecal samples were analyzed by direct coproparasitic methods, flotation, and sedimentation with centrifugation using saline solution, whereby the presence of Entamoeba histolytica eggs was determined. Likewise, she underwent an ultrasound, in which hepatic hydatid cysts were observed. Subsequently, the cysts were treated and surgically removed, and parasitic forms of E. granulosus were identified. Later, coproparasitic analysis of her 2 domestic dogs for coproantigen ELISA were performed, by which the presence of this cestode was also identified and confirmed. CONCLUSIONS Hydatidosis is a zoonosis that can affect the population, especially in endemic areas of developed and underdeveloped countries. In this case, hepatic hydatidosis was identified in a 40-year-old woman. Additionally, the presence of E. granulosus eggs was determined in the fecal matter of her dogs, which indicated that the patient's relatives and other people around them were exposed to this zoonosis.

Identification of infection by Leishmania spp. in wild and domestic animals in Brazil: a systematic review with meta-analysis (2001-2021).

Leishmaniasis is a zoonosis caused by protozoan species of the genus Leishmania. It generates different clinical manifestations in humans and animals, and it infects multiple hosts. Leishmania parasites are transmitted by sandfly vectors. The main objective of this systematic review was to identify the host, or reservoir animal species, of Leishmania spp., with the exception of domestic dogs, that were recorded in Brazil. This review included identification of diagnostic methods, and the species of protozoan circulating in the country. For this purpose, a literature search was conducted across index journals. This study covered the period from 2001 to 2021, and 124 studies were selected. Eleven orders possible hosts were identified, including 229 mammalian species. Perissodactyla had the highest number of infected individuals (30.69%, 925/3014), with the highest occurrence in horses. In Brazil, the most commonly infected species were found to be: horses, domestic cats, rodents, and marsupials. Bats, that were infected by one or more protozoan species, were identified as potential reservoirs of Leishmania spp. Molecular tests were the most commonly used diagnostic methods (94 studies). Many studies have detected Leishmania spp. (n = 1422): Leishmania (Leishmania) infantum (n = 705), Leishmania (Viannia) braziliensis (n = 319), and Leishmania (Leishmania) amazonensis (n = 141). Recognizing the species of animals involved in the epidemiology and biological cycle of the protozoan is important, as this allows for the identification of environmental biomarkers, knowledge of Leishmania species can improve the control zoonotic leishmaniasis.

Subsistence hunting and the introduction of Neotropical echinococcosis into the domestic environment in the Brazilian Amazon / Caça de subsistência e a introdução da equinococose neotropical no ambiente doméstico na Amazónia brasileira

The present study recorded the consumption of paca and agouti meat and revealed the presence of hydatid cysts in the livers of these rodents in extractivist communities in Brazilian Amazonia. A total of 42 families (with a median four of members per household) were interviewed, of which 98% (n=41) reported the consumption of paca and 86% (n=36) the consumption of agouti. Structures consistent with hydatid cysts were detected more frequently in the liver tissue of the pacas (74% ­ 31 of 42 samples) than the agoutis (26% ­ 11/42). The parasitological analysis of a paca liver confirmed the presence of E. vogeli. The consumption of the meat of these rodents and the confirmation of infection by E. vogeli represent preoccupying risk factors for the inhabitants of these forest communities, given that the uncooked viscera of both rodents are often fed to domestic dogs.

O presente estudo registrou o consumo de carne de paca e cutia e revelou a presença de cistos hidáticos nos fígados desses roedores em comunidades extrativistas da Amazônia brasileira. Foram entrevistadas 42 famílias (mediana quatro membros/família), destas 98% (n=41) informaram o consumo de paca e 86% (n=36) o consumo de cutia. Estruturas compatíveis com cistos hidáticos foram relatadas com maior frequência em fígados de pacas 74% (31/42) do que em cutias 26% (11/42). A análise parasitológica de um fígado de paca confirmou a presença de E. vogeli. O consumo da carne desses roedores e a confirmação da infecção por E. vogeli representam fatores de risco preocupantes para os moradores dessas comunidades florestais, uma vez que as vísceras cruas de ambos os roedores são utilizadas na alimentação de cães domésticos.

Inquérito epidemiológico sobre Lagoquilascaríase em Felinos da Serra Gaúcha / Epidemiological survey on Lagoquilascariasis in felines of Serra Gaucha

O nematoide Lagochilascaris sp. pertencente à família Ascarididae é um parasito cujo o hospedeiro definitivo pode ser o gato. Considerada uma zoonose rara na medicina veterinária, a lagoquilascaríase é responsável por causar lesões luminais e possui um tropismo particular pela região cervical e cabeça. A infecção ocorre através da ingestão da carne de animais silvestres mal cozida pelo homem e através da caça pelos felinos. Este trabalho tem como objetivo realizar um levantamento dos casos de lagoquilascaríase ocorridos em gatos domésticos nas cidades de Bento Gonçalves, Farroupilha e Caxias do Sul, localizadas na região da Serra Gaúcha. Foi realizada uma pesquisa através de questionário encaminhado por e-mail, durante os meses de abril a julho de 2020, a 44 médicos veterinários dos municípios de Bento Gonçalves, Farroupilha e Caxias do Sul, sendo 13 (29,54%) veterinários de Bento Gonçalves, 10 (22,73%) de Farroupilha e 21 (47,73%) de Caxias do Sul. Destes profissionais, 17 (38,63%) já atenderam casos de animais parasitados por este nematódeo; 9 (20,45%) em Bento Gonçalves; 3 (6,81%) em Farroupilha e 5 (11,36%) em Caxias do Sul. No total foram atendidos 36 casos de lagoquilascaríase no período de 2016 a 2020, sendo que a maior ocorrência foi na cidade de Bento Gonçalves, com 25 casos, seguida por Caxias do Sul com 6 casos e Farroupilha com apenas 5 casos relatados. Apesar da literatura considerar a lagoquilascaríase uma doença rara, este levantamento mostra que há vários casos acontecendo na espécie felina na Serra Gaúcha.

The nematode Lagochilascaris sp. belonging to the family Ascarididae is a parasite whose definitive host may be the cat. Considered a rare zoonosis in veterinary medicine, lagochilascariasis is responsible for causing luminal lesions and has a particular tropism for the cervical region and head. Infection occurs through the ingestion of undercooked meat from wild animals by humans and through hunting by felines. This work aims to carry out a survey of cases of lagochilascariasis that occurred in domestic cats in the cities of Bento Gonçalves, Farroupilha and Caxias do Sul, located in the Serra Gaúcha region. A survey was carried out through a questionnaire sent by email, during the months of April to July 2020, to 44 veterinarians from the municipalities of Bento Gonçalves, Farroupilha and Caxias do Sul, of which 13 (29.54%) were veterinarians from Bento. Gonçalves, 10 (22.73%) from Farroupilha and 21 (47.73%) from Caxias do Sul. Of these professionals, 17 (38.63%) have already treated cases of animals parasitized by this nematode; 9 (20.45%) in Bento Gonçalves; 3 (6.81%) in Farroupilha and 5 (11.36%) in Caxias do Sul. In total, 36 cases of lagochilascariasis were treated in the period from 2016 to 2020, with the highest occurrence being in the city of Bento Gonçalves, with 25 cases, followed by Caxias do Sul with 6 cases and Farroupilha with only 5 reported cases. Although the literature considers lagochilascariasis a rare disease, this survey shows that there are several cases happening in feline species in Serra Gaúcha.

Parasitological, serological and molecular diagnosis of Dirofilaria immitis in dogs in Northeastern Brazil.

Dirofilaria immitis is a zoonotic filarid that mainly affects the domestic dog, causing a generally fatal chronic disease, known as heart worm disease. In addition to dogs, the parasite can affect wild canids, cats, and humans. Due to its importance to One Health, detection of parasitism by D. immitis in dogs can help the adoption of control measures that aim to reduce the occurrence of parasitosis in animals and humans. The detection of D. immitis is based on the use of parasitological, serological, and molecular methods, which vary in sensitivity and specificity. Therefore, the objective was to evaluate and compare the efficiency and performance of parasitological, serological, and molecular tests in the detection of D. immitis in dogs in Northeastern Brazil. Whole blood and serum from 140 dogs from the municipality of Sousa were used, varying between males and females; aged one to 17 years; pure and mixed breeds; domiciled and stray. Three microscopic parasitological techniques (MPT) were used: capillary blood smear (CBS), peripheral (PBS) and modified Knott test (MK) associated with the morphometric diagnosis of the microfilariae. For the detection of D. immitis antigens, a rapid immunochromatographic test (RIT) (ALERE Dirofilariose AG Teste kit®, Seogu-dong, Korea) was used, and polymerase chain reaction (PCR) as a molecular method. To evaluate the tests, PCR was considered the gold standard, and sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) values were calculated. To verify the agreement of the tests, the Kappa test was performed (p ≤ 0.05). From the 140 analyzed samples, 33.6% (48/140) presented microfilariae, antigen and/or parasitic DNA. 23.6% (33/140) were positive in the CBS; 25.7% (36/140) in the PBS; 29.3% (41/140) in the MK; 30% (42/140) in the RIT and 28.6% (40/140) in the PCR. All methods showed almost perfect agreement with PCR, high sensitivity (0.8-0.95), specificity (0.94-0.99), and values established with VPP (0.8571-0.9722) and VPN (0.9519-0.9797). The CBS and PBS showed less sensitivity and greater specificity. MK presented the highest sensitivity and RIT was the choice for hidden infections. Considering the occurrence of D. immitis in dogs in a non-coastal region of Northeastern Brazil, an epidemiological approach is recommended to identify risk factors for this zoonotic parasitosis.

Molecular detection of Mansonella mariae incriminates Simulium oyapockense as a potentially important bridge vector for Amazon-region zoonoses.

OBJECTIVE: To assess the emergent zoonotic disease risk posed by the voracious human-biting blackfly species Simulium oyapockense in the peripheral regions of an expanding urban centre situated deep in the Brazilian Amazon rainforest. METHODS: We performed nine human landing catches at three periurban sites surrounding the Brazilian Amazon town of São Gabriel da Cachoeira. Using the detection of non-human primate filarial parasites as an indicator of the zoonotic disease threat posed by a biting insect, we screened 3328 S. oyapockense blackflies for the presence of zoonotic filarial DNA with an ITS-1 PCR assay and Sanger sequencing. RESULTS: Between 98 and 100% of the biting insects captured during our nine collections were identified as S. oyapockense; at our three collection sites and during our three seasonally-distinct collections this species was captured at rates between 28 and 294 blackflies per hour. PCR screening of the march-collected S. oyapockense detected infectious-stage (L3) Mansonella mariae parasites (which are only known to infect non-human primates) in >0.15% of the tested head samples. CONCLUSIONS: Our results show that residents of the periurban regions of São Gabriel da Cachoeira are routinely exposed to the bites of S. oyapockense blackflies which have previously fed on non-human primates.

The connection between Trypanosoma cruzi transmission cycles by Triatoma brasiliensis brasiliensis: A threat to human health in an area susceptible to desertification in the Seridó, Rio Grande do Norte, Brazil.

An outbreak of Chagas disease, possibly involving its vector Triatoma brasiliensis brasiliensis, was identified in the state of Rio Grande do Norte (RN). Given the historical significance of this vector in public health, the study aimed to evaluate its role in the transmission dynamics of the protozoan Trypanosoma cruzi in an area undergoing desertification in the Seridó region, RN, Brazil. We captured triatomines in sylvatic and anthropic ecotopes. Natural vector infection was determined using parasitological and molecular methods and we identified discrete typing units (DTUs) of T. cruzi by analyzing the COII gene of mtDNA, 24Sα rDNA, and mini-exon gene. Their blood meals sources were identified by amplification and sequencing of the mtDNA cytochrome b gene. A total of 952 T. b. brasiliensis were captured in peridomestic (69.9%) and sylvatic ecotopes (30.4%). A wide range of natural infection rates were observed in peridomestic (36.0% - 71.1%) and sylvatic populations (28.6% - 100.0%). We observed the circulation of TcI and TcII DTUs with a predominance of Tcl in sylvatic and peridomestic environments. Kerodon rupestris, rocky cavy (13/39), Homo sapiens, human (8/39), and Bos taurus, ox (6/39) were the most frequently detected blood meals sources. Thus, Triatoma b. brasiliensis is invading and colonizing the human dwellings. Furthermore, high levels of natural infection, coupled with the detection of TcI and TcII DTUs, and also the detection of K. rupestris and H. sapiens as blood meals sources of infected T. b. brasiliensis indicate a risk of T. cruzi transmission to human populations in areas undergoing desertification.

The burden of zoonoses in Paraguay: A systematic review.

INTRODUCTION: Underestimation of zoonoses is exacerbated in low and middle-income countries due mainly to inequalities with serious consequences in healthcare. This is difficult to gauge and reduce the impact of those diseases. Our study focuses on Paraguay, where the livestock industry is one of the major components of the country's economy. Therefore, the rationale of this study was to develop a case study in Paraguay to estimate the dual impact of zoonotic diseases on both the human health and animal health sector and thus determine the societal burden of such diseases. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a systemic review (including a meta-analysis) to assess the burden of zoonoses in Paraguay, including official reports and grey literature of disease incidence and prevalence. We estimated the Disability Adjusted Life Years (DALYs) and Zoonosis Disability Adjusted Life Years (zDALYs) to measure the difference between the current health status and the desired health situation of animals and the Paraguayan population based on 50 zoonotic diseases suggested by the WHO (World Health Organization), OIE (World Organization for Animal Health) and the National Health in Paraguay. The total DALYs represent 19,384 (95% CI: from 15,805 to 29,733), and zDALYs, 62,178 (95% CI: from 48,696 to 77,188). According to the results, the priority pathogens for DALYs are E. coli, Trypanosoma cruzi, Leishmania spp, and Toxoplasma gondii. When we include the additional animal health burden, the most important pathogens are Brucella spp, E. coli, Trypanosoma cruzi, and Fasciola hepatica for zDALYs. CONCLUSION/SIGNIFICANCE: This is the first study to integrate DALYs and zDALYs with important clues related to the health status of Paraguay. Through DALYs and zDALYs, our perspective becomes more complete because we consider not only human health but also animal health. This is important for setting priorities in disease control, especially in a society where livestock contribute significantly to the economy and to human well-being.

Validation of a spatial agent-based model for Taenia solium transmission ("CystiAgent") against a large prospective trial of control strategies in northern Peru.

BACKGROUND: The pork tapeworm (Taenia solium) is a parasitic helminth that imposes a major health and economic burden on poor rural populations around the world. As recognized by the World Health Organization, a key barrier for achieving control of T. solium is the lack of an accurate and validated simulation model with which to study transmission and evaluate available control and elimination strategies. CystiAgent is a spatially-explicit agent based model for T. solium that is unique among T. solium models in its ability to represent key spatial and environmental features of transmission and simulate spatially targeted interventions, such as ring strategy. METHODS/PRINCIPAL FINDINGS: We validated CystiAgent against results from the Ring Strategy Trial (RST)-a large cluster-randomized trial conducted in northern Peru that evaluated six unique interventions for T. solium control in 23 villages. For the validation, each intervention strategy was replicated in CystiAgent, and the simulated prevalences of human taeniasis, porcine cysticercosis, and porcine seroincidence were compared against prevalence estimates from the trial. Results showed that CystiAgent produced declines in transmission in response to each of the six intervention strategies, but overestimated the effect of interventions in the majority of villages; simulated prevalences for human taenasis and porcine cysticercosis at the end of the trial were a median of 0.53 and 5.0 percentages points less than prevalence observed at the end of the trial, respectively. CONCLUSIONS/SIGNIFICANCE: The validation of CystiAgent represented an important step towards developing an accurate and reliable T. solium transmission model that can be deployed to fill critical gaps in our understanding of T. solium transmission and control. To improve model accuracy, future versions would benefit from improved data on pig immunity and resistance, field effectiveness of anti-helminthic treatment, and factors driving spatial clustering of T. solium infections including dispersion and contact with T. solium eggs in the environment.

The potential risk of enzootic Trypanosoma cruzi transmission inside four training and re-training military battalions (BITER) in Colombia.

BACKGROUND: Colombia's National Army is one of the largest military institutions in the country based on the number of serving members and its presence throughout the country. There have been reports of cases of acute or chronic cases of Chagas disease among active military personnel. These may be the result of military-associated activities performed in jungles and other endemic areas or the consequence of exposure to Trypanosoma cruzi inside military establishments/facilities located in endemic areas. The aim of the present study was to describe the circulation of T. cruzi inside facilities housing four training and re-training battalions [Battalions of Instruction, Training en Re-training (BITERs)] located in municipalities with historical reports of triatomine bugs and Chagas disease cases. An entomological and faunal survey of domestic and sylvatic environments was conducted inside each of these military facilities. METHODS: Infection in working and stray dogs present in each BITER location was determined using serological and molecular tools, and T. cruzi in mammal and triatomine bug samples was determined by PCR assay. The PCR products of the vertebrate 12S rRNA gene were also obtained and subjected to Sanger sequencing to identify blood-feeding sources. Finally, we performed a geospatial analysis to evaluate the coexistence of infected triatomines and mammals with the military personal inside of each BITER installation. RESULTS: In total, 86 specimens were collected: 82 Rhodnius pallescens, two Rhodnius prolixus, one Triatoma dimidiata and one Triatoma maculata. The overall T. cruzi infection rate for R. pallescens and R. prolixus was 56.1 and 100% respectively, while T. dimidiata and T. maculata were not infected. Eight feeding sources were found for the infected triatomines, with opossum and humans being the most frequent sources of feeding (85.7%). Infection was most common in the common opossum Didelphis marsupialis, with infection levels of 77.7%. Sylvatic TcI was the most frequent genotype, found in 80% of triatomines and 75% of D. marsupialis. Of the samples collected from dogs (n = 52), five (9.6%; 95% confidence interval: 3.20-21.03) were seropositive based on two independent tests. Four of these dogs were creole and one was a working dog. The spatial analysis revealed a sympatry between infected vectors and mammals with the military population. CONCLUSIONS: We have shown a potential risk of spillover of sylvatic T. cruzi transmission to humans by oral and vectorial transmission in two BITER installations in Colombia. The results indicate that installations where 100,000 active military personnel carry out training activities should be prioritized for epidemiological surveillance of Chagas disease.

Molecular characterization of Cryptosporidium spp. in dogs and cats in the city of Rio de Janeiro, Brazil, reveals potentially zoonotic species and genotype.

Intestinal cryptosporidiosis is a diarrheal disease caused by protists of genus Cryptosporidium that infect a wide variety of hosts, primarily vertebrates. Due to the close contact between humans and their companion animals, especially dogs and cats, there is concern about the potential for zoonotic transmission of this enteric protozoan parasite by infected animals. This study aimed to perform a microscopic and molecular diagnosis of Cryptosporidium spp. in fecal samples from domiciled dogs and cats. One hundred and nineteen fecal samples were processed using sugar centrifugal flotation followed by molecular detection of Cryptosporidium spp. DNA using nested PCR. Subtyping of isolates positive for C. parvum was performed by sequence analysis of the 60 kDa glycoprotein gene (GP60). Cryptosporidium oocysts were detected in 7.8% (5/64) and 5.4% (3/55) of the fecal samples from dogs and cats, respectively. Cryptosporidium canis (n = 3) and C. parvum (n = 2) were the main species found in dogs, whereas C. felis (n = 3) was prevalent in cats. Subtype IIaA17G2R2 (potentially zoonotic) was identified in samples positive for C. parvum. Despite the low prevalence of Cryptosporidium observed in the domiciled dogs and cats, the presence of potentially zoonotic C. parvum in dogs evidences a public health concern. Further research is needed to better understand the epidemiology, source, and potential impacts of Cryptosporidium infection in cats and dogs.