One Health Approach on Dog Bites: Demographic and Associated Socioeconomic Factors in Southern Brazil.

Despite being an important public health issue, particularly due to rabies, dog bites and associated risk factors have rarely been assessed by health services from a One Health perspective. Accordingly, the present study aimed to assess dog biting and associated demographic and socioeconomic risk factors in Curitiba, the eighth-largest Brazilian city with approximately 1.87 million people, based on the post-exposure prophylaxis (PEP) rabies reports between January/2010 and December/2015. The total of 45,392 PEP reports corresponded to an average annual incidence of 4.17/1000 habitants, mainly affecting white (79.9%, 4.38/1000 population), males (53.1%, 4.81/1000 population), and children aged 0-9 years (20.1%, 6.9/1000 population), with severe accidents associated with older victims (p < 0.001) and mainly caused by dogs known to the victims. An increase of USD 100.00 in the median neighborhood income was associated with a 4.9% (95% CI: 3.8-6.1; p < 0.001) reduction in dog bites. In summary, dog biting occurrence was associated with victims' low income, gender, race/color, and age; severe accidents were associated with elderly victims. As dog bites have been described as multifactorial events involving human, animal, and environmental factors, the characteristics presented herein should be used as a basis to define mitigation, control, and prevention strategies from a One Health perspective.

Porcine reproductive and respiratory syndrome virus 2 (PRRSV-2) genetic diversity and occurrence of wild type and vaccine-like strains in the United States swine industry.

Porcine reproductive and respiratory syndrome virus genotype 2 (PRRSV-2) genetic diversity in the U.S. was assessed using a database comprising 10 years' worth of sequence data obtained from swine production systems routine monitoring and outbreak investigations. A total of 26,831 ORF5 PRRSV-2 sequences from 34 production systems were included in this analysis. Within group mean genetic distance (i.e. mean proportion of nucleotide differences within ORF5) per year according to herd type was calculated for all PRRSV-2 sequences. The percent nucleotide difference between each sequence and the ORF5 sequences from four commercially available PRRSV-2 vaccines (Ingelvac PRRS MLV, Ingelvac PRRS ATP, Fostera PRRS, and Prevacent PRRS) within the same lineage over time was used to classify sequences in wild-type or vaccine-like. The mean ORF5 genetic distance fluctuated from 0.09 to 0.13, being generally smaller in years in which there was a relative higher frequency of dominant lineage. Vaccine-like sequences comprised about one fourth of sequences obtained through routine monitoring of PRRS. We found that lineage 5 sequences were mostly Ingelvac PRRS MLV-like. Lineage 8 sequences up to 2011 were 62.9% Ingelvac PRRS ATP-like while the remaining were wild-type viruses. From 2012 onwards, 51.9% of lineage 8 sequences were Ingelvac PRRS ATP-like, 45.0% were Fostera PRRS-like, and only 3.2% were wild-type. For lineage 1 sequences, 0.1% and 1.7% of the sequences were Prevacent PRRS-like in 2009-2018 and 2019, respectively. These results suggest that repeated introductions of vaccine-like viruses through use of modified live vaccines might decrease within-lineage viral diversity as vaccine-like strains become more prevalent. Overall, this compilation of private data from routine monitoring provides valuable information on PRRSV viral diversity.

Forecasting viral disease outbreaks at the farm-level for commercial sow farms in the U.S.

Porcine epidemic diarrhea virus (PEDv) was introduced to the U.S. in 2013 and is now considered to be endemic. Like many endemic diseases, it is challenging for producers to estimate and respond to spatial and temporal variation in risk. Utilizing a regional spatio-temporal dataset containing weekly PEDv infection status for ∼15 % of the U.S. sow herd, we present a machine learning platform developed to forecast the probability of PEDv infection in sow farms in the U.S. Participating stakeholders (swine production companies) in a swine-dense region of the U.S. shared weekly information on a) PEDv status of farms and b) animal movements for the past week and scheduled movements for the upcoming week. Environmental (average temperature, humidity, among others) and land use characteristics (hog density, proportion of area with different land uses) in a 5 km radius around each farm were summarized. Using the Extreme Gradient Boosting (XGBoost) machine learning model with Synthetic Minority Over-sampling Technique (SMOTE), we developed a near real-time tool that generates weekly PEDv predictions (pertaining to two-weeks in advance) to farms of participating stakeholders. Based on retrospective data collected between 2014 and 2017, the sensitivity, specificity, positive and negative predictive values of our model were 19.9, 99.9, 70.5 and 99.4 %, respectively. Overall accuracy was 99.3 %, although this metric is heavily biased by imbalance in the data (less than 0.7 % of farms had an outbreak each week). This platform has been used to deliver weekly real-time forecasts since December 2019. The forecast platform has a built-in feature to re-train the predictive model in order to remain as relevant as possible to current epidemiological situations, or to expand to a different disease. These dynamic forecasts, which account for recent animal movements, present disease distribution, and environmental factors, will promote data-informed and targeted disease management and prevention within the U.S. swine industry.

Temporal Dynamics of Co-circulating Lineages of Porcine Reproductive and Respiratory Syndrome Virus.

Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) is the most important endemic pathogen in the U.S. swine industry. Despite control efforts involving improved biosecurity and different vaccination protocols, the virus continues to circulate and evolve. One of the foremost challenges in its control is high levels of genetic and antigenic diversity. Here, we quantify the co-circulation, emergence and sequential turnover of multiple PRRSV lineages in a single swine-producing region in the United States over a span of 9 years (2009-2017). By classifying over 4,000 PRRSV sequences (open-reading frame 5) into phylogenetic lineages and sub-lineages, we document the ongoing diversification and temporal dynamics of the PRRSV population, including the rapid emergence of a novel sub-lineage that appeared to be absent globally pre-2008. In addition, lineage 9 was the most prevalent lineage from 2009 to 2010, but its occurrence fell to 0.5% of all sequences identified per year after 2014, coinciding with the emergence or re-emergence of lineage 1 as the dominant lineage. The sequential dominance of different lineages, as well as three different sub-lineages within lineage 1, is consistent with the immune-mediated selection hypothesis for the sequential turnover in the dominant lineage. As host populations build immunity through natural infection or vaccination toward the most common variant, this dominant (sub-) lineage may be replaced by an emerging variant to which the population is more susceptible. An analysis of patterns of non- synonymous and synonymous mutations revealed evidence of positive selection on immunologically important regions of the genome, further supporting the potential that immune-mediated selection shapes the evolutionary and epidemiological dynamics for this virus. This has important implications for patterns of emergence and re-emergence of genetic variants of PRRSV that have negative impacts on the swine industry. Constant surveillance on PRRSV occurrence is crucial to a better understanding of the epidemiological and evolutionary dynamics of co-circulating viral lineages. Further studies utilizing whole genome sequencing and exploring the extent of cross-immunity between heterologous PRRS viruses could shed further light on PRRSV immunological response and aid in developing strategies that might be able to diminish disease impact.

Effect of an intervention in storm drains to prevent Aedes aegypti reproduction in Salvador, Brazil.

BACKGROUND: Aedes aegypti, the principal vector for dengue, chikungunya and Zika viruses, is a synanthropic species that uses stagnant water to complete its reproductive cycle. In urban settings, rainfall water draining structures, such as storm drains, may retain water and serve as a larval development site for Aedes spp. reproduction. Herein, we describe the effect of a community-based intervention on preventing standing water accumulation in storm drains and their consequent infestation by adult and immature Ae. aegypti and other mosquitoes. METHODS: Between April and May of 2016, local residents association of Salvador, Brazil, after being informed of water accumulation and Ae. aegypti infestation in the storm drains in their area, performed an intervention on 52 storm drains. The intervention consisted of placing concrete at the bottom of the storm drains to elevate their base to the level of the outflow tube, avoiding water accumulation, and placement of a metal mesh covering the outflow tube to avoid its clogging with debris. To determine the impact of the intervention, we compared the frequency at which the 52 storm drains contained water, as well as adult and immature mosquitoes using data from two surveys performed before and two surveys performed after the intervention. RESULTS: During the pre-intervention period, water accumulated in 48 (92.3%) of the storm drains, and immature Ae. aegypti were found in 11 (21.2%) and adults in 10 (19.2%). After the intervention, water accumulated in 5 (9.6%) of the storm drains (P < 0.001), none (0.0%) had immatures (P < 0.001), and 3 (5.8%) contained adults (P = 0.039). The total number of Ae. aegypti immatures collected decreased from 109 to 0 (P < 0.001) and adults decreased from 37 to 8 (P = 0.011) after the intervention. Collection of immature and adult non-Aedes mosquitoes (mainly Culex spp.) in the storm drains also decreased after the intervention. CONCLUSION: This study exemplifies how a simple intervention targeting storm drains can result in a major reduction of water retention, and, consequently, impact Ae. aegypti larval populations. Larger and multi-center evaluations are needed to confirm the potential of citywide structural modifications of storm drains to reduce Aedes spp. infestation level.

Storm drains as larval development and adult resting sites for Aedes aegypti and Aedes albopictus in Salvador, Brazil.

BACKGROUND: Dengue (DENV), Chikungunya (CHIKV), Zika (ZIKV), as well as yellow fever (YFV) viruses are transmitted to humans by Aedes spp. females. In Salvador, the largest urban center in north-eastern Brazil, the four DENV types have been circulating, and more recently, CHIKV and ZIKV have also become common. We studied the role of storm drains as Aedes larval development and adult resting sites in four neighbourhoods of Salvador, representing different socioeconomic, infrastructure and topographic conditions. RESULTS: A sample of 122 storm drains in the four study sites were surveyed twice during a 4-month period in 2015; in 49.0 % of the visits, the storm drains contained water. Adults and immatures of Aedes aegypti were captured in two of the four sites, and adults and immatures of Aedes albopictus were captured in one of these two sites. A total of 468 specimens were collected: 148 Ae. aegypti (38 adults and 110 immatures), 79 Ae. albopictus (48 adults and 31 immatures), and 241 non-Aedes (mainly Culex spp.) mosquitoes (42 adults and 199 immatures). The presence of adults or immatures of Ae. aegypti in storm drains was independently associated with the presence of non-Aedes mosquitoes and with rainfall of ≤ 50 mm during the preceding week. CONCLUSIONS: We found that in Salvador, one of the epicentres of the 2015 ZIKV outbreak, storm drains often accumulate water and serve as larval development sites and adult resting areas for both Ae. aegypti and Ae. albopictus. Vector control campaigns usually overlook storm drains, as most of the effort to prevent Ae. agypti reproduction is directed towards containers in the domicile environment. While further studies are needed to determine the added contribution of storm drains for the maintenance of Aedes spp. populations, we advocate that vector control programs incorporate actions directed at storm drains, including regular inspections and use of larvicides, and that human and capital resources are mobilized to modify storm drains, so that they do not serves as larval development sites for Aedes (and other) mosquitoes.

Mycobacterium tuberculosis complex infection in Barbary sheep (Ammotragus lervia) at the Curitiba Zoo, southern Brazil: case report / Infecção pelo complexo Mycobacterium tuberculosis em carneiro da Barbária (Ammotragus lervia) no Zoológico de Curitiba, sul do Brasil: relato de caso

Tuberculosis is one of the most important mandatory notification diseases in the world caused by bacteria of the Mycobacterium tuberculosis complex, infecting both humans and animals. A sudden death of a Barbary sheep in Curitiba Zoo, and presence of multifocal nodules in lungs at necropsy raised suspicion of tuberculosis. Quantitative polymerase chain reaction (qPCR) from organs and fluid was performed and detected M. tuberculosis complex in a lung sample. This research reports the M. tuberculosis complex infection in Barbary sheep, a zoonosis of great relevance to public health and emphasizes the need to implement prevention measures. Furthermore, the research may provide a better understanding for species conservation, occurrence and transmission of diseases in captivity, reservoir potential and public health impact to zoo personnel and visitors.(AU)

A tuberculose é uma das doenças mundiais de notificação obrigatória mais importantes causada pelo complexo Mycobacterium tuberculosis que pode infectar pessoas e animais. A morte repentina de um carneiro da Barbária no Zoológico de Curitiba, que apresentou nódulos multifocais no pulmão à necropsia, levantou a suspeita de tuberculose. Foi realizada a Reação em Cadeia da Polimerase Quantitativa (qPCR) de fragmentos de órgãos e fluido. A qPCR detectou a presença do complexo M. tuberculosis nas amostras de pulmão. Este estudo relata a infecção pelo complexo M. tuberculosis no carneiro da Barbária, uma zoonose de grande relevância para a saúde pública, ressaltando-se a necessidade da implementação de medidas de prevenção. Além disso, pode prover um melhor entendimento sobre conservação de espécies, ocorrência e transmissão de doenças em cativeiro, potencial reservatório e impacto na saúde pública para visitantes e funcionários dos zoológicos.(AU)

Seroprevalence and seroincidence of Leptospira infection in dogs during a one-year period in an endemic urban area in Southern Brazil.

INTRODUCTION: Leptospirosis is a zoonosis that affects both humans and animals. Dogs may serve as sentinels and indicators of environmental contamination as well as potential carriers for Leptospira. This study aimed to evaluate the seroprevalence and seroincidence of leptospirosis infection in dogs in an urban low-income community in southern Brazil where human leptospirosis is endemic. METHODS: A prospective cohort study was designed that consisted of sampling at recruitment and four consecutive trimestral follow-up sampling trials. All households in the area were visited, and those that owned dogs were invited to participate in the study. The seroprevalence (MAT titers ≥100) of Leptospira infection in dogs was calculated for each visit, the seroincidence (seroconversion or four-fold increase in serogroup-specific MAT titer) density rate was calculated for each follow-up, and a global seroincidence density rate was calculated for the overall period. RESULTS: A total of 378 dogs and 902.7 dog-trimesters were recruited and followed, respectively. The seroprevalence of infection ranged from 9.3% (95% CI; 6.7 - 12.6) to 19% (14.1 - 25.2), the seroincidence density rate of infection ranged from 6% (3.3 - 10.6) to 15.3% (10.8 - 21.2), and the global seroincidence density rate of infection was 11% (9.1 - 13.2) per dog-trimester. Canicola and Icterohaemorraghiae were the most frequent incident serogroups observed in all follow-ups. CONCLUSIONS: Follow-ups with mean trimester intervals were incapable of detecting any increase in seroprevalence due to seroincident cases of canine leptospirosis, suggesting that antibody titers may fall within three months. Further studies on incident infections, disease burden or risk factors for incident Leptospira cases should take into account the detectable lifespan of the antibody.

Seroprevalence and seroincidence of Leptospira infection in dogs during a one-year period in an endemic urban area in Southern Brazil

INTRODUCTION: Leptospirosis is a zoonosis that affects both humans and animals. Dogs may serve as sentinels and indicators of environmental contamination as well as potential carriers for Leptospira. This study aimed to evaluate the seroprevalence and seroincidence of leptospirosis infection in dogs in an urban low-income community in southern Brazil where human leptospirosis is endemic. METHODS: A prospective cohort study was designed that consisted of sampling at recruitment and four consecutive trimestral follow-up sampling trials. All households in the area were visited, and those that owned dogs were invited to participate in the study. The seroprevalence (MAT titers ≥100) of Leptospira infection in dogs was calculated for each visit, the seroincidence (seroconversion or four-fold increase in serogroup-specific MAT titer) density rate was calculated for each follow-up, and a global seroincidence density rate was calculated for the overall period. RESULTS: A total of 378 dogs and 902.7 dog-trimesters were recruited and followed, respectively. The seroprevalence of infection ranged from 9.3% (95% CI; 6.7 - 12.6) to 19% (14.1 - 25.2), the seroincidence density rate of infection ranged from 6% (3.3 - 10.6) to 15.3% (10.8 - 21.2), and the global seroincidence density rate of infection was 11% (9.1 - 13.2) per dog-trimester. Canicola and Icterohaemorraghiae were the most frequent incident serogroups observed in all follow-ups. CONCLUSIONS: Follow-ups with mean trimester intervals were incapable of detecting any increase in seroprevalence due to seroincident cases of canine leptospirosis, suggesting that antibody titers may fall within three months. Further studies on incident infections, disease burden or risk factors for incident Leptospira cases should take into account the detectable lifespan of the antibody. .

Occurrences of anti-Toxoplasma gondii and anti-Neospora caninum antibodies in Barbary sheep at Curitiba zoo, southern Brazil.

Barbary 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 anti-Toxoplasma 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.

Occurrences of anti-Toxoplasma gondii and anti-Neospora caninum antibodies in Barbary sheep at Curitiba zoo, southern Brazil / Ocorrências de anticorpos anti-Toxoplasma gondii e anti-Neospora caninum em aoudads no zoológico de Curitiba, sul do Brasil

Barbary 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 anti-Toxoplasma 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.

Aoudads (Ammotragus lervia) têm o potencial para atuar como hospedeiros de importantes doenças infecciosas, em particular as zoonoses. Amostras de sangue de 17 aoudads do zoológico de Curitiba foram coletadas para avaliar ocorrências de anticorpos anti-Toxoplasma gondii e anti-Neospora caninum, testados pela reação de imunofluorescência indireta (RIFI). Anticorpos anti-T. gondii e anti-N. caninum foram detectados em 4/17 (23,5%) e 4/17 (23,5%) das amostras dos aoudads, respectivamente. O presente estudo revelou que os aoudads no zoológico de Curitiba estão expostos a T. gondii e N. caninum e, portanto, podem atuar como hospedeiros intermediários e fatores de difusão da toxoplasmose e da neosporose intra e interespécies em áreas compartilhadas.

Neighborhood and postal worker characteristics associated with dog bites in postal workers of the Brazilian National Postal Service in Curitiba.

Dog bites are the third most common cause of absenteeism among postal workers of the Brazilian National Postal Service in Southern Brazil, with an average off-work time of approximately two days for each biting episode. The objective of this study was to evaluate the neighborhood characteristics involving dog bites that occurred during work time in postal workers, its impact on work and consequent preventive alternatives. A descriptive and analytical cross-sectional study was designed for all Curitiba postal workers. Data were descriptively analyzed and the hypothesis of correlation between median monthly income, population density and occurrence of dog bites was tested. A total of 34.9% of the postal workers answered the questionnaire and 64.6% of them had been bitten while working. The odds of bites occurring in a neighborhood increase by 1.035 times for every increase in one unit in the population density and decrease by 0.998 times for every increase of US$ 1.00 in the neighborhood median monthly income of the head of the family. The occurrence of dog bites among postal workers in Curitiba is related to income and population density and prevention strategies should address mailbox position and adequate fencing to provide protection for postal workers.

Neighborhood and postal worker characteristics associated with dog bites in postal workers of the Brazilian National Postal Service in Curitiba / Características do bairro e de carteiros associadas com mordidas de cães em trabalhadores postais dos Correios em Curitiba

Dog bites are the third most common cause of absenteeism among postal workers of the Brazilian National Postal Service in Southern Brazil, with an average off-work time of approximately two days for each biting episode. The objective of this study was to evaluate the neighborhood characteristics involving dog bites that occurred during work time in postal workers, its impact on work and consequent preventive alternatives. A descriptive and analytical cross-sectional study was designed for all Curitiba postal workers. Data were descriptively analyzed and the hypothesis of correlation between median monthly income, population density and occurrence of dog bites was tested. A total of 34.9% of the postal workers answered the questionnaire and 64.6% of them had been bitten while working. The odds of bites occurring in a neighborhood increase by 1.035 times for every increase in one unit in the population density and decrease by 0.998 times for every increase of US$ 1.00 in the neighborhood median monthly income of the head of the family. The occurrence of dog bites among postal workers in Curitiba is related to income and population density and prevention strategies should address mailbox position and adequate fencing to provide protection for postal workers.

Mordidas de cães são a terceira causa mais frequente de absenteísmo ao trabalho em carteiros do Correio no sul do Brasil, com uma média de dois dias de ausência a cada episódio de mordida. O objetivo deste estudo foi avaliar as características de bairros onde ocorreram mordidas de cães em carteiros durante o período de serviço, o impacto disto no trabalho e desenvolver alternativas preventivas. Um corte-transversal descritivo e analítico foi desenhado e aplicado a todos os carteiros de Curitiba. Os dados foram analisados de forma descritiva e foi testada a hipótese de que renda mediana mensal, densidade populacional e ocorrência de mordidas em cada bairro estão correlacionadas. Um total de 34,9% dos carteiros de Curitiba respondeu ao questionário e 64,6% deles já haviam sido mordidos enquanto trabalhavam. A chance de ocorrerem mordidas em um bairro aumenta em 1,035 vezes a cada aumento em uma unidade na densidade populacional e diminui 0,998 vezes para cada aumento de US$ 1,00 na renda mediana mensal do chefe de família. A ocorrência de mordidas de cães em carteiros de Curitiba está correlacionada com renda e densidade populacional. Estratégias de prevenção devem visar um adequado posicionamento da caixa de correio e a instalação de cercas adequadas para proteger os carteiros.

História natural da leptospirose urbana: influência do sexo e da idade no risco de infecção, progressão clínica da doença e óbito / Natural history of urban leptospirosis: influence of gender and age on the risk of infection, clinical disease progression and death

Leptospirose é causada por bactérias do gênero Leptospira e é transmitida aos humanos pela urina de animais contaminados. Apenas uma parcela dos indivíduos infectados desenvolvem manifestações clínicas graves que requerem hospitalização e são potencialmente fatais. Os fatores que determinam que uma infecção por Leptospira evolua de forma autolimitada e outra progrida para uma doença grave e fatal ainda são pouco claros. Nós hipotetizamos que características demográficas como o sexo e a idade influenciem o risco de progressão clínica de indivíduos infectados pela Leptospira. OBJETIVO Investigar a influência do sexo e da idade no risco de progressão clínica da leptospirose após a infecção e estimar a razão entre o número de infecções subclínicas para cada caso grave e cada óbito por leptospirose em comunidades com alta transmissão da doença. MÉTODO Um estudo de coorte foi conduzido entre 2003 e 2006 para determinar a incidência de infecções subclínicas por Leptospira no bairro de Pau da Lima, uma comunidade carente de Salvador - BA . Paralelamente, pacientes com leptospirose grave e óbitos por leptospirose foram identificados através de vigilância populacional ativa no Hospital Couto Maia, em Salvador. Foi calculada a incidência de leptospirose grave e a mortalidade por leptospirose para áreas da cidade com características socioeconômicas similares a da área do estudo de coorte. Todas as incidências foram estratificadas por faixa etária e sexo, sendo em seguida comparadas através de razões de risco. RESULTADOS Foi identificada uma incidência média anual de 23,8 (IC 95%, 19,7 – 28,8) casos de infecção subclínica/1.000 habitantes na área da coorte. Em habitantes de áreas da cidade com características socioeconômicas similares a da área do estudo de coorte a incidência média anual de formas graves foi de 8,2 (IC 95%, 7,0 – 9,4) casos/100.000, sendo que a mortalidade por leptospirose média anual nesta população foi de 1,6 (IC 95%, 1,2 – 2,0) óbitos/100.000 habitantes. Homens apresentaram um risco 2,0 (IC 95%, 1,6 – 2,6) vezes maior de desenvolverem infecções subclínicas, 6,1 (IC 95%, 5,2 – 7,2) vezes maior de desenvolverem infecções graves e 0,6 (IC 95%, 0,4 – 1,0) vezes menor de evoluir para óbito do que mulheres. Indivíduos da faixa etária de 25 a 34 anos e de 35 a 44 anos de idade apresentaram um risco de desenvolverem infecções subclínicas 2,5 (IC 95%, 1,8 – 3,6) e 1,3 (IC 95%, 0,8 – 2,3) vezes maior, respectivamente, em comparação aos com idade entre 5 a 14 anos, enquanto que os indivíduos das mesmas faixas etárias apresentaram riscos de leptospirose grave de 4,5 (IC 95%, 2,2 – 9,0) e 5,1 (IC 95%, 2,5 – 10,3) vezes, respectivamente. Estima-se que ocorreram 289 e 1.510 infecções subclínicas para cada caso grave e para cada óbito, respectivamente, identificados e analisados neste estudo. CONCLUSÕES O sexo e a idade influenciam de risco de infecção subclínica, grave e de óbito por leptospirose. Homens tem maior risco de infecção subclínica e grave, entretanto mulheres apresentam maior letalidade de leptospirose. O risco para infecções subclínicas alcança o pico em indivíduos de 25 a 34 anos, entretanto o risco para infecções graves e óbito não se comporta da mesma maneira e aumenta com a idade.