Epidemiological profile of malaria in a rural community in the Amazon, Mato Grosso State, Brazil, 2011.

BACKGROUND: More than 95% of malaria transmission in Brazil occurs in the Legal Amazon Region, which in 2010 recorded around 333,429 cases reported in the Epidemiological Surveillance Information System-Malaria (Sivep_malaria), presenting an annual parasitic incidence (IPA) of 13.1 cases/1000 inhabitants. METHODS: This was a descriptive study that measured the community prevalence of Plasmodium infection and its relationship with land use in Três Fronteiras District, Colniza Municipality, Mato Grosso State. Data were collected during household visits in July 2011, with blood collection from finger pricks for the preparation of thick smear slides, and completion of a standardized case notification form. A georeferenced database was analysed, with land use evaluated as categorical variables. A kernel density map was built to show the density of cases and their location. RESULTS: Of the 621 respondents, 68(11%) had Plasmodium infection: 39 (57.4%) with Plasmodium vivax, 27(39.7%) with Plasmodium falciparum and two (2.9%) with mixed infections. Among infected individuals, 49 (72.1%) were men. Cases of malaria were distributed over the district, with greater occurrence of cases per household in open areas close to the mining company and artisanal mining sites. The was a greater density of cases located in the gold mining region. CONCLUSION: Transmission of malaria in Três Fronteiras District has a heterogeneous distribution. Individuals residing in mining and timber extraction sites have increased occurrence of Plasmodium infection.

Inflammatory and cytotoxic mediators in COVID-19 patients and in ChAdOx1 nCoV-19 (AZD1222) vaccine recipients.

Immunological and cytotoxic mediators are induced in natural infection and are essential for the effectiveness of vaccination. Vaccination is useful to prevent the spread of SARS-CoV-2 and limit the morbidity/mortality of COVID-19. ChAdOx1 nCoV-19 is one of the most widespread vaccines in the world. We compared the detection of anti-S1 SARS-CoV2 IgG and the profile of inflammatory and cytotoxic responses of patients who developed different clinical outcomes of COVID-19 with individuals previously exposed or not to the virus received the first and booster doses of ChAdOx1 nCoV-19. Plasma from 35 patients with COVID-19 and 11 vaccinated were evaluated by multiplex assay. Here, no vaccinated subjects had serious adverse effects. Those vaccinated with a booster dose had higher anti-S1 IgG than mild/moderate and recovered patients. Critically ill and deceased patients had IgG levels like those immunized. By univariate analysis, IL-2, IL-17, and perforin do not differentiate between patients and vaccinated individuals. Granzyme A increased at dose 1, while patients had their levels reduced. High levels of granulysin, sFas, and IL-6 were detected in the deaths, but after vaccination, all were declined. The multivariate analysis supports the role of IL-6 and granulysin as associated and non-confounding variables related to the worst clinical outcome of COVID-19, but not sFas. Our data confirm the ability of the ChAdOx1 vaccine to produce specific antibody levels up to booster time. Furthermore, our data suggest that the vaccine can regulate both the hyper-production and the kinetics of the production of inflammatory and cytotoxic mediators involved in the cytokine storm, such as granulysin and IL-6.

In silico analyses and design of chimeric proteins containing epitopes of Bartonella henselae antigens for the control of cat scratch disease.

Bartonella henselae is a Gram-negative bacterium that causes cat scratch disease (CSD), as well as bacteremia, endocarditis, and other clinical presentations. CSD remains one of the most common infections caused by bacteria in the genus Bartonella, and it is transmitted to humans through a scratch or cat bite. Vaccination and more efficient diagnostic methods would represent a promising and sustainable alternative measure for CSD control in humans and animals. Here, we described the in silico analyses and design of three recombinant chimeric proteins (rC1, rC2, and rC3), for use in the control of CSD. The chimeras were constructed with epitopes identified from the sequences of the GroEL, 17 kDa, P26, BadA, Pap31, OMP 89, and OMP 43, previously described as the most important B. henselae antigens. The rC1, rC2, and rC3 were expressed and purified using a heterologous system based on Escherichia coli and reacted with antibodies present in the sera of humans naturally infected. The chimeric proteins were used to immunize mice using Freund adjuvant, and the humoral immune response was evaluated. Animals immunized with rC1 and rC3 showed a significant IgG antibodies response from the 28th day (P < 0.05), and the animals immunized with the rC2 from the 35th day (P < 0.05) remained until the 56th day of experimentation, with a titer of 1:3200 (P < 0.05), 1:1600 (P < 0.05) and 1:1600 (P < 0.05) from rC1, rC2, and rC3, respectively. Significant production of IgA and IgG1 isotype was detected in animals immunized with rC1 and rC2 proteins. Additionally, analysis using 13 serum samples from naturally infected patients showed that the proteins are recognized by antibodies present in sera, reinforcing the possibility of using these chimeras for CSD control. KEY POINTS: • The recombinant chimeras were expressed in Escherichia coli with 37 kDa (rC1), 35 kDa (rC2), and 38 kDa (rC3). • Animals immunized with rC1, rC2, and rC3 showed significant antibody response. • The chimeras were recognized by the sera of naturally infected patients.

Molecular and Serological Survey of the Cat-Scratch Disease Agent (Bartonella henselae) in Free-Ranging Leopardus geoffroyi and Leopardus wiedii (Carnivora: Felidae) From Pampa Biome, Brazil.

The genus Bartonella comprises emerging bacteria that affect humans and other mammals worldwide. Felids represent an important reservoir for several Bartonella species. Domestic cats are the main reservoir of Bartonella henselae, the agent of cat scratch disease (CSD). It can be transmitted directly by scratches and bites from infected cats and via cat fleas. This study aims to investigate the circulation of Bartonella spp. in free-ranging Neotropical wild felids from Southern Brazil using serological and molecular methods. In this study, 53 live-trapped free-ranging wild felids were sampled, 39 Leopardus geoffroyi and 14 Leopardus wiedii, from five municipalities in the Rio Grande, do Sul state, southern Brazil. All captured animals were clinically healthy. Two blood samples of L. geoffroyi were positive, by PCR, for the presence of B. henselae DNA. Conversely, none of L. wiedii blood samples were positive when tested using PCR. Indirect immunofluorescence assay (IFA) showed that 28% of serum samples of wild felids were reactive (seropositive) for B. henselae by immunofluorescence, with titers ranging from 64 to 256. The results presented here provide the first evidence of a Bartonella-enzootic cycle involving L. geoffroyi and L. wiedii, which may account for the spillover of the emerging zoonotic pathogen B. henselae for the indigenous fauna in Southern Brazil.

The mystery of the phylogeographic structural pattern in rodent-borne hantaviruses.

Hantaviruses (order Bunyavirales, family Hantaviridae) are important zoonotic pathogens. Because of the great diversity of their reservoir hosts, hantaviruses are excellent models to evaluate the dynamics of virus-host co-evolution. To understand the mechanisms behind the evolutionary history of hantaviruses through virus-reservoir interactions, it is important to know how the radiation and diversity of hantaviruses occurred. In this paper, we evaluate the pattern of hantavirus diversification based on a complete S segment representing major groups of hantaviruses found in the Americas. Phylogenetic analyses revealed a high degree of phylogeographic structure and a surprising pattern of geographical distribution of New World hantaviruses. The available data suggest that hantaviruses related to the Arvicolinae rodent subfamily in North America probably emerged and initially adapted from a shared common ancestor of the Tula virus. The first clade of hantaviruses associated with Neotominae occupied a stem lineage, especially those that emerged in Central America or Mexico. Hantaviruses from Central America and Mexico found in Neotominae rodents spread northward and probably gave rise to the first phylogroup of hantaviruses associated with Sigmodontinae in North America. Two preferential host-switching transmissions in hantaviruses apparently gave rise to two different paraphyletic group in Neotominae and Sigmodontinae. Our study supports a probable epicenter of diversification in Central America and/or Mexico for hantaviruses related to both the Neotominae and Sigmodontinae subfamilies.

Zika virus found in brain tissue of a multiple sclerosis patient undergoing an acute disseminated encephalomyelitis-like episode.

BACKGROUND: A range of different neurological manifestations has been reported in fetuses and adults after Zika virus (ZIKV) infection. OBJECTIVE: We describe a detection of the ZIKV in the brain tissue from a multiple sclerosis (MS) patient with acute disseminated encephalomyelitis (ADEM)-like event in Rio de Janeiro, Brazil. METHODS: Biological samples collected during the hospitalization were tested by serology and molecular diagnostic for various infectious agents. Histopathological analysis was performed using the anti-flavivirus group 4G2 monoclonal antibody, anti-ZIKV non-structural 1 (NS1) monoclonal antibody, and anti-CD4, CD8, and CD11b antibodies. RESULTS: Anti-ZIKV IgM and IgG antibodies were positive in the serum and urine. A brain biopsy showed ZIKV protein in brain cells and T CD8 infiltration in brain tissue. CONCLUSION: Our data describe the coexistence of a recent central nervous system (CNS) ZIKV infection accompanied by a severe ADEM-like syndrome outcome in a patient with clinical history of MS. A de novo immune response concomitant with ZIKV infection might be involved in the mechanism of the ADEM-like syndrome and response to immunotherapy. The present report reinforces the importance of providing the differential diagnosis of acute episodes of MS exacerbation in an environment prone to ZIKV expression.

Aporé virus, a novel mammarenavirus (Bunyavirales: Arenaviridae) related to highly pathogenic virus from South America.

Here, we report the complete genome sequence of the Aporé virus (Bunyavirales: Arenaviridae), obtained from a wild rodent Oligoryzomys mattogrossae captured in Mato Grosso do Sul state, Brazil. The genome of this virus showed strong similarity to highly pathogenic mammarenavirus from South America.

Co-circulation of Araraquara and Juquitiba Hantavirus in Brazilian Cerrado.

Hantavirus cardiopulmonary syndrome is an emerging serious disease in the Americas, transmitted from wild rodents to humans through inhalation of aerosol containing virus. Herein, we characterized two distinct hantaviruses circulating in rodent species form Central Plateau, Midwestern region of Brazil in the Cerrado (savanna-like) biome, an area characterized by small trees and grasses adapted to climates with long dry periods. In this study, we identified the co-circulation of the Araraquara virus and a possible new lineage of the Juquitiba virus (JUQV) in Oligoryzomys nigripes. The implications of co-circulation are still unknown, but it can be the key for increasing viral diversity or emergence of new species through spillover or host switching events leading to co-infection and consequently recombination or reassortment between different virus species. Phylogenetic analyses based on the complete S segment indicated that, alongside with Oligoryzomys mattogrossae rodents, O. nigripes species could also have a whole as JUQV reservoir in the Cerrado biome. Although these rodents' species are common in the Cerrado biome, they are not abundant demonstrating how complex and different hantavirus enzootic cycles can be in this particular biome.

Coxiella and Bartonella spp. in bats (Chiroptera) captured in the Brazilian Atlantic Forest biome.

BACKGROUND: The role of bats as reservoirs of zoonotic agents, especially pathogenic bacteria such as Bartonella and Coxiella, has been discussed around the world. Recent studies have identified bats as potential hosts of species from the proteobacteria phylum. In Brazil, however, the role of bats in the natural cycle of these agents is poorly investigated and generally neglected. In order to analyze the participation of bats in the epidemiology of diseases caused by Bartonella, Coxiella, Rickettsia, Anaplasma and Ehrlichia, we conducted a descriptive epidemiological study in three biogeographic regions of the Brazilian Atlantic Forest. RESULTS: Tissues of 119 bats captured in preserved areas in the states of Rio de Janeiro, Bahia and Santa Catarina from 2014 to 2015 were submitted to molecular analysis using specific primers. Bartonella spp. was detected in 22 spleen samples (18.5%, 95% CI: 11.9-26.6), whose phylogenetic analysis revealed the generation of at least two independent clusters, suggesting that these may be new unique genotypes of Bartonella species. In addition, four samples (3.4%, 95% CI: 0.9-8.3) were positive for the htpAB gene of C. burnetii [spleen (2), liver (1) and heart (1)]. Rickettsia spp., Anaplasma and Ehrlichia were not identified. This is the first study reporting C. burnetii and Bartonella spp. infections in bats from the Atlantic Forest biome. CONCLUSIONS: These findings shed light on potential host range for these bacteria, which are characterized as important zoonotic pathogens.

Rodent-borne viruses survey in rural settlers from Central Brazil.

Anthropogenic environmental changes arising from settlement and agriculture include deforestation and replacement of natural vegetation by crops providing opportunities for pathogen spillover from animals to humans. This study aimed to investigate the prevalence of rodent-borne virus infections in seven rural settlements from Midwestern Brazil. Of the 466 individuals tested 12 (2.57%) were reactive for orthohantavirus and 3 (0.64%) for mammarenavirus. These rural settlers lived under unfavorable infrastructure, socioeconomic disadvantages, and unsanitary conditions, representing a risk for rodent-borne infections. Development of public policies towards the improvement of health, sanitation and awareness of rodent-borne diseases in improvised camps and settlements is imperative, in order to reduce morbidity and mortality caused by these diseases.

Association of Bartonella Species with Wild and Synanthropic Rodents in Different Brazilian Biomes.

Bartonella spp. comprise an ecologically successful group of microorganisms that infect erythrocytes and have adapted to different hosts, which include a wide range of mammals, besides humans. Rodents are reservoirs of about two-thirds of Bartonella spp. described to date; and some of them have been implicated as causative agents of human diseases. In our study, we performed molecular and phylogenetic analyses of Bartonella spp. infecting wild rodents from five different Brazilian biomes. In order to characterize the genetic diversity of Bartonella spp., we performed a robust analysis based on three target genes, followed by sequencing, Bayesian inference, and maximum likelihood analysis. Bartonella spp. were detected in 25.6% (117/457) of rodent spleen samples analyzed, and this occurrence varied among different biomes. The diversity analysis of gltA sequences showed the presence of 15 different haplotypes. Analysis of the phylogenetic relationship of gltA sequences performed by Bayesian inference and maximum likelihood showed that the Bartonella species detected in rodents from Brazil was closely related to the phylogenetic group A detected in other cricetid rodents from North America, probably constituting only one species. Last, the Bartonella species genogroup identified in the present study formed a monophyletic group that included Bartonella samples from seven different rodent species distributed in three distinct biomes. In conclusion, our study showed that the occurrence of Bartonella bacteria in rodents is much more frequent and widespread than previously recognized. IMPORTANCE: In the present study, we reported the occurrence of Bartonella spp. in some sites in Brazil. The identification and understanding of the distribution of this important group of bacteria may allow the Brazilian authorities to recognize potential regions with the risk of transmission of these pathogens among wild and domestic animals and humans. In addition, our study accessed important gaps in the biology of this group of bacteria in Brazil, such as its low host specificity, high genetic diversity, and relationship with other Bartonella spp. detected in rodents trapped in America. Considering the diversity of newly discovered Bartonella species and the great ecological plasticity of these bacteria, new studies with the aim of revealing the biological aspects unknown until now are needed and must be performed around the world. In this context, the impact of Bartonella spp. associated with rodents in human health should be assessed in future studies.

The Silent Threat: Unraveling the Impact of Rabies in Herbivores in Brazil.

Rabies, a zoonotic viral disease, poses a significant threat due to its adaptability to diverse environments. Herbivore rabies, predominantly affecting cattle, horses, and goats in Brazil, remains a concern, results in substantial losses in the livestock industry, and poses risks to public health. Rabies virus transmission, primarily through hematophagous bats in Latin America, underscores the need for effective strategies, and vaccination plays a crucial role in controlling herbivorous rabies, with systematic vaccination beingly the primary method. Efforts to control rabies in herbivores include vaccination campaigns, public awareness programs, and the enhancement of surveillance systems. Despite these initiatives, rabies persists and imposes an economic burden and a significant health risk. Economic impacts include losses in the livestock industry, trade restrictions on livestock products, and financial burdens on governments and farmers owing to control measures. Despite the considerable costs of campaigns, surveillance, and control, investing in rabies vaccination and control not only safeguards livestock, but also preserves public health, reduces human cases, and strengthens the sustainability of the livestock industry. Mitigating the impact of herbivorous rabies in Brazil requires integrated approaches and continuous investments in vaccination, surveillance, and control measures to protect public health and ensure the sustainability of the livestock industry, thus contributing to food and economic security.

Overview of Q fever in Brazil: an underestimated zoonosis.

This review aims to provide current information about Q fever, elucidating the etiological, epidemiological, pathogenic, clinical, diagnostic, therapeutic, and prophylactic aspects of the disease for the medical community. We discuss the main forms of presentation of the agent, its ability to persist in the body, the infinite possibilities of susceptible hosts, the main known forms of transmission, its importance in populations at occupational risk, and the role of arthropods in the natural history of the disease. Focusing on Brazil, we present the cases already described and studies developed since its first report, and how there is still much to unravel. We are aware of the possibilities of the persistence of the agent and the development of severe clinical pictures and the specific treatments currently instituted. We also wish to raise awareness about the future, the new genotypes that are emerging, the need to study the effects of vaccines, and the impact of Q fever on the population. Q fever is a poorly understood disease in Latin America, and recent studies, especially in Brazil, have revealed the importance of developing new studies.

Emergence of melioidosis in Brazil: a case series.

BACKGROUND: Melioidosis is a serious disease caused by the bacterium Burkholderia pseudomallei which affects humans and animals. It results in a wide spectrum of clinical manifestations, mainly in the respiratory tract, progressing to septic shock and death. CASE PRESENTATION: Herein, we present a series of seven patients (median age: 41 years) with confirmed melioidosis, treated at a public hospital in Piauí State, Brazil between 2019 and 2021. The most common clinical presentations were fever, cough, pneumonia, and abdominal pain. The mean duration of antibacterial therapy with 1 g of meropenem was 28.6 ± 1.1 days. Six patients recovered and one died. The mean hospitalization time was 51.0 ± 39.2 days. CONCLUSIONS: Melioidosis is an emerging infectious disease in Brazil. Health professionals in endemic areas need to be aware of the clinical presentation and appropriate clinical management of the disease because early diagnosis and early initiation of antibiotic therapy can be life-saving.

Seroprevalence of Hantavirus among Manual Cane Cutters and Epidemiological Aspects of HPS in Central Brazil.

Hantavirus pulmonary syndrome (HPS) is a rodent-borne zoonotic disease that is endemic throughout the Americas. Agricultural activities increase exposure to wild rodents, especially for sugarcane cutters. We carried out a survey of the epidemiological aspects of HPS and investigated the prevalence of hantavirus infection in the sugarcane cutter population from different localities in the Brazilian Midwest region. We conducted a retrospective study of all confirmed HPS cases in the state of Goiás reported to the National HPS surveillance system between 2007 and 2017, along with a seroepidemiological study in a population of sugarcane cutters working in Goiás state in 2016, using the anti-hantavirus (Andes) ELISA IgG. A total of 634 serum samples from cane cutters were tested for hantavirus antibodies, with 44 (6.9%) being IgG-reactive according to ELISA. The destination of garbage was the only statistically significant variable (p = 0.03) related to the detection of hantavirus IgG (p < 0.05). We described the epidemiological profile of reported hantavirus cases in Goiás-a highly endemic area for HPS, and where the seroepidemiological study was conducted. Our results increase our knowledge about hantavirus infections in Brazil and highlight the vulnerability of sugarcane cutters to a highly lethal disease that, to date, has no specific treatment or vaccination.

Trends of Infective Endocarditis at Two Teaching Hospitals: A 12-Year Retrospective Cohort Study in Rio de Janeiro, Brazil.

BACKGROUND: Despite advances in diagnosis and treatment, the incidence and mortality of infective endocarditis (IE) have increased in recent decades. Studies on the risk factors for mortality in endocarditis in Latin America are scarce. METHODS: This retrospective cohort study included 240 patients diagnosed with IE according to the modified Duke criteria who were admitted to two university hospitals in Rio de Janeiro, Brazil from January 2009 to June 2021. Poisson regression analysis was performed for trend tests. The multivariate Cox proportional hazards model was used to estimate the hazard ratio (HR) of predictors of in-hospital mortality. FINDINGS: The median age was 55 years (IQR: 39-66 years), 57% were male, and 41% had a Charlson comorbidity index (CCI) score > 3. Healthcare-associated infective endocarditis (54%), left-sided native valve IE (77.5%), and staphylococcal IE (26%) predominated. Overall, in-hospital mortality was 45.8%, and mortality was significantly higher in the following patients: aged ≥ 60 years (53%), CCI score ≥ 3 (60%), healthcare-associated infective endocarditis (HAIE) (53%), left-sided IE (51%), and enterococcal IE (67%). Poisson regression analysis showed no trend in in-hospital mortality per year. The adjusted multivariate model determined that age ≥ 60 years was an independent risk factor for in-hospital mortality (HR = 1.9; 95% CI 1.2-3.1; p = 0.008). INTERPRETATION: In this 12-year retrospective cohort, there was no evidence of an improvement in survival in patients with IE. Since older age is a risk factor for mortality, consensus is needed for the management of IE in this group of patients.

Infectious endocarditis caused by Bartonella henselae associated with infected pets: two case reports.

BACKGROUND: Blood culture-negative infective endocarditis is a potentially severe disease that can be associated with infectious agents such as Bartonella spp., Coxiella burnetti, Tropheryma whipplei, and some fungi. CASE PRESENTATION: Reported here are two cases of blood culture-negative infective endocarditis in patients with severe aortic and mitral regurgitation in Brazil; the first case is a 47-year-old white man and the second is a 62-year-old white woman. Bartonella henselae deoxyribonucleic acid was detectable in the blood samples and cardiac valve with vegetation paraffin-fixed tissue samples. Additionally, an investigation was carried out on patients' pets, within the context of One Health, and serum samples collected from cats and dogs were reactive by indirect immunofluorescence assay. CONCLUSIONS: Even though the frequency of bartonellosis in Brazil is unknown, physicians should be aware of the possibility of blood culture-negative infective endocarditis caused by Bartonella, particularly in patients with weight loss, kidney changes, and epidemiological history for domestic animals.

Correction: Frequency of co-seropositivities for certain pathogens and their relationship with clinical and histopathological changes and parasite load in dogs infected with Leishmania infantum.

[This corrects the article DOI: 10.1371/journal.pone.0247560.].

Lessons from a Multilaboratorial Task Force for Diagnosis of a Fatal Toxoplasmosis Outbreak in Captive Primates in Brazil.

Toxoplasmosis is an important zoonotic disease caused by the parasite Toxoplasma gondii and is especially fatal for neotropical primates. In Brazil, the Ministry of Health is responsible for national epizootic surveillance, but some diseases are still neglected. Here, we present an integrated investigation of an outbreak that occurred during the first year of the COVID-19 pandemic among eleven neotropical primates housed at a primatology center in Brazil. After presenting non-specific clinical signs, all animals died within four days. A wide range of pathogens were evaluated, and we successfully identified T. gondii as the causative agent within four days after necropsies. The liver was the most affected organ, presenting hemorrhage and hepatocellular necrosis. Tachyzoites and bradyzoite cysts were observed in histological examinations and immunohistochemistry in different organs; in addition, parasitic DNA was detected through PCR in blood samples from all specimens evaluated. A high prevalence of Escherichia coli was also observed, indicating sepsis. This case highlights some of the obstacles faced by the current Brazilian surveillance system. A diagnosis was obtained through the integrated action of researchers since investigation for toxoplasmosis is currently absent in national guidelines. An interdisciplinary investigation could be a possible model for future epizootic investigations in animals.

Molecular epidemiology of Laguna Negra virus, Mato Grosso State, Brazil.

We associated Laguna Negra virus with hantavirus pulmonary syndrome in Mato Grosso State, Brazil, and a previously unidentified potential host, the Calomys callidus rodent. Genetic testing revealed homologous sequencing in specimens from 20 humans and 8 mice. Further epidemiologic studies may lead to control of HPS in Mato Grosso State.