Breaking Barriers: A Future Perspective on Glioblastoma Therapy with mRNA-Based Immunotherapies and Oncolytic Viruses

The use of mRNA-based immunotherapies that leverage the genomes of oncolytic viruses holds significant promise in addressing glioblastoma (GBM), an exceptionally aggressive neurological tumor. We explore the significance of mRNA-based platforms in the area of immunotherapy, introducing an innovative approach to mitigate the risks associated with the use of live viruses in cancer treatment. The ability to customize oncolytic virus genome sequences enables researchers to precisely target specific cancer cells, either through viral genome segments containing structural proteins or through a combination of regions with oncolytic potential. This strategy may enhance treatment effectiveness while minimizing unintended impacts on non-cancerous cells. A notable case highlighted here pertains to advanced findings regarding the application of the Zika virus (ZIKV) in GBM treatment. ZIKV, a member of the family Flaviviridae, shows oncolytic properties against GBM, opening novel therapeutic avenues. We explore intensive investigations of glioblastoma stem cells, recognized as key drivers in GBM initiation, progression, and resistance to therapy. However, a comprehensive elucidation of ZIKV's underlying mechanisms is imperative to pave the way for ZIKV-based clinical trials targeting GBM patients. This investigation into harnessing the potential of oncolytic-virus genomes for mRNA-based immunotherapies underscores its noteworthy implications, potentially paving the way for a paradigm shift in cancer treatment strategies.

Molecular survey of potentially pathogenic microorganisms in ticks collected from coatis (Nasua nasua) in Iguaçu National Park, Atlantic Forest biome, southern Brazil

Human contact with wild animals in synanthropic habits is often mediated by arthropod vectors such as ticks. This is an important method of spreading infectious agents that pose a risk to human health. Thus, this study aimed to molecularly detect Ehrlichia spp., Anaplasma spp., Borrelia spp., and protozoa of the order Piroplasmida in ticks collected from coatis of Iguaçu National Park (PNI), Paraná, Brazil. This study involved 553 ticks DNA, including Amblyomma spp. larvae, Haemaphysalis juxtakochi nymphs, Amblyomma brasiliense, Amblyomma coelebs, and adults of Amblyomma ovale. The DNA extracted from each sample was subjected to polymerase chain reaction (PCR) targeting the genes 23S rRNA for the Anaplasmataceae family, 16S rRNA for Anaplasma spp., dsb for Ehrlichia spp., flaB, 16S rRNA, hpt, and glpQ for Borrelia spp., and 18S rRNA for Piroplasmid protozoans. DNA from Anaplasma sp. was detected in ticks of the species A. coelebs (4/553); Borrelia sp. DNA was detected in A. coelebs (3/553), A. ovale (1/553), and Amblyomma larvae (1/553); and Theileria sp. was detected in A. coelebs (2/553). All tested samples were negative for Ehrlichia spp. Our study constitutes the newest report in South America of these microorganisms, which remain poorly studied.

The role of immune subtyping in glioma mRNA vaccine development

Studies on the development of mRNA vaccines for central nervous system tumors have used gene expression profiles, clinical data and RNA sequencing from sources such as The Cancer Genome Atlas and Chinese Glioma Genome Atlas to identify effective antigens. These studies revealed several immune subtypes of glioma, each one linked to unique prognoses and genetic/immune-modulatory changes. Potential antigens include ARPC1B, BRCA2, COL6A1, ITGB3, IDH1, LILRB2, TP53 and KDR, among others. Patients with immune-active and immune-suppressive phenotypes were found to respond better to mRNA vaccines. While these findings indicate the potential of mRNA vaccines in cancer therapy, further research is required to optimize administration and adjuvant selection, and precisely identify target antigens.

Viral load: We need a new look at an old problem?

The concept of viral load was introduced in the 1980s to measure the amount of viral genetic material in a person's blood, primarily for human immunodeficiency virus (HIV). It has since become crucial for monitoring HIV infection progression and assessing the efficacy of antiretroviral therapy. However, during the coronavirus disease 2019 pandemic, the term "viral load" became widely popularized, not only for the scientific community but for the general population. Viral load plays a critical role in both clinical patient management and research, providing valuable insights for antiviral treatment strategies, vaccination efforts, and epidemiological control measures. As measuring viral load is so important, why don't researchers discuss the best way to do it? Is it simply acceptable to use raw Ct values? Relying solely on Ct values for viral load estimation can be problematic due to several reasons. First, Ct values can vary between different quantitative polymerase chain reaction assays, platforms, and laboratories, making it difficult to compare data across studies. Second, Ct values do not directly measure the quantity of viral particles in a sample and they can be influenced by various factors such as initial viral load, sample quality, and assay sensitivity. Moreover, variations in viral RNA extraction and reverse-transcription steps can further impact the accuracy of viral load estimation, emphasizing the need for careful interpretation of Ct values in viral load assessment. Interestingly, we did not observe scientific articles addressing different strategies to quantify viral load. The absence of standardized and validated methods impedes the implementation of viral load monitoring in clinical management. The variability in cell quantities within samples and the variation in viral particle numbers within infected cells further challenge accurate viral load measurement and interpretation. To advance the field and improve patient outcomes, there is an urgent need for the development and validation of tailored, standardized methods for precise viral load quantification.

Borrelia theileri in Bovine in the northern and southeastern regions of Brazil

The present study aimed to describe the occurrence of Borrelia spp. in cattle in the states of Minas Gerais and Pará in southeastern and northern Brazil, respectively. Bovine whole blood samples were examined by blood smear and polymerase chain reaction (PCR) to detect the flagellin B (flaB) gene of Borrelia spp. Frequencies of positive animals for Borrelia spp. were 1.52% (2/132) in the municipality of Unaí, Minas Gerais, and 14.2% (2/7) in the municipality of Marabá, Pará. Subsequent genetic sequencing confirmed that the detected spirochetes close to the species B. theileri. In both locations, the animals positive for B. theileri were also highly infested by Rhipicephalus microplus ticks. Despite the low frequency of Borrelia spp., the occurrence of this spirochete indicates that further studies are needed to determine the consequences in cattle herds.

miR-383-5p, miR-181a-5p, and miR-181b-5p as Predictors of Response to First-Generation Somatostatin Receptor Ligands in Acromegaly

Acromegaly is a chronic systemic disease caused in the vast majority of cases by growth hormone (GH)-secreting adenoma, with surgery being the first-line treatment. When a cure is not attained with surgery, first-generation somatostatin receptor ligands (fg-SRLs) are the most common medication prescribed. Predictors of response to fg-SRLs have been studied; however, they cannot fully predict the response to fg-SRL. MicroRNAs are small RNAs, the main role of which is messenger RNA (mRNA) post-transcriptional regulation. This study aimed to identify the microRNAs involved in resistance to treatment with fg-SRLs in acromegaly. Ten patients with acromegaly undergoing treatment with fg-SRLs were selected to undergo miRNA sequencing: five controlled and five uncontrolled with treatment. Bioinformatic analysis was performed to detect differentially expressed miRNAs. Then, the same 10 samples were used for validation by qPCR and an additional 22 samples were analyzed, totaling 32 samples. e We found 59 differentially expressed miRNAs in the first analysis. miR-181a-5p and miR-181b-5p were downregulated, and miR-383-5p was upregulated in the uncontrolled group. Receiver operating characteristic (ROC) curve analysis of miR-383-5p showed an NPV of 84.3% and a PPV of 84.5%. In summary, miR-181a-5p, miR-181b-5p, and miR-383-5p are biomarkers of response to fg-SRLs, and they can be used individually or included in prediction models as tools to guide clinical decisions.

Characterization of sporadic somatotropinomas with high GIP receptor expression

PURPOSE

To analyze the expression of glucose-dependent insulinotropic polypeptide receptor (GIPR) in somatotropinomas specimens and compare clinical, biochemical, radiological, therapeutic, molecular, and pathological data among those who overexpressed (GIPR +) and those who did not overexpress (GIPR - ) GIPR.

METHODS

Clinical, biochemical, radiological, molecular, and pathological data were collected. GNAS1 sequencing was performed with the Sanger method. Protein expression of somatostatin receptor subtypes 2 and 5 and CAM 5.2 were analyzed by immunohistochemistry. Quantitative real-time PCR was performed to analyze the mRNA expression of GIPR with the TaqMan® method. Positive expression was considered when the fold change (FC) was above 17.2 (GIPR +).

RESULTS

A total of 74 patients (54% female) were included. Eighteen tumors (24%) were GIPR + . Gsp mutation was detected in 30 tumors (40%). GIPR + tumors were more frequently densely granulated adenomas (83% vs 47%, p = 0.028). There was no difference in clinical, biochemical, radiological, therapeutic (surgical cure or response to medical therapy), or other pathological features between GIPR + and GIPR -  tumors. Twenty-eight out of 56 (50%) GIPR -  tumors harbored a gsp mutation, whereas two out of 18 (11%) GIPR + tumors harbored a gsp mutation (p = 0.005).

CONCLUSION

We described, for the first time, that GIPR + and gsp mutations are not mutually exclusive, but gsp mutations are less common in GIPR + tumors. GIPR + and GIPR -  tumors have similar clinical, biochemical, radiological, therapeutic, and pathological features, with the exception of a high frequency of densely granulated adenomas among GIPR + tumors.

Survey of bacterial and protozoan agents in ticks and fleas found on wild animals in the state of Rio de Janeiro, Brazil

This study evaluates the presence of bacterial and protozoan agents in ticks and fleas found on wild animals in the state of Rio de Janeiro, Brazil. These ectoparasites were collected on mammal species Hydrochoerus hydrochaeris, Tapirus terrestris, Dicotyles tajacu, Didelphis aurita, Cuniculus paca, Cerdocyon thous, and Coendou prehensilis, and on the terrestrial bird Dromaius novaehollandiae. Ticks and fleas were identified morphologically using specific taxonomic keys. A total of 396 ticks and 54 fleas were tested via polymerase chain reaction (PCR) for the presence of Rickettsia spp., Borrelia spp., microorganisms of the order Piroplasmida and Anaplasmataceae family. This total is distributed among nine tick species of the genus Amblyomma and one flea species. Rickettsia bellii was detected in Amblyomma dubitatum and Amblyomma pacae; Rickettsia sp. strain AL was found in Amblyomma longirostre; Rickettsia parkeri strain Atlantic rainforest was found in Amblyomma ovale; and "Candidatus Rickettsia senegalensis" and Rickettsia felis were detected in Ctenocephalides felis felis. Wolbachia sp. was detected in C. f. felis, and Borrelia sp. was detected in Amblyomma calcaratum (here named Borrelia sp. strain Acalc110). All tested samples were negative for Ehrlichia spp. and microorganisms of the Piroplasmida order. This study detected a new bacterial strain, Borrelia sp. strain Acalc 110 (which is genetically close to B. miyamotoi and B. venezuelensis) and the Rickettsia sp. strain 19P, which is 100% similar to "Ca. R. senegalensis", a bacterium recently discovered and now being reported for the first time in Brazil.

Detection of Rickettsia spp. in ring-tailed coatis (Nasua nasua) and ticks of the Iguaçu National Park, Brazilian Atlantic Rainforest

Wild animals are of considerable importance in the ecology of infectious agents, as they can function as hosts and even as possible vectors. In this study, DNA from Rickettsia spp. was detected on ticks and fragments of skin collected from wild coatis with synanthropic habits in the Iguaçu National Park (INP) in the state of Paraná in southern Brazil. Testing was carried out on a total of 566 ticks, comprising Amblyomma spp. larvae, nymphs of Haemaphysalis juxtakochi, Amblyomma brasiliense, Amblyomma coelebs, and adults of Amblyomma ovale. The samples were tested by polymerase chain reaction (PCR) by amplifying htrA, gltA, ompA, and ompB gene fragments to detect Rickettsia spp. A fragment of each positive sample was sequenced in both directions, submitted to Genbank for a homology search, and also used for phylogenetic analyses. Samples of A. coelebs (1.90%, 8/420), A. ovale (13%, 6/45), and ring-tailed coati skin (1%, 1/75) amplified Rickettsia spp. DNA. Through sequencing, Rickettsia bellii was observed in A. ovale, Rickettsia amblyommatis in A. coelebs, while Rickettsia rhipicephali was detected in the skin samples. Wild ring-tailed coatis with synanthropic habits in the INP and their ticks are infected by Rickettsia spp., and associations with new hosts have been described.

Orthohantavirus Survey in Indigenous Lands in a Savannah-Like Biome, Brazil

In Brazil, the first confirmed cases of hantavirus cardiopulmonary syndrome in Indigenous populations occurred in 2001. The purpose of this study was to determine the seroprevalence of orthohantavirus infections in the Utiariti Indigenous land located in the southeastern region of the Brazilian Amazon. In December 2014 and 2015, a survey was conducted using an enzyme-linked immunosorbent assay in nine villages belonging to the Haliti–Paresí Indigenous communities. A total of 301 participants were enrolled in the study. Of the two study cohorts, the one from 2014 showed a prevalence of 12.4%, whereas the one from 2015 had a serum prevalence of 13.4%. Analysis of the paired samples of 110 Indigenous people who participated in both stages of the study enabled identification of four individuals who had seroconverted during the study period. Identifying the circulation of orthohantaviruses in the Utiariti Indigenous land highlights a serious public health problem in viral expansion and highlights the need to implement preventive measures appropriate to the sociocultural reality of these communities.

USP8 Somatic Mutations in Cushing’s Disease and Silent Corticotropinomas

Background: Somatic mutations in the ubiquitin-specific peptidase 8 (USP8) gene have been described in Cushing’s disease (CD). These mutations increase proopiomelanocortin transcription resulting in ACTH production and seem to correlate with somatostatin receptor type 5 (SST5) expression. Aims: Screen USP8 in patients with corticotropinomas and correlate USP8 mutational status with SST5 expression in CD. Methods: Tumor DNA was extracted and then exon 14 amplified by PCR. SST5 was assessed by immunohistochemistry (clone UMB4) and quantified multiplying the percentage of positive cells (0,0%; <10%,1;10-50%, 2; 51-80%, 3; >80%, 4) and intensity (mild, 1; moderate, 2; intense, 3), giving a score (IRS) from 0-12 with ≥ 6 considered high. Results: Among 59 patients, 38 had CD and 21 silent corticotropinomas. In CD, 13 (34.2%) patients had pathogenic mutations (6 had p.Ser719del; 5 had p.Pro720Arg and 2 had p.Pro720Gln). In the mutated CD group, all were women and had median age of 34.5 years (20-46). Median ACTH was 64.7pg/mL [(34.8-330.0), normal <46], urinary free cortisol (UFC) 435.0μg/24h [(87.0-1386.0), normal <100], cortisol after overnight 1mg dexamethasone suppression test (ODST) 17.4μg/dL [(5.0-48.7), normal <1.8], salivary cortisol (SC) 8.1μg/dL [(1.0-15.5), normal <0.35]. Median largest tumor size was 0.9 cm (0-1.9), ki-67 1.7 (0.2-10.0) and IRS 12 (1-12). In wild-type CD group, 19 (76.0%) were women and had median age was 35.0 years old (14-62). Median ACTH was 59.7 (39.0-137.0), UFC 305.8 (77.0-1302.0), cortisol after ODST 23.6 (10.0-33.3), SC 0.67 (0.27-1.28). Median largest tumor diameter 0.7cm (0-3.3), ki-67 1.8 (0.2-10) and IRS 4 (0-12). SC was higher in mutated group compared to wild-type (p=0.001) as well as IRS (p=0.009). In silent corticotropinomas, 2 (9.5%) had pathogenic mutations (1 p.Ser718Pro and 1 p.Pro720Arg): male, 36 years old, 3.2 cm tumor, Ki-67 4%, IRS 6; and female, 52 years old, 3.4 cm tumor, Ki-67 2.5%, IRS 12, respectively. One tumor had a variant not reported as pathogenic (p.Thr739Ala): male, 46 years old, 3.7 cm tumor, Ki-67 0.5%, IRS 0. USP8-wild-type silent corticotropinomas had IRS 0-2. Conclusion: One third of CD patients presented with somatic USP8 mutation. Similar to another study, about 10% of silent corticotropinomas also presented somatic USP8 mutation. Expression of SST5 was high in USP8-mutated CD and higher than wild-type group.

Telomerase expression in clinically non-functioning pituitary adenomas

PURPOSE

Non-functioning pituitary adenomas (NFPA) are benign tumors, however, some are agressive. We aimed to assess if human telomerase reverse transcriptase (hTERT) is present in NFPA and if it can be used as a marker of aggressiveness and proliferation.

METHODS

Consecutive patients operated for NFPA whose fresh frozen tumors were available were included. We analyzed tumor's aggressiveness (based on radiological progression) and proliferation (based on Ki-67), as well as hTERT mRNA by quantitative real-time polymerase chain reaction (RT-qPCR).

RESULTS

We included 109 samples from 86 patients followed for a median period of 60 months (5-120 months). Aggressive tumors were present in 66% cases and proliferative tumors in 47.7%. Seven (6.4%) samples expressed hTERT: 3 (42.8%) had aggressive and proliferative tumors, 2 (28.6%) only exhibited aggressiveness and the remaining 2 (28.6%) only proliferation. From the aggressive and proliferative tumors, 14% and 16%, respectively, expressed hTERT. From the non-aggressive and non-proliferative tumors, 9% and 6%, respectively, expressed hTERT.

CONCLUSION

hTERT expression is present in a minority of NFPA and does not seem to be related to aggressiveness or proliferation in NFPA.

Misinterpretation of viral load in COVID-19 clinical outcomes

Knowledge of viral load is essential to formulate strategies for antiviral treatment, vaccination, and epidemiological control of COVID-19. Moreover, identification of patients with high viral loads can also be useful to understand risk factors such as age, comorbidities, severity of symptoms and hypoxia, to decide on the need for hospitalization. Several ongoing studies are analyzing viral load in different types of samples and evaluating its relationship with clinical outcomes and viral transmission pathways. However, in a great number of emerging studies, cycle threshold (Ct) values alone are often used as viral load indicators, which may be a mistake. In this study, we compared tracheal aspirate with nasopharyngeal swab samples obtained from critically ill COVID-19 patients and here we report how the raw Ct can lead to misinterpretation of results. Furthermore, based on analysis of nasopharyngeal swab samples we propose a method to reduce evaluation errors that could occur from using raw Ct data. Based on these findings, we show the impact that normalization of Ct values has on interpretation of SARS-CoV-2 viral load from different biological samples.

Effect of Convalescent Plasma in Critically Ill Patients With COVID-19: An Observational Study

Background: Convalescent plasma is a potential therapeutic option for critically ill patients with coronavirus disease 19 (COVID-19), yet its efficacy remains to be determined. The aim was to investigate the effects of convalescent plasma (CP) in critically ill patients with COVID-19.

Methods: This was a single-center prospective observational study conducted in Rio de Janeiro, Brazil, from March 17th to May 30th, with final follow-up on June 30th. We included 113 laboratory-confirmed COVID-19 patients with respiratory failure. Primary outcomes were time to clinical improvement and survival within 28 days. Secondary outcomes included behavior of biomarkers and viral loads. Kaplan–Meier analyses and Cox proportional-hazards regression using propensity score with inverse-probability weighing were performed.

Results: 41 patients received CP and 72 received standard of care (SOC). Median age was 61 years (IQR 48–68), disease duration was 10 days (IQR 6–13), and 86% were mechanically ventilated. At least 29 out of 41CP-recipients had baseline IgG titers ≥ 1:1,080. Clinical improvement within 28 days occurred in 19 (46%) CP-treated patients, as compared to 23 (32%) in the SOC group [adjusted hazard ratio (aHR) 0.91 (0.49–1.69)]. There was no significant change in 28-day mortality (CP 49% vs. SOC 56%; aHR 0.90 [0.52–1.57]). Biomarker assessment revealed reduced inflammatory activity and increased lymphocyte count after CP.

Conclusions: In this study, CP was not associated with clinical improvement or increase in 28-day survival. However, our study may have been underpowered and included patients with high IgG titers and life-threatening disease.

Clinical Trial Registration: The study protocol was retrospectively registered at the Brazilian Registry of Clinical Trials (ReBEC) with the identification RBR-4vm3yy (http://www.ensaiosclinicos.gov.br).

2020 taxonomic update for phylum Negarnaviricota (Riboviria: Orthornavirae), including the large orders Bunyavirales and Mononegavirales

In March 2020, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. At the genus rank, 20 new genera were added, two were deleted, one was moved, and three were renamed. At the species rank, 160 species were added, four were deleted, ten were moved and renamed, and 30 species were renamed. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV.

MicroRNAs and Mammarenaviruses: Modulating Cellular Metabolism

Mammarenaviruses are a diverse genus of emerging viruses that include several causative agents of severe viral hemorrhagic fevers with high mortality in humans. Although these viruses share many similarities, important differences with regard to pathogenicity, type of immune response, and molecular mechanisms during virus infection are different between and within New World and Old World viral infections. Viruses rely exclusively on the host cellular machinery to translate their genome, and therefore to replicate and propagate. miRNAs are the crucial factor in diverse biological processes such as antiviral defense, oncogenesis, and cell development. The viral infection can exert a profound impact on the cellular miRNA expression profile, and numerous RNA viruses have been reported to interact directly with cellular miRNAs and/or to use these miRNAs to augment their replication potential. Our present study indicates that mammarenavirus infection induces metabolic reprogramming of host cells, probably manipulating cellular microRNAs. A number of metabolic pathways, including valine, leucine, and isoleucine biosynthesis, d-Glutamine and d-glutamate metabolism, thiamine metabolism, and pools of several amino acids were impacted by the predicted miRNAs that would no longer regulate these pathways. A deeper understanding of mechanisms by which mammarenaviruses handle these signaling pathways is critical for understanding the virus/host interactions and potential diagnostic and therapeutic targets, through the inhibition of specific pathologic metabolic pathways.

What is the potential function of microRNAs as biomarkers and therapeutic targets in COVID-19?

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of COVID-19, a pandemic associated with substantial morbidity and mortality. Despite of this, no vaccine or approved drug is available to eradicate the virus. In this manuscript, we present an alternative study area that may contribute to development of diagnostic biomarkers and therapeutic targets for COVID-19. We analyzed sixty SARS-CoV-2 genomes to identify regions that could work as virus-encoded miRNA seed sponges and potentially bind to human miRNA seed sites and prevent interaction with their native targets thereby relieving native miRNA suppression. MicroRNAs (miRNAs) are evolutionally conserved single-stranded RNAs that regulate gene expression at the posttranscriptional level by disrupting translation. MiRNAs are key players in variety of biological processes that regulate differentiation, development and activation of immune cells in both innate and adaptive immunity. We find 34 miRNAs for positive-sense viral RNA and 45 miRNAs for negative-sense that can strongly bind to certain key SARS-CoV-2 genes. The disruption and dysfunction of miRNAs may perturb the immune response and stimulate the release of inflammatory cytokines altering the cellular response to viral infection. Previous studies demonstrate that miRNAs have the potential to be used as diagnostic and therapeutic biomarkers. Therefore, its discovery and validation are essential for improving the diagnosis of infection and clinical monitoring in COVID-19.

Cyclin A in nonfunctioning pituitary adenomas

PURPOSE

Assess cyclin A in nonfunctioning pituitary adenomas (NFPA) and compare its expression in non-invasive and non-proliferative tumors with invasive and proliferative tumors (12× higher risk of recurrence).

METHODS

Quantitative real time polymerase chain reaction to analyze cyclin A using normal pituitary gland as reference. Fold change (FC) > 1 was considered as increased. Tumor invasion was based on Knosp criteria (grades 3-4 considered invasive) and proliferation on the presence of at least two of three criteria: Ki-67 ≥ 3%; mitoses > 2/10; positive p53. Both groups were compared with Mann-Whitney test considering p value < 0.05 as statistically significant.

RESULTS

Thirty-one patients with NFPA were included. Tumors were mainly of gonadotrophic origin (74.2%), followed by corticotrophic (19.4%) and lactotrophic (3.2%) origins and null-cell adenomas (3.2%). Median tumor diameter was 3.5 cm (1.8-8.0) and Ki-67 was 3.0% (0.3-11%). Sixteen patients had tumors classified as non-invasive and non-proliferative and 15 as invasive and proliferative. Median FC was 0.31 in all tumors (0.13-1.94). Cyclin A was not related to invasion or proliferation (FC 0.41 in non-invasive and non-proliferative tumors and FC 0.30 in invasive and proliferative tumors; p = 0.968). Four (12.9%) patients had tumors that exhibited increased cyclin A [median FC of 1.04 (1.02-1.94)]-three of gonadotrophic origin and one null-cell adenoma, with two tumors classified as non-invasive and non-proliferative and two tumors classified as invasive and proliferative. Median tumor diameter in these samples was 3.4 cm (2.4-3.6) and Ki-67 was 5.1% (2-11%).

CONCLUSIONS

Cyclin A was increased in a minority of NFPA and does not seem to be related to invasion or proliferation.

Genetic diversity of Anaplasma marginale in calves with anaplasmosis on farms in Minas Gerais, Brazil

The objective of this study was to identify Anaplasma marginale strains in dairy heifers from farms with a history of anaplasmosis in the northwest region of the State of Minas Gerais, Brazil. Among the examined animals of the four farms, the overall prevalence total of A. marginale was 55.7 % for gene msp5 and 36.7 % for blood smear. Thirty DNA samples (from 24 asymptomatic and six symptomatic animals) positive for A. marginale msp1α were sequenced to study genotype and strain diversity. The majority (28/30) were the E genotype, followed by C (1/30) and G (1/30). Thirteen different strains were found: α-β-F-F-F (nine animals), 13-27-27 (three animals), τ-27-18 (three animals), α-β-β- BRA1-31 (three animals), α- 22-1318 (three animals), 80-F-F- F-F (three animals), and α -22-13-13, α-β-β-Г, M-φ-φ-φ-φ-F, 42-25- 25-31, Q-Q-Q-M, B-Q-B-Q-B-M, and 16-17-F-F (one animal each). A new structure repeated in tandem was described and named BRA 1 (TDSSSASGVLSQSGQASTSSQLG). The α-β-F-F-F strain was present in all animals with acute anaplasmosis and in three animals asymptomatic. Thus, although 13 strains were observed in the animals evaluated, only the α-β-F-F-F strain was identified during occurrence of acute disease and mortality, we suggest that this strain has important pathogenicity for calves in northeastern Minas Gerais.

A Retrospective Survey of Rodent-borne Viruses in Rural Populations of Brazilian Amazon

INTRODUCTION:

The Amazon tropical rainforest has the most dense and diverse ecosystem worldwide. A few studies have addressed rodent-borne diseases as potential hazards to humans in this region.

METHODS:

A retrospective survey was conducted using enzyme-linked immunosorbent assay for detecting mammarenavirus and orthohantavirus antibodies in 206 samples collected from rural settlers of the Brazilian Western Amazonian region.

RESULTS:

Six (2.91%) individuals in the age group of 16 to 36 years were found to possess antibodies against mammarenavirus.

CONCLUSION:

Evidence of previous exposure to mammarenavirus in the rural population points to its silent circulation in this region.

Hantavirus pulmonary syndrome in children: case report and case series from an endemic area of Brazil

Hantavirus Cardiopulmonary Syndrome (HCPS) is an important emergent zoonosis associated with wild rodents in Brazil, where this viral infection in children is generally rare. We present HCPS in a child from the Pantanal Biome and a review of all reported pediatric cases in Mato Grosso State, an endemic area for HCPS in Brazil. The investigation used the Information System for Notifiable Diseases database (SINAN). A 12-year-old boy was hospitalized with fever and respiratory failure and hantavirus IgM and IgG antibodies were detected by ELISA in serum samples. During the period of 1999 to 2016, 32 HCPS pediatric cases confirmed by serology were reported to SINAN with a mortality rate of 34.4%. The possibility of hantavirus infection in children with acute febrile illness associated with respiratory failure should be considered mainly in recognized endemic areas as Mato Grosso State, contradicting a hypothesis that children are more protected from lung involvement.

Hemoparasites in ticks of wild birds of Serra dos Órgãos National Park, state of Rio de Janeiro, Brazil

The aim of this study is to detect the presence of tick-borne agents of genera Rickettsia, Borrelia, Babesia, Ehrlichia and Anaplasma in ticks collected from native wild birds in the state of Rio de Janeiro. Birds were captured and observed carefully to find the ectoparasites. DNA detection of hemoparasites was performed by means of the polymerase chain reaction (PCR). The sequences obtained were analyzed and their homologies were compared to the available isolates in the GenBank platform database. A total of 33 birds were captured from 20 different species, of which 14 were parasitized by Amblyomma longirostre (n = 22). There was absence of DNA from agents of the genera Babesia, Anaplasma and Ehrlichia in the evaluated samples. The phylogenetic analysis indicated that one sample had 100% identity with Rickettsia bellii (KJ534309), the other two samples showed 100% identity with Rickettsia sp. Aranha strain and strain AL (EU274654 and AY360216). The positive sample for R. bellii was also demonstrated to be positive for Borrelia sp., which presented a similarity of 91% with Borrelia turcica (KF422815). This is the first description of Borrelia sp. in ticks of the genus Amblyomma in South America.

Malaria and Hantavirus Pulmonary Syndrome in Gold Mining in the Amazon Region, Brazil

People living in mining regions are exposed to numerous biological agents by several specific types of transmission mechanisms. This study is designed to describe fatal hantavirus pulmonary syndrome (HPS) cases confirmed by serology and molecular analysis, where a seroprevalence survey was conducted in the gold mining regions of the state of Mato Grosso, in the official Amazon region, Brazil. Two fatal cases of HPS were confirmed in a mining area in the Legal Amazon, where malaria is one of the most important public health problems. A molecular analysis detected the presence of the genome of the Castelo dos Sonhos virus. Out of the 112 blood samples analyzed, five were positive for Plasmodium infection (four P. falciparum and one P. vivax), and four were seropositive for hantavirus, showing a seroprevalence of 3.57%. One of the four miners who was seroreactive for hantavirus concomitantly had P. falciparum infection, which was confirmed by thick blood smear. This manuscript highlights the importance of considering hantavirus pulmonary syndrome as a diagnostic possibility in febrile infection associated with pulmonary manifestations in mining areas where malaria cases are often identified.

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.

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.

Seroprevalence of rodent-borne viruses in Afro-descendent communities in Brazil

During the Brazilian slavery period, many African migrants were brought to the American continent. Historically, some of these migrants escaped from the Brazilian gold mines and farms to which they had been brought and settled in remote valleys and this was the main mode of resistance to the slavery system. These runaway-slave descendant communities are called quilombos, a group with distinct ethnic identity, specific behavioral habits, including geographic isolation and conservative practices. The objective of this study was to investigate the prevalence of rodent-borne viruses in two Afro-descendent communities from Mato Grosso do Sul State, Midwestern Brazil. A total of 319 individuals from rural and urban quilombola communities were enrolled. Twelve (3.76%) had anti-rodent-borne virus IgG antibodies. Seven (2.19%) were anti-mammarenavirus reactive and nine (2.82%) had anti-orthohantavirus antibodies. The literature includes limited data on the health status of quilombola communities, but all the studies emphasize the disparity of attention of local healthcare personnel to these communities compared to the general population. The findings of this study highlight the vulnerability and the precarious health conditions of quilombola groups, especially those living in rural areas and thus, point to the need of preventive measures to improve access to healthcare for this ethnic group.

Novel variants of human herpesvirus 2 from Brazilian HIV-1 coinfected subjects

BACKGROUND Human herpesvirus 2 (HHV-2) have DNA genome with a limited genetic variability and have been classified into two clades. OBJECTIVES To identify and characterise six HHV-2 isolates derived from Brazilian women. METHODS HHV-2 isolates were performed polymerase chain reaction (PCR) and sequencing of 2250 pb of the glycoprotein B (gB) coding regions. FINDINGS Four HHV-2 isolates were classified into clade B, while the remaining two, derived from HIV-1 co-infected women, showed a notable genetic divergence (> 1%). MAIN CONCLUSION The results reveal novel HHV-2 variants. The impact of these novel variants on HHV-2 pathogenesis and HIV/HHV-2 coinfection need to be investigated.

Morphological, molecular and phylogenetic characterization of Borrelia theileri in Rhipicephalus microplus

Abstract This study aimed to perform a morphological, molecular and phylogenetic characterization of Borrelia theileri obtained from infected Rhipicephalus microplus in Brazil. Fifty engorged R. microplus females from cattle in the municipality of Seropédica, Rio de Janeiro, were analyzed for spirochetes by hemolymph smear. Macerated eggs and positive ticks, as well as blood from the bovine infested by these ticks, were analyzed the glpQ, flaB and hpt genes by PCR. The PCR products were purified and sequenced for analysis and construction of a phylogenetic tree. Only 2% (1/50) of the ticks generated a positive result by both smear and PCR. The spiral forms (n = 50) had (media ± SD) a mean length of 19.17 ± 4.12 µm, diameter of 0.2935 ± 0.0469 and number of turns 8.44 ± 2.59. Sequence alignments of the three evaluated genes exhibited 98% similarity to B. theileri isolates, occurring in a clade highly related to B. theileri strain KAT. Egg maceration samples were positive for the three evaluated genes, whereas bovine blood was negative by PCR. This is the most detailed characterization of B. theileri in the Americas to-date, presenting morphological, molecular and phylogenetic data, including the transovarial transmission of the spirochete in the host tick.

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.

Xapuri virus, a novel mammarenavirus: natural reassortment and increased diversity between New World viruses

Mammarenavirus RNA was detected in Musser’s bristly mouse (Neacomys musseri) from the Amazon region, and this detection indicated that rodents were infected with a novel mammarenavirus, with the proposed name Xapuri virus (XAPV), which is phylogenetically related to New World Clade B and Clade C viruses. XAPV may represent the first natural reassortment of the Arenaviridae family and a new unrecognized clade within the Tacaribe serocomplex group.

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.

Detection of Latino virus (Arenaviridae: Mammarenavirus) naturally infecting Calomys callidus

Mammarenavirus species are associated with a specific rodent host species, although an increasing number of virus has been associated to more than one host, suggesting that co-evolution is less robust than initially thought. There are few eco-epidemiological studies of South America mammarenaviruses in non-endemic areas of Arenavirus Hemorrhagic Fever, affecting specially our current knowledge about animal reservoirs and virus range and host-virus relations. In Brazil, seven arenavirus species were described in seven different rodent species. Here in we describe a new rodent reservoir species in Brazil related to the previously described Latino mammarenavirus (LATV) MARU strain. Samples of 148 rodents from Mato Grosso state, Brazil were analyzed. Amplification of the glycoprotein precursor gene (GPC) was observed in six Calomys callidus rodents. According to phylogenetic inferences, is observed a well-supported monophyletic clade of LATV from C. callidus and other Clade C mammarenavirus. In addition, the phylogenetic relations of both genes showed a close relation between LATV MARU and Capão Seco strains, two distinct lineages. Additionally, the results obtained in this study point out to a change of scenario and in previously stabilized patterns in the dynamics of South American mammarenaviruses, showing that with more studies in AHF non-endemic or silent areas, more potential hosts for this virus will be discovered.

Serological Survey of Rabies Virus Infection among Bats in Brazil

Rabies is a disease caused by a virus belonging to the family Rhabdoviridae, genus Lyssavirus (RABV), and is characterized as a progressive and acute encephalitis that presents high lethality. Between 2002 and 2012, 2149 wild animals were found positive for RABV in Brazil where 79% were associated with the aerial cycle of the disease. As part of the active surveillance of rabies in Brazil, the objective of this study was to investigate the presence of RABV infection in bats captured in two different regions of Brazil. Bat specimens were collected in (i) the metropolitan region of Rio de Janeiro city, (ii) Igrapiúna Municipality, Bahia State, and (iii) Serra do Tabuleiro State Park (PEST) in Santa Catarina State. Forty-four bats from the two first areas were tested for RABV at Institute Jorge Vaitsman (IJV), reference laboratory for rabies in Rio de Janeiro State. Of the individuals captured and sent for the diagnosis of rabies, a total of 15 were identified as being hematophagous, all of them belonging to the species Desmodus rotundus. Twenty-four individuals were considered as frugivorous, four as insectivores and one individual (Lonchophylla peracchii) identified as having a pollen/nectar feeding habit. All specimen sent to RABV diagnosis presented negative results. Considering the active surveillance for RABV in Brazil, studies of fauna survey with serological characterization are important in the strengthening of epidemiological surveillance and protection of human life.

Clinical and epidemiological use of nested PCR targeting the repetitive element IS1111 associated with the transposase gene from Coxiella burnetii

Q fever is a worldwide zoonosis caused by Coxiella burnetii-a small obligate intracellular Gram-negative bacterium found in a variety of animals. It is transmitted to humans by inhalation of contaminated aerosols from urine, feces, milk, amniotic fluid, placenta, abortion products, wool, and rarely by ingestion of raw milk from infected animals. Nested PCR can improve the sensitivity and specificity of testing while offering a suitable amplicon size for sequencing. Serial dilutions were performed tenfold to test the limit of detection, and the result was 10× detection of C. burnetti DNA with internal nested PCR primers relative to trans-PCR. Different biological samples were tested and identified only in nested PCR. This demonstrates the efficiency and effectiveness of the primers. Of the 19 samples, which amplify the partial sequence of C. burnetii, 12 were positive by conventional PCR and nested PCR. Seven samples-five spleen tissue samples from rodents and two tick samples-were only positive in nested PCR. With these new internal primers for trans-PCR, we demonstrate that our nested PCR assay for C. burnetii can achieve better results than conventional PCR.

A Fatal Hantavirus Pulmonary Syndrome Misdiagnosed as Dengue: An Investigation into the First Reported Case in Rio de Janeiro State, Brazil

We report the results of an investigation into a fatal case of hantavirus pulmonary syndrome (HPS) in Rio de Janeiro State, Brazil, where the disease had not been reported previous to 2015. Following the notification of an HPS case, serum samples were collected from the household members and work contacts of the HPS patient and tested for antibody to hantaviruses. Seroprevalence of 22% (10/45) was indicated for hantavirus out of 45 human samples tested. Blood and tissue samples were collected from 72 rodents during fieldwork to evaluate the prevalence of hantavirus infection, by using enzyme-linked immunosorbent assay IgG, and to characterize the rodent hantavirus reservoir(s), by reverse transcription polymerase chain reaction and sequencing. Antibody prevalence was 6.9%. The circulation of a single genotype, the Juquitiba hantavirus, carried by two rodent species, black-footed pigmy rice rat (Oligoryzomys nigripes) and cursor grass mouse (Akodon cursor), was shown by analysis of the nucleotide sequences of the S segment. Juquitiba hantavirus circulates in rodents of various species, but mainly in the black-footed pigmy rice rat. HPS is a newly recognized clinical entity in Rio de Janeiro State and should be considered in patients with febrile illness and acute respiratory distress.

New bunya-like viruses: Highlighting their relations

The standard virus classification scheme for arenaviruses and bunyaviruses shifted dramatically when several groups reported the detection and isolation of divergent groups of viruses in a variety of insect collections. Although these viral families can differ in terms of morphology, structure and genetics, recent findings indicate these viruses may have a shared evolutionary origin. To determine the phylogenetic relations among these families, we inferred phylogenetic trees using three methods. The Maximum Likelihood and Bayesian trees were rooted as suggested by the (molecular clock-rooted) BEAST tree. Our results highlight a noteworthy relation among these viral supergroups of different genome organizations. Our study suggests that the best scenario is the existence of at least three monophyletic supergroups, all of them well supported. The recent data indicate that these viruses are evolutionarily and genetically interconnected. While these supergroups appear to be closely related in our phylogenetic analysis, other viruses should be investigated in future research. In sum, our results also provide insights into the classification scheme, thereby providing a new perspective about the fundamental questions of family origins, diversity and genome evolution.

Serologic evidence of the exposure of small mammals to spotted-fever Rickettsia and Rickettsia bellii in Minas Gerais, Brazil

INTRODUCTION

Sources of pathogenic Rickettsia in wildlife are largely unknown in Brazil. In this work, potential tick vectors and seroreactivity of small mammals against four spotted-fever group Rickettsia (R. rickettsii, R. parkeri, R. amblyommii and R. rhipicephali) and Rickettsia bellii from peri-urban areas of Uberlândia, a major town in Brazil, are described for the first time.

METHODOLOGY

Small mammals were captured and blood samples collected. Ticks were collected from the surface of the host and the environment and posteriorly identified. Reactivity of small mammal sera to Rickettsia was tested by indirect immunofluorescence assay (IFA) using crude antigens from five Brazilian Rickettsia isolates.

RESULTS

Information was obtained from 416 small mammals (48 Marsupialia and 368 Rodentia). Forty-eight animals were parasitized and two tick species, Ixodes loricatus and Amblyomma dubitatum, were found on several host species, with a few tick-host relationships described for the first time. From the 416 tested sera, 70 reacted to at least one Rickettsia antigen (prevalence of 16.8%) and from these, 19 (27.1%) reacted to two or more antigens. Seroprevalence was higher for marsupials (39.6%) than for rodents (13.8%). Marsupial and Rhipidomys spp. sera reacted mainly (highest seroprevalence and titers) to R. bellii, and that of Necromys lasiurus mainly to R. rickettsii.

CONCLUSIONS

Although the serologic assays poorly discriminate between closely related spotted-fever group Rickettsia, the observed small mammal seroreactivity suggests the circulation of Rickettsia in the peri-urban area of Uberlândia, albeit at low levels.

Molecular Identification of Q Fever in Patients with a Suspected Diagnosis of Dengue in Brazil in 2013-2014

Q fever is an important cause of undifferentiated fever that is rarely recognized or reported in Brazil. The objective of this study was to look for the presence of Coxiella burnetii during a dengue fever outbreak in the municipality of Itaboraí, Rio de Janeiro, Brazil, where this bacterium had previously infected humans and domesticated animals. Blood samples from clinically suspected dengue fever patients were tested by polymerase chain reaction (PCR) for C. burnetii; the DNA was detected in nine (3.3%) of 272 patients. One was coinfected with dengue virus, which was also detected in another 166 (61.3%) patients. The nucleotide sequence of PCR amplification and DNA sequencing of the IS1111 transposase elements in the genome of C. burnetii exhibited 99% identity with the sequence in GenBank. The detection of C. burnetii in patients suspected of dengue fever indicates that awareness and knowledge of Q fever should be strengthened and that this bacterium is present in Brazil. Finally, because a negative molecular result does not completely rule out the diagnosis of Q fever and the serological assay based on seroconversion was not available, the actual number of this zoonosis is likely to be much higher than that reported in this study.

Detection of different South American hantaviruses

Hantaviruses are the etiologic agents of Hemorrhagic Fever with Renal Syndrome (HFRS) in Old World, and Hantavirus Pulmonary Syndrome (HPS)/Hantavirus Cardiopulmonary Syndrome (HCPS), in the New World. Serological methods are the most common approach used for laboratory diagnosis of HCPS, however theses methods do not allow the characterization of viral genotypes. The polymerase chain reaction (PCR) has been extensively used for diagnosis of viral infections, including those caused by hantaviruses, enabling detection of few target sequence copies in the sample. However, most studies proposed methods of PCR with species-specific primers. This study developed a simple and reliable diagnostic system by RT-PCR for different hantavirus detection. Using new primers set, we evaluated human and rodent hantavirus positive samples of various regions from Brazil. Besides, we performed computational analyzes to evaluate the detection of other South American hantaviruses. The diagnostic system by PCR proved to be a sensible and simple assay, allowing amplification of Juquitiba virus, Araraquara virus, Laguna Negra virus, Rio Mamore virus and Jabora virus, beyond of the possibility of the detecting Andes, Anajatuba, Bermejo, Choclo, Cano Delgadito, Lechiguanas, Maciel, Oran, Pergamino and Rio Mearim viruses. The primers sets designed in this study can detect hantaviruses from almost all known genetics lineages in Brazil and from others South America countries and also increases the possibility to detect new hantaviruses. These primers could easily be used both in diagnosis of suspected hantavirus infections in humans and also in studies with animals reservoirs.

Co-circulation of Clade C New World Arenaviruses: New geographic distribution and host species

Clade C, of the New World Arenaviruses, is composed of only the Latino and Oliveros viruses and, besides the geographic range of their rodent reservoirs, the distribution of these viruses has been restricted to Bolivia and Argentina. In this study, the genetic detection and phylogenetic analysis of the complete S segment sequences of sympatric arenaviruses from Brazil revealed a new geographic distribution of clade C arenaviruses, as well as the association of Oliveros virus with a new rodent reservoir.

Molecular identification of the agent of Q fever - Coxiella burnetii - in domestic animals in State of Rio de Janeiro, Brazil

INTRODUCTION

Over the last recent years, the number of Q fever cases have has increased throughout the world. An epidemiological investigation was performed in the area in which the first molecular documentation of Q fever in Brazil was previously reported.

METHODS

Indirect immunofluorescence assay (IFA) and PCR of Coxiella burnetii targeting the htpAB gene were performed in samples from 14 dogs (blood); 1 cat (blood); 10 goats (blood, milk, vaginal swab and anal swab); 3 sheep (blood); and 2 horses (blood).

RESULTS

Two dogs, two sheep and five goats were seroreactive. DNA was amplified from 6 milk and 2 blood samples from goats and from dogs, respectively. The sequence of the amplicons exhibited 99% sequence similarity with the homologous sequence of the htpAB gene of C. burnetii RSA 331 (GenBank - CP000890).

CONCLUSIONS

The results confirm C. burnetii infection in animals in Rio de Janeiro and reinforce the need for the surveillance of Q fever in Brazil.

Population ecology of hantavirus rodent hosts in southern Brazil

In this study we analyze population dynamics of hantavirus rodent hosts and prevalence of infection over a 2-year period in Southern Brazil, a region with a high incidence of hantavirus pulmonary syndrome. The 14 small mammal species captured were composed of 10 rodents and four marsupials, the six most abundant species being Akodon serrensis, Oxymycterus judex, Akodon montensis, Akodon paranaensis, Oligoryzomys nigripes, and Thaptomys nigrita. These species displayed a similar pattern with increasing population sizes in fall/winter caused by recruitment and both, increase in reproductive activity and higher hantavirus prevalence in spring/summer. Specific associations between A. montensis/Jaborá Virus (JABV) and O. nigripes/Juquitiba-like Virus (JUQV-like) and spillover infections between A. paranaensis/JABV, A. serrensis/JABV, and A. paranaensis/JUQV-like were observed. Spillover infection in secondary hosts seems to play an important role in maintaining JABV and JUQV-like in the hantavirus sylvatic cycle mainly during periods of low prevalence in primary hosts.

Rickettsia bellii, Rickettsia amblyommii, and Laguna Negra hantavirus in an Indian reserve in the Brazilian Amazon

Background

The purpose of this study was to identify the presence of rickettsia and hantavirus in wild rodents and arthropods in response to an outbreak of acute unidentified febrile illness among Indians in the Halataikwa Indian Reserve, northwest of the Mato Grosso state, in the Brazilian Amazon. Where previously surveillance data showed serologic evidence of rickettsia and hantavirus human infection.

Methods

The arthropods were collected from the healthy Indian population and by flagging vegetation in grassland or woodland along the peridomestic environment of the Indian reserve. Wild rodents were live-trapped in an area bordering the reserve limits, due the impossibility of capturing wild animals in the Indian reserve. The wild rodents were identified based on external and cranial morphology and karyotype. DNA was extracted from spleen or liver samples of rodents and from invertebrate (tick and louse) pools, and the molecular characterization of the rickettsia was through PCR and DNA sequencing of fragments of two rickettsial genes (gltA and ompA). In relation to hantavirus, rodent serum samples were serologically screened by IgG ELISA using the Araraquara-N antigen and total RNA was extracted from lung samples of IgG-positive rodents. The amplification of the complete S segment was performed.

Results

A total of 153 wild rodents, 121 louse, and 36 tick specimens were collected in 2010. Laguna Negra hantavirus was identified in Calomys callidus rodents and Rickettsia bellii, Rickettsia amblyommii were identified in Amblyomma cajennense ticks.

Conclusions

Zoonotic diseases such as HCPS and spotted fever rickettsiosis are a public health threat and should be considered in outbreaks and acute febrile illnesses among Indian populations. The presence of the genome of rickettsias and hantavirus in animals in this Indian reserve reinforces the need to include these infectious agents in outbreak investigations of febrile cases in Indian populations.

Ecological study of hantavirus infection in wild rodents in an endemic area in Brazil

A 3-year ecological study of small mammals was carried out in an endemic area for hantavirus pulmonary syndrome in the state of Santa Catarina in Southern Brazil. A total of 994 rodents of 14 different species corresponding to the subfamilies of Sigmodontinae, Murinae, Eumysopinae, and Caviinae were captured during 2004-2006. Oligoryzomys nigripes and Akodon montensis were the most abundant species and showed a clear seasonal pattern with higher population sizes during the winter. Rodent population outbreaks, associated within bamboo mast seeding events, were detected predominantly in areas where hantavirus pulmonary syndrome cases were notified in the state. Antibody reactivity to Hantavirus was detected in five sigmodontine species: O. nigripes (39/435), A. montensis (15/318), Akodon paranaensis (4/37), Thaptomys nigrita (1/86) and Sooretamys angouya (1/12). The highest hantavirus antibody prevalence occurred during the period of highest population size in A. montensis. For O. nigripes, hantavirus prevalence was higher in late spring, when reproduction was more frequent. Co-circulation of Juquitiba (JUQV) and Jabora (JABV) viruses was observed - JABV in A. paranaensis and A. montensis; JUQV in O. nigripes and T. nigrita. JABV occurrence was associated to gender and population size of the rodent while JUQV was related to gender, season, temperature, and locality.