Genomic and eco-epidemiological investigations in Uruguay reveal local Chikungunya virus transmission dynamics during its expansion across the Americas in 2023

Uruguay experienced its first Chikungunya virus outbreak in 2023, resulting in a significant burden to its healthcare system. We conducted analysis based on real-time genomic surveillance (30 novel whole genomes) to offer timely insights into recent local transmission dynamics and eco-epidemiological factors behind its emergence and spread in the country.

North-south pathways, emerging variants, and high climate suitability characterize the recent spread of dengue virus serotypes 2 and 3 in the Dominican Republic

We employ a multidisciplinary approach, integrating genomics and epidemiology, to uncover recent dengue virus transmission dynamics in the Dominican Republic. Our results highlight a previously unknown north-south transmission pathway within the country, with the co-circulation of multiple virus lineages. Additionally, we examine the historical climate data, revealing long-term trends towards higher theoretical potential for dengue transmission due to rising temperatures. These findings provide information for targeted interventions and resource allocation, informing as well towards preparedness strategies for public health agencies in mitigating climate and geo-related dengue risks.

Exploring the Genomic Dynamics of the Monkeypox Epidemic in Paraguay

In recent months, Paraguay has been grappled with a notable monkeypox outbreak, straining its healthcare infrastructure. The sudden spike in cases underlines the imperative need for a comprehensive understanding of the virus's dynamics, enabling the formulation of robust containment measures. To address this challenge, our team joined forces with the Central Public Health Laboratory of Asunción and the Pan-American Health Organization. Through this collaboration, we employed portable whole-genome sequencing combined with phylodynamic analysis to examine the MPXV strains circulating in Paraguay. Our genomic monitoring approach has produced the first 30 whole-genome sequences from Paraguay, all of which were identified under lineage IIb. Interestingly, our data suggest that the origin of the monkeypox virus in Paraguay at the beginning of 2022 can be traced back to Brazil. This introduction subsequently catalyzed further community spread that was further exacerbated by several independent introduction events as time progressed. These findings not only shed light on the transmission patterns of the virus but also highlight the pivotal role such insights play in sculpting effective response strategies and driving impactful public health measures. Furthermore, our findings strongly advocate intensified surveillance at international borders, ensuring swift detection and proactive countermeasures against potential outbreaks in the future.

A Multiplex Nanopore Sequencing Approach for the Detection of Multiple Arboviral Species

The emergence and continued geographic expansion of arboviruses and the growing number of infected people have highlighted the need to develop and improve multiplex methods for rapid and specific detection of pathogens. Sequencing technologies are promising tools that can help in the laboratory diagnosis of conditions that share common symptoms, such as pathologies caused by emerging arboviruses. In this study, we integrated nanopore sequencing and the advantages of reverse transcription polymerase chain reaction (RT-PCR) to develop a multiplex RT-PCR protocol for the detection of Chikungunya virus (CHIKV) and several orthoflaviviruses (such as dengue (Orthoflavivirus dengue), Zika (Orthoflavivirus zikaense), yellow fever (Orthoflavivirus flavi), and West Nile (Orthoflavivirus nilense) viruses) in a single reaction, which provides data for sequence-based differentiation of arbovirus lineages.

Genomics-based timely detection of Dengue Virus type I genotypes I and V in Uruguay

We report the first whole-genome sequences of Dengue Virus type I genotypes I and V from Uruguay, including the first cases ever reported in the country. Through timely genomic analysis, identification of these genotypes was possible, aiding in timely public health responses and intervention strategies to mitigate the impact of dengue outbreaks.

Genomic and eco-epidemiological investigations in Uruguay reveal local Chikungunya virus transmission dynamics during its expansion across the Americas in 2023

Uruguay experienced its first Chikungunya virus outbreak in 2023, resulting in a significant burden to its healthcare system. We conducted analysis based on real-time genomic surveillance (30 novel whole genomes) to offer timely insights into recent local transmission dynamics and eco-epidemiological factors behind its emergence and spread in the country.

Technology transfer during the COVID-19 pandemic: report on the first face-to-face practical training course in Brazil

MAIN RESULTS

Technology transfer can take place at large events, as long as safety protocols are strictly enforced. It is important to disseminate, at these events, the concepts of the Responsible Research and Innovation (RRI). Implications for services: Face-to-face training course is fundamental for training public health professionals. Technology transfer between research institutions and health services results in updating and improving health system performance.

PERSPECTIVES

Based on the success of the reported technology transfer, a new module will be incorporated into the next edition of VEME (Panama 2022), entitled Virus Evolution to Public Health Policy Makers. The objective of this report was to describe the first face-to-face course aimed at training public health professionals in performing real-time genomic surveillance during the pandemic period. Experience report on a theoretical-practical course focusing on genomic research and surveillance, including mobile sequencing technologies, bioinformatics, phylogenetics and epidemiological modeling. There were 162 participants in the event and it was the first major face-to-face training course conducted during the COVID-19 epidemic in Brazil. No cases of SARS-CoV-2 infection was detected among the participants at the end of the event, suggesting the safety and effectiveness of all safety measures adopted. The results of this experience suggest that it is possible to conduct professional training safely during pandemics, as long as all safety protocols are followed.

Increased interregional virus exchange and nucleotide diversity outline the expansion of chikungunya virus in Brazil

The emergence and reemergence of mosquito-borne diseases in Brazil such as yellow fever, zika, chikungunya, and dengue have had serious impacts on public health. Concerns have been raised due to the rapid dissemination of the chikungunya virus across the country since its first detection in 2014 in Northeast Brazil. In this work, we carried out on-site training activities in genomic surveillance in partnership with the National Network of Public Health Laboratories that have led to the generation of 422 chikungunya virus genomes from 12 Brazilian states over the past two years (2021-2022), a period that has seen more than 312 thousand chikungunya fever cases reported in the country. These genomes increased the amount of available data and allowed a more comprehensive characterization of the dispersal dynamics of the chikungunya virus East-Central-South-African lineage in Brazil. Tree branching patterns revealed the emergence and expansion of two distinct subclades. Phylogeographic analysis indicated that the northeast region has been the leading hub of virus spread towards other regions. Increased frequency of C > T transitions among the new genomes suggested that host restriction factors from the immune system such as ADAR and AID/APOBEC deaminases might be driving the genetic diversity of the chikungunya virus in Brazil.

Retrospective Spatio-Temporal Dynamics of Dengue Virus 1, 2 and 4 in Paraguay

Dengue virus (DENV) has been a major public health concern in Paraguay, with frequent outbreaks occurring since early 1988. Although control measures have been implemented, dengue remains a significant health threat in the country, and continued efforts are required for prevention and control. In response to that, in collaboration with the Central Public Health Laboratory in Asunción, we conducted a portable whole-genome sequencing and phylodynamic analysis to investigate DENV viral strains circulating in Paraguay over the past epidemics. Our genomic surveillance activities revealed the co-circulation of multiple DENV serotypes: DENV-1 genotype V, the emerging DENV-2 genotype III, BR4-L2 clade, and DENV-4 genotype II. Results additionally highlight the possible role of Brazil as a source for the international dispersion of different viral strains to other countries in the Americas emphasizing the need for increased surveillance across the borders, for the early detection and response to outbreaks. This, in turn, emphasizes the critical role of genomic surveillance in monitoring and understanding arbovirus transmission and persistence locally and over long distances.

Rapid epidemic expansion of chikungunya virus-ECSA lineage in Paraguay

The spread of vector-borne viruses, such as CHIKV, is a significant public health concern in the Americas, with over 120,000 cases and 51 deaths in 2023, of which 46 occurred in Paraguay. Using a suite of genomic, phylodynamic, and epidemiological techniques, we characterized the ongoing large CHIKV epidemic in Paraguay.

Article Summary Line

Genomic and epidemiological characterization of the ongoing Chikungunya virus epidemic in Paraguay.

Increased interregional virus exchange and nucleotide diversity outline the expansion of the chikungunya virus ECSA lineage in Brazil

The emergence and reemergence of mosquito-borne diseases in Brazil such as Yellow Fever, Zika, Chikungunya, and Dengue have had serious impacts on public health. Concerns have been raised due to the rapid dissemination of the chikungunya virus (CHIKV) across the country since its first detection in 2014 in Northeast Brazil. Faced with this scenario, on-site training activities in genomic surveillance carried out in partnership with the National Network of Public Health Laboratories have led to the generation of 422 CHIKV genomes from 12 Brazilian states over the past two years (2021-2022), a period that has seen more than 312 thousand chikungunya fever cases reported in the country. These new genomes increased the amount of available data and allowed a more comprehensive characterization of the dispersion dynamics of the CHIKV East-Central-South-African (ECSA) lineage in Brazil. Tree branching patterns revealed the emergence and expansion of two distinct subclades. Phylogeographic analysis indicated that the northeast region has been the leading hub of virus spread towards other regions. Increased frequency of C>T transitions among the new genomes suggested that host restriction factors from the immune system such as ADAR and AID/APOBEC deaminases might be driving CHIKV ECSA lineage genetic diversity in Brazil.

Field and classroom initiatives for portable sequence-based monitoring of dengue virus in Brazil

Brazil experienced a large dengue virus (DENV) epidemic in 2019, highlighting a continuous struggle with effective control and public health preparedness. Using Oxford Nanopore sequencing, we led field and classroom initiatives for the monitoring of DENV in Brazil, generating 227 novel genome sequences of DENV1-2 from 85 municipalities (2015-2019). This equated to an over 50% increase in the number of DENV genomes from Brazil available in public databases. Using both phylogenetic and epidemiological models we retrospectively reconstructed the recent transmission history of DENV1-2. Phylogenetic analysis revealed complex patterns of transmission, with both lineage co-circulation and replacement. We identified two lineages within the DENV2 BR-4 clade, for which we estimated the effective reproduction number and pattern of seasonality. Overall, the surveillance outputs and training initiative described here serve as a proof-of-concept for the utility of real-time portable sequencing for research and local capacity building in the genomic surveillance of emerging viruses.

Human respiratory syncytial virus and metapneumovirus in patients with acute respiratory infection in Colombia, 2000 - 2011

OBJECTIVE

To describe the epidemiology of respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) in Colombia from 2000 - 2011, including seasonal trends.

METHODS

Nasopharyngeal aspirates and/or throat swabs from 14 870 patients with acute respiratory infections (ARI) were studied. Two subgroups were analyzed using molecular biology techniques. The first consisted of 264 RSV indirect fluorescence assay (IFA)-positive samples, the second of 264 RSV IFA-negative samples. RSV and hMPV were detected using reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

2 799 samples (18.8%) contained a respiratory virus. RSV was detected by IFA in 1 333 samples (8.9%). RSV was detected by RT-PCR in 192 samples from the RSV IFA-positive subgroup and in 25 samples from the RSV IFA-negative subgroup. hMPV was detected in eight samples from the RSV IFA-positive subgroup and in 11 samples from the RSV IFA-negative subgroup. Among the RSV infections, subtype A was dominant in two-year intervals, subtype B was dominant in one-year intervals. 85.3% of RSV and 74% of hMPV infections occurred in children younger than 5 years old. RSV and hMPV infections were associated with rainy seasons. Co-infection with RSV A and RSV B was detected in two patients. Five cases of co-infection with RSV and hMPV were detected.

CONCLUSIONS

This report is the first to examine the epidemiology of ARIs in Colombia, with an emphasis on RSV and hMPV. The samples studied here were obtained over a 12-year period and represent all age groups and both genders.

The influence of vacuum mixing on methylmethacrylate liberation from acrylic cement powder

Polymethylmethacrylate (PMMA) bone cement is a biomaterial used to anchor prostheses during joint replacement surgery. Residual methylmethacrylate monomer (MMA) may be related with the cytotoxic effect of PMMA. The aim of the present paper was to investigate the effect of two different cement mixing methods: hand stirring at atmospheric pressure and under partial vacuum (0.330 and 0.154 bar) on residual monomer liberation in phosphate buffer saline solution from acrylic cement powder. Residual MMA content was determined by high-performance liquid chromatography. Mathematical models were applied to experimental dissolution data revealing that monomer release was significantly reduced in bone cement powder obtained at 0.154 bar vacuum pressure compared to the other mixing conditions. The kinetic models applied are consistent with a simple diffusion mechanism of the monomer from the polymer matrix.

In vitro release studies of methylmethacrylate liberation from acrylic cement powder

Bone cement or polymethylmethacrylate (PMMA) is commonly used for anchoring cemented prosthesis to the bone. Cytotoxic effect of culture media exposed to PMMA powder may be related with long term problems associated with acrylic cement application, being the monomer (methylmethacrylate) one of the cement's component partly responsible for the cytotoxic effect. The present work reports the studies of monomer release from acrylic bone cement powder under different experimental conditions: setting time of PMMA (in solution and air) and different culture media composition. High-performance liquid chromatography was used for the determination of residual monomer. Mathematical models were applied to experimental dissolution data revealing that monomer release is lightly affected by the studied variables. The monomer release seems to be a surface phenomena, suggesting that the possible actions of monomer will mainly be due to the initial loss of non polymerized monomer rather than to further depolymerization of the already polymerized cement.

Dietary beta-adrenoceptor agonists have a persistent effect on nitric oxide synthesis in rat cultured smooth muscle cells

Several compounds including lipopolysaccharide and sympathomimetics stimulate the expression of the inducible nitric oxide synthase in vascular smooth muscle cells. We evaluated the effect of clenbuterol on nitric oxide (NO) production by vascular smooth muscle cells of the rat aorta in culture. Wistar rats were divided into three diet groups (control, clenbuterol and washout). Aortic vascular smooth muscle cells from rats from these 3 diet groups were cultured in the presence and absence of lipopolysaccharide and/or beta-adrenoceptor agonists. NO release was measured by Griess reagent. Clenbuterol or salbutamol added to cells from control rats potentiated lipopolysaccharide-induced NO release. Cells from rats fed on clenbuterol, in a medium without beta-adrenoceptor agonists, showed a similar potentiation, even after a 10-day washout period. The addition of beta-adrenoceptor agonists to the latter cells did not increase NO production. NG-Nitro-L-arginine decreased nitrite production in lipopolysaccharide-stimulated cells. Our results demonstrate that dietary clenbuterol has a persistent 'ex vivo' effect on lipopolysaccharide-induced NO production by cultured vascular smooth muscle cells.

DL-propranolol augments production of NO induced by cytokines in cultured aortic smooth muscle of the rat

The effect of DL-propranolol on the production of nitric oxide (NO.) by cultured arterial smooth muscle cells from normotensive (WKY) and spontaneously hypertensive rats (SHR) was studied before and after stimulation by lipopolysaccharide or interleukin-1 beta. The influence of L-arginine and NG-nitro-L-arginine on these events was also studied. Lipopolysaccharide-stimulated SHR-derived smooth muscle cells produced less NO. than WKY cells. However the amounts produced in response to interleukin-1 beta were similar for the two cell types. DL-propranolol increased the NO. production in both types of cells exposed to lipopolysaccharide, but had no significant effect on this parameter in WKY-derived cells exposed to interleukin-1 beta. Inclusion of L-arginine during incubations with propranolol had no effect on the levels of NO. produced by either cell type exposed to lipopolysaccharide. The basal production of NO. was enhanced in smooth muscle cells from both normotensive and hypertensive rats when the cells were treated with L-arginine after exposure to interleukin-1 beta. L-Arginine increased the response to DL-propranolol only in the WKY cells. NO. production was depressed by inclusion of NG-nitro-L-arginine during incubations in both cell types regardless of the treatment regime used to induce NO. synthase activity. The results suggest that DL-propranolol may induce the production of NO. by cultured smooth muscle cells exposed to cytokines.

Effect of Ca2+ modulators on acetylcholine-induced phasic and tonic contractions and A23187-induced contractions in ileal longitudinal muscle and IP3 production

The influence of different sources of Ca2+ on the Emax and ED50 values of acetylcholine (ACh)-induced phasic and tonic contractions and on A23187-induced contractions was studied using different extracellular Ca2+ concentrations ([Ca2+]o) and the Ca2+ modulators TMB-8 and D600. IP3 production induced by both stimulants was also studied. The results are compatible with: (a) the mobilization of Ca2+ from an intracellular source as a primary event in the phasic response. (b) The primary involvement of a D600-sensitive inward Ca2+ current in the ACh-tonic response. (c) An inward D600-sensitive Ca2+ current associated with the ionophore transported ion. (d) The involvement of an IP3 independent, TMB-8 sensitive mechanism of Ca2+ mobilization involved in the A23187-induced responses.

[Left atrial thrombus. Its evolution with oral anticoagulation]

Left ventricular thrombi were found in 25 patients by two-dimensional echocardiography. All patients were in atrial fibrillation, 16 had mitral or mitroaortic valve diseases and nine mitral or mitroaortic bioprosthetic valves. Nine patients (36%) had history of arterial embolism. At diagnostic time, oral anticoagulation with coumadin was instaured in all the patients. Periodic clinic and echocardiography follow-up was performed. Left atrial thrombi either disappeared (18 patients [72%]) or reduced their size (one patient). Six patients with mitral stenosis were considered as candidates to percutaneous mitral valvuloplasty, which was performed in 4 patients whose thrombi disappeared with anticoagulation therapy in 6 months. During the follow-up one patient had cerebral embolism without sequelae.

CONCLUSIONS

1st. Patients with left atrial thrombi have high risk for arterial embolism. 2nd. Left atrial thrombi disappear in a high proportion after prescribing oral anticoagulation, which has some important therapeutic implications.

The effect of strontium on the drug-receptor interaction on cholinergic drugs

The effect of replacing calcium with strontium in the perfusion fluid was qualitatively and quantitatively studied in the isolated longitudinal muscle of the guinea-pig ileum. In the presence of strontium hyoscine could be considered a competitive antagonist of acetylcholine for the acetylcholine receptor of the longitudinal muscle of the guinea-pig ileum; dibenamine still blocked this receptor in an irreversible way. The equilibrium constants for acetylcholine (KA) and hyoscine (KI) were obtained in the presence of calcium (KA = 3.16 +/- 0.63 microM; KI = 0.38 +/- 0.07 nM), and strontium (KA = 7.00 +/- 0.89 microM; KI = 0.93 +/- 0.16 nM). The results show a decrease in the affinity of both drugs for the muscarinic receptor in the presence of strontium.

Modification by indomethacin of the blood pressure lowering effect of pindolol and propranolol in conscious rabbits

In conscious rabbits, the intravenous administration of pindolol (0.125 mg/kg) and propranolol (1 mg/kg) induced a highly significant (p less than 0.001) decrease of mean arterial blood pressure and with propranolol, a significant (p less than 0.01) bradycardia. In the same model the intravenous administrtion of saline (1 ml/kg) and of indomethacin (1 mg/kg) did not affect mean arterial blood pressure or heart rate (p greater than 0.3). Pretreatment of the animals with indomethacin (1 mg/kg) abolished the effect of both beta-blockers on mean arterial blood pressure (p greater than 0.05) and had no significant effect on heart rate.