Last data update: May 06, 2024. (Total: 46732 publications since 2009)
Records 1-24 (of 24 Records) |
Query Trace: Andres E[original query] |
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Survival of patient with hemorrhagic meningitis associated with inhalation anthrax
Lombarte Espinosa E , Villuendas Usón MC , Arribas García J , Jado García I , Huarte Lacunza R , Zárate Chug P , Claraco Vega LM , Jesús Santed Andrés M , Ríos MJ , Cook R , Simard JM , Boyer AE , Rezusta A . Clin Infect Dis 2022 75 S364-s372 This report describes a 49-year-old male construction worker who acquired a Bacillus anthracis infection after working on a sheep farm. He experienced a severe respiratory infection, septic shock, and hemorrhagic meningoencephalitis with severe intracranial hypertension. After several weeks with multiple organ dysfunction syndrome, he responded favorably to antibiotic treatment. Three weeks into his hospitalization, an intracranial hemorrhage and cerebral edema led to an abrupt deterioration in his neurological status. A single dose of raxibacumab was added to his antimicrobial regimen on hospital day 27. His overall status, both clinical and radiographic, improved within a few days. He was discharged 2 months after admission and appears to have fully recovered. |
Performance of Xpert MTB/RIF and mycobacterial culture on multiple specimen types for diagnosis of tuberculosis disease in young children and clinical characterization according to standardized research case definitions
Click ES , Song R , Smith JP , McHembere W , Fajans M , Hariri P , Okeyo E , McCarthy KD , Gethi D , Odeny L , Musau S , Okumu A , Orwa J , Perez-Velez CM , Wright CA , Andres MM , Marais BJ , Schaaf HS , Graham SM , Cruz AT , Cain KP . Pediatr Infect Dis J 2022 41 (8) 671-677 BACKGROUND: Tuberculosis (TB) is a leading cause of illness and death in children globally. Improved bacteriologic and clinical diagnostic approaches in children are urgently needed. METHODS: In a prospective cohort study, a consecutive series of young (<5 years) children presenting with symptoms suggestive of TB and parenchymal abnormality on chest radiograph in inpatient and outpatient settings in Kisumu County, Kenya from October 2013 to August 2015 were evaluated at baseline and over 6 months. Up to 14 specimens per child were tested for the Mycobacterium tuberculosis complex by fluorescence microscopy, Xpert MTB/RIF and mycobacterial culture. Using detailed clinical characterization, cases were retrospectively classified according to standardized research case definitions and the sensitivity and specificity of microbiological tests on different specimen types were determined. RESULTS: Among 300 young children enrolled, 266 had sufficient information to be classified according to the research clinical case definition. Of these, 36% (96/266) had TB disease; 32% (31/96) with bacteriologically confirmed intrathoracic TB. Compared to culture, the sensitivity of a single Xpert test ranged from 60 to 67% and specificity from 97.5 to 100% for different specimen types. CONCLUSIONS: Despite extensive specimen collection and laboratory testing, TB could not be bacteriologically confirmed in almost two-thirds of children with intrathoracic TB classified by research clinical case definitions. Improved diagnostic tests are needed to identify children with TB and to exclude other potential causes of illness. |
Divergent Rabies Virus Variant of Probable Bat Origin in 2 Gray Foxes, New Mexico, USA.
Condori Rene E, Aragon Adam, Breckenridge Mike, Pesko Kendra, Mower Kerry, Ettestad Paul, Melman Sandra, Velasco-Villa Andres, Orciari Lillian A, Yager Pamela, Streicker Daniel G, Gigante Crystal M, Morgan Clint, Wallace Ryan, Li Yu. Emerging infectious diseases 2022 28(6) 1137-1145 . Emerging infectious diseases 2022 28(6) 1137-1145 Condori Rene E, Aragon Adam, Breckenridge Mike, Pesko Kendra, Mower Kerry, Ettestad Paul, Melman Sandra, Velasco-Villa Andres, Orciari Lillian A, Yager Pamela, Streicker Daniel G, Gigante Crystal M, Morgan Clint, Wallace Ryan, Li Yu. Emerging infectious diseases 2022 28(6) 1137-1145 |
SARS-CoV-2 Variants of Interest and Concern naming scheme conducive for global discourse.
Konings F , Perkins MD , Kuhn JH , Pallen MJ , Alm EJ , Archer BN , Barakat A , Bedford T , Bhiman JN , Caly L , Carter LL , Cullinane A , de Oliveira T , Druce J , El Masry I , Evans R , Gao GF , Gorbalenya AE , Hamblion E , Herring BL , Hodcroft E , Holmes EC , Kakkar M , Khare S , Koopmans MPG , Korber B , Leite J , MacCannell D , Marklewitz M , Maurer-Stroh S , Rico JAM , Munster VJ , Neher R , Munnink BO , Pavlin BI , Peiris M , Poon L , Pybus O , Rambaut A , Resende P , Subissi L , Thiel V , Tong S , van der Werf S , von Gottberg A , Ziebuhr J , Van Kerkhove MD . Nat Microbiol 2021 6 (7) 821-823 A group convened and led by the Virus Evolution Working Group of the World Health Organization reports on its deliberations and announces a naming scheme that will enable clear communication about SARS-CoV-2 variants of interest and concern. | | Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), has a linear, unsegmented, positive-sense RNA genome. As with all viruses, SARS-CoV-2 continuously adapts to changing environments in real time via random genome mutations that are subject to natural selection. Most mutations are neutral or detrimental to the virus; however, a small number of mutations may provide a selective advantage, such as escape from the host immune system or resistance to antiviral drugs. Such mutations may also lead to increased fitness for transmissibility. As mutated forms of viruses or variants spread from person to person, they will eventually be detected at the population level. |
Use of partial N-gene sequences as a tool to monitor progress on rabies control and elimination efforts in Ethiopia.
Binkley L , Deressa A , Shi M , Jara M , Escobar LE , Mauldin MR , Matheny A , O'Quin J , Pieracci EG , Kling C , Hartloge C , Yimer G , Abate E , Gebreyes W , Reynolds M , Belay E , Shiferaw M , Nakazawa Y , Velasco-Villa A . Acta Trop 2021 221 106022 Ethiopia is one of the African countries most affected by rabies. A coarse catalog of rabies viruses (RABV) was created as a benchmark to assess the impact of control and elimination activities. We evaluated a 726 bp amplicon at the end of the N-gene to infer viral lineages in circulation using maximum likelihood and Bayesian methods for phylogenetic reconstruction. We sequenced 228 brain samples from wild and domestic animals collected in five Ethiopian regions during 2010-2017. Results identified co-circulating RABV lineages that are causing recurrent spillover infections into wildlife and domestic animals. We found no evidence of importation of RABVs from other African countries or vaccine-induced cases in the area studied. A divergent RABV lineage might be involved in an independent rabies cycle in jackals. This investigation provides a feasible approach to assess rabies control and elimination efforts in resource-limited countries. |
SARS-CoV-2 transmission in a Georgia school district - United States, December 2020-January 2021.
Gettings JR , Gold JAW , Kimball A , Forsberg K , Scott C , Uehara A , Tong S , Hast M , Swanson MR , Morris E , Oraka E , Almendares O , Thomas ES , Mehari L , McCloud J , Roberts G , Crosby D , Balajee A , Burnett E , Chancey RJ , Cook P , Donadel M , Espinosa C , Evans ME , Fleming-Dutra KE , Forero C , Kukielka EA , Li Y , Marcet PL , Mitruka K , Nakayama JY , Nakazawa Y , O'Hegarty M , Pratt C , Rice ME , Rodriguez Stewart RM , Sabogal R , Sanchez E , Velasco-Villa A , Weng MK , Zhang J , Rivera G , Parrott T , Franklin R , Memark J , Drenzek C , Hall AJ , Kirking HL , Tate JE , Vallabhaneni S . Clin Infect Dis 2021 74 (2) 319-326 BACKGROUND: To inform prevention strategies, we assessed the extent of SARS-CoV-2 transmission and settings in which transmission occurred in a Georgia public school district. METHODS: During December 1, 2020-January 22, 2021, SARS-CoV-2-infected index cases and their close contacts in schools were identified by school and public health officials. For in-school contacts, we assessed symptoms and offered SARS-CoV-2 RT-PCR testing; performed epidemiologic investigations and whole-genome sequencing to identify in-school transmission; and calculated secondary attack rate (SAR) by school setting (e.g., sports, elementary school classroom), index case role (i.e., staff, student), and index case symptomatic status. RESULTS: We identified 86 index cases and 1,119 contacts, 688 (63.1%) of whom received testing. Fifty-nine (8.7%) of 679 contacts tested positive; 15 (17.4%) of 86 index cases resulted in ≥2 positive contacts. Among 55 persons testing positive with available symptom data, 31 (56.4%) were asymptomatic. Highest SAR were in indoor, high-contact sports settings (23.8%, 95% confidence interval [CI] 12.7, 33.3), staff meetings/lunches (18.2%, CI 4.5-31.8), and elementary school classrooms (9.5%, CI 6.5-12.5). SAR was higher for staff (13.1%, CI 9.0-17.2) versus student index cases (5.8%, CI 3.6-8.0) and for symptomatic (10.9%, CI 8.1-13.9) versus asymptomatic index cases (3.0%, CI 1.0-5.5). CONCLUSIONS: Indoor sports may pose a risk to the safe operation of in-person learning. Preventing infection in staff members, through measures that include COVID-19 vaccination, is critical to reducing in-school transmission. Because many positive contacts were asymptomatic, contact tracing should be paired with testing, regardless of symptoms. |
Immunoglobulin A Targets a Unique Subset of the Microbiota in Inflammatory Bowel Disease.
Shapiro JM , de Zoete MR , Palm NW , Laenen Y , Bright R , Mallette M , Bu K , Bielecka AA , Xu F , Hurtado-Lorenzo A , Shah SA , Cho JH , LeLeiko NS , Sands BE , Flavell RA , Clemente JC . Cell Host Microbe 2020 29 (1) 83-93 e3 The immunopathogenesis of inflammatory bowel disease (IBD) has been attributed to a combination of host genetics and intestinal dysbiosis. Previous work in a small cohort of IBD patients suggested that pro-inflammatory bacterial taxa are highly coated with secretory immunoglobulin IgA. Using bacterial fluorescence-activated cell sorting coupled with 16S rRNA gene sequencing (IgA-SEQ), we profiled IgA coating of intestinal microbiota in a large cohort of IBD patients and identified bacteria associated with disease and treatment. Forty-three bacterial taxa displayed significantly higher IgA coating in IBD compared with controls, including 8 taxa exhibiting differential IgA coating but similar relative abundance. Patients treated with anti-TNF-α therapies exhibited dramatically altered microbiota-specific IgA responses compared with controls. Furthermore, increased IgA coating of Oscillospira was associated with a delay in time to surgery. These results demonstrate that investigating IgA responses to microbiota can uncover potential disease-modifying taxa and reveal improved biomarkers of clinical course in IBD. |
Understanding the Emergence of Multidrug-Resistant Candida : Using Whole-Genome Sequencing to Describe the Population Structure of Candida haemulonii Species Complex.
Gade L , Munoz JF , Sheth M , Wagner D , Berkow EL , Forsberg K , Jackson BR , Ramos-Castro R , Escandon P , Dolande M , Ben-Ami R , Espinosa-Bode A , Caceres DH , Lockhart SR , Cuomo CA , Litvintseva AP . Front Genet 2020 11 554 The recent emergence of a multidrug-resistant yeast, Candida auris, has drawn attention to the closely related species from the Candida haemulonii complex that include C. haemulonii, Candida duobushaemulonii, Candida pseudohaemulonii, and the recently identified Candida vulturna. Here, we used antifungal susceptibility testing and whole-genome sequencing (WGS) to investigate drug resistance and genetic diversity among isolates of C. haemulonii complex from different geographic areas in order to assess population structure and the extent of clonality among strains. Although most isolates of all four species were genetically distinct, we detected evidence of the in-hospital transmission of C. haemulonii and C. duobushaemulonii in one hospital in Panama, indicating that these species are also capable of causing outbreaks in healthcare settings. We also detected evidence of the rising azole resistance among isolates of C. haemulonii and C. duobushaemulonii in Colombia, Panama, and Venezuela linked to substitutions in ERG11 gene as well as amplification of this gene in C. haemulonii in isolates in Colombia suggesting the presence of evolutionary pressure for developing azole resistance in this region. Our results demonstrate that these species need to be monitored as possible causes of outbreaks of invasive infection. |
Spatio-temporal dynamics of Plasmodium falciparum transmission within a spatial unit on the Colombian Pacific Coast.
Knudson A , Gonzalez-Casabianca F , Feged-Rivadeneira A , Pedreros MF , Aponte S , Olaya A , Castillo CF , Mancilla E , Piamba-Dorado A , Sanchez-Pedraza R , Salazar-Terreros MJ , Lucchi N , Udhayakumar V , Jacob C , Pance A , Carrasquilla M , Apraez G , Angel JA , Rayner JC , Corredor V . Sci Rep 2020 10 (1) 3756 As malaria control programmes concentrate their efforts towards malaria elimination a better understanding of malaria transmission patterns at fine spatial resolution units becomes necessary. Defining spatial units that consider transmission heterogeneity, human movement and migration will help to set up achievable malaria elimination milestones and guide the creation of efficient operational administrative control units. Using a combination of genetic and epidemiological data we defined a malaria transmission unit as the area contributing 95% of malaria cases diagnosed at the catchment facility located in the town of Guapi in the South Pacific Coast of Colombia. We provide data showing that P. falciparum malaria transmission is heterogeneous in time and space and analysed, using topological data analysis, the spatial connectivity, at the micro epidemiological level, between parasite populations circulating within the unit. To illustrate the necessity to evaluate the efficacy of malaria control measures within the transmission unit in order to increase the efficiency of the malaria control effort, we provide information on the size of the asymptomatic reservoir, the nature of parasite genotypes associated with drug resistance as well as the frequency of the Pfhrp2/3 deletion associated with false negatives when using Rapid Diagnostic Tests. |
Molecular Confirmation of Rickettsia parkeri in Amblyomma ovale Ticks, Veracruz, Mexico.
Sanchez-Montes S , Ballados-Gonzalez GG , Hernandez-Velasco A , Zazueta-Islas HM , Solis-Cortes M , Miranda-Ortiz H , Canseco-Mendez JC , Fernandez-Figueroa EA , Colunga-Salas P , Lopez-Perez AM , Delgado-de la Mora J , Licona-Enriquez JD , Delgado-de la Mora D , Karpathy SE , Paddock CD , Rangel-Escareno C . Emerg Infect Dis 2019 25 (12) 2315-2317 We found Rickettsia parkeri in Amblyomma ovale ticks collected in Veracruz, Mexico, in 2018. We sequenced gene segments of gltA, htrA, sca0, and sca5; phylogenetic reconstruction revealed near-complete identity with R. parkeri strain Atlantic Rainforest. Enhanced surveillance is needed in Mexico to determine the public health relevance of this bacterium. |
Isolation and growth characterization of novel full length and deletion mutant human MERS-CoV strains from clinical specimens collected during 2015.
Tamin A , Queen K , Paden CR , Lu X , Andres E , Sakthivel SK , Li Y , Tao Y , Zhang J , Kamili S , Assiri AM , Alshareef A , Alaifan TA , Altamimi AM , Jokhdar H , Watson JT , Gerber SI , Tong S , Thornburg NJ . J Gen Virol 2019 100 (11) 1523-1529 Middle East respiratory syndrome (MERS) is a viral respiratory illness first reported in Saudi Arabia in September 2012 caused by the human coronavirus (CoV), MERS-CoV. Using full-genome sequencing and phylogenetic analysis, scientists have identified three clades and multiple lineages of MERS-CoV in humans and the zoonotic host, dromedary camels. In this study, we have characterized eight MERS-CoV isolates collected from patients in Saudi Arabia in 2015. We have performed full-genome sequencing on the viral isolates, and compared them to the corresponding clinical specimens. All isolates were clade B, lineages 4 and 5. Three of the isolates carry deletions located on three independent regions of the genome in the 5'UTR, ORF1a and ORF3. All novel MERS-CoV strains replicated efficiently in Vero and Huh7 cells. Viruses with deletions in the 5'UTR and ORF1a exhibited impaired viral release in Vero cells. These data emphasize the plasticity of the MERS-CoV genome during human infection. |
Peaks, Means, and Determinants of Real-Time TVOC Exposures Associated with Cleaning and Disinfecting Tasks in Healthcare Settings.
Virji MA , Liang X , Su FC , LeBouf RF , Stefaniak AB , Stanton ML , Henneberger PK , Houseman EA . Ann Work Expo Health 2019 63 (7) 759-772 Cleaning and disinfecting tasks and product use are associated with elevated prevalence of asthma and respiratory symptoms among healthcare workers; however, the levels of exposure that pose a health risk remain unclear. The objective of this study was to estimate the peak, average, and determinants of real-time total volatile organic compound (TVOC) exposure associated with cleaning tasks and product-use. TVOC exposures were measured using monitors equipped with a photoionization detector (PID). A simple correction factor was applied to the real-time measurements, calculated as a ratio of the full-shift average TVOC concentrations from a time-integrated canister and the PID sample, for each sample pair. During sampling, auxiliary information, e.g. tasks, products used, engineering controls, was recorded on standardized data collection forms at 5-min intervals. Five-minute averaged air measurements (n = 10 276) from 129 time-series comprising 92 workers and four hospitals were used to model the determinants of exposures. The statistical model simultaneously accounted for censored data and non-stationary autocorrelation and was fit using Markov-Chain Monte Carlo within a Bayesian context. Log-transformed corrected concentrations (cTVOC) were modeled, with the fixed-effects of tasks and covariates, that were systematically gathered during sampling, and random effect of person-day. The model-predicted geometric mean (GM) cTVOC concentrations ranged from 387 parts per billion (ppb) for the task of using a product containing formaldehyde in laboratories to 2091 ppb for the task of using skin wipes containing quaternary ammonium compounds, with a GM of 925 ppb when no products were used. Peak exposures quantified as the 95th percentile of 15-min averages for these tasks ranged from 3172 to 17 360 ppb. Peak and GM task exposures varied by occupation and hospital unit. In the multiple regression model, use of sprays was associated with increasing exposures, while presence of local exhaust ventilation, large room volume, and automatic sterilizer use were associated with decreasing exposures. A detailed understanding of factors affecting TVOC exposure can inform targeted interventions to reduce exposures and can be used in epidemiologic studies as metrics of short-duration peak exposures. |
Molecular epidemiology of Candida auris in Colombia reveals a highly-related, country-wide colonization with regional patterns in Amphotericin B resistance.
Escandon P , Chow NA , Caceres DH , Gade L , Berkow EL , Armstrong P , Rivera S , Misas E , Duarte C , Moulton-Meissner H , Welsh RM , Parra C , Pescador LA , Villalobos N , Salcedo S , Berrio I , Varon C , Espinosa-Bode A , Lockhart SR , Jackson BR , Litvintseva AP , Beltran M , Chiller TM . Clin Infect Dis 2018 68 (1) 15-21 Background: Candida auris is a multidrug-resistant yeast associated with hospital outbreaks worldwide. During 2015-2016, multiple outbreaks were reported in Colombia. We aimed to understand the extent of contamination in healthcare settings and to characterize the molecular epidemiology of C. auris in Colombia. Methods: We sampled patients, patient contacts, healthcare workers, and the environment in four hospitals with recent C. auris outbreaks. Using standardized protocols, people were swabbed at different body sites. Patient and procedure rooms were sectioned into four zones and surfaces were swabbed. We performed whole-genome sequencing (WGS) and antifungal susceptibility testing (AFST) on all isolates. Results: Seven (41%) of the 17 people swabbed were found to be colonized. C. auris was isolated from 37/322 (12%) environmental samples. These were collected from a variety of items in all four zones. WGS and AFST revealed that although isolates were similar throughout the country, isolates from the northern region were genetically distinct and more resistant to amphotericin B (AmB) than the isolates from central Colombia. Four novel non-synonymous mutations were found to be significantly associated with AmB resistance. Conclusions: Our results show that extensive C. auris contamination can occur and highlight the importance of adherence to appropriate infection control practices and disinfection strategies. Observed genetic diversity supports healthcare transmission and a recent expansion of C. auris within Colombia with divergent AmB susceptibility. |
Detection and Molecular Characterization of Zoonotic Poxviruses Circulating in the Amazon Region of Colombia, 2014.
Usme-Ciro JA , Paredes A , Walteros DM , Tolosa-Perez EN , Laiton-Donato K , Pinzon MD , Petersen BW , Gallardo-Romero NF , Li Y , Wilkins K , Davidson W , Gao J , Patel N , Nakazawa Y , Reynolds MG , Satheshkumar PS , Emerson GL , Paez-Martinez A . Emerg Infect Dis 2017 23 (4) 649-653 During 2014, cutaneous lesions were reported in dairy cattle and farmworkers in the Amazon Region of western Colombia. Samples from 6 patients were analyzed by serologic and PCR testing, and results demonstrated the presence of vaccinia virus and pseudocowpox virus. These findings highlight the need for increased poxvirus surveillance in Colombia. |
A Pan-Lyssavirus Taqman Real-Time RT-PCR Assay for the Detection of Highly Variable Rabies virus and Other Lyssaviruses.
Wadhwa A , Wilkins K , Gao J , Condori Condori RE , Gigante CM , Zhao H , Ma X , Ellison JA , Greenberg L , Velasco-Villa A , Orciari L , Li Y . PLoS Negl Trop Dis 2017 11 (1) e0005258 Rabies, resulting from infection by Rabies virus (RABV) and related lyssaviruses, is one of the most deadly zoonotic diseases and is responsible for up to 70,000 estimated human deaths worldwide each year. Rapid and accurate laboratory diagnosis of rabies is essential for timely administration of post-exposure prophylaxis in humans and control of the disease in animals. Currently, only the direct fluorescent antibody (DFA) test is recommended for routine rabies diagnosis. Reverse-transcription polymerase chain reaction (RT-PCR) based diagnostic methods have been widely adapted for the diagnosis of other viral pathogens, but there is currently no widely accepted rapid real-time RT-PCR assay for the detection of all lyssaviruses. In this study, we demonstrate the validation of a newly developed multiplex real-time RT-PCR assay named LN34, which uses a combination of degenerate primers and probes along with probe modifications to achieve superior coverage of the Lyssavirus genus while maintaining sensitivity and specificity. The primers and probes of the LN34 assay target the highly conserved non-coding leader region and part of the nucleoprotein (N) coding sequence of the Lyssavirus genome to maintain assay robustness. The probes were further modified by locked nucleotides to increase their melting temperature to meet the requirements for an optimal real-time RT-PCR assay. The LN34 assay was able to detect all RABV variants and other lyssaviruses in a validation panel that included representative RABV isolates from most regions of the world as well as representatives of 13 additional Lyssavirus species. The LN34 assay was successfully used for both ante-mortem and post-mortem diagnosis of over 200 clinical samples as well as field derived surveillance samples. This assay represents a major improvement over previously published rabies specific RT-PCR and real-time RT-PCR assays because of its ability to universally detect RABV and other lyssaviruses, its high throughput capability and its simplicity of use, which can be quickly adapted in a laboratory to enhance the capacity of rabies molecular diagnostics. The LN34 assay provides an alternative approach for rabies diagnostics, especially in rural areas and rabies endemic regions that lack the conditions and broad experience required to run the standard DFA assay. |
Use of DNA barcoding to distinguish the malaria vector Anopheles neivai in Colombia.
Lopez-Rubio A , Suaza-Vasco J , Marcet PL , Ruiz-Molina N , Caceres L , Porter C , Uribe S . Zootaxa 2016 4175 (4) 377-389 A reference 535 bp barcode sequence from a fragment of the mitochondrial gene cytochrome oxidase I (COI), acquired from specimens of An. neivai Howard, Dyar & Knab, 1913 from its type locality in Panama, was used as a tool for distinguishing this species from others in the subgenus Kerteszia. Comparisons with corresponding regions of COI between An. neivai and other species in the subgenus (An. bellator Dyar & Knab 1906, An. homunculus Komp 1937, An cruzii Dyar & Knab, 1908 and An. laneanus Correa & Cerqueira, 1944) produced K2P genetic distances of 8.3-12.6%, values well above those associated with intraspecific variation. In contrast, genetic distances among 55 specimens from five municipalities in the Colombian Pacific coastal state of Choco were all within the range of 0-2.5%, with an optimized barcode threshold of 1.3%, the limit for unambiguous differentiation of An. neivai. Among specimens from the Choco region, 18 haplotypes were detected, two of which were widely distributed over the municipalities sampled. The barcode sequence permits discrimination of An. neivai from sympatric species and indicates genetic variability within the species; aspects key to malaria surveillance and control as well as defining geographic distribution and dispersion patterns. |
Identification of Blood Meals from Potential Arbovirus Mosquito Vectors in the Peruvian Amazon Basin.
Palermo PM , Aguilar PV , Sanchez JF , Zorrilla V , Flores-Mendoza C , Huayanay A , Guevara C , Lescano AG , Halsey ES . Am J Trop Med Hyg 2016 95 (5) 1026-1030 The transmission dynamics of many arboviruses in the Amazon Basin region have not been fully elucidated, including the vectors and natural reservoir hosts. Identification of blood meal sources in field-caught mosquitoes could yield information for identifying potential arbovirus vertebrate hosts. We identified blood meal sources in 131 mosquitoes collected from areas endemic for arboviruses in the Peruvian Department of Loreto by sequencing polymerase chain reaction amplicons of the cytochrome b gene. Psorophora (Janthinosoma) albigenu, Psorophora (Grabhamia) cingulata, Mansonia humeralis, Anopheles oswaldoi s.l., and Anopheles benarrochi s.l. had mainly anthropophilic feeding preferences; Aedes (Ochlerotatus) serratus, and Aedes (Ochlerotatus) fulvus had feeding preferences for peridomestic animals; and Culex (Melanoconion) spp. fed on a variety of vertebrates, mainly rodents (spiny rats), birds, and amphibians. On the basis of these feeding preferences, many mosquitoes could be considered as potential enzootic and bridge arbovirus vectors in the Amazon Basin of Peru. |
Host-pathogen evolutionary signatures reveal dynamics and future invasions of vampire bat rabies.
Streicker DG , Winternitz JC , Satterfield DA , Condori-Condori RE , Broos A , Tello C , Recuenco S , Velasco-Villa A , Altizer S , Valderrama W . Proc Natl Acad Sci U S A 2016 113 (39) 10926-31 Anticipating how epidemics will spread across landscapes requires understanding host dispersal events that are notoriously difficult to measure. Here, we contrast host and virus genetic signatures to resolve the spatiotemporal dynamics underlying geographic expansions of vampire bat rabies virus (VBRV) in Peru. Phylogenetic analysis revealed recent viral spread between populations that, according to extreme geographic structure in maternally inherited host mitochondrial DNA, appeared completely isolated. In contrast, greater population connectivity in biparentally inherited nuclear microsatellites explained the historical limits of invasions, suggesting that dispersing male bats spread VBRV between genetically isolated female populations. Host nuclear DNA further indicated unanticipated gene flow through the Andes mountains connecting the VBRV-free Pacific coast to the VBRV-endemic Amazon rainforest. By combining Bayesian phylogeography with landscape resistance models, we projected invasion routes through northern Peru that were validated by real-time livestock rabies mortality data. The first outbreaks of VBRV on the Pacific coast of South America could occur by June 2020, which would have serious implications for agriculture, wildlife conservation, and human health. Our results show that combining host and pathogen genetic data can identify sex biases in pathogen spatial spread, which may be a widespread but underappreciated phenomenon, and demonstrate that genetic forecasting can aid preparedness for impending viral invasions. |
Genome of Rhodnius prolixus, an insect vector of Chagas disease, reveals unique adaptations to hematophagy and parasite infection.
Mesquita RD , Vionette-Amaral RJ , Lowenberger C , Rivera-Pomar R , Monteiro FA , Minx P , Spieth J , Carvalho AB , Panzera F , Lawson D , Torres AQ , Ribeiro JM , Sorgine MH , Waterhouse RM , Montague MJ , Abad-Franch F , Alves-Bezerra M , Amaral LR , Araujo HM , Araujo RN , Aravind L , Atella GC , Azambuja P , Berni M , Bittencourt-Cunha PR , Braz GR , Calderon-Fernandez G , Carareto CM , Christensen MB , Costa IR , Costa SG , Dansa M , Daumas-Filho CR , De-Paula IF , Dias FA , Dimopoulos G , Emrich SJ , Esponda-Behrens N , Fampa P , Fernandez-Medina RD , da Fonseca RN , Fontenele M , Fronick C , Fulton LA , Gandara AC , Garcia ES , Genta FA , Giraldo-Calderon GI , Gomes B , Gondim KC , Granzotto A , Guarneri AA , Guigo R , Harry M , Hughes DS , Jablonka W , Jacquin-Joly E , Juarez MP , Koerich LB , Latorre-Estivalis JM , Lavore A , Lawrence GG , Lazoski C , Lazzari CR , Lopes RR , Lorenzo MG , Lugon MD , Majerowicz D , Marcet PL , Mariotti M , Masuda H , Megy K , Melo AC , Missirlis F , Mota T , Noriega FG , Nouzova M , Nunes RD , Oliveira RL , Oliveira-Silveira G , Ons S , Pagola L , Paiva-Silva GO , Pascual A , Pavan MG , Pedrini N , Peixoto AA , Pereira MH , Pike A , Polycarpo C , Prosdocimi F , Ribeiro-Rodrigues R , Robertson HM , Salerno AP , Salmon D , Santesmasses D , Schama R , Seabra-Junior ES , Silva-Cardoso L , Silva-Neto MA , Souza-Gomes M , Sterkel M , Taracena ML , Tojo M , Tu ZJ , Tubio JM , Ursic-Bedoya R , Venancio TM , Walter-Nuno AB , Wilson D , Warren WC , Wilson RK , Huebner E , Dotson EM , Oliveira PL . Proc Natl Acad Sci U S A 2015 112 (48) 14936-14941 Rhodnius prolixus not only has served as a model organism for the study of insect physiology, but also is a major vector of Chagas disease, an illness that affects approximately seven million people worldwide. We sequenced the genome of R. prolixus, generated assembled sequences covering 95% of the genome ( approximately 702 Mb), including 15,456 putative protein-coding genes, and completed comprehensive genomic analyses of this obligate blood-feeding insect. Although immune-deficiency (IMD)-mediated immune responses were observed, R. prolixus putatively lacks key components of the IMD pathway, suggesting a reorganization of the canonical immune signaling network. Although both Toll and IMD effectors controlled intestinal microbiota, neither affected Trypanosoma cruzi, the causal agent of Chagas disease, implying the existence of evasion or tolerance mechanisms. R. prolixus has experienced an extensive loss of selenoprotein genes, with its repertoire reduced to only two proteins, one of which is a selenocysteine-based glutathione peroxidase, the first found in insects. The genome contained actively transcribed, horizontally transferred genes from Wolbachia sp., which showed evidence of codon use evolution toward the insect use pattern. Comparative protein analyses revealed many lineage-specific expansions and putative gene absences in R. prolixus, including tandem expansions of genes related to chemoreception, feeding, and digestion that possibly contributed to the evolution of a blood-feeding lifestyle. The genome assembly and these associated analyses provide critical information on the physiology and evolution of this important vector species and should be instrumental for the development of innovative disease control methods. |
Eco-epidemiological study of an endemic Chagas disease region in northern Colombia reveals the importance of Triatoma maculata (Hemiptera: Reduviidae), dogs and Didelphis marsupialis in Trypanosoma cruzi maintenance.
Cantillo-Barraza O , Garces E , Gomez-Palacio A , Cortes LA , Pereira A , Marcet PL , Jansen AM , Triana-Chavez O . Parasit Vectors 2015 8 (1) 482 BACKGROUND: In Colombia, Rhodnius prolixus and Triatoma dimidiata are the main domestic triatomine species known to transmit T. cruzi. However, there are multiple reports of T. cruzi transmission involving secondary vectors. In this work, we carried out an eco-epidemiological study on Margarita Island, located in the Caribbean region of Colombia, where Chagas disease is associated with non-domiciliated vectors. METHODS: To understand the transmission dynamics of Trypanosoma cruzi in this area, we designed a comprehensive, multi-faceted study including the following: (i) entomological evaluation through a community-based insect-surveillance campaign, blood meal source determination and T. cruzi infection rate estimation in triatomine insects; (ii) serological determination of T. cruzi prevalence in children under 15 years old, as well as in domestic dogs and synanthropic mammals; (iii) evaluation of T. cruzi transmission capacity in dogs and Didelphis marsupialis, and (iv) genetic characterization of T. cruzi isolates targeting spliced-leader intergene region (SL-IR) genotypes. RESULTS: Out of the 124 triatomines collected, 94 % were Triatoma maculata, and 71.6 % of them were infected with T. cruzi. Blood-meal source analysis showed that T. maculata feeds on multiple hosts, including humans and domestic dogs. Serological analysis indicated 2 of 803 children were infected, representing a prevalence of 0.25 %. The prevalence in domestic dogs was 71.6 % (171/224). Domestic dogs might not be competent reservoir hosts, as inferred from negative T. cruzi xenodiagnosis and haemoculture tests. However, 61.5 % (8/13) of D. marsupialis, the most abundant synanthropic mammal captured, were T. cruzi-positive on xenodiagnosis and haemocultures. CONCLUSIONS: This study reveals the role of peridomestic T. maculata and dogs in T. cruzi persistence in this region and presents evidence that D. marsupialis are a reservoir mediating peridomestic-zoonotic cycles. This picture reflects the complexity of the transmission dynamics of T. cruzi in an endemic area with non-domiciliated vectors where active human infection exists. There is an ongoing need to control peridomestic T. maculata populations and to implement continuous reservoir surveillance strategies with community participation. |
Molecular Epidemiology of Plasmodium falciparum Malaria Outbreak, Tumbes, Peru, 2010-2012.
Baldeviano GC , Okoth SA , Arrospide N , Gonzalez RV , Sanchez JF , Macedo S , Conde S , Tapia LL , Salas C , Gamboa D , Herrera Y , Edgel KA , Udhayakumar V , Lescano AG . Emerg Infect Dis 2015 21 (5) 797-803 During 2010-2012, an outbreak of 210 cases of malaria occurred in Tumbes, in the northern coast of Peru, where no Plasmodium falciparum malaria case had been reported since 2006. To identify the source of the parasite causing this outbreak, we conducted a molecular epidemiology investigation. Microsatellite typing showed an identical genotype in all 54 available isolates. This genotype was also identical to that of parasites isolated in 2010 in the Loreto region of the Peruvian Amazon and closely related to clonet B, a parasite lineage previously reported in the Amazon during 1998-2000. These findings are consistent with travel history of index case-patients. DNA sequencing revealed mutations in the Pfdhfr, Pfdhps, Pfcrt, and Pfmdr1 loci, which are strongly associated with resistance to chloroquine and sulfadoxine/pyrimethamine, and deletion of the Pfhrp2 gene. These results highlight the need for timely molecular epidemiology investigations to trace the parasite source during malaria reintroduction events. |
Virology, immunology and pathology of human rabies during treatment.
Caicedo Y , Paez A , Kuzmin I , Niezgoda M , Orciari LA , Yager PA , Recuenco S , Franka R , Velasco-Villa A , Willoughby RE Jr . Pediatr Infect Dis J 2014 34 (5) 520-8 BACKGROUND: Rabies is an acute fatal encephalitis caused by all members of the Lyssavirus genus. The first human rabies survivor without benefit of prior vaccination was reported from Milwaukee in 2005. We report a second unvaccinated patient who showed early recovery from rabies and then died accidentally during convalescence, providing an unparalleled opportunity to examine the histopathology as well as immune and virological correlates of early recovery from human rabies. METHODS: Case report, rapid fluorescent focus inhibition test, enzyme-linked immunosorbent assay, indirect and direct fluorescent antibody assays, reverse-transcriptase polymerase chain reaction, phylogenetic reconstruction, isolation in tissue culture, pathology and immunohistochemistry. RESULTS: The 9 year old died 76 days after presenting with rabies of vampire bat phylogeny transmitted by cat bite. Antibody response in serum and CSF was robust and associated with severe cerebral edema. No rabies virus was cultured at autopsy. Rabies virus antigen was atypical in size and distribution. Rabies virus genome was present in neocortex but absent in brainstem. CONCLUSIONS:: Clinical recovery was associated with detection of neutralizing antibody and clearance of infectious rabies virus in the CNS by 76 days, but not clearance of detectable viral subcomponents such as nucleoprotein antigen or RNA in brain. |
Detection of North American orthopoxviruses by real time-PCR.
Gallardo-Romero NF , Velasco-Villa A , Weiss SL , Emerson GL , Carroll DS , Hughes CM , Li Y , Karem KL , Damon IK , Olson VA . Virol J 2011 8 313 The prevalence of North American orthopoxviruses in nature is unknown and may be more difficult to ascertain due to wide spread use of vaccinia virus recombinant vaccines in the wild. A real time PCR assay was developed to allow for highly sensitive and specific detection of North American orthopoxvirus DNA in animal tissues and bodily fluids. This method is based on the amplification of a 156 bp sequence within a myristylated protein, highly conserved within the North American orthopoxviruses but distinct from orthologous genes present in other orthopoxviruses. The analytical sensitivity was 1.1 fg for Volepox virus DNA, 1.99 fg for Skunkpox virus DNA, and 6.4 fg for Raccoonpox virus DNA with a 95% confidence interval. Our assay did not cross-react with other orthopoxviruses or ten diverse representatives of the Chordopoxvirinae subfamily. This new assay showed more sensitivity than tissue culture tests, and was capable of differentiating North American orthopoxviruses from other members of Orthopoxvirus. Thus, our assay is a promising tool for highly sensitive and specific detection of North American orthopoxviruses in the United States and abroad. |
Human peripheral blood B-cell compartments: A crossroad in B-cell traffic
Perez-Andres M , Paiva B , Nieto WG , Caraux A , Schmitz A , Almeida J , Vogt Jr RF , Marti GE , Rawstron AC , Van Zelm MC , Van Dongen JJ , Johnsen HE , Klein B , Orfao A . Cytometry B Clin Cytom 2010 78 Suppl 1 S47-60 A relatively high number of different subsets of B-cells are generated through the differentiation of early B-cell precursors into mature B-lymphocytes in the bone marrow (BM) and antigen-triggered maturation of germinal center B-cells into memory B-lymphocytes and plasmablasts in lymphoid tissues. These B-cell subpopulations, which are produced in the BM and lymphoid tissues, recirculate through peripheral blood (PB), into different tissues including mucosa and the BM, where long-living plasma cells produce antibodies. These circulating PB B-cells can be classified according to their maturation stage into i) immature/transitional, ii) naive, and iii) memory B-lymphocytes, and iv) plasmablasts/plasma cells. Additionally, unique subsets of memory B-lymphocytes and plasmablasts/plasma cells can be identified based on their differential expression of unique Ig-heavy chain isotypes (e.g.: IgM, IgD, IgG, IgA). In the present paper, we review recent data reported in the literature about the distribution, immunophenotypic and functional characteristics of these cell subpopulations, as well as their distribution in PB according to age and seasonal changes. Additional information is also provided in this regard based on the study of a population-based cohort of 600 healthy adults aged from 20 to 80 years, recruited in the Salamanca area in western Spain. Detailed knowledge of the distribution and traffic of B-cell subsets through PB mirrors the immune status of an individual subject and it may also contribute to a better understanding of B-cell disorders related to B-cell biology and homeostasis, such as monoclonal B-cell lymphocytosis (MBL). |
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