Laboratory-Based Prospective Surveillance for Community Outbreaks of Shigella spp. in Argentina

Background: To implement effective control measures, timely outbreak detection is essential. Shigella is the most common cause of bacterial diarrhea in Argentina. Highly resistant clones of Shigella have emerged, and outbreaks have been recognized in closed settings and in whole communities. We hereby report our experience with an evolving, integrated, laboratory-based, near real-time surveillance system operating in six contiguous provinces of Argentina during April 2009 to March 2012. Methodology To detect localized shigellosis outbreaks timely, we used the prospective space-time permutation scan statistic algorithm of SaTScan, embedded in WHONET software. Twenty three laboratories sent updated Shigella data on a weekly basis to the National Reference Laboratory. Cluster detection analysis was performed at several taxonomic levels: for all Shigella spp., for serotypes within species and for antimicrobial resistance phenotypes within species. Shigella isolates associated with statistically significant signals (clusters in time/space with recurrence interval ≥365 days) were subtyped by pulsed field gel electrophoresis (PFGE) using PulseNet protocols. Principal Findings In three years of active surveillance, our system detected 32 statistically significant events, 26 of them identified before hospital staff was aware of any unexpected increase in the number of Shigella isolates. Twenty-six signals were investigated by PFGE, which confirmed a close relationship among the isolates for 22 events (84.6%). Seven events were investigated epidemiologically, which revealed links among the patients. Seventeen events were found at the resistance profile level. The system detected events of public health importance: infrequent resistance profiles, long-lasting and/or re-emergent clusters and events important for their duration or size, which were reported to local public health authorities. Conclusions/Significance: The WHONET-SaTScan system may serve as a model for surveillance and can be applied to other pathogens, implemented by other networks, and scaled up to national and international levels for early detection and control of outbreaks

Prevalence, associated risk factors, and antimicrobial resistance profiles of non-typhoidal Salmonella in large scale swine production in Córdoba, Argentina

Fil: Vico, J. P. Universidad Católica de Córdoba. Facultad de Ciencias Agropecuarias, Veterinaria. Instituto de Investigaciones en Recursos Humanos y Sustentabilidad, José Sánchez Labrador S.J.; Córdoba, Argentina.Fil: Lorenzutti, A. M. Universidad Católica de Córdoba. Facultad de Ciencias Agropecuarias, Veterinaria. Instituto de Investigaciones en Recursos Humanos y Sustentabilidad, José Sánchez Labrador S.J.; Córdoba, Argentina.Fil: Zogbi, A. P. Universidad Católica de Córdoba. Facultad de Ciencias Agropecuarias, Veterinaria. Instituto de Investigaciones en Recursos Humanos y Sustentabilidad, José Sánchez Labrador S.J.; Córdoba, Argentina.Fil: Aleu, G. Universidad Católica de Córdoba. Facultad de Ciencias Agropecuarias, Veterinaria. Instituto de Investigaciones en Recursos Humanos y Sustentabilidad, José Sánchez Labrador S.J.; Córdoba, Argentina.Fil: Sánchez, I. C. Universidad Católica de Córdoba. Facultad de Ciencias Agropecuarias, Veterinaria. Instituto de Investigaciones en Recursos Humanos y Sustentabilidad, José Sánchez Labrador S.J.; Córdoba, Argentina.Fil: Caffer, M. I. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Servicio de Enterobacterias; Argentina.Fil: Rosmini, M. R. Universidad Nacional del Litoral, Facultad de Ciencias Veterinarias; Santa Fe, Argentina.Fil: Mainar-Jaime, R. C. Universidad de Zaragoza. Instituto Agroalimentario de Aragón - IA2. Facultad de Veterinaria. Departamento de Patología Animal; España.Non-typhoidal Salmonella is considered a major public health concern. The growing relevance of pigs as reservoir of Salmonella spp. has prompted several countries to set up surveillance and control programs to fight Salmonella infection in swine and reduce public health risk. In the last decade, pork production in Córdoba increased significantly to become one of the most important pig production provinces in Argentina. The aim of this study was to estimate Salmonella spp. prevalence and associated risk factors in large scale-farms in this province. Mesenteric lymph nodes (MLN) of 580 pigs from 20 finishing large-scale farms were collected between 2014 and 2015 to estimate Salmonella infection. A prevalence of 41.5% (95%CI: 37.6-45.6%) was observed. Two major risk factors were significantly associated with Salmonella infection, both related to the pre-slaughter period (distance from the farm to the slaughterhouse and lairage time), highlighting the need to pay special attention to pre-slaughter practices in the province. Shortening transport times and complying with national regulations for lairage time at slaughter may help to reduce the prevalence of infection. Sixteen different serovars were identified, being S. Anatum and S. Typhimurium the most prevalent ones. Moreover, two isolate of the monophasic variant of Salmonella Typhimurium (I 4,5,12:i:-) resistant to enrofloxacin and which also displayed multidrug resistance was isolated for first time from pigs in Córdoba. The moderate to high levels of antimicrobial resistance detected for antibiotics commonly used in the pig sector suggested the need for implementing a plan to limit their use in the province

Aislamiento de Salmonella typhimurium a partir de guacamayas azul y amarillo (Ara ararauna) muertas

Dos polluelos de guacamayas azul y amarillo (Ara ararauna) murieron por una salmonelosis fatal en la Provincia de Buenos Aires, Argentina. Las aves se examinaron por histopatología y microbiología. La Salmonella enterica subespecies enterica serovar Typhimurium fue aislada de hígado, bazo, corazón, pulmón, riñón e intestino de ambas aves. Todas las cepas fueron susceptibles a ampicilina, cefalotina, cefotaxima, enrofloxacina, ácido nadilixico, gentamicina, estreptomicina, cloranfenicol, fosfomicina, tetraciclina, nitrofurantoina y la combinación trimetoprim-sulfametoxazol. El perfil XbaI de la Salmonella Typhimurium aislada de los dos animales que compartían la misma jaula fueron idénticos mediante electroforesis en gel de campos pulsantes (por sus siglas en inglés PFGE), y mostraron un patrón único comparado con 301 aislamientos que están incluidos en la base de datos nacional de patrones de PFGE de Salmonella, denominada PulseNet. Este es el primer reporte que describe casos fatales de salmonelosis en guacamayas azul y amarillo.Two blue and gold macaw (Ara ararauna) chicks died of fatal salmonellosis in Buenos Aires Province, Argentina. The birds were histopathologically and microbiologically examined. Salmonella enterica subspecies enterica serovar Typhimurium was isolated from the liver, spleen, heart, lung, kidney, and intestine of both birds. All strains were susceptible to ampicillin, cephalothin, cefotaxime, enrofloxacin, nalidixic acid, gentamicin, streptomycin, chloramphenicol, fosfomycin, tetracycline, nitrofurantoin, and trimethoprim-sulfamethoxazole. The XbaI-PFGE profile of the Salmonella Typhimurium isolated from the two animals, which shared the same cage, was identical and showed a unique pattern compared with 301 isolates included in the PulseNet national database of Salmonella pulsed-field gel electrophoresis patterns. This is the first report that describes fatal cases of salmonellosis from blue and gold macaws.Fil: Vigo, Germán Blás. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Microbiología. Cátedra de Microbiología; ArgentinaFil: Origlia, Javier Anibal. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Cátedra de Patología de Aves y Pilíferos; ArgentinaFil: Gornatti Churria, Carlos Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Cátedra de Patología de Aves y Pilíferos; ArgentinaFil: Piscopo, Miguel Victor. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Cátedra de Patología de Aves y Pilíferos; ArgentinaFil: Salve, Angela. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorios e Institutos de Salud. Instituto Nacional de Enfermedades Infecciosas; ArgentinaFil: Caffer, María I.. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorios e Institutos de Salud. Instituto Nacional de Enfermedades Infecciosas; ArgentinaFil: Pichel, Mariana. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorios e Institutos de Salud. Instituto Nacional de Enfermedades Infecciosas; ArgentinaFil: Binsztein, Norma. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorios e Institutos de Salud. Instituto Nacional de Enfermedades Infecciosas; ArgentinaFil: Leotta, Gerardo Anibal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentin

Events with epidemiologic evidence.

<p>Prov/Lab: Province/Laboratory.</p><p>LA: Latin America.</p

Time series of cases of <i>Shigella sonnei</i> isolates detected by SaTScan programme from December 2009 to March 2010.

<p>The rectangle highlights the time series of cases corresponding to the detection and evolution of Event 7.</p

Dendrogram showing the genetic relatedness of isolates of <i>S. flexneri</i> 2 included in Event 1 and 6.

<p>Isolates recovered in Santa Rosa, La Pampa (Event 1 and 6), and selected isolates for comparison, including one from an outbreak in San Luis and three from sporadic cases in 2009. The rectangle highlights isolates of <i>S. flexneri</i> 2 recovered in March–April 2009 (Event 1) and October–November 2009 (Event 6).</p

Geographic distribution of laboratories including in this study.

<p>The 23 participating laboratories of six provinces of Argentina are indicated with a green circle : 11 hospitals in the three contiguous provinces HAC, BAR, HAZ and HGR from Río Negro province (RN); HLM, HGC from La Pampa province (LP); HHH, NEU, HJA, HNB, SMA from Neuquén province (NEU); and with a red circle: 12 additional hospitals from the three additional contiguous provinces: PJC, RFB, IMC, HST, VIL, HDF and VSW from Córdoba province; PVM and HSL of San Luis province and H09, NOT and HTS from Mendoza province.</p

Detection of events of <i>Shigella</i> by the SaTScan software, January 2012–March 2012 period.

<p>MFP: (the most frequent pattern).</p>a<p>: % indistinguishable isolates with the first enzyme and confirmed with the second enzyme.</p>b<p>: bands of difference (bd) to the MFP.</p

Dendrogram showing the genetic relatedness of <i>S. sonnei</i> SXT resistant isolates included in the Event 7.

<p>Isolates recovered in Santa Rosa, La Pampa in January – February 2010. The rectangle highlights the 7 <i>S. sonnei</i> isolates with an indistinguishable PFGE pattern which had not previously been recorded in the National Data Base (NDB). The remaining 7 isolates identified statistically and epidemiologically as part of Event 7, exhibited high genetic relatedness (from 91.4 to 97.4% similarity, 1 to 3 bands of difference) to the most frequent pattern within the event, confirming the relation of the cases.</p

Settings of the WHONET-SaTScan surveillance system over the April 2009–March 2012.

<p>Settings of the WHONET-SaTScan surveillance system over the April 2009–March 2012.</p