Epidemiological Investigation Of Outbreak Research Articles

Epidemiological Outbreaks of Pneumocystis jirovecii Pneumonia Are Not Limited to Kidney Transplant Recipients: Genotyping Confirms Common Source of Transmission in a Liver Transplantation Unit.

Over a 5-month period, four liver transplant patients at a single hospital were diagnosed with Pneumocystis jirovecii pneumonia (PCP). This unusually high incidence was investigated using molecular genotyping. Bronchoalveolar lavage fluids (BALF) obtained from the four liver recipients diagnosed with PCP were processed for multilocus sequence typing (MLST) at three loci (SOD, mt26s, and CYB). Twenty-four other BALF samples, which were positive for P. jirovecii and collected from 24 epidemiologically unrelated patients with clinical signs of PCP, were studied in parallel by use of the same method. Pneumocystis jirovecii isolates from the four liver recipients all had the same genotype, which was different from those of the isolates from all the epidemiologically unrelated individuals studied. These findings supported the hypothesis of a common source of contamination or even cross-transmission of a single P. jirovecii clone between the four liver recipients. Hospitalization mapping showed several possible encounters between these four patients, including outpatient consultations on one particular date when they all possibly met. This study demonstrates the value of molecular genotyping of P. jirovecii isolated from clinical samples for epidemiological investigation of PCP outbreaks. It is also the first description of a common source of exposure to a single P. jirovecii clone between liver transplant recipients and highlights the importance of prophylaxis in such a population.

Kingella kingae infections can cluster among young children in close contact

Over the last few decades Kingella kingae has ascended in the family of pathogenic bacteria from a rare cause of endocarditis to a relatively common cause of osteoarticular infections in children younger than 4 years of age. Fastidious nature of growth in culture likely hampered establishing the organism's rightful place among infectious diseases in children. Molecular diagnostic techniques now available will permit a better assessment of the role(s) of K kingae in an expected wider spectrum of infections and across continents. To date, much of what is known of the clinical epidemiology of disease and colonization patterns in young children are from studies in Israel. In this issue of The Journal, Yagupsky et al add another Kingella insight from studying daycares in relatively close communities in Israel in which contact is intense. They found clustering of disease, in association with clonal spread of presumably more pathogenic strains, and high oropharyngeal transmissibility among colleagues under 24 months of age. Article page 135▶ Outbreaks of Invasive Kingella kingae Infections in Closed CommunitiesThe Journal of PediatricsVol. 169PreviewTo describe the results of the epidemiologic investigation of outbreaks of invasive Kingella kingae infections among attendees at daycare facilities located in 4 closed communities in Israel. Full-Text PDF

Epidemiological investigation and containment measures of a dengue fever outbreak in an institutional set up in South India

Epidemiological investigation and containment measures of a dengue fever outbreak in an institutional set up in South India

Antibiotic Resistance and Molecular Characterization of Seafood Isolates of Nontyphoidal Salmonella by PFGE

Emergence of multidrug resistant nontyphoidal Salmonella is a major health concern worldwide due to the predominant occurrence of Salmonella enterica sub-species enterica serovar Typhimurium phage type 104 (DT104) conferring resistance to ampicillin, chloramphenicol, streptomycin, sulphonamide and tetracycline. Apart from antibiotic resistance, the identification and genotypic characterization of pathogens is essential for epidemiological surveillance and outbreak investigations. In this study 39 isolates of Salmonella obtained from seafood samples were examined for their susceptibility to various antibiotics and subjected to PFGE analysis using the restriction enzyme Xba1. The highest percentage resistance was for erythromycin (100%) followed by nalidixic acid (15.38%), co-trimoxazole (15.38%), chloramphenicol (12.82%), ampicillin (12.82%) and tetracycline (10.25%). Six (15.38%) of the 39 isolates were multidrug resistant. The XbaI digested chromosomal DNA generated 7 clusters suggesting the presence of diverse Salmonella strains in seafood. The Discriminatory Index for PFGE obtained by XbaI restriction enzyme was 0.91. The PFGE has been found highly discriminatory for subtyping S. Weltevreden and S. Newport. The XbaI PFGE was not only discriminatory but could also distinguish multidrug-resistant strains from the sensitive ones as the two groups they belonged to different pulsotypes. The study also demonstrated multiple clones of S. Weltevreden, S. Newport and S. Oslo present in seafood from the south west coast of India. Genetic diversity among the similar seafood sources suggests the presence of different clones of Salmonella which further increases the risk of seafood being a potential source of highly pathogenic bacteria like Salmonella.

The baseline characteristics and interim analyses of the high-risk sentinel cohort of the Vietnam Initiative on Zoonotic InfectiONS (VIZIONS).

The Vietnam Initiative for Zoonotic Infections (VIZIONS) includes community-based ‘high-risk sentinel cohort’ (HRSC) studies investigating individuals at risk of zoonotic infection due to occupational or residential exposure to animals. A total of 852 HRSC members were recruited between March 2013 and August 2014 from three provinces (Ha Noi, Dak Lak, and Dong Thap). The most numerous group (72.8%) corresponded to individuals living on farms, followed by slaughterers (16.3%) and animal health workers (8.5%). Nasal/pharyngeal and rectal swabs were collected from HRSC members at recruitment and after notifying illness. Exposure to exotic animals (including wild pigs, porcupine, monkey, civet, bamboo rat and bat) was highest for the Dak Lak cohort (53.7%), followed by Ha Noi (13.7%) and Dong Thap (4.0%). A total of 26.8% of individuals reported consumption of raw blood over the previous year; 33.6% slaughterers reported no use of protective equipment at work. Over 686 person-years of observation, 213 episodes of suspect infectious disease were notified, equivalent of 0.35 reports per person-year. Responsive samples were collected from animals in the farm cohort. There was noticeable time and space clustering of disease episodes suggesting that the VIZIONS set up is also suitable for the formal epidemiological investigation of disease outbreaks.

Outbreaks of Invasive Kingella kingae Infections in Closed Communities

To describe the results of the epidemiologic investigation of outbreaks of invasive Kingella kingae infections among attendees at daycare facilities located in 4 closed communities in Israel. The preschool-aged population of communities with clusters of Kingella cases had oropharyngeal cultures performed. K kingae isolates from infected patients and healthy contacts were genotyped by pulsed field gel electrophoresis to determine the spread of outbreak strains. The affected closed communities (3 military bases and 1 "kibbutz" commune) were characterized by tight social and family networks and intensive mingling. The outbreaks affected 9 of 51 attendees (attack rate: 17.6%) age 8-19 months (median: 12 months), within a 21-day period. Cases included skeletal system infections (n = 8) and bacteremia (n = 1); K kingae isolates were confirmed by the use of blood culture vials and selective media. Clinical presentation was mild and acute-phase reactants were usually normal or only moderately elevated. Thirty out of 55 (54.5%) asymptomatic children carried the outbreak strains. Analysis of the 3 clusters in which the entire preschool-aged population was cultured revealed that 31 of 71 (43.7%) children younger than 24 months of age were colonized with K kingae organisms compared with 8 of 105 (7.6%) older children (P < .001). Clusters of invasive K kingae infections characterized by sudden onset, high attack rate, and wide dissemination of the outbreak strain can occur in daycare facilities and closed communities. Because the mild clinical presentation of invasive K kingae infections and the fastidious nature of the organism, a high index of suspicion and use of sensitive detection methods are recommended.

Highly Pathogenic Avian Influenza H5N8 in Germany: Outbreak Investigations.

Epidemiological outbreak investigations were conducted in highly pathogenic avian influenza virus of the subtype H5N8 (HPAIV H5N8)-affected poultry holdings and a zoo to identify potential routes of entry of the pathogen via water, feedstuffs, animals, people, bedding material, other fomites (equipment, vehicles etc.) and the presence of wild birds near affected holdings. Indirect introduction of HPAIV H5N8 via material contaminated by infected wild bird seems the most reasonable explanation for the observed outbreak series in three commercial holdings in Mecklenburg-Western Pomerania and Lower Saxony, while direct contact to infected wild birds may have led to outbreaks in a zoo in Rostock and in two small free-range holdings in Anklam, Mecklenburg-Western Pomerania.

Improved traceability of Shiga-toxin-producing Escherichia coli using CRISPRs for detection and typing.

Among strains of Shiga-toxin-producing Escherichia coli (STEC), seven serogroups (O26, O45, O103, O111, O121, O145, and O157) are frequently associated with severe clinical illness in humans. The development of methods for their reliable detection from complex samples such as food has been challenging thus far, and is currently based on the PCR detection of the major virulence genes stx1, stx2, and eae, and O-serogroup-specific genes. However, this approach lacks resolution. Moreover, new STEC serotypes are continuously emerging worldwide. For example, in May 2011, strains belonging to the hitherto rarely detected STEC serotype O104:H4 were identified as causative agents of one of the world's largest outbreak of disease with a high incidence of hemorrhagic colitis and hemolytic uremic syndrome in the infected patients. Discriminant typing of pathogens is crucial for epidemiological surveillance and investigations of outbreaks, and especially for tracking and tracing in case of accidental and deliberate contamination of food and water samples. Clustered regularly interspaced short palindromic repeats (CRISPRs) are composed of short, highly conserved DNA repeats separated by unique sequences of similar length. This distinctive sequence signature of CRISPRs can be used for strain typing in several bacterial species including STEC. This review discusses how CRISPRs have recently been used for STEC identification and typing.

Seroprevalence of mumps in an epidemic period in Medellín, Colombia

ObjectiveWe related seroprevalence and outbreaks data in order to identify factors that could explain the occurrence of outbreaks despite high vaccination coverage in Medellín Colombia. MethodsSamples from a population seroprevalence data obtained in 2009 in a random survey were analyzed. IgG levels were determined for mumps using 2 commercial tests of 2119 individuals aged 6–64 years. A comparative analysis was undertaken using age–specific mumps seroprevalence data and information of 98 epidemiological investigations of mumps outbreaks reported in 2009. ResultsOverall, seroprevalence was 91.6% (95% CI=89.3–93.5%). The age-specific seronegativity was 20.3% and 20.6% in age groups 11–15 years and 16–20 years respectively. Individuals aged 6–20 years were the most affected during outbreaks. In individuals born in 2003, a year after the change in the booster schedule from 10 to 5 years, the proportion of unvaccinated individuals (14%) and those who received only one dose of MMR (45%) increased substantially. On average, 23.5 days elapsed between the onset of symptoms in secondary cases and the outbreak investigation. ConclusionPotential contributing factors for the occurrence of outbreaks of mumps were the relatively high prevalence of seronegativity among individuals aged 11–20 years, delays in investigation and control of outbreaks, and incomplete vaccination schedules.

Trends in the longterm dynamics of morbidity of acute intestinal infections and epidemiological features of outbreaks in recent years

There was performed the analysis of long-term dynamics ofmorbidity of certain nosologicalforms ofacute intestinal infections (AII) of the population of the Perm region and the Russian Federation in 2000-2014. There are summarized results of the epidemiological investigation of AII outbreaks recorded in the Perm region in 2009-2014. It was found that in recent years in the territory of the Perm region and the Russian Federation as a whole against the background of significant reduction or stabilization of the population incidence of certain bacterial AII there was noted the gain in the population incidence of viral AII. According to the materials of the Perm region in recent years, there were most frequently recorded food outbreaks of salmonellosis and food outbreaks of norovirus and rotavirus infections involving water as an intermediate factor of transmission.

Diverse Genotypes of Yersinia pestis Caused Plague in Madagascar in 2007.

Background Yersinia pestis is the causative agent of human plague and is endemic in various African, Asian and American countries. In Madagascar, the disease represents a significant public health problem with hundreds of human cases a year. Unfortunately, poor infrastructure makes outbreak investigations challenging.Methodology/Principal FindingsDNA was extracted directly from 93 clinical samples from patients with a clinical diagnosis of plague in Madagascar in 2007. The extracted DNAs were then genotyped using three molecular genotyping methods, including, single nucleotide polymorphism (SNP) typing, multi-locus variable-number tandem repeat analysis (MLVA), and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) analysis. These methods provided increasing resolution, respectively. The results of these analyses revealed that, in 2007, ten molecular groups, two newly described here and eight previously identified, were responsible for causing human plague in geographically distinct areas of Madagascar.Conclusions/SignificancePlague in Madagascar is caused by numerous distinct types of Y. pestis. Genotyping method choice should be based upon the discriminatory power needed, expense, and available data for any desired comparisons. We conclude that genotyping should be a standard tool used in epidemiological investigations of plague outbreaks.

Timeliness of epidemiological outbreak investigations in peer-reviewed European publications, January 2003 to August 2013.

Timely outbreak investigations are central in containing communicable disease outbreaks; despite this, no guidance currently exists on expectations of timeliness for investigations. A literature review was conducted to assess the length of epidemiological outbreak investigations in Europe in peer-reviewed publications. We determined time intervals between outbreak declaration to hypothesis generation, and hypothesis generation to availability of results from an analytical study. Outbreaks were classified into two groups: those with a public health impact across regions within a country and requiring national coordination (level 3) and those with a severe or catastrophic impact requiring direction at national level (levels 4 and 5). Investigations in Europe published between 2003 and 2013 were reviewed. We identified 86 papers for review: 63 level 3 and 23 level 4 and 5 investigations. Time intervals were ascertained from 55 papers. The median period for completion of an analytical study was 15 days (range: 4-32) for levels 4 and 5 and 31 days (range: 9-213) for level 3 investigations. Key factors influencing the speed of completing analytical studies were outbreak level, severity of infection and study design. Our findings suggest that guidance for completing analytical studies could usefully be provided, with different time intervals according to outbreak severity.

Molecular epidemiology of Mycoplasma hyopneumoniae from outbreaks of enzootic pneumonia in domestic pig and the role of wild boar

Mycoplasma hyopneumoniae is the major cause of enzootic pneumonia (EP) in domestic pigs, a disease with low mortality but high morbidity, having a great economic impact for producers. In Switzerland EP has been successfully eradicated, however, sporadic outbreaks are observed with no obvious source. Besides the possibility of recurrent outbreaks due to persisting M. hyopneumoniae strains within the pig population, there is suspicion that wild boars might introduce M. hyopneumoniae into swine herds. To elucidate possible links between domestic pig and wild boar, epidemiological investigations of recent EP outbreaks were initiated and lung samples of pig and wild boar were tested for the presence of specific genotypes by multilocus sequence typing (MLST). Despite generally different genotypes in wild boar, outbreak strains could be found in geographically linked wild boar lungs after, but so far not before the outbreak. Recurrent outbreaks in a farm were due to the same strain, indicating unsuccessful sanitation rather than reintroduction by wild boar. In another case outbreaks in six different farms were caused by the same strain never found in wild boar, confirming spread between farms due to hypothesized animal transport. Results indicate the presence of identical lineages of wild boar and domestic pig strains, and possible transmission of M. hyopneumoniae between wild boar and pig. However, the role of wild boar might be rather one as a recipient than a transmitter. More important than contact to wild boar for sporadic outbreaks in Switzerland is apparently persistence of M. hyopneumoniae within a farm as well as transmission between farms.

Rapid genotyping of beak and feather disease virus using high-resolution DNA melt curve analysis

Beak and feather disease virus (BFDV) is a significant pathogen both for wild and captive psittacine birds globally. Genotypic differentiation of BFDV isolates is crucial to establish effective control strategies for the conservation of endangered species and epidemiological investigations of disease outbreaks. The technique developed in this study is a simple, rapid and inexpensive genotyping method for BFDV using PCR and subsequent high-resolution melt (HRM) curve analysis. This was achieved using PCR amplification of the conserved Rep gene in the presence of a fluorescent DNA intercalating dye (SYTO9). HRM curve analysis of the resultant amplicon could readily differentiate between reference strain (92-SR14) and 18 other BFDV isolates used in this study. Analysis of the nucleotide sequences of the amplicon from each isolate revealed that each melt curve profile was related to a unique DNA sequence. The potential of the PCR–HRM curve analysis to differentiate inter-host genetic variation among critically endangered orange-bellied parrots, lorikeets and cockatoos was also evaluated. Phylogenetic tree topology based on partial Rep gene sequences used in this study showed that BFDV Rep gene sequence patterns were correlated with the results of HRM curve analysis. The results presented in this study indicate that this technique could be used in both clinical research and differentiation of BFDV isolates in a fraction of time without further nucleotide sequencing and provides a novel approach for the genetic screening of BFDV in clinical virology laboratories.

THE OUTBREAK OF PARVOVIRAL INFECTION IN THE TERRITORY OF NORTH-WESTERN FEDERAL REGION OF RUSSIA

Abstract. The results of clinical, epidemiological and laboratory investigation of outbreak of exanthemic infection occurred in the Lomonosov district of Leningrad oblast in May, 2012 are presented in this article. The clinical diagnosis of parvoviral infection was laboratory confirmed by specific IgM antibodies detection in patients’ sera by ELISA. It is emphasized the importance of virological monitoring for viral infections on the stage of measles elimination and sporadic level of rubella cases.

Epidemiologia molecular de surto de raiva bovina na região central do Rio Grande do Sul, 2012

A raiva é uma doença infecciosa do sistema nervoso central de mamíferos causada pelo vírus da raiva (RabV), geralmente, transmitido pela mordedura de animais infectados. No Brasil, os morcegos hematófagos Desmodus rotundus são as principais fontes de infecção do RabV para bovinos e equinos. Este artigo descreve uma investigação epidemiológica e molecular de surtos de raiva ocorridos na região central do Rio Grande do Sul, entre maio e agosto de 2012. Nesse período, 45 casos suspeitos de raiva foram relatados em 22 pequenos rebanhos, localizados dentro de um raio de 4,7km, no município de Pinhal Grande. Desses, 32 amostras foram submetidas para diagnóstico da raiva, sendo que o RabV e/ou antígenos virais foram identificados em 27 amostras. Em um segundo momento, 11 amostras foram submetidas à transcrição reversa/reação em cadeia da polimerase (RT-PCR) para o gene da nucleoproteína (N) do RabV, seguido de sequenciamento nucleotídico e análise filogenética. Sete das 11 amostras apresentaram sequências nucleotídicas idênticas e uma apresentou mutação sinônima, não-codificante, indicando uma provável origem comum dos vírus. Por outro lado, três amostras apresentaram mutações que resultaram em alterações de aminoácidos, sugerindo uma origem diferente do vírus. Esses resultados sugerem que RabV de diferentes origens/linhagens co-circulam na região e foram envolvidos nos surtos descritos. Investigações sobre a circulação de ambos os genótipos em morcegos na região estão em andamento.

Investigation of a Mycobacterium bovis outbreak in cattle at a Colorado dairy in 2010

To describe an epidemiological investigation of a bovine tuberculosis outbreak on a Colorado dairy operation. A cull dairy cow infected with Mycobacterium bovis (index cow) was detected at a Texas abattoir during routine slaughter surveillance and subsequent diagnostic testing. This initiated an epidemiological investigation that was performed in accordance with USDA regulations. The index cow was traced back to a Colorado dairy (index herd). Of the 908 cattle in the index herd, 101 (11.1%; 86 adult cattle > 2 years old and 15 immature cattle ≤ 2 years old) were infected with M bovis. Fourteen M bovis-infected cattle ≤ 2 years old were identified on 5 additional premises that had purchased cattle from the index herd directly or indirectly. All 115 affected cattle were infected with the same genetic type (spoligotype) of M bovis. A substantial proportion of cattle that left the index herd during the 5 years previous to the identification of the index cow were untraceable because of a lack of unique animal identification and inadequate records. Results indicated that neonatal calves can have an important role in the transmission of M bovis. Also, this report highlights the exigent need for unique individual identification of livestock, including neonatal animals, so that thorough epidemiological investigations of reportable (zoonotic or foreign animal) diseases can be conducted when necessary.

Large multistate outbreak of norovirus gastroenteritis associated with frozen strawberries, Germany, 2012

From 20 September through 5 October 2012, the largest recorded food-borne outbreak in Germany occurred. Norovirus was identified as the causative agent. We conducted four analytical epidemiological studies, two case–control studies and two surveys (in total 150 cases) in secondary schools in three different federal states. Overall, 390 institutions in five federal states reported nearly 11,000 cases of gastroenteritis. They were predominantly schools and childcare facilities and were supplied almost exclusively by one large catering company. The analytical epidemiological studies consistently identified dishes containing strawberries as the most likely vehicle, with estimated odds ratios ranging from 2.6 to 45.4. The dishes had been prepared in different regional kitchens of the catering company and were served in the schools two days before the peaks of the respective outbreaks. All affected institutions had received strawberries of one lot, imported frozen from China. The outbreak vehicle was identified within a week, which led to a timely recall and prevented more than half of the lot from reaching the consumer. This outbreak exemplifies the risk of large outbreaks in the era of global food trade. It underlines the importance of timely surveillance and epidemiological outbreak investigations for food safety.

Implementasi Standar Pelayanan Minimal Bidang Kesehatan Di RSUD Kota Baubau

The hospital has a strategic role in the effort to accelerate the improvement of public health degree. The new para-digm of health care requires hospitals provide quality services according to the needs and wishes of the patient with reference to the code of professional conduct and medical. Performance of health care organizations typically use a minimum standard criteria of service in accordance with the Regulation of the Minister of Health No. 741 / Menkes / Per / VII / 2008. These regulations outline covers; a) basic health services, b) health care referrals, c) epidemiological investigation and prevention of outbreaks and d) health promotion and community development. The purpose of this study was to determine the implementation of the minimum service standards in the field of health referral at RSUD Baubau and to determine the factors that affect the minimum service standard reference in the field of health at RSUD Baubau. The method used in this research is descriptive qualitative. The data collection techniques in this research is interview and documentation. Meanwhile, the techniques used to analyze the data in this study is a descriptive analysis techniques. This analysis includes data checking, data grouping, data checking, data analysis and conclusion. The results of this experiment showed that the implementation of the minimum service standards in the field of health referral at RSUD Baubau has been good. A slight lack of implementation of the health sector MSS reference in RSUD Baubau is the amount of human resources required. The factors that affect the implementation of minimum service standard reference in the field of health, namely RSUD Baubau; Communication, disposition and bureaucratic struc-ture. As for the factor of resources because there is still a shortage of only 80% to meet the needs of human resources at RSUD Baubau.

Implementasi Standar Pelayanan Minimal Bidang Kesehatan Di RSUD Kota Baubau

The hospital has a strategic role in the effort to accelerate the improvement of public health degree. The new para-digm of health care requires hospitals provide quality services according to the needs and wishes of the patient with reference to the code of professional conduct and medical. Performance of health care organizations typically use a minimum standard criteria of service in accordance with the Regulation of the Minister of Health No. 741 / Menkes / Per / VII / 2008. These regulations outline covers; a) basic health services, b) health care referrals, c) epidemiological investigation and prevention of outbreaks and d) health promotion and community development. The purpose of this study was to determine the implementation of the minimum service standards in the field of health referral at RSUD Baubau and to determine the factors that affect the minimum service standard reference in the field of health at RSUD Baubau. The method used in this research is descriptive qualitative. The data collection techniques in this research is interview and documentation. Meanwhile, the techniques used to analyze the data in this study is a descriptive analysis techniques. This analysis includes data checking, data grouping, data checking, data analysis and conclusion. The results of this experiment showed that the implementation of the minimum service standards in the field of health referral at RSUD Baubau has been good. A slight lack of implementation of the health sector MSS reference in RSUD Baubau is the amount of human resources required. The factors that affect the implementation of minimum service standard reference in the field of health, namely RSUD Baubau; Communication, disposition and bureaucratic struc-ture. As for the factor of resources because there is still a shortage of only 80% to meet the needs of human resources at RSUD Baubau.