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PubMedDate not supplied

First documented outbreak of hepatitis E virus transmission in Java, Indonesia.

A suspected hepatitis outbreak occurred in Bondowoso District, East Java Province, Indonesia, in March-May 1998. An investigation was initiated in April 1998, involving a retrospective review of hospital records, a community-based cross-sectional study, and a health service-based case detection and household follow-up. Sera and epidemiological information were collected from 962 individuals: 235 from 3 outbreak-affected communities along the same rural stretch of river, 101 from community controls living distant from the river, 151 cases detected in health centres, 141 family members of the cases, and 334 subjects from neighbouring families. The prevalence of acute hepatitis E virus (HEV), based on anti-HEV IgM, total antibody (Ig) to HEV and polymerase chain reaction (PCR), was significantly (P < 0.00001) higher (52.4%) among the outbreak communities than among the community controls (3%). The background prevalence of HEV, based on anti-HEV IgG, was also significantly (P < 0.00001) higher (47%) among the outbreak communities than among the community controls (3%). None of the 476 sera screened for anti-HAV (hepatitis A virus) IgM was positive. These results indicate that HEV was the aetiological agent responsible for the outbreak. The overall attack rate (AR) for the 3 outbreak-affected communities surveyed was 19%, with AR determined on the basis of clinically recognized, acute jaundice illness. The usage of river water as primary source for bathing, human-waste disposal, and drinking purposes differed significantly (P < 0.00001) between the communities in outbreak areas and those in non-outbreak areas. There is no significant influence attributed to 'boiling water' on acute HEV. No climatic influences (flooding or drought) predisposed this instance of epidemic HEV transmission. This outbreak represents the first documented evidence of epidemic HEV transmission in Java, Indonesia.

Adolescent↗
PubMed2003

Outbreaks of typhoid fever in the United States, 1960-99.

Although the incidence of typhoid fever in the United States has been low since the 1940s, Salmonella Typhi continues to cause outbreaks. We reviewed reported outbreaks of typhoid fever from 1960 to 1999. There were 60 outbreaks; in 54, exposure occurred within the United States. These 54 outbreaks accounted for 957 total cases (median 10) and 4 deaths. In 36 (67%) outbreaks the route of transmission was identified, and in 16 (62%) of the 26 foodborne outbreaks an asymptomatic carrier was identified by culture or serology. The median incubation period was 2 weeks. Isolates from 10 (40%) of 25 outbreaks were phage type E1. The average frequency of outbreaks decreased from 1.85/year during 1960-79 to 0.85/year during 1980-99 (P=0.0001). S. Typhi outbreaks in the United States are generally small in size but can cause significant morbidity, and are often foodborne, warranting thorough investigation.

Adolescent↗
PubMed1999

Outbreaks of enterotoxigenic Escherichia coli infection in American adults: a clinical and epidemiologic profile.

Because enterotoxigenic Escherichia coli (ETEC) is not identified by routine stool culture methods, ETEC outbreaks may go unrecognized, and opportunities for treatment and prevention may be missed. To improve recognition of adult ETEC outbreaks, we compared them with reported outbreaks of viral gastroenteritis. During 1975-95, we identified 14 ETEC outbreaks in the United States and 7 on cruise ships, caused by 17 different serotypes and affecting 5683 persons. Median symptom prevalences were: diarrhoea 99%, abdominal cramps 82%, nausea 49%, fever 22%, vomiting 14%. The median incubation period was 42 h, and for 8 of 10 outbreaks, the mean or median duration of illness was > 72 h (range 24-264). For 17 (81%) ETEC outbreaks, but for only 2 (8%) viral outbreaks, the prevalence of diarrhoea was > or = 2.5 times the prevalence of vomiting. ETEC outbreaks may be differentiated from viral gastroenteritis outbreaks by a diarrhoea-to-vomiting prevalence ratio of > or = 2.5 and a longer duration of illness.

Adult↗
PubMed2002

Surveillance of foodborne outbreaks of infectious intestinal disease in England and Wales 1992-1999: contributing to evidence-based food policy?

Between 1992 and 1999, a total of 1426 general outbreaks of infectious intestinal disease reported to the Public Health Laboratory Service (PHLS) Communicable Disease Surveillance Centre (CDSC) were described as foodborne. Where the evidence base to support the conclusions drawn was provided (66.3% of outbreaks) a combination of microbiological and analytical evidence was reported in 4% of outbreaks (60/1426); microbiological evidence alone in 10% of outbreaks (149/1426); analytical evidence alone in 23% of outbreaks (322/1426); microbiological evidence in combination with descriptive epidemiology in 3% of outbreaks (46/1426) and descriptive epidemiology alone in 26% of outbreaks (365/1426). Information supplied to CDSC by local investigators appears to be of varying quality and depth and may be influenced by the individual characteristics of outbreaks such as size and duration, outbreak setting, causative organism, vehicles of infection and time of year. These findings have implications for the use of these surveillance data in developing evidence-based food policy.

Communicable Diseases↗
PubMed2004

Investigation of outbreaks of highly pathogenic H5N1 avian influenza in waterfowl and wild birds in Hong Kong in late 2002.

Outbreaks of highly pathogenic H5N1 avian influenza have occurred in Hong Kong in chickens and other gallinaceous poultry in 1997, 2001, twice in 2002 and 2003. High mortality rates were seen in gallinaceous birds but not in domestic or wild waterfowl or other wild birds until late 2002 when highly pathogenic H5N1 avian influenza occurred in waterfowl (geese, ducks and swans), captive Greater Flamingo (Phoenicopterus ruber) and other wild birds (Little Egret Egretta garzetta) at two waterfowl parks and from two dead wild Grey Heron (Ardea cinerea) and a Black-headed Gull (Larus ridibundus) in Hong Kong. H5N1 avian influenza virus was also isolated from a dead feral pigeon (Columba livia) and a dead tree sparrow (Passer montanus) during the second outbreak. The first waterfowl outbreak was controlled by immediate strict quarantine and depopulation 1 week before the second outbreak commenced. Control measures implemented for the second outbreak included strict isolation, culling, increased sanitation and vaccination. Outbreaks in gallinaceous birds occurred in some live poultry markets concurrently with the second waterfowl outbreak, and infection on a chicken farm was detected 1 week after the second waterfowl park outbreak was detected, on the same day the second grey heron case was detected. Subsequent virus surveillance showed the outbreaks had been contained.

Animals↗
PubMed2006

A role of high impact weather events in waterborne disease outbreaks in Canada, 1975 - 2001.

Recent outbreaks of Escherichia coli O157:H7, Campylobacter, and Cryptosporidium have heightened awareness of risks associated with contaminated water supply. The objectives of this research were to describe the incidence and distribution of waterborne disease outbreaks in Canada in relation to preceding weather conditions and to test the association between high impact weather events and waterborne disease outbreaks. We examined extreme rainfall and spring snowmelt in association with 92 Canadian waterborne disease outbreaks between 1975 and 2001, using case-crossover methodology. Explanatory variables including accumulated rainfall, air temperature, and peak stream flow were used to determine the relationship between high impact weather events and the occurrence of waterborne disease outbreaks. Total maximum degree-days above 0 degrees C and accumulated rainfall percentile were associated with outbreak risk. For each degree-day above 0 degrees C the relative odds of an outbreak increased by a factor of 1.007 (95% confidence interval [CI] = 1.002 - 1.012). Accumulated rainfall percentile was dichotomized at the 93rd percentile. For rainfall events greater than the 93rd percentile the relative odds of an outbreak increased by a factor of 2.283 (95% [CI] = 1.216 - 4.285). These results suggest that warmer temperatures and extreme rainfall are contributing factors to waterborne disease outbreaks in Canada. This could have implications for water management and public health initiatives.

Animals↗
PubMed2004

An outbreak of conjunctivitis due to a novel unencapsulated Streptococcus pneumoniae among military trainees.

BACKGROUND: Bacterial conjunctivitis usually occurs as sporadic cases; outbreaks are uncommon and usually are associated with school campuses. We report an outbreak of Streptococcus pneumoniae conjunctivitis at a military training facility. METHODS: An outbreak investigation was done. Each case of conjunctivitis was evaluated with an assessment tool including demographic and clinical data. Conjunctival swabs were obtained. Pneumococci underwent standard testing, including serotyping with the Quellung reaction, capsular staining, and multilocus sequence typing. Sequence types were compared with previous reported outbreak strains by construction of dendrograms. Carriage rates of S. pneumoniae were determined among previously undiagnosed case patients with conjunctivitis, and a case-control study was performed. Control measures included education to increase hand washing, distribution of alcohol-based hand gel, and prompt treatment of patients with conjunctivitis. RESULTS: During a 6-week period, 92 cases of conjunctivitis occurred among 3500 persons, with an attack rate of 1.75 cases per 100 person-months. Eighty cases (87%) were due to S. pneumoniae; 45 (49%) were confirmed, and 35 (38%) were probable. Ten percent of recruits surveyed carried the outbreak strain. Twenty-two percent self-reported symptoms consistent with conjunctivitis during the outbreak period; sharing washcloths was associated with conjunctivitis (odds ratio, 11.7; P=.03). The causative organism was resistant to azithromycin but susceptible to telithromycin. The outbreak strain was an unencapsulated S. pneumoniae that has not been previously described; it was most closely related to the sequence type causing the Dartmouth College (Hanover, NH) outbreak of conjunctivitis in 2002. CONCLUSIONS: We report a conjunctivitis outbreak among military trainees caused by a novel, unencapsulated strain of S. pneumoniae.

Adolescent↗
PubMed2003

Analysis of three outbreaks due to Klebsiella species in a neonatal intensive care unit.

OBJECTIVE: To investigate the clinical, microbiological, and epidemiologic features of three outbreaks caused by Klesiella during 3 years. SETTING: Neonatal intensive care unit of a university hospital. PATIENTS: Thirty affected neonates. METHODS: Data were collected through chart reviews and conversations with physicians. Screening samples were obtained from the staff, the neonates, and the environment. Antibiogram typing and arbitrarily primed polymerase chain reaction-based fingerprinting were used to type the strains. RESULTS: The first outbreak had 13 K. pneumoniae strains isolated. The second outbreak had 10 K. oxytoca strains isolated. The third outbreak had 20 K. pneumoniae strains isolated. More than half of the patients had low birth weights, were premature, and underwent mechanical ventilation and intravenous catheterization. Approximately three-fourths of the patients died. The isolates tested were completely susceptible to meropenem, cefoxitin, and ciprofloxacin and were resistant to cephalothin. More than half of these strains were resistant to many beta-lactam antibiotics, amikacin, and trimethoprim/sulfamethoxazole. Typing procedures yielded 3 antibiotypes and 3 genotypes among the isolates of the first outbreak, 3 antibiotypes with 1 subtype and 2 genotypes with 1 subtype in the second outbreak, and 2 antibiotypes and 2 genotypes in the third outbreak. CONCLUSIONS: Klebsiella outbreaks mainly affected premature neonates with intravenous catheters, mechanical ventilation, or both. The high mortality rate (76.7%) was notable. Resistance to multiple antibiotics, but mainly to broad-spectrum beta-lactam antibiotics, was observed, particularly in K. pneumoniae isolates. Molecular typing indicated that the three outbreaks were not related to one other.

Anti-Bacterial Agents↗
PubMed2006

Management of an outbreak of Clostridium difficile-associated disease among geriatric patients.

OBJECTIVE: To describe a nosocomial outbreak of Clostridium difficile-associated disease (CDAD). DESIGN: A traditional outbreak investigation. SETTING: Geriatric department of a tertiary care teaching hospital from March through April 2003. METHODS: The outbreak was detected by the C. difficile surveillance program of the infection control unit. CDAD was diagnosed by stool culture and fecal toxin A detection with a qualitative rapid immunoassay. Isolates of C. difficile were serotyped and genotyped using pulsed-field gel electrophoresis. RESULTS: The incidence of CDAD increased from 27 cases per 100,000 patient-days in the 6-month period before the outbreak to 99 cases per 100,000 patient-days during the outbreak. This outbreak involved 21 of 92 patients in 4 geriatric wards, which were located at 2 geographically distinct sites and staffed by the same medical team. The mean age of patients was 83 years (range, 71-100 years). Five (24%) of the 21 patients had community-acquired diarrhea, and secondary hospital transmission resulted in 3 clusters involving 16 patients. Serotyping and genotyping were performed on isolates in stool specimens from 19 different patients; 16 of these isolates were serotype A1, whereas 3 displayed profiles different from the outbreak strain. Management of this outbreak consisted in reinforcement of contact isolation precautions for patients with diarrhea, cohorting of infected patients in the same ward, and promotion of hand hygiene. Relapses occurred in 6 (29%) of 21 patients. CONCLUSION: Control of this rapidly developing outbreak of CDAD was obtained with early implementation of cohorting and ward closure and reinforcement of environmental disinfection, hand hygiene, and enteric isolation precautions.

Aged↗
PubMed1998

Measles outbreaks in Micronesia, 1991 to 1994.

BACKGROUND: Several islands in Micronesia experienced large measles outbreaks, during 1991 through 1994. Except for Guam, none of the islands had reported measles outbreaks during the previous 20 years. METHODS: To characterize the outbreaks, measles surveillance data, hospital records and death certificates were reviewed. Preoutbreak vaccination coverage rates were assessed by reviewing public health vaccination records. Viral isolates were genetically sequenced to determine the source of transmission. Linear regression analysis was performed to assess the effectiveness of outbreak control measures. RESULTS: Between 1991 and 1994 more than 1300 measles cases and 16 measles-related deaths were reported in Micronesia. Preoutbreak vaccination coverage rates among 2-year-old children were 55 to 94%. Genetic sequencing of the viral isolates and epidemiologic investigations suggested transmission between islands and new importations from outside of Micronesia. The highest attack rates were among children ages < 5 years (20/1000) and 10 to 19 years (38/1000). Compared with attack rates among children ages < 1 and 10 to 19 years, attack rates were lower among those ages 5 to 9 years, in whom 2-dose vaccination coverage rates were highest (P < 0.001). Early and rapid implementation of mass vaccination campaigns was significantly associated with shorter duration of outbreaks (P = 0.049). CONCLUSION: The measles outbreaks in Micronesia show that island populations may be highly susceptible to measles. High two-dose vaccination coverage levels must be maintained to prevent such outbreaks. Early and rapidly implemented mass measles vaccination campaigns were effective in control of island outbreaks. Strengthening public health infrastructure and surveillance is necessary for early identification of outbreaks and rapid implementation of mass campaigns.

Adolescent↗
PubMed2006

Multiple outbreaks of dengue serotype 2 in north Queensland, 2003/04.

OBJECTIVES: To describe the various investigations and responses to multiple outbreaks of dengue serotype 2 that occurred in north Queensland in 2003/04. METHODS: Details about each case were collated so as to target mosquito-control responses including control of mosquito breeding sites, interior spraying of selected premises, and a novel 'lure and kill' approach using lethal ovitraps. Phylogenetic analyses were undertaken to determine the genetic relatedness of viruses isolated during the outbreaks. RESULTS: Except for a two-month hiatus in mid-2003, the outbreaks continued for 16 months and included approximately 900 confirmed cases, with three severe cases and one death. The available evidence suggests that the mosquito-control measures were effective, but delays in recognising the outbreaks in Cairns and the Torres Strait coupled with intense mosquito breeding contributed to the extensive nature of the outbreaks. Phylogenetic analyses showed that there had been only two major outbreaks, one that spread from Cairns to Townsville, the other from the Torres Strait to Cairns; both were initiated by viraemic travellers from Papua New Guinea. CONCLUSIONS: Phylogenetic analyses were essential in understanding how the outbreaks were related to each other, and in demonstrating that dengue had not become endemic. Further innovative approaches to dengue surveillance and mosquito control in north Queensland are necessary. IMPLICATIONS: Dengue outbreaks have become more frequent and more severe in north Queensland in recent years, raising the possibility that dengue viruses could become endemic in the region leading to outbreaks of dengue haemorrhagic fever.

Aedes↗
PubMed1996

[Characterization of Salmonella ser. enteritidis phage type 34 isolated from food poisoning outbreaks in Tokyo by epidemiological makers].

Since 1989, outbreaks of Salmonella ser. Enteritidis food poisoning has dramatically increased in Tokyo, and a total of 95 outbreaks has been reported between 1989 and 1993. As the results of examination of phage type by the method of Ward, et al., strains isolated from 31 (32.6%) of 95 outbreaks were phage type 34 which is a very rare type in Europe and America. To characterize these unique strains of phage type (PT) 34, 302 isolates obtained from patients and vehicle foods of the outbreaks, eggs and environments in Tokyo were examined for plasmid DNA profiles and antimicrobial resistance patterns. Plasmid DNA was extracted by the Kado's method, and analysed by agalose gel electrophoresis. Antimicrobial susceptibility was tested for CP, TC, SM, KM, ABPC, NA, SXT, FOM and NFLX by the K-B disc method. The strains of PT 34 were further subdivided to 4 types by plasmid profile and antibiogram. The prevalent pattern of PT 34 strains was type plasmid profile which carried 2 different plasmids (> 250 and 60 kb) and was streptomysin-resistant. A total of 28 (90.3%) of 31 outbreaks were found to be caused by this specific type of Salmonella ser. Enteritidis. Several kinds of egg-related foods were suspected for the vehicles of transmission among 12 outbreaks. Especially, in 5 outbreaks, this specific type (type B plasmid profile and streptomysin resistant) of Salmonella ser. Enteritidis strains were isolated both from patients and incriminated food which were cooked with eggs. The phase type of Salmonella ser. Enteritidis strains isolated from raw egg and poultry or environmental specimens from poultry farm showed that the prevailing phage types were almost the same as those of foods poisoning outbreaks. This strongly suggests that these foods may be considered as a source of infection in Salmonella ser. Enteritidis outbreaks.

Anti-Bacterial Agents↗
PubMed2001

[The trends of Vibrio parahaemolyticus foodborne outbreaks in Tokyo: 1989-2000].

The total number of foodborne outbreaks due to Vibrio parahaemolyticus in Tokyo during the last 12 years between 1989 and 2000 were 710. The number of outbreaks in a year was 55 in 1989, 75 in 1990, and there was a gradual decrease to 24 outbreaks in 1993 which was the smallest number during those 12 years. After 1994, the number of outbreaks increased dramatically year by year until 1998 (107 outbreaks). Then they had decreased slightly to 74 in 1999, 65 in 2000. The monthly incidence of V. parahaemolyticus foodborne outbreaks showed a peak in August (44.2%) each year. In the last 12 years, 88.7% of V. parahaemolyticus foodborne outbreaks occurred during the 3 months between July and September, while 99.9% occurred between June and October. The most prevalent serotype of V. parahaemolyticus also changed, the most prevalent was O4:K4 in 1989, O4:K8 in both 1990 and 1991, O1:K56 in 1992, and O4:K8 from 1993 through 1995. Serotype O3:K6 became the most prevalent in 1996 and has remained so to date. In addition, the new serotype O4:K68 had also appeared in 1998. The number of outbreaks due to serotype O4:K68 followed that of O3:K6. Thus, the trends of V. parahaemolyticus foodborne outbreaks during the last 12 years in Tokyo showed various characteristics and dramatic changes in causal organisms.

Disease Outbreaks↗
PubMed1994

Laboratory investigation of a multistate food-borne outbreak of Escherichia coli O157:H7 by using pulsed-field gel electrophoresis and phage typing.

Two hundred thirty-three isolates of Escherichia coli O157:H7 were analyzed by both pulsed-field gel electrophoresis (PFGE) and bacteriophage typing. All 26 isolates from persons whose illness was associated with a recent multistate outbreak of E. coli O157:H7 infections linked to the consumption of undercooked hamburgers and all 27 isolates from incriminated lots of hamburger meat had the same phage type and the same PFGE pattern. Twenty-five of 74 E. coli O157:H7 isolates from Washington State and 10 of 27 isolates from other states obtained during the 6 months before the outbreak had the same phage type as the outbreak strain, but only 1 isolate had the same PFGE pattern. PFGE thus appeared to be a more sensitive method than bacteriophage typing for distinguishing outbreak and non-outbreak-related strains. The PFGE patterns of seven preoutbreak sporadic isolates and five sporadic isolates from the outbreak period differed from that of the outbreak strain by a single band, making it difficult to identify these isolates as outbreak or non-outbreak related. Phage typing and PFGE with additional enzymes were helpful in resolving this problem. While not as sensitive as PFGE, phage typing was helpful in interpreting PFGE data and could have been used as a simple, rapid screen to eliminate the need for performing PFGE on unrelated isolates.

Animals↗
PubMed2001

Evaluation of pulsed-field gel electrophoresis in epidemiological investigations of meningococcal disease outbreaks caused by Neisseria meningitidis serogroup C.

Since 1990, the frequency of Neisseria meningitidis serogroup C (NMSC) outbreaks in the United States has increased. Based on multilocus enzyme electrophoresis (MEE), the current molecular subtyping standard, most of the NMSC outbreaks have been caused by isolates of several closely related electrophoretic types (ETs) within the ET-37 complex. We chose 66 isolates from four well-described NMSC outbreaks that occurred in the United States from 1993 to 1995 to evaluate the potential of pulsed-field gel electrophoresis (PFGE) to identify outbreak-related isolates specific for each of the four outbreaks and to differentiate between them and 50 sporadic isolates collected during the outbreak investigations or through active laboratory-based surveillance from 1989 to 1996. We tested all isolates collected during the outbreak investigations by four other molecular subtyping methods: MEE, ribotyping (ClaI), random amplified polymorphic DNA assay (two primers), and serotyping and serosubtyping. Among the 116 isolates, we observed 11 clusters of 39 NheI PFGE patterns. Excellent correlation between the PFGE and the epidemiological data was observed, with an overall sensitivity of 85% and specificity of 71% at the 95% pattern relatedness breakpoint using either 1.5 or 1.0% tolerance. For all four analyzed outbreaks, PFGE would have given public health officials additional support in declaring an outbreak and making appropriate public health decisions.

Arizona↗
PubMed2003

Utility of multilocus sequence typing as an epidemiological tool for investigation of outbreaks of gastroenteritis caused by Campylobacter jejuni.

Multilocus sequence typing (MLST) has been proven useful for the study of the global population structure of Campylobacter jejuni; however, its usefulness for the investigation of outbreaks of disease caused by C. jejuni has not been proven. In this study, MLST plus sequencing of the flaA short variable region (SVR) were applied to 47 isolates from 12 outbreaks of C. jejuni infection whose relatedness has been determined previously, and the results were compared to those of serotyping and pulsed-field gel electrophoresis (PFGE). Isolates implicated in an outbreak were indistinguishable by all four subtyping methods, with sporadic isolates being distinguished from outbreak isolates. Two sporadic isolates from one outbreak were resistant to SmaI digestion and therefore nontypeable by PFGE but were differentiated from the outbreak strain by the other methods. PFGE and flaA SVR typing were the most discriminatory methods, with discriminatory indices (DI) of 0.930 and 0.923, respectively. However, an epidemic strain from one outbreak was distinguished from the other outbreak isolates by flaA SVR typing; its flaA allele was different at five nucleotides, suggesting that this change was possibly mediated by recombination. MLST was less discriminatory than PFGE and flaA SVR typing (DI = 0.859), and many of the epidemic strains possessed common sequence types (STs) including ST-8, -21, -22, and -42. However, further discrimination within STs was achieved by flaA SVR typing or PFGE. The results from this study demonstrate that a combined approach of MLST plus flaA SVR typing provides a level of discrimination equivalent to PFGE for outbreak investigations.

Animals↗
PubMed2004

Computer-assisted surveillance for detecting clonal outbreaks of nosocomial infection.

Whole-house surveillance for healthcare-associated infection is no longer the recommended practice because of the large personnel time investment required. We developed a computer-based tracking system using microbiologic data as an aid in detecting potential outbreaks of healthcare-associated infections on a hospital-wide basis. Monthly total isolates of 25 clinically significant hospital pathogens were tallied from 1991 to 1998 to form a database for future comparison. Two different algorithm tools (based on increases of organism numbers over baseline) were applied to determine alert thresholds for suspected outbreaks using this information. The first algorithm (2SD) defined an alert as two standard deviations above the mean monthly number of isolates. The second (MI) defined an alert as either a 100% increase from the baseline organism number over 2 months or a >/=50% increase (compared to baseline) during a three-consecutive-month period. These two methods were compared to standard infection control professional surveillance (ICP) for the detection of clonal outbreaks over 12 months. Overall, a total of seven clonal outbreaks were detected during the 1-year study. Using standard methods, ICP investigated nine suspected outbreaks, four of which were associated with clonal microbes. The 2SD method signaled a suspected outbreak 15 times, of which three were clonal and ICP had detected one. The MI method signaled a suspected outbreak 30 times; four of these were clonal, and ICP had detected one. The sensitivity and specificity values for ICP, 2SD, and MI for detecting clonal outbreaks were 57, 43, and 57% and 17, 83, and 67%, respectively. Statistical methods applied to clinical microbiology laboratory information system data efficiently supplement infection control efforts for outbreak detection.

Algorithms↗
PubMedDate not supplied

[Descriptive study of hepatitis outbreaks occurring in Catalonia (1999-2003)].

BACKGROUND AND OBJECTIVE: The currently low endemic level of hepatitis A in Spain favors manifestation of the disease as outbreaks among specific risk groups. The aim of this study is to analyze the hepatitis A outbreaks investigated in Catalonia (Spain) during the period of 1999 to 2003. METHODS: The criteria for including an outbreak were defined and outbreaks were classified according to the type of transmission. The variables analyzed were space, time, socio-demographic parameters, setting, risk factors, and preventive measures adopted. The incidence rate and rate ratio were calculated according to age and sex. RESULTS: Among 74 outbreaks, 73 fulfilled the inclusion criteria. Most outbreaks involved person-to-person transmission (83.8%) and the rest had a common source of infection (14.9%). In total, 334 cases were included (cumulative incidence 1999-2003: 5.27 per 100,000 inhabitants), with an average age of 24.5 years. The settings yielding the most cases were family (143), community (97) and schools/preschools (87). The number of cases per outbreak ranged from 2 to 11, except one outbreak that occurred in 83 young homosexual men with high-risk sexual practices. The main factors related to the case index or to coprimary cases included belonging to age groups with low immunity (children and young adults) and travelling to or from endemic areas. CONCLUSION: Hepatitis A outbreaks in Catalonia are still frequent. They mainly occur in the family environment, by person-to-person transmission and in the most vulnerable groups (preschool or school employees, travelers, and men who perform high-risk sexual practices with other men).

Adolescent↗