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PubMed2006

Salmonella Montevideo outbreak in military kennel dogs caused by contaminated commercial feed, which was only recognized through monitoring.

A large outbreak of canine salmonellosis in military watch dogs due to Salmonella Montevideo and/or Salmonella Give was only recognized through a monitoring program, implemented by the military forces. In 51 out of 80 exposed dogs (63.8%) from four kennels Salmonella was isolated from fecal samples. The prevalence per sampling day ranged from 5.6 to 77.8%. Clinical disease with mild diarrhea but without fever appeared only in nine dogs (11.3% of study population, 16.9% of cases) from one kennel (***P < 0.001). Risk analysis identified "dog food A" (odds ratio 3.33 [1.12 < OR < 10.06] *P < 0.05) and "dog food C" (odds ratio 3.40 [1.07 < OR < 11.22] *P < 0.05), two commercial dehydrated dog feeds, as suspected infectious sources. Feeding "dog food C" alone or together with "dog food A" was significantly associated with clinical disease (***P < 0.001). S. Montevideo and S. Give with similar plasmid profiles and PFGE-restriction patterns were isolated from the suspected dog feeds and fecal samples. This outbreak demonstrates not only that Salmonella infections in dogs occur without clinical symptoms but also that large outbreaks occur after feeding dehydrated dog feeds. Especially in households with known risk group patients this finding demonstrates a particular risk for their owners, as they often live in close contact with their animals.

Animal Feed↗

PubMed2006

Severe outbreak of disease in the southern chamois (Rupicapra pyrenaica) associated with border disease virus infection.

An outbreak of a previously unreported disease affecting southern chamois (Rupicapra pyrenaica) in the central Pyrenees (NE Spain) was recorded in 2001 and 2002. There was a marked temporal distribution, most animals being found between February and June. After the outbreak, the population was found to have decreased by about 42%, most probably due to the disease. We examined 20 affected chamois. Clinical manifestations included depression, weakness and movement difficulties in all cases. Three chamois presented abnormal behaviour, with absence of flight reaction, and 16 showed different degrees of alopecia with skin hyperpigmentation. At necropsy cachexia was observed in all animals, four chamois had abscesses in different parts of the body, four had pneumonia, one had an extensive subcutaneous infection on the head and neck and one had severe orchitis. Microscopic lesions were found in the brain, mainly edema, gliosis, espongiosis, cariorrexis and neuronal multifocal necrosis. A perivascular mononuclear inflammatory infiltrate was present in three of them. Skin lesions included marked follicular atrophy, mild to moderate epidermal hyperplasia with orthokeratotic hyperkeratosis and follicular hyperkeratosis, and hypermelanosis. In 13 chamois there were haemosiderin deposits in the spleen, and in three individuals kidney "cloissone" was observed. Intraeritrocitic parasites were detected either by direct observation or PCR in 8 of 17 chamois. A pestivirus was isolated and detected by RT-PCR from 12 of 13 affected chamois and antigenic characterized as border disease virus by monoclonal antibodies. This is the first time a border disease virus has been associated with an outbreak of a high-mortality disease in a wild species.

Animals↗

PubMed2005

Outbreak of trichinellosis associated with consumption of game meat in West Greenland.

The Inuit population of the Arctic has always been at risk of acquiring trichinellosis and severe outbreaks have been recorded in Alaska and Canada. In West Greenland, a number of large outbreaks took place during the 1940s and 1950s; they involved total 420 cases including 37 deaths. Since then only sporadic cases have been reported. Here, we describe an outbreak of infection with Trichinella spp. after consumption of infected meat presumably from walrus or polar bear caught in western Greenland. Six persons who had eaten of the walrus and polar bear meat were two males and four females, age range 6--47 years. Using ELISA and Western blot analysis (Trichinella-specific IgG antibodies against excreted/secreted antigen and synthetic tyvelose antigen, respectively) four of these persons were found to be sero-positive for Trichinella antibodies, with three of these having clinical symptoms compatible with trichinellosis. On re-test, 12--14 months later one of the two sero-negative persons had sero-converted, probably due to a new, unrelated infection. This study demonstrates that acquiring Trichinella from the consumption of marine mammals remains a possibility in Greenland, and that cases may go undetected. Trichinellosis in Greenland can be prevented by the implementation of public health measures.

Adult↗

PubMed2002

Molecular characterization of Vibrio cholerae O1 outbreak strains in Miri, Sarawak (Malaysia).

Bacterial resistance to various antimicrobial agents is common in area with high usage of antibiotics. In this study, the data on antimicrobial susceptibility patterns of Vibrio cholerae O1 from patients during an outbreak period was found to be high but variable rates of multidrug resistance. Thirty-two of 33 V. cholerae isolates harboured the tcp, ctx, zot and ace genes, suggesting their possible roles in the outbreak cases. We analyzed the molecular diversity of a total of 33 strains of V. cholerae O1 isolated from 33 patients between November 1997 and April 1998 using random amplified polymorphic DNA (RAPD) analysis. The 30 typable isolates could be separated into four major clusters containing 5, 17, 2 and 6 isolates, respectively. However, no particular RAPD pattern was predictive of a particular pattern of antibiotic susceptibility. The findings of this study showed that multiple clones seemed to be responsible for cases in the outbreaks in the study area.

Cholera↗

PubMed1997

Preliminary observations on factors responsible for long persistence and continued outbreaks of plague in Lushoto district, Tanzania.

Human plague has been an important public health problem in Tanzania for over a century. Recorded outbreaks of the disease have been reported from various parts of Tanzania, including Iringa, Kagera, Singida, Mbulu, Arusha and Kilimanjaro since 1886. Since 1980 however, only Lushoto, Singida and Karatu districts have experienced outbreaks of the disease. Of these areas, Lushoto has disproportionately high incidences of the disease and this has persisted for nearly 17 years. Efforts to curb the disease through conventional methods, including control of vectors and reservoirs, chemotherapy and chemoprophylaxis, enforcement of sanitation improvement as well as health education, have been applied every year, but plague cases and deaths continue to occur in the area to date. During the period April 1980 to December 1996, a total of 6599 cases with 580 (8.8%) deaths were recorded. Biological factors, such as the presence of suitable rodent reservoirs, efficient flea vectors and plague bacillus, could be partly responsible for the long persistence and recurrence of the disease. Since such factors are also common in other plague foci where the disease has never been persistently recurrent, and where indigenous people are culturally different from those in Lushoto, it is assumed that socio-cultural factors play an important role as determinants of the disease in the latter district. This paper reports preliminary observations on socio-cultural, biological and environmental factors which are thought to be, at least partly, responsible for the long persistence and repeated outbreaks of plague in the district. These include traditional beliefs on the cause and health seeking behaviour for treatment of plague, sleeping and food storage habits, large populations of rodents and fleas, and status of the immediate environment.

Adult↗

PubMed2006

[Waterborne outbreak of gastroenteritis caused by Norovirus transmitted through drinking water].

BACKGROUND: The aim of this study was to conduct an investigation into an outbreak of waterborne disease caused by Norovirus due to the consumption of contaminated drinking water. METHODS: The first week after the school summer holidays we detected an outbreak of gastroenteritis at a school in Borges Blanques (Lleida, Spain). A retrospective cohort study was carried out to investigate: water consumption and food (six items). We assessed RNA Norovirus by RT-PCR in 6 stool samples. The risk of gastroenteritis was assessed by applying adjusted risk ratio (RRa) analysis at 95% confidence intervals (CI). RESULTS: The overall attack rate was 45% (96/213). The main symptoms were: abdominal pain, 88.4% (84/95); nausea, 65.9% (62/94), and vomiting, 64.6% (62/96). The consumption of school drinking water was statistically associated with the disease (RRa: 2.8; 95% CI: 1.3-6.2). The school water tank was dirty, but this drinking water was qualified as potable. Six stool samples gave positive results for Norovirus. CONCLUSIONS: Norovirus caused this waterborne outbreak of gastroenteritis transmitted through treated drinking water. It should be obligatory to regularly clean school drinking water deposit tanks, especially after the summer holidays.

Adolescent↗

PubMed1993

An extended outbreak of infectious peritonitis in a closed colony of European wildcats (Felis silvestris).

Feline infectious peritonitis is a multisystemic disease of domestic and exotic cats caused by a coronavirus. An outbreak of feline infectious peritonitis was investigated in a closed colony of European wildcats (Felis silvestris) at a zoological garden. Over a six-year period, a putative fading kitten syndrome occurred in six of 11 litters born and severe lesions of infectious peritonitis occurred in five of the eight wildcats retained in the colony during this period. Lesions were more acute in the early stages of the outbreak and included perivascular pyogranulomatous inflammation with exudative serositis. Lesions occurred only in males. Vascular lesions were common in the liver of all affected wildcats, serositis occurred in the abdominal and thoracic cavities in most cases and meningeal lesions were present in two cases. Immunohistochemistry with specific antisera detected viral antigen within macrophages in all lesions. This outbreak demonstrates that the lesions of feline infectious peritonitis can become modified over time and that the virus can persist in a closed colony, possibly via carrier wildcats.

Animals↗

PubMed1991

Mumps outbreak in a highly vaccinated population.

From October 1988 to April 1989, a large mumps outbreak occurred in Douglas County, Kansas. Of the 269 cases, 208 (77.3%) occurred among primary and secondary school students, of whom 203 (97.6%) had documentation of mumps vaccination. Attack rates were highest for students attending junior high school (8.0%), followed by high school (2.0%) and elementary school (0.7%). A retrospective cohort study conducted at one junior high school with an attack rate of 12.9% did not find age at vaccination or type of vaccine received (single or combined antigen) to be risk factors for vaccine failure. Students vaccinated more than 4 years before the outbreak appeared to have a higher attack rate than those vaccinated more recently (relative risk (RR) = 4.3; 95% confidence interval (CI) = 0.6, 30.0); however, this association did not exist when risk was evaluated based on number of vaccine doses received. Students who had documentation of receiving only one dose of vaccine were at greater risk than those who had received two doses (RR = 5.2; 95% CI = 1.0, 206.2). Overall, vaccine effectiveness among Douglas County junior high school students was estimated to be 83% (95% CI = 57%, 94%). These data suggest that mumps vaccine failure and the failure to vaccinate have contributed to the relative resurgence of mumps observed in the United States since 1986. The recent change in immunization policy to recommend a two-dose schedule of measles-mumps-rubella vaccine should help reduce the occurrence of mumps outbreaks in highly vaccinated populations.

Age Factors↗

PubMed1992

Outbreak of Candida bloodstream infections associated with retrograde medication administration in a neonatal intensive care unit.

An outbreak of candidemia involving five infants receiving total parenteral nutrition in the neonatal intensive care unit was investigated. Cultures of the intravenous fluids demonstrated that the retrograde medication syringe fluids were significantly more likely to be contaminated with Candida than were other fluids being administered to the infants (p less than 0.001). Candidemia was significantly associated with total parenteral nutrition (p = 0.04) and retrograde medication administration (p = 0.02). A survey of nursing practice found that reuse of the retrograde syringes was the most likely cause of contamination. Molecular typing showed that the strains of Candida albicans that were isolated from the bloodstream were also found in the retrograde syringes and that at least three strains of C. albicans and one strain each of Candida tropicalis and Candida parapsilosis were involved. In vitro growth curves demonstrated that Candida species had a selective growth advantage versus bacteria in the total parenteral nutrition fluid. An in vitro simulation of the retrograde medication administration system suggested that the outbreak probably developed after the frequency of changing intravenous tubing was decreased from every 24 hours to every 72 hours. The outbreak was terminated by using syringes only once and resuming intravenous tubing changes every 24 hours. Retrograde medication administration in association with total parenteral nutrition may increase the risk of Candida line infection.

Candida↗

PubMed1998

An outbreak of salmonellosis among children attending a reptile exhibit at a zoo.

OBJECTIVE: In January 1996, an outbreak of diarrhea caused by Salmonella Enteritidis occurred in children attending a Komodo dragon exhibit at a metropolitan zoo. We sought to determine the extent of the outbreak and mode of transmission. STUDY DESIGN: A case-control study was conducted. Controls were randomly selected from zoo membership lists and matched to patients by age group and date of exhibit visit. RESULTS: Of 65 patients identified, 39 had confirmed and 26 had suspected cases. The median age was 7 years (range, 3 months to 48 years); 55% were enrolled in the case-control study. No patients and two (4%) controls reported touching a dragon; however, 83% of patients but only 52% of controls touched the wooden barrier that surrounded the dragon pen (odds ratio = 4.0, 95% CI 1.2 to 13.9). Washing hands at the zoo after visiting the dragons was highly protective (OR = 0.14, 95% CI 0.03 to 0.7). Cultures from the patients, one dragon, and the exhibit barriers yielded Salmonella Enteritidis, phage type 8. On the basis of an attack rate of 4.3% among exhibit attendees under 13 years old on whom data were collected, we estimate that 315 additional cases of salmonellosis occurred among visitors in this age group. CONCLUSION: This large outbreak demonstrates the importance of environmental contamination in the transmission of Salmonella from reptiles, and the protective value of hand washing. Recommendations regarding reptile exhibits and reptilian pets should emphasize this indirect route.

Adolescent↗

PubMed2002

[Nosocomial epidemic outbreak of acute gastroenteritis by Norwalk-like virus].

BACKGROUND: From the notification of an acute gastroenteritis outbreak in a nursing home, an epidemiological study was started to determine the characteristics of the outbreak and its spreading pattern and to identify determining factors. PATIENTS AND METHOD: A study of historic cohorts was performed and the case was defined by the presence of diarrhea and vomiting. Spatial aggregation in double rooms was analyzed by a binomial distribution and temporal aggregation was analyzed by a relative risks model. The variables in the study allowed us to calculate the adjusted relative risk; the odds ratio was calculated in relation to the meal on day January 30. RESULTS: We studied 95.9% residents. The total attack rate was 28.7% (31.8% employees, 30.1% permanent residents and 15.2% day residents). The attack rate in rotation health personnel was 45.2%. Spatial and temporal spread in double rooms was negative. There was a significant association with the disease in rotator employees (RR = 3.22; CI 95%, 1.30-7.99; p = 0.02). No association was found between eating and disease (OR = 1.5; CI 95%, 0.4-6.1; p = 0.46). Norwalk-like virus was isolated in four faecal samples. CONCLUSIONS: This epidemic outbreak had the characteristic of a nosocomial infection with a likely person-to-person transmission mechanism. The main factor contributing to the spread of the infection was the existence of employees in permanent contact with residents with an important physical and mental impairment, hence highly dependent on the care provided by these health workers.

Acute Disease↗

PubMed2002

[Outbreak of foodborne disease by Norwalk-like viruses genogroup II].

BACKGROUND: Our goal was to investigate the epidemiological characteristics and etiology of an outbreak of food-borne disease caused by Norwalk-like viruses, genogroup II. PATIENTS AND METHOD: We performed a historical cohort study on the consumption of 21 food items and clinical symptoms. We assessed RNA Norwalk-like viruses by RT- PCR in stool samples from 5 patients and 2 food-handlers. The potential involvement of each food item was assessed by relative risk at 95% confidence intervals (CI). RESULTS: The overall attack rate was 70.0% (7/10). The median incubation period was 35.0 hours. Symptoms included: vomits 85.7% (6/7), fever 85.7% (6/7) and diarrhoea 71.4% (5/7). Four food items were involved [fish (RR = 1.7; CI 95% 0.9-3.3); 'selection of cold meats' (RR = 1.6; CI 95% 0.9-2.7); yoghurt (RR = 1.5; CI 95% 1.0-2.4) and lamb (RR = 1.3; CI 95% 0.6-3.0)]. Three stool sample gave positive results for Norwalk-like viruses genogroup II. Important oversights in food-handlers' work were detected. CONCLUSIONS: RT-PCR enabled us to confirm the etiology of this outbreak as Norwalk-like viruses genogroup II. Although patients recovered quickly, the outbreak caused considerable public alarm.

Botulism↗

PubMed2002

[Outbreak of gastroenteritis caused by Campylobacter jejuni transmitted through drinking water].

BACKGROUND: The aim of this study was to conduct a clinical-epidemiological and microbiological investigation into an outbreak of waterborne disease caused by Campylobacter jejuni due to the consumption of drinking water. PATIENTS AND METHOD: A historical cohort study was carried out among 237 residents of Torres de Segre (Lleida, Spain) who were selected using a systematic sample. We conducted a telephone interview about water consumption, symptoms and the onset of disease. We investigated samples of drinking water and stools from 14 patients. The risk associated with each water source was assessed by applying relative risk (RR) analysis at 95% confidence (CI) intervals. RESULTS: The overall attack rate was 18.3% (43/237). The symptoms were: diarrhoea, 93.0% (18/43); abdominal pain, 80.9% (34/42); nausea; 56,1% (23/41); vomits, 42.9% (18/42), and fever, 11.9% (5/42). Only 5.8% of patients contact with his physician. The consumption of drinking water was statistically associated with the disease (RR = 3.0; 95% CI, 1.7-5.3), while the consumption of bottled water (RR = 0.6; 95% CI 0.3-1.0) and water from other villages (RR = 0.3; 95% CI, 0.1-1.1) were a protection factor. The day of outbreak notification we did not detect any residual chlorine in the drinking water: it was qualified as no potable and we isolated Campylobacter jejuni in 8 samples stools. CONCLUSIONS: This research highlights the potential importance of waterborne outbreaks of gastroenteritis due to Campylobacter jejuni transmitted through untreated drinking water and suggests to need systematic controls over drinking water and the proper register of their results.

Adolescent↗

PubMed2006

[Norovirus gastroenteritis outbreak by person-to-person transmission in a nursing home].

BACKGROUND AND OBJECTIVE: The aim of this study was to conduct an investigation into an outbreak of gastroenteritis among health workers and residents (with different grades of dependence) at a nursing home. PATIENTS AND METHOD: We detected an outbreak of gastroenteritis in a group of 52 health workers and 124 residents at a nursing home in Oliana, Lleida (Spain). A bidirectional prospective and retrospective cohort study was conducted into the consumption of water, food, grade of dependence (high, medium and low), and specific job. We studied the water supply and six food items. Faecal specimens from 30 patients were cultured and examined for Norovirus by polymerase chain reaction-reverse transcription. The possible implication of different factors associated with gastroenteritis was assessed by relative risk (RR) at 95% confidence intervals (CI). RESULTS: We interviewed 97% of the patients (172/176). The overall attack rate was 53.3% (92/172). The symptoms were: diarrhoea 68.5% (63/92), vomiting 64.1% (59/92), nausea 63.0% (58/92), fever 33.7% (31/92), abdominal pain 28.3% (26/92), and headache 14.1% (13/92). The epidemic curve highlighted transmission for 19 days. The risk factors associated with gastroenteritis were high (RR = 1.6; 95% CI, 1.0-2.6) and medium (RR = 2.8; 95% CI, 1.0-8.0) levels of dependence, health worker with high level of contact with residents (RR = 2.8; 95% CI, 1.1-7.3) and those doing cleaning work (RR = 2.8; 95% CI, 1.0-8.0). Bacterial cultures were negative for samples of food and water. Also, cultures were negative for bacteria in faecal samples but tests were positive for Norovirus in 12 faecal samples. CONCLUSIONS: We showed a Norovirus outbreak in a nursing home, person-to-person spread, associated to high and medium grades of dependence among residents, health worker with high level of contact with them and with those doing cleaning work.

Adult↗

PubMed2006

[Cryptosporidium hominis diarrhea outbreak and transmission linked to diaper infant use].

BACKGROUND AND OBJECTIVE: On the basis of several cases of cryptosporidiosis detected in a child day-care center, we stablished the extent of the outbreak and investigated causes of parasite transmission. PATIENTS AND METHOD: A retrospective cohort study was designed on all children attending day-care center and care givers to determine their infection status and identify risk factors associated to the outbreak. RESULTS: 24 cases of cryptosporidiosis were detected, with an attack rate of 0.46 (24/52); 12 of them were parasitologycally confirmed. All care givers were negative for Cryptosporidium and none of them reported symptoms of acute gastroenteritis. Transmission pattern was compatible with person to person modes. Among the factors investigated, two were associated with the risk of disease: diaper wear (relative risk = 2.06; p = 0.059); and diarrhea in relatives (relative risk = 2.05; p = 0.01). In all confirmed cases, Cryptosporidium hominis (previously known as C. parvum, genotype 1), was identified. CONCLUSIONS: Cryptosporidiosis should be considered as a possible cause of outbreaks of gastroenteritis at day-care centers. Increasing care on diaper changing practices, specially over children with diarrhea, may be the key factor to prevent transmission of Cryptosporidium.

Child Day Care Centers↗

PubMed1993

Measles outbreak in Fife: which MMR policy?

The introduction of measles, mumps and rubella vaccine (MMR) into the United Kingdom childhood immunisation schedule has resulted in a substantial reduction in the incidence of all three diseases. None the less, there have recently been outbreaks of measles in parts of the country which have a record of high MMR uptake among young children. In these outbreaks it is mainly older children who have been affected. This report documents such an outbreak in Fife, an area with a very high MMR uptake among two-year-old children (96%). The current policy of giving MMR vaccine only once to children at 15 months of age may not be sufficient to enable the United Kingdom to achieve the WHO target of measles elimination by the year 2000. Other possible strategies to achieve this objective are discussed.

Adolescent↗

PubMed1992

Outbreak of food poisoning due to Salmonella typhimurium DT4 in mayonnaise.

In July 1989 a large outbreak of food poisoning (68 cases) occurred at a private club in Teddington (London Borough of Richmond-upon-Thames). Initial enquiries indicated that the peak of the outbreak occurred between 20th and 26th July. An epidemiological investigation (using self-completed questionnaires) was set up to determine the probable source of infection. Two groups among those exposed were selected: club staff (129), and cricket teams playing in a club tournament (105). Response rates were 89% and 64% respectively. Overall 50% (89) had gastrointestinal symptoms, including two hospital admissions. A highly significant association was found between illness and eating sandwiches containing mayonnaise. Microbiological investigations found Salmonella typhimurium DT4 in 36 of 68 faecal samples taken. This organism is not usually associated with food poisoning outbreaks. The probable source was identified as a flock of one of the egg suppliers.

Bacterial Typing Techniques↗

PubMed1996

A prolonged outbreak of streptococcal infection among workers at a meat plant.

We describe an outbreak of skin sepsis due to an erythromycin-resistant strain of Streptococcus pyogenes in workers at a meat plant. The outbreak began among butchers in the boning room but subsequently spread to other groups of workers in the plant. Despite the introduction of additional control measures, the outbreak persisted for 7 months and affected 46/194 staff with 'hands on' occupations. Spread of infection from the plant to a retail butcher was documented.

Disease Outbreaks↗