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Neonatal diarrhea of pigs in Quebec: infectious causes of significant outbreaks.

To evaluate the relative importance of the various enteropathogens causing neonatal diarrhea in Quebec farrowing operations, observations were made on 749 diarrheic pigs from 325 outbreaks of diarrhea. They were one to 15 days of age, and were obtained alive for necropsy generally within 48 hours of the onset of diarrhea. Some pigs were from severe, explosive outbreaks of diarrhea with high morbidity and mortality rates, while others were from herds with chronic neonatal diarrhea with lower morbidity and mortality rates. A combination of bacteriological, virological and histological methods were used to study the pigs. Viruses were incriminated in 60%, bacteria in 23% and coccidia in 15.3% of the 325 diarrhea outbreaks. Transmissible gastroenteritis virus was by far the most common enteropathogen with a prevalence of 52%; rotavirus was implicated in 9.2% of the outbreaks while adenovirus was incriminated in 0.30% of the outbreaks. Enterotoxigenic Escherichia coli were involved in 22.4% of the cases while Clostridium perfringens type C was an occasional finding. Coccidia involved in our herds were identified as Isospora suis. The disease was attributed to infection with a single etiologic agent in 590 diarrheic pigs (78%) while combinations of agents were present in only 90 (12%). The age-specific occurrence of the various enteropathogens was evaluated. Transmissible gastroenteritis virus was the most common enteropathogen in all age groups. Colibacillosis was common in pigs which became diarrheic under five days of age; in this age group, the enterotoxigenic E. coli were frequently found alone, but were usually combined with other agents in older pigs. The prevalence of coccidia was high in pigs which became diarrheic between five and 15 days of age. Rotavirus infection was common in diarrheic pigs older than ten days of age. Although individual baby pigs were commonly infected with a single enteropathogen, it was very common to see more than one agent involved in an outbreak of diarrhea, particularly when pigs of different ages were affected. Observations on the occurrence of the enteropathogens according to the seasons were also made. Occurrence of transmissible gastroenteritis was throughout the year with the highest prevalence during the fall, winter and spring months. Colibacillosis and coccidiosis were more common in the summer, fall and early winter months with the lowest prevalence in the spring months.

Adenoviridae↗

[Persistence of virus in swine stock and breeding farms following an outbreak of Aujeszky's disease].

On seven fattening farms and seven breeding farms, investigations were carried out to examine whether Aujeszky virus was capable of persisting in particular animal groups or units of the farm as a productive infection following a virologically verified outbreak. After an outbreak on fattening farms, virus persisted temporarily as newly arrived piglets became systematically infected. On the farms on which this could be accurately followed, virus persistence continued for at least 1 1/2 to 2 months. However, this cycle of infection was found to be interrupted on each farm within approximately three months after the outbreak, which resulted in a gradual return to a totally sensitive animal population, so that new outbreaks could occur. On the seven swine breeding farms, virus persistence in the farrowing house was examined by placing seronegative sentinel piglets with sows during the immediate post-partum period. Twelve sentinel piglets were placed in the various farrowing houses for a total period of sixty-seven weeks, during which time 172 sows farrowed. None of these piglets became seropositive during their stay on the breeding farms. The results of this study show that Aujeszky's disease virus did not persist on breeding farms and that the productive infection on fattening farms in only transient following an outbreak. Therefore, it is very likely that new outbreaks of the disease are due to reintroduction of Aujeszky's disease virus on the farm. Though the role of latent carrier animals cannot be totally disregarded, natural reactivation of latent virus is believed an exception rather than the general rule.

Animals↗

The impact of college prematriculation immunization requirements on risk for measles outbreaks.

OBJECTIVE: To assess whether prematriculation immunization requirements (PIRs) affect the number of measles cases on college campuses. DESIGN: We surveyed a stratified random sample of 880 colleges and universities to determine their immunization policies and practices and occurrence of measles outbreaks from 1988 through 1991. We merged national measles surveillance data with survey data by county to determine the risk for measles introduction on college campuses. We used logistic regression methods to estimate the effect of PIRs and assess risk factors for college measles outbreaks. SETTING: A total of 3205 US colleges and universities listed in standard guides. RESULTS: Of selected schools, 91 (11%) of the 796 responding schools reported one or more measles cases occurring from 1988 through 1991. Schools with a state-mandated PIR were significantly less likely to report measles outbreaks of two or more cases than other institutions (adjusted relative risk [RR] = 0.30; 95% confidence interval [Cl], 0.11 to 0.84). None of the 14 schools that reported outbreaks of 10 or more cases was subject to state regulation or had a PIR specifying two doses of measles vaccine in place. Of schools with introduction of measles, residential colleges were more likely to report extensive spread of measles (five or more cases) than nonresidential colleges (RR = 35.8; 95% Cl, 2.08 to 617.0). Of public schools, 4-year programs had a higher risk of a large outbreak (five or more cases) than 2-year programs. CONCLUSIONS: These results strongly support current recommendations for requiring proof of vaccination of college students to decrease the risk for measles outbreaks on college campuses. State regulations mandating PIRs ensure the best protection against widespread measles transmission.

Adolescent↗

A community-wide outbreak of cryptosporidiosis associated with swimming at a wave pool.

OBJECTIVE: To determine the cause of a community-wide outbreak of cryptosporidiosis. DESIGN: A matched case-control study. SETTING: General community of Lane County, Oregon. PATIENTS AND OTHER PARTICIPANTS: Persons with Cryptosporidium detected in their stool from June to October 1992 were identified by contacting laboratories serving the area. Exposures of the first 18 case patients identified were compared with those of 18 age- and neighborhood-matched controls selected from a reverse telephone directory. MAIN OUTCOME MEASURES: Reported exposures to risk factors for cryptosporidiosis and abatement of cryptosporidiosis outbreak. RESULTS: Fifty-five patients with cryptosporidiosis were detected, including 37 who were the first individuals ill in their households. The case-control study involving the first 18 case patients showed no association between illness and attendance at day care or drinking municipal water or drinking untreated surface waters (river or lake water) in the 2 weeks before onset of illness. However, nine of 18 case patients reported swimming at a local wave pool, compared with none of 18 controls. We ultimately identified 17 case patients who reported swimming at the same wave pool during their incubation periods, whose exposure dates spanned a 2-month period. Inspection of the pool's filtration system did not detect any abnormalities. The outbreak subsided after the pool water was drained and replaced. CONCLUSIONS: This prolonged outbreak of cryptosporidiosis was likely caused by exposure to fecally contaminated wave pool water. Since Cryptosporidium is highly chlorine resistant and inadequately removed by sand filters, such outbreaks may represent an unrecognized hazard of wave pools, where the likelihood of inadvertent water ingestion is high. Such outbreaks may go undetected in areas where cryptosporidiosis is not reportable or laboratory screening is infrequent.

Adolescent↗

Piccadilly Circus legionnaires' disease outbreak.

BACKGROUND: An outbreak of legionnaires' disease occurred in central London in January and February 1989. An Infection Control Committee was established to investigate the outbreak and institute control measures. The objective of this paper is to describe the investigation and control of the outbreak. METHODS: An epidemiological survey and case-control study were carried out. The subjects were cases of community acquired pneumonia associated with central London with onset of illness in January and February 1989. RESULTS: Thirty-three confirmed cases, including five deaths, and ten suspected cases, including three deaths, were identified with dates of onset from 1 January to 11 February. A clustering of visits by cases to the vicinity of Piccadilly Circus was noted, and a case-control study demonstrated a strong association between illness and visits to this area in the two weeks before onset of symptoms. The causative organism, Legionella pneumophila serogroup 1, was isolated from six patients. Legionella pneumophila of the same serogroup was isolated from water samples from five wet cooling systems (cooling towers) in the area under investigation, but in only two systems was the organism indistinguishable by subtyping from the patients' strains. Many of the cooling towers examined were inadequately maintained, including one of the two above a building adjacent to Piccadilly Circus from which a strain indistinguishable from the outbreak strain was isolated. All cooling towers in the area were shut down until inspected, and only allowed to restart after appropriate maintenance had been instigated. CONCLUSIONS: This outbreak showed the continuing risk of legionnaires' disease posed by wet cooling systems, including cooling towers, and highlighted the need to assess this risk so that appropriate maintenance is carried out. Regulations have recently been introduced, under the Health and Safety at Work Act, requiring notification of all wet cooling systems to the local authority to facilitate the investigation of outbreaks of legionnaires' disease.

Adolescent↗

An outbreak of encephalomyocarditis-virus infection in free-ranging African elephants in the Kruger National Park.

A cluster of four deaths in late December 1993, marked the onset of an outbreak of disease of African elephants (Loxodonta africana) in the Kruger National Park (KNP) in South Africa, which has an estimated population of 7,500 elephants. Mortalities peaked in January 1994, with 32 deaths, and then declined steadily to reach pre-outbreak levels by September, but sporadic losses continued until November. During the outbreak altogether 64 elephants died, of which 53 (83%) were adult bulls. Archival records revealed that, in addition to the usual losses from known causes such as poaching and intraspecific fighting, sporadic deaths from unexplained causes had, in fact, occurred in widely scattered locations from at least 1987 onwards, and from that time until the perceived outbreak of disease there had been 48 such deaths involving 33 (69%) adult bulls. Carcases had frequently become decomposed or had been scavenged by the time they were found, but seven of eight elephants examined early in 1994 had lesions of cardiac failure suggestive of encephalomyocarditis (EMC)-virus infection, and the virus was isolated from the heart muscles of three fresh carcases. The results of tests for neutralizing antibody on 362 elephant sera collected for unrelated purposes from 1984 onwards and kept frozen, indicated that the virus had been present in the KNP since at least 1987. Antibody prevalences of 62 of 116 (53%) 18 of 139 (13%) and seven of 33 (21%) were found in elephants in three different regions of the KNP in 1993 and 1994. Studies had been conducted on myomorph rodents in the KNP for unrelated purposes since 1984, and trapping attempts were increased during the perceived outbreak of disease in elephants. There was a striking temporal correlation between the occurrence of a population explosion (as evidenced by markedly increased catch rates per trap-night) and a surge in prevalence of antibody to EM virus in rodents, and the occurrence of the outbreak of disease in elephants.

Animals↗

Meningococcal meningitis group A: a successful control of an outbreak by mass vaccination.

Jeddah is the main point of entry to the holy places in Saudi Arabia. An outbreak of meningococcal disease (MCD) occurred during the fasting lunar month for Muslims, Ramadan (March-April) of 1992. To assess the threat of local spread of MCD within Jeddah, the effects of previous and a mass vaccination programme against MCD during the outbreak, we reviewed the medical records of confirmed cases (CC) of MCD (defined as a bacteriologically confirmed case or a case diagnosed by latex test) and their vaccination status in the last five years before the outbreak. There were 41 CC of meningitis due to Neisseria meningitidis (group A). The ratio of males to females was 4.1:1. Thirty two percent of the cases were religious visitors. About one fourth (22%) of the cases were Pakistani. More than half (57%) of the cases, who were residents of Jeddah, lived in the north-eastern part of the city, as did half of the Pakistani cases. The case-fatality rate among CC was 19.5%. Persons who visited the Makkah (Mecca) during Ramadan were more likely to get the disease than those who did not (odds ratio [OR] = 6.1; 95% confidence interval [CI] 1.4-40.7). Unvaccinated persons were more likely to get the disease than those who were vaccinated against MCD (OR = 13.9; 95% CI 1.8-296). Meningococcal vaccine (MCV) against MCD was effective in preventing the disease. However, MCV was of no protective value if it had been administered more than five years before the outbreak. The reason mentioned most frequently for not being vaccinated by both cases (84%) and controls (57%) was lack of knowledge about the disease. Health education programmes should be strengthened and promoted. A good collaborative surveillance system between Jeddah and other holy cities, especially Makkah, is needed to abort outbreaks among religious visitors and to prevent the spread of MCD outbreaks.

Adolescent↗

Outbreak of measles in a highly vaccinated secondary school population.

OBJECTIVE: To examine the factors associated with measles vaccine effectiveness and the effect of two doses of vaccine on measles susceptibility during an outbreak. DESIGN: Retrospective cohort study. SETTING: A secondary school in the City of Toronto. SUBJECTS: The entire school population (1135 students 14 to 21 years of age). MAIN OUTCOME MEASURES: Risk of measles during an outbreak associated with age at first measles vaccination, length of time since vaccination, vaccination before 1980 and whether date of vaccination was estimated; vaccine efficacy of one dose versus two doses. RESULTS: Eighty-seven laboratory-confirmed or clinically confirmed cases of measles were identified (for an attack rate of 7.7%). The measles vaccination rate was 94.2%, and 10% of the students had received two doses of measles vaccine before the outbreak. Among those who had received only one dose of vaccine, vaccination at less than 15 months of age was associated with vaccine failure (relative risk 3.62, 95% confidence interval 2.32 to 5.66). There was no increased risk of vaccine failure associated with length of time since vaccination once the relative risk was adjusted for age at vaccination in a stratified analysis. Vaccination before 1980 and an estimated date of vaccination were not associated with increased risk of vaccine failure. Administration of a second dose of vaccine during the outbreak was not protective. Two doses of vaccine given before the outbreak conferred significant protection, and the relative risk of failure after one dose versus two doses was 5.0 (95% confidence interval 1.25 to 20.15). Of the 87 cases, 76 (87%) could have been prevented had all the students received two doses of measles vaccine before the outbreak, with the first at 12 months of age or later. CONCLUSIONS: Delayed primary measles vaccination (at 15 months of age or later) significantly reduced measles risk at later ages. However, revising the timing of the current 12-month dose would leave children vulnerable during a period in which there is increased risk of complications. The findings support a population-based two-dose measles vaccination strategy for optimal measles control and eventual disease elimination.

Adolescent↗

Outbreaks of campylobacter infection: rare events for a common pathogen.

Campylobacter has been the commonest enteric pathogen isolated from humans in England and Wales since 1981, but few cases are linked to outbreaks. Twenty-one general outbreaks of campylobacter infection in England and Wales were reported to the PHLS Communicable Disease Surveillance Centre from 1992 to 1994. Seven hundred and six people were affected, nine cases were admitted to hospital, and no deaths were reported. The mean attack rate was 46.2% (SD 25.7%) and the mean duration of illness was 11 days (range 3 to 61 days). Outbreaks occurred throughout the year and throughout England and Wales. Infection in 18 outbreaks was reported to have been transmitted by food or water: eight were related to food (particularly poultry), six to contaminated water from a private water supply, and four to raw or inadequately pasteurised milk. General outbreaks of campylobacter infection appear to be unusual and should be investigated thoroughly. The new PHLS Campylobacter Reference Unit will assist in the identification of outbreaks of campylobacter infection and help to identify the risk factors associated.

Campylobacter Infections↗

Outbreak of viral gastroenteritis due to a contaminated well. International consequences.

CONTEXT: Small round-structured viruses (SRSVs) are known to cause viral gastroenteritis, but until now have not been confirmed in the implicated vehicle in outbreaks. OBJECTIVE: Investigation of a gastroenteritis outbreak. DESIGN: After applying epidemiologic methods to locate the outbreak source, we conducted environmental and laboratory investigations to elucidate the cause. SETTING: Tourists traveling by bus through Alaska and the Yukon Territory of Canada. PARTICIPANTS: Staff of a restaurant at a business complex implicated as the outbreak source, convenience sample of persons on buses that had stopped there, and bus employees. MAIN OUTCOME MEASURES: Odds ratios (ORs) for illness associated with exposures. Water samples from the restaurant and stool specimens from tourists and restaurant staff were examined by nucleic acid amplification using reverse transcription polymerase chain reaction and sequencing of viral amplification products. RESULTS: The itineraries of groups of tourists manifesting vomiting or diarrhea were traced back to a restaurant where buses had stopped 33 to 36 hours previously. Water consumption was associated with illness (OR, 5.3; 95% confidence interval [CI], 2.3-12.6). Eighteen of 26 employees of the business complex were ill; although not the index case, an employee ill shortly before the outbreak lived in a building connected to a septic pit, which was found to contaminate the well supplying the restaurant's water. Genotype 2/P2B SRSV was identified in stool specimens of 2 tourists and 1 restaurant employee. Stools and water samples yielded identical amplification product sequences. CONCLUSIONS: The investigation documented SRSVs in a vehicle epidemiologically linked to a gastroenteritis outbreak. The findings demonstrate the power of molecular detection and identification and underscore the importance of fundamental public health practices such as restaurant inspection, assurance of a safe water supply, and disease surveillance.

Base Sequence↗

Financial impact of the 1995 outbreak of vesicular stomatitis on 16 beef ranches in Colorado.

OBJECTIVE: To determine financial impact of an outbreak of vesicular stomatitis in the San Luis Valley of southern Colorado. DESIGN: Survey and financial analysis. SAMPLE POPULATION: 16 ranchers whose beef herds were affected by the 1995 outbreak. PROCEDURE: Information concerning financial effects during the outbreak year was collected by personal interview of each rancher and examination of financial records. RESULTS: Affected herds ranged from 79 to 956 cows (mean, 345). Cow case-fatality rates ranged from 0 to 80%, with calf case-fatality rates ranging from 0 to 28% and overall case-fatality rates of 0 to 15%. Median financial loss was $7,818/ranch and mean financial loss was $15,565/ranch, excluding total financial losses associated with sale of calves. Primary financial losses for these beef herds were attributed to increased culling rates, death of pregnant cows, loss of income from calves, and costs for additional labor during the outbreak. Some costs were attributable to a decrease in market price for beef and a drought during the year after the outbreak. CLINICAL IMPLICATIONS: Financial losses for an outbreak of vesicular stomatitis can be attributed to effects of the disease and costs associated with imposed quarantines.

Animal Husbandry↗

Agents, vehicles, and causal inference in bacterial foodborne disease outbreaks: 82 reports (1986-1995).

OBJECTIVE: To examine the study design of, and the practice of causal inference in, investigations of bacterial foodborne disease outbreaks occurring in the United States and to summarize agents and vehicles identified. DESIGN: Retrospective study. PROCEDURE: An online medical reference database was searched for reports of bacterial foodborne disease outbreak investigations published between 1986 and 1995. Reports were retrieved and reviewed for use of 9 causal criteria in investigations. Information on etiologic agents, vehicles, seasonality, and primary study design from each outbreak was also retrieved. RESULTS: 82 reports were retrieved and reviewed. Coherence, consistency, temporality, and strength of association were the causal criteria most commonly used in foodborne disease outbreak investigations. Coherence was used in all investigations. The number of criteria used ranged from 3 to 7. Meat (n = 20) and eggs (12) were the most commonly implicated vehicles. Salmonella sp and Escherichia coli O157:H7 accounted for 55% of agents reportedly isolated. Cohort and case-control methods were the most common study designs. CLINICAL RELEVANCE: Patterns were found in the use of causal criteria in foodborne disease outbreak investigations. These criteria can provide veterinarians and other public health practitioners with a means to effectively conceptualize, communicate, and summarize causal conclusions. The 4 most commonly used criteria may represent core criteria that investigators consider most useful in explaining food-borne disease outbreaks.

Animals↗

Ventilator-related Acinetobacter outbreak in an intensive care unit.

An outbreak of 16 cases of ciprofloxacin-resistant Acinetobacter baumannii (calcoaceticus subspecies anitratus) infections occurred during a 7-month period in a medical intensive care unit. Fifteen of the patients developed pneumonia associated with ventilator support. Possible sources considered in the outbreak investigation were sinks, ice, personnel, patients on multiple antibiotic therapy, reusable ventilator circuits, and hemodialysis. The equipment and environment associated with the outbreak were cultured. Patients on ventilators were significantly more susceptible to Acinetobacter nosocomial infection compared with the rest of the patients in the medical intensive care unit (p < 0.05). Sputum cultures were only 5% sensitive to ciprofloxacin and gentamicin, but they were 100% sensitive to imipenem (p < 0.0001). Uncloaking imipenem was a significant contributing factor in controlling this outbreak. Once outbreak control measures were instituted, Acinetobacter isolates dropped from 77 (during the outbreak year) to 9 (during the subsequent year) and no new pneumonia cases occurred.

Acinetobacter Infections↗

[An Acinetobacter baumanii outbreak at the Versailles Hospital Center].

A. baumannii is a multiresistant bacteria which is recognised as responsible for nosocomial infections and hospital outbreaks. The control of these outbreaks depends on the strain's typing and on the fight's policy against nosocomial infections. An outbreak of A. baumannii is occurred to patients who were hospitalized in Centre Hospitalier de Versailles. To investigate this outbreak, we have determined the biotype (Bouvet's method), the succeptibility pattern (disk diffusion and agar dilution results were analysed with the hierarchical classification and main component analysis) and the total DNA macrorestriction pattern (Pulse Field Gel Electrophoresis using SmaI restriction enzyme). A risk factors for A. baumannii acquisition were delineated in case-control study. During 2 years, 38 patients have been infected or colonized to A. baumannii. Thirty two patients were hospitalized in ICU. We studied 38 non repetitive clinical isolates and 9 strains of the patient's rooms. Four biotypes were defined by the Bouvet's typing method. Fourteen groups were obtained when succeptibility results were analysed with the hierarchical classification and 6 with the main composant analysis. The molecular typing permit us to define 4 epidemic and 6 sporadic strains. All the epidemic strains were isolated on ICU hospitalized patients. Our study has shown wide contamination in patient's rooms (Water tap, dry surfaces, patient's mattresses...). Environmental objects have been a major risk factor for A. baumannii acquisition. The control of this outbreak has been possible by application of hygienic measures (hands washing, isolment, meticulous cleaning of the ICU and environmental controls). No new case is occurred in the last year. Typing methods and case-control study are necessary to investigate cross-infections and take efficient measures against these outbreaks.

Acinetobacter↗

Multiple analysis of a foodborne outbreak caused by infant formula contaminated by an atypical Salmonella virchow strain.

An outbreak of food poisoning involving most autonomous Spanish communities was detected in the first half of 1994. The causative food was infant formula milk contaminated by lactose-fermenting Salmonella virchow. It was not possible to isolate the causative strain from the manufacturer's facilities. During the same period of time, there was a significant increase in lactose-non-fermenting Salmonella virchow strains compared with the same period in previous years. Simultaneously, lactose-non-fermenting strains were recovered from clinical samples from children and from some milk samples that were involved in the outbreak. Therefore, it was speculated that the outbreak might be more extensive than initially thought. The following epidemiological markers were used for typing the Salmonella virchow strains involved in the outbreak: (i) phage typing: (ii) ribotyping, using a set of 20 different endonucleases: and (iii) pulsed-field gel electrophoresis, using three different endonucleases. The most useful markers for this serotype were phage typing and pulsed-field gel electrophoresis, since ribotyping was not able to distinguish all strains tested. The results obtained revealed that the outbreak was caused by at least two strains: one presenting phage type 4-4a and pulsed-field patterns A1 or A2 and L+ or L-, and another presenting phage type 2 and pulsed-field patterns A1 or A2 and L+ or L-. The results indicate that the outbreak was more extensive than initially thought and that the Virchow serotype is very clonal in Spain.

Animals↗

Outbreaks of Gastrointestinal Diseases on Cruise Ships: Lessons from Three Decades of Progress.

Dramatic improvements in sanitary engineering and, especially, operational procedures aboard cruise ships began in the mid-1970s after several large outbreaks of acute gastroenteritis. The US Centers for Disease Control and Prevention's Vessel Sanitation Program, working with the cruise industry, conducts ship inspections, provides public access to ship sanitation scores, and reports outbreak investigations. The significant increase in median ship sanitation scores over the past decade has been concomitant with a reduction in outbreak frequency to 3.7 per 1000 cruises. Most outbreaks of the past decade were linked to noroviruses (Norwalk-like viruses), enterotoxigenic Escherichia coli, or the residual "unknown" causes. Although norovirus outbreaks may begin as foodborne or waterborne disease, easy person-to-person transmission occurs through fecal- or vomitus-splattered surfaces, other items, clothing, and especially, hands. Control of person-to-person spread of illness among crew and passengers becomes the major objective. Rigorous handwashing, environmental disinfection, and other food service job-related restrictions are required to prevent multiple outbreaks on the same ship. Vigilance by public health and industry officials has prevented many thousands of illnesses and some associated deaths. Clinicians providing pretravel health advice and post-travel diagnoses and care can benefit from and contribute to epidemiologic investigations and thereby enhance the health of cruise passengers individually and collectively.

Journal Article↗

An outbreak of fetal and neonatal losses associated with the diagnosis of bovine viral diarrhea virus.

A severe outbreak of dairy herd pregnancy wastage was investigated. At the beginning of the outbreak, a total of 121 lactating cattle were pregnant and considered to be at risk. Overall, 33.1% of the population at risk aborted, while 25.6% gave birth to calves that either died during the early neonatal period or demonstrated signs compatible with congenital defects (abnormal births). A laboratory diagnosis of bovine viral diarrhea virus (BVDV) infection was made in two surviving neonatal calves with symptoms of cerebellar hypoplasia and blindness. An on-farm investigation was conducted to determine if the abortions and abnormal births were associated with BVDV infection. The rate of abortions versus abnormal births was biphasic when graphed by the date of occurrence. The cases of abortion occurred early in the outbreak and were followed by the neonatal losses. Within the population at risk, the mean values for gestational age at the beginning of the outbreak were different between the subpopulations described by gestational outcome. The outcome of each pregnancy that existed at the beginning of the outbreak was determined. Classifications included normal birth (birth of a normal calf), abnormal birth (a neonatal loss of the type described above), abortion, and continued gestation (normal, uncompleted pregnancy). The average gestational age at the time of the index case (the first cases of pregnancy wastage) for these four pregnancy outcome classfications was 142.0, 106.2, 86.7 and 31.3 days, respectively. Reasons for assuming that this outbreak was related to BVDV are discussed.

Journal Article↗

Outbreak of staphylococcal scalded skin syndrome among neonates.

Over a period of 2 months, 12 babies born in the maternity unit at Guy's Hospital developed staphylococcal scalded skin syndrome in two distinct outbreaks. Staphylococci isolated from the babies, together with those from the mothers and attending medical staff were phage-typed. All isolates from the babies were of type 3A/3C. During the first outbreak only one carrier of the epidemic strain (a paediatrician) was found but a further 12 persons were identified as possible carriers during the second outbreak. In order to confirm the link between outbreaks, all phage group II isolates were subjected to reverse phage-typing, testing for metal-ion resistance, plasmid profiling and in-vivo testing for production of epidermolytic toxin. It was shown that the same epidemic strain of toxin-producing Staphylococcus aureus was responsible for both outbreaks. The affected neonates responded rapidly to a short course of intravenous flucloxacillin. The outbreak ceased after appropriate treatment of all carriers and the implementation of an extensive disinfection policy within the maternity unit.

Carrier State↗