Showing papers on "Outbreak published in 1994"
TL;DR: This massive outbreak of watery diarrhea among the residents of Milwaukee was caused by cryptosporidium oocysts that passed through the filtration system of one of the city's water-treatment plants, and water-quality standards and the testing of patients for cryptOSporidium were not adequate to detect this outbreak.
Abstract: Background Early in the spring of 1993 there was a widespread outbreak of acute watery diarrhea among the residents of Milwaukee. Methods We investigated the two Milwaukee water-treatment plants, gathered data from clinical laboratories on the results of tests for enteric pathogens, and examined ice made during the time of the outbreak for cryptosporidium oocysts. We surveyed residents with confirmed cryptosporidium infection and a sample of those with acute watery diarrhea consistent with cryptosporidium infection. To estimate the magnitude of the outbreak, we also conducted a survey using randomly selected telephone numbers in Milwaukee and four surrounding counties. Results There were marked increases in the turbidity of treated water at the city's southern water-treatment plant from March 23 until April 9, when the plant was shut down. Cryptosporidium oocysts were identified in water from ice made in southern Milwaukee during these weeks. The rates of isolation of other enteric pathogens remained stab...
2,040 citations
01 Jan 1994
TL;DR: What Is Special About Infectious Disease Epidemiology?
Abstract: What Is Special About Infectious Disease Epidemiology? Definitions Risk, Relative Risk and Attack Rate Descriptive Epidemiology The Case-Control Study: Odds, Odds Ratios. The Concepts of Confounding The Cohort Study: Rates. The Concept of Bias Some Statistical Procedures That Are Often Used in Epidemiology Clinical Epidemiology: Sensitivity, Specificity, Misclassification Multivariate Analysis and Interaction Survival Analysis Mathematical Models for Epidemics Detection and Analysis of Outbreaks Routine Surveillance of Infectious Diseases Measuring Infectivity Studying The Natural History of Infectious Diseases Seroepedemiology The Study of Contact Patterns Methods to Decide Whether or Not an Illness is Infectious The Epidemiology of Vaccination The Epidemiology of Aids and VCJD More To Read
272 citations
TL;DR: Eggborne S. enteritidis infections are a major public health problem and educating consumers about proper handling of eggs, using pasteurized eggs, and controlling infections on egg farms may stem the impact of this disease.
Abstract: The spread of Salmonella enteritidis infections in the United States was tracked to identify potential risk factors and preventive measures. Isolation rates and information regarding outbreaks of S. enteritidis from 1985 through 1991 were determined by reports to the national Salmonella surveillance system and through the foodborne disease outbreak surveillance system. From 1985 through 1991, 380 outbreaks were reported involving 13,056 ill persons and 50 deaths. The proportion of Northeast outbreaks fell from 81% in 1985 to 55% in 1991 as the number of outbreaks in other areas increased. Grade A shell eggs were implicated in 82% of outbreaks. Case-fatality rates in nursing homes and hospitals were 70 times higher than in other settings. Cultures of environmental or animal specimens from all farms tested yielded S. enteritidis. Eggborne S. enteritidis infections are a major public health problem. Preventive measures, including educating consumers about proper handling of eggs, using pasteurized eggs, and controlling infections on egg farms, may stem the impact of this disease.
230 citations
TL;DR: An outbreak of poliomyelitis occurred in the Netherlands between September, 1992, and February, 1993 and Sequence analysis of the viral genome showed closest similarity with a strain isolated in India in 1992, indicating that the virus probably originates from the Indian subcontinent.
221 citations
TL;DR: Typing of the isolates by three methods revealed that two distinct strains were involved in the first 9 cases of the outbreak and that one of these strains, which had acquired a higher level of imipenem resistance as well as resistance to all aminoglycosides, accounted for 21 of 22 cases in the second part of the outbreaks.
Abstract: During a 13-month period, 31 patients hospitalized primarily in two intensive care units (ICUs) were either colonized or infected by imipenem-resistant Acinetobacter baumannii. Typing of the isolates by three methods (antibiotyping, biotyping, and pulsed-field gel electrophoresis) revealed that two distinct strains were involved in the first 9 cases of the outbreak and that one of these strains, which had acquired a higher level of imipenem resistance as well as resistance to all aminoglycosides, accounted for 21 of 22 cases in the second part of the outbreak. ICU environmental contamination was recognized as an important reservoir of this epidemic strain. The outbreak ceased only after the ICUs were closed for complete cleaning and disinfection.
192 citations
TL;DR: An environmental survey and a cohort study were done to analyze an outbreak of infections in a burn unit caused by a serotypes O:11 and a multidrug-resistant serotype O:12 Pseudomonas aeruginosa, finding prior treatment with ceftazidime (3 g/day) was the only independent risk factor for P. aerug inosa O: 12 infection.
Abstract: An environmental survey and a cohort study were done to analyze an outbreak of infections in a burn unit caused by a serotype O:11 and a multidrug-resistant serotype O:12 Pseudomonas aeruginosa. The P. aeruginosa O:11 outbreak was controlled by eradicating an environmental source, contaminated hydrotherapy equipment. To assess risk factors for infections caused by P. aeruginosa O:12, 15 infected burn patients were compared with 32 noninfected burn patients hospitalized during the outbreak. Patients had similar extent, severity, location, and care of burn injuries, exposure to invasive procedures, and past history of P. aeruginosa infection. Prior treatment with ceftazidime (3 g/day) was the only independent risk factor for P. aeruginosa O:12 infection. The outbreak was controlled by increasing the daily administration of ceftazidime from 3 to 6 g and by a reinforcement of isolation precautions.
180 citations
TL;DR: From 20 April through 13 May 1992, 9 children were hospitalized with hemolytic-uremic syndrome in Lombardia, Italy, where only 14 cases of this syndrome had occurred in the preceding 4 years.
Abstract: From 20 April through 13 May 1992, 9 children were hospitalized with hemolytic-uremic syndrome in Lombardia, Italy, where only 14 cases of this syndrome had occurred in the preceding 4 years. Cases were scattered in a large area encompassing five provinces, and the source of the outbreak was not identified. Eight patients needed dialysis, and there was 1 death. Seven of the 9 cases were examined for evidence of infection by Vero cytotoxin (VT)-producing Escherichia coli (VTEC). Six children had serum antibodies to the lipopolysaccharide of E. coli O111, and a VT-producing E. coli O111:NM was isolated from stool in 1 case. This is the first outbreak of VTEC infection recognized in Italy and the first associated with an E. coli serotype other than O157:H7.
168 citations
TL;DR: Serological surveys in conjunction with isolation studies have shown that velogenic NDV strains are endemic in rural poultry populations even in isolated villages and possibly in isolated flocks, although NDV is endemic in village poultry, the clinical disease usually follows an epidemic pattern.
Abstract: Rural poultry are the dominant form of poultry kept in the developing world. They are a natural resource whose potential is not fully exploited for the welfare of rural populations. The most devastating disease of rural poultry is Newcastle disease (ND). ND is an epidemic disease in intensive poultry and is responsible for high economic losses. Its epidemiology in intensive poultry is well understood, but little has been published on its behaviour in village poultry populations. Some research has been carried out during the past few years and it now appears that rural poultry are receiving increasing support for research and development from many government and international funding agencies throughout the world. All strains of Newcastle disease virus (NDV) occur in rural poultry, but velogenic strains are reported to be more common. Serological surveys in conjunction with isolation studies have shown that velogenic NDV strains are endemic in rural poultry populations even in isolated villages and possibly in isolated flocks. Although NDV is endemic in village poultry, the clinical disease usually follows an epidemic pattern. ND outbreaks often occur once or twice a year at regular intervals affirming the endemicity of the virus, however, 'mini' outbreaks in individual flocks and sporadic cases in individual birds may occur. Epidemics usually occur at times of climatic stress, leading to seasonal occurrence. The spread of NDV within and between village poultry populations is relatively slow due to a low contact rate. The major mode of transmission appears to be by the faecal-oral route. The respiratory route may also play a role in flocks where close bird-to-bird associations exist. Other poultry species, wild and feral birds, wild animals, communal water reservoirs and domestic animals may play a role in transmission; however, their role has not been properly investigated. In non-immune, intensively reared poultry, introduction of a sufficient quantity of virulent NDV is sufficient to cause severe outbreaks, but in rural poultry epidemic disease depends upon a number of factors. These include NDV pathotype, age structure and immunity of the host population, breed susceptibility, concurrent disease and seasonal influences. Although ND is endemic in rural poultry, many aspects of the epidemiology and economics of ND have not been fully understood. Well-designed, longitudinal studies made within a socio-economic framework are required to improve our understanding of the main problems of rural poultry systems.
162 citations
TL;DR: In the six-month period 1 November 1991 to 1 May 1992 175 patients developed diarrhoea due to Clostridium difficile in three hospitals in Manchester, UK, and there has been a substantial and sustained decrease in the number of new cases.
150 citations
148 citations
TL;DR: It is suggested that aerosolization of vomit was of major importance in transmission of infection during the outbreak of gastroenteritis and the implications for infection control are discussed.
TL;DR: Since no other cattle were present in the area and no outbreaks of SAT 1 had occurred in Zimbabwe since 1989, it was concluded that the disease had been transmitted from buffalo to cattle.
Abstract: An outbreak of foot-and-mouth disease (FMD) occurred during April 1991 in a trypanosomiasis sentinel cattle herd by the Rifa River to the east of Lake Kariba, Zimbabwe. Despite the cattle having been vaccinated biannually for the previous five years the disease was severe. The viruses isolated from the affected animals were typed as FMD virus type SAT 1. Free-living African buffalo (Syncerus caffer) which had been using the same watering place as the affected cattle were sampled and FMD type SAT 1 virus was isolated. Partial nucleotide sequencing of the gene coding for the capsid protein 1D (VP1) of one of the viruses isolated from cattle and two of the viruses isolated from buffalo demonstrated a close relationship between the three viruses. Since no other cattle were present in the area and no outbreaks of SAT 1 had occurred in Zimbabwe since 1989, it was concluded that the disease had been transmitted from buffalo to cattle.
TL;DR: DNA fragments generated by four restriction endonucleases and analysed by pulsed-field gel electrophoresis (PFGE) provided definitive evidence that all isolates from nine different counties in California and Nevada were derived from a single strain of S. intermedius.
Abstract: An outbreak of food intoxication involving over 265 cases in western United States occurred in October 1991. Staphylococcus intermedius was implicated as the aetiologic agent. Representative outbreak isolates (five clinical and ten from foods) produced type A enterotoxin. DNA fragments generated by four restriction endonucleases and analysed by pulsed-field gel electrophoresis (PFGE) provided definitive evidence that all isolates from nine different counties in California and Nevada were derived from a single strain. The PFGE pattern of these outbreak isolates was distinct from those of a heterogeneous collection of seven S. intermedius strains of veterinary origin and five unrelated S. aureus laboratory strains. The data show a significant PFGE pattern heterogeneity not only among members of different Staphylococcus species but also within members of the same species and even the same enterotoxin type. The results indicate that PFGE is a valuable strain-specific discriminator for the epidemiological characterization of S. intermedius. To our knowledge, this represents the first documented foodborne outbreak caused by S. intermedius. These findings suggest that the presence of S. intermedius and other species such as S. hyicus in food should be reason for concern.
TL;DR: The various manifestations of Lyme disease can usually be treated successfully with oral doxycycline or amoxicillin, except for objective neurologic manifestations, which seem to require intravenous therapy.
Abstract: Lyme disease or Lyme borreliosis, which is caused by three groups of the spirochete Borrelia burgdorferi, is transmitted in North America, Europe, and Asia by ticks of the Ixodes ricinus complex. The primary areas around the world that are now affected by Lyme disease are near the terminal moraine of the glaciers 15,000 years ago. The emergence of Lyme disease in the United States in this century is thought to have occurred because of ecological conditions favorable for deer. From 1982 through 1991, 40,195 cases occurring in 47 states were reported to the Centers for Disease Control, but enzootic cycles of B. burgdorferi have been identified in only 19 states. During the last several decades, the disease has spread to new areas and has caused focal outbreaks, including locations near Boston, New York, and Philadelphia. Lyme disease is like syphilis in its multisystem involvement, occurrence in stages, and mimicry of other diseases. Diagnosis of late neurologic abnormalities of the disorder has created the most difficulty. A recent phenomenon is that a number of poorly understood conditions, such as chronic fatigue syndrome or fibromyalgia, are misdiagnosed as "chronic Lyme disease." Part of the reason for misdiagnosis is due to problems associated with diagnostic tests. The various manifestations of Lyme disease can usually be treated successfully with oral doxycycline or amoxicillin, except for objective neurologic manifestations, which seem to require intravenous therapy. Vector control of thick-borne diseases has been difficult and, therefore, reduction of the risk of infection has been limited primarily to personal protection measures.
TL;DR: The timing of outbreaks did not differ significantly between most regions; the few differences were small, and no region consistently had early or late outbreaks, consistent with RSV transmission within communities rather than between communities or regions.
Abstract: Respiratory syncytial virus (RSV) causes pneumonia and bronchiolitis in infants and young children and serious disease in the elderly and persons with compromised immune systems. To determine the temporal and geographic patterns of RSV outbreaks in the United States, monthly reports from 74 laboratories were analyzed for July 1985 through June 1990. RSV outbreaks were identified in 197 (93%) of the 211 laboratory years analyzed, with widespread activity beginning each fall, peaking in winter, and returning to baseline in April or May. Each year, the timing of outbreaks did not differ significantly between most regions; the few differences were small, and no region consistently had early or late outbreaks. These findings are consistent with RSV transmission within communities rather than between communities or regions. Health care personnel should consider the possibility of RSV infection in their treatment and prevention efforts from November through April each year in the United States.
TL;DR: A lack of treatment or inadequate treatment accounted for the majority of outbreaks, and most (76 percent) were associated with well water.
Abstract: For 1991 and 1992, 17 states and territories reported 34 outbreaks of disease associated with drinking water, which affected an estimated 17,464 people A protozoal parasite (Giardia lamblia or Cryptosporidium) was identified as the etiologic agent for seven of the eleven outbreaks for which an agent was determined; the remaining four were due to hepatitis A, Shigella sonnei, or chemicals A lack of treatment or inadequate treatment accounted for the majority of outbreaks, and most (76 percent) were associated with well water
TL;DR: A survey was conducted in the summer of 1991 in the western Mediterranean to map the distribution and to estimate the number of striped dolphins surviving the 1990 outbreak of the morbillivirus epizootic, which suggests segregation similar to that seen in populations of this species elsewhere in the world.
Abstract: A survey was conducted in the summer of 1991 in the western Mediterranean to map the distribution and to estimate the number of striped dolphins surviving the 1990 outbreak of the morbillivirus epizootic. The highest densities of striped dolphins were found in the Alboran Sea and the Ligurian Sea. Total numbers were estimated at 117,880 (SE: 38,962; 95% CI: 68,379–214,800). The mortality resulting from the epizootic is unknown but may have been severe because the mean size of dolphin schools observed during the epizootic outbreak was significantly smaller than that before the event. A return to larger school sizes after the 1990 outbreak is not evidence of a recovery but can be viewed as a regrouping of individuals into schools of a preferred size. Calves were observed in 24.6% of the schools. They were not seen in schools of ten or less but were present in about half the schools of 30 or more dolphins, a result which suggests segregation similar to that seen in populations of this species elsewhere in the world.
TL;DR: It is demonstrated that child care provides an opportunity for outbreak of invasive pneumococcal disease in young children in child-care facilities and underscores the necessity for a pneumitiscal vaccine that is effective in infants and young children.
Abstract: Objective. —To investigate a cluster of invasive pneumococcal disease in children 8 to 26 months of age, using standard microbiological procedures and ribosomal DNA gene-restriction patterns to characterize the outbreak strain. Design. —Outbreak investigation. Setting. —A family child-care home with six children in Baltimore, Md. Results. —During an 8-day period, three of the six children in the family child-care home had febrile illnesses with pneumococcal bacteremia, and a fourth had purulent pneumococcal conjunctivitis. Type 12F Streptococcus pneumoniae was isolated from the four ill children and from the nasopharynges of the two healthy children. Ribotyping revealed all outbreak isolates had an identical ribotype pattern. Administration of rifampin to the children did not eradicate carriage of the organism. Conclusions. —Our data demonstrate that child care provides an opportunity for outbreak of invasive pneumococcal disease in young children. This observation suggests a need for increased alertness for clusters of pneumococcal disease in young children in child-care facilities and underscores the necessity for a pneumococcal vaccine that is effective in infants and young children. ( JAMA . 1994;271:695-697)
TL;DR: This prolonged outbreak of cryptosporidiosis was likely caused by exposure to fecally contaminated wave pool water, and may represent an unrecognized hazard of wave pools, where the likelihood of inadvertent water ingestion is high.
Abstract: 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. ( JAMA . 1994;272:1597-1600)
TL;DR: During a 9-month period at a small surgical center, seven cases of postarthroscopic septic arthritis occurred after 352 arthroscopic procedures, for an infection rate of 2.0%.
TL;DR: Clinical, microbiological and epidemiological evidence available indicated that a children's paddling pool served as the focal point in the transmission of infection causing the outbreak.
Abstract: In May 1992, a small, circumscribed community outbreak of infection due to verotoxin-producing Escherichia coli O157 phage type 49 occurred in a semi-rural area of south-east Scotland. On the basis of stool cultures, six cases were identified, one of whom was asymptomatic. One child developed the haemolytic uraemic syndrome. Although the source of infection of the index case was not established nor could the extent of person-to-person spread be fully determined, the clinical, microbiological and epidemiological evidence available indicated that a children's paddling pool served as the focal point in the transmission of infection causing the outbreak.
Journal Article•
TL;DR: Several arboviruses were endemic and some of them may have caused human disease in the Northern Province of Sudan coinciding with a high population density of phlebotomine sandflies.
Abstract: An outbreak of acute febrile illness occurred during August and September 1989 in the Northern Province of Sudan coinciding with a high population density of phlebotomine sandflies. An investigation was conducted to determine whether arboviruses were associated with human illness during this outbreak. Sera were obtained from 185 febrile individuals and tested for IgG and IgM antibody to selected arboviruses by enzyme immunoassay (EIA). The prevalence of IgG antibody was 59% for West Nile (WN), 53% for Sandfly Fever Sicilian (SFS), 32% for Sandfly Fever Naples (SFN), 39% for Yellow Fever (YF), 24% for dengue-2 (DEN-2), 23% for Rift Valley Fever (RVF), 12% for Chikungunya (CHIK) and 5% for Crimean-Congo haemorrhagic Fever (CCHF) viruses. Antibody prevalences tended to increase with age for WN and YF viruses. Antibody rates were about the same for males and females for most of the viruses tested. The prevalence of IgM antibody to SFN was 24% and reciprocal IgM titre exceeded 12,800 for some individuals suggesting that this virus was the cause of recent infection. The prevalence of IgM antibody for the other viruses did not exceed 5%. The study indicated that several arboviruses were endemic and some of them may have caused human disease in the Northern Province of Sudan.
TL;DR: During 1993 outbreaks of diarrhoea in adult dairy cows in three geographically unrelated herds were found to be caused by bovine viral diarrhea virus (BVDV), and the disease spread rapidly in each case.
Abstract: During 1993 outbreaks of diarrhoea in adult dairy cows in three geographically unrelated herds were found to be caused by bovine viral diarrhoea virus (BVDV). The affected animals showed signs of acute watery diarrhoea, agalactia and pyrexia (39.4 to 42 degrees C). Ulceration of the buccal mucosa, a mucoid nasal discharge and stiffness were inconsistent signs. The disease spread rapidly in each case. The diagnosis was confirmed by the isolation of non-cytopathic BVDV from blood and tissues and by the demonstration of significantly rising titres to BVDV by an ELISA. The highest morbidity recorded was 40 per cent with one herd experiencing a 10 per cent mortality. There was no increased incidence of abortion in any of the herds, either at the time of or subsequent to the outbreaks of diarrhoea. In one herd the purchase of a persistently viraemic heifer 14 days before the outbreak was thought to be the source of infection, but in the other two herds the source was not established.
TL;DR: Residents of the community infected during the first outbreak were significantly less likely to have been reinfected during the second outbreak and results of the investigations are consistent with an acquired, protective immunity lasting at least 5 years.
Abstract: A waterborne outbreak of giardiasis which occurred 5 years after another in the same town in Canada was investigated. Sera from residents defined as cases or non-cases were tested by enzyme-linked immunosorbent assay ( elisa ) and compared with sera from symptomatic and asymptomatic control groups. The outbreak-associated Giardia isolate was retrieved from contaminated drinking water and antigen from this strain was used in the serological investigation. Up to 84% of cases were identified by elisa . More cases were identified by elevated immunoglobulin (Ig) G than by either elevated anti- Giardia IgA or IgM levels. Residents of the community infected during the first outbreak were significantly less likely to have been reinfected during the second outbreak. This is the first report of a second waterborne outbreak occurring in a community and results of the investigations are consistent with an acquired, protective immunity lasting at least 5 years.
TL;DR: A field test showed that oral administration of oxytetracycline at a dose of 30-50 mg per kg body weight for 10-14 days was effective to control the disease and clinical signs, susceptibility of various fishes to the pathogen and transmission electron-microscopy findings are described.
Abstract: An organism, measuring 0.86±0.32×0.63 ±0.24 μm, likely to be member of family Rickettsiaceae, was detected for the first time from an outbreak of a disease with mass mortality among pond-reared tilapia in Taiwan. The pathogen was demonstrated to be Gram-negative and stained positively with Liu's solution and to grow on To2 and EPC cell cultures but not on nine artificial media selected and the pathogenicity was confirmed by Koch's postulates. Haematocrit in affected fish was decreased to 16.1±5.2% versus 28.3±5.1% for normal value. Typical lesions in moribund fish included marked white nodules and microscopical granulomatous formation all over the organs. The spleen enlarged to 5-50 times of the normal organ. Horizontal transmission without parasite vectors occurred. The experimental infection showed higher mortality at 15°C than at 30°C. In vitro experiments revealed that oxytetracycline which is legally permitted would probably be an effective antibiotic to control this disease. A field test showed that oral administration of oxytetracycline at a dose of 30-50 mg per kg body weight for 10-14 days was effective to control the disease. Clinical signs, susceptibility of various fishes to the pathogen and transmission electron-microscopy findings are described.
TL;DR: Serological evidence suggests that low-level endemic transmission occurs regularly throughout much of the African continent, but most of this remains unrecognized due to inadequate surveillance and health care facilities.
Abstract: Since 1930 when it was first described during an e p h t i c among domestic ungulates in Kenya,’ Rift Valley fever (RVF) has appeared in dozens of temporally and spatially punctuated animal and human outbreaks that even today defy prediction. Sudden and severe e h t i c s , sometimes accompanied by epidemic human disease, have occurrecf)throughout sub-Saharan Africa.2 An acute viral infection producing inapparent or mild disease in adult sheep and cattle, RVF provokes abortion among pregnant ungulates and often is fatal to young animal^.^,^ Human disease is characterized initially by abrupt onset of high fever, severe headache, myalgia, conjunctival injection and incapacitating prostration of several days d ~ r a t i o n . ~ Some patients develop fatal hemorrhagic fever or ence halitis, and those who survive may experience ocular disease (primarily retinJvasculitis). Serological evidence suggests that low-level endemic transmission occurs regularly throughout much of the African continent, but most of this remains unrecognized due to inadequate surveillance and health care facilities.2 Transmission of RVF virus (a phlebovirus of the family Bunyaddue) is principally mosquito-borne to both animals and Potential mosquito vectors include more than 30 species from which RVF virus has been isolated.z Experimental and field studies suggest that certain floodwater Aehs spp. which emerge from temporay ground pools following seasonal rains are important enzootic E p h t i c transmission correlates temporally with periods of heavy rainfall in East Africa,13 when particular Culex species become infected.6i8 Then, and perhaps also during enzootic transmission, human infections may result from exposure to infected animal tissue^.'^-'^ The risk factors associated with human exposure have not yet been completely defined. l7 Some of the main interactions of RVF virus cycles are represented schematically in FIGURE 1.
TL;DR: Methods for prevention and control of nosocomial outbreaks are discussed, in particular the susceptibility to Legionnaires' disease of certain groups of hospital patients.
Abstract: Two hundred and eighteen nosocomial cases of Legionnaires' disease with 68 deaths were reported to the National Surveillance Scheme for Legionnaires Disease between 1980 and 1992, representing 15% of the reported infections acquired in England and Wales. Twenty-two nosocomial outbreaks accounted for 135 (62%) of these cases, the remainder occurring as single cases either in hospitals where other single cases or outbreaks had been reported in different years or as 'sporadic' cases in hospitals from which no other cases were reported. A clinical history prior to onset of Legionnaires' disease was available for 124 patients, 61 of whom had undergone recent transplant therapy or were immunosuppressed for other reasons. Sixty cases (27%) were diagnosed by culture of the organism and isolates from 56 patients were typed; 25 (42%) were non L. pneumophila serogroup 1 infections. Methods for prevention and control of nosocomial outbreaks are discussed, in particular the susceptibility to Legionnaires' disease of certain groups of hospital patients.
TL;DR: This paper attempts to draw on overseas historical outbreak experiences and research findings to gain insights into the epidemiology of foot-and-mouth disease as it would relate to New Zealand.
Abstract: Foot-and-mouth disease is an acute, highly communicable disease affecting cloven-hoofed animals, both domesticated and wild. It may well be the most contagious disease known in the animal kingdom. The key features that contribute to this include its ability to gain entry and initiate infection through a variety of sites, the small infective dose, the short incubation period, the release of virus before the onset of clinical signs, the massive quantities of virus excreted from infected animals, its ability to spread large distances due to airborne dispersal, and the persistence of the virus in the environment. These features, plus the ability of the virus to be disseminated through the movements of animals, animal products, people, and plant and equipment makes the disease very difficult to control. New Zealand has never experienced a foot-and-mouth disease epidemic, and the economic consequences of an outbreak would be disastrous, due to the eradication costs, the loss of productivity and the imp...
01 Nov 1994-Zentralblatt Fur Bakteriologie-international Journal of Medical Microbiology Virology Parasitology and Infectious Diseases
TL;DR: The high infectivity of the organism which was demonstrated by person-to-person transmission and propagation within certain groups of children stresses the need for strict hygienic measures and early case reporting when such infections occur in susceptible settings like day care centres, nursing homes, or hospitals.
Abstract: Summary An outbreak of gastrointestinal disease and haemolytic uraemic syndrome caused by Escherichia coli O157: H7 was investigated.The outbreak occurred in a day care centre located in northern Germany in August 1992 and involved 39 children and two adults.Furthermore, four asymptomatic infections were detected among the staff.Initial and secondary cases were reported over a 30-day interval, with cases occurring in three waves.Personto-person contact and environmental contamination were assumed to be the main mode of transmission.The source of the outbreak has remained unknown but it is likely that primary or secondary contamination of the day care centre's kitchen, too, played a role in the spread of infections.The organisms were isolated from two open packs of deep-frozen stuffed cabbage rolls and turkey scallops in batter, furthermore from swabs from two kitchen utensils. Of the 39 cases with diarrhoea, three developed a haemolytic uraemic syndrome; one of the latter patients died.In 8 of the cases as well as in four healthy adult employes, E.coli O157: H7 was isolated from stool samples, in two stool culture-negative cases the presence of IgM antibody to O157 LPS indicated recent infection.The E.coli O157: H7 isolates from the cases and the kitchen were of identical phage type and yielded identical biochemical reactions.All E.coli O157: H7 isolates harboured stable slt -I genes.However, sit-I genes could only be demonstrated in the primary cultures and were lost during subcultivation. This is the largest outbreak caused by enterohaemorrhagic E.coli O157: H7 that has been documented in Germany so far.The high infectivity of the organism which was demonstrated by person-to-person transmission and propagation within certain groups of children stresses the need for strict hygienic measures and early case reporting when such infections occur in susceptible settings like day care centres, nursing homes, or hospitals.