Postexposure prophylaxis, isolation, and quarantine to control an import-associated measles outbreak--Iowa, 2004.
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On March 12, 2004, a college student infectious with measles returned to Iowa from India by a commercial airliner; the case was subsequently linked to two other measles cases. This report updates information about this outbreak and provides details regarding vaccination, quarantine, and other measures used by Iowa public health authorities to interrupt disease transmission in a vulnerable population. The effective uses of quarantine and isolation during the outbreak underscore the utility of these public health tools in halting communicable disease transmission. (+info)
Modelling strategies for controlling SARS outbreaks.
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Severe acute respiratory syndrome (SARS), a new, highly contagious, viral disease, emerged in China late in 2002 and quickly spread to 32 countries and regions causing in excess of 774 deaths and 8098 infections worldwide. In the absence of a rapid diagnostic test, therapy or vaccine, isolation of individuals diagnosed with SARS and quarantine of individuals feared exposed to SARS virus were used to control the spread of infection. We examine mathematically the impact of isolation and quarantine on the control of SARS during the outbreaks in Toronto, Hong Kong, Singapore and Beijing using a deterministic model that closely mimics the data for cumulative infected cases and SARS-related deaths in the first three regions but not in Beijing until mid-April, when China started to report data more accurately. The results reveal that achieving a reduction in the contact rate between susceptible and diseased individuals by isolating the latter is a critically important strategy that can control SARS outbreaks with or without quarantine. An optimal isolation programme entails timely implementation under stringent hygienic precautions defined by a critical threshold value. Values below this threshold lead to control, but those above are associated with the incidence of new community outbreaks or nosocomial infections, a known cause for the spread of SARS in each region. Allocation of resources to implement optimal isolation is more effective than to implement sub-optimal isolation and quarantine together. A community-wide eradication of SARS is feasible if optimal isolation is combined with a highly effective screening programme at the points of entry. (+info)
Quarantine after an international biological weapons attack: medical and public health requirements for containment.
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The world now faces the dreadful possibility of biological weapons attacks by terrorists. Healthcare systems would have to cope with such emergencies should all preemptive measures fail. Information gained from the Global Mercury exercise and the SARS outbreak has shown that containing an outbreak at the start is more effective than reacting to it once it has spread and that containment should be treated both nationally and internationally. On the national level this entails developing rapid and effective methods to detect and identify infected cases, and implementing isolation and control measures to lower the risk of further transmission of the disease while assuring the safety of medical teams and laboratory workers. Strategic contingency plans should incorporate well-defined procedures for hospitalization and isolation of patients, providing regional backup of medical personnel and equipment and maintaining close cooperation between the various bodies in the healthcare system. Quarantine is an effective containment measure, especially if voluntarily imposed. Modern communication systems can help by sending professional teams timely instructions and providing the public with information to reduce panic and stress during quarantine procedures. Informing the public poses a dilemma: finding a balance between giving advance warning of an imminent epidemic outbreak and ascertaining the likelihood of its occurrence. Containment of international bioterrorist attacks depends entirely on close international cooperation to implement national and international strategic contingency plans with free exchange of information and recognition of procedures. (+info)
Health surveillance of specific pathogen-free and conventionally-housed mice and rats in Korea.
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The present study contains information about proper microbiological monitoring of laboratory animals' health and the standardization of microbiological monitoring methods in Korea. Microbiological quality control for laboratory animals, composed of biosecurity and health surveillance, is essential to guard against research complications and public health dangers that have been associated with adventitious infections. In this study, one hundred and twenty-two mice and ninety rats from laboratory animal breeding companies and one animal facility of the national universities in Korea were monitored in 2000-2003. Histopathologically, thickening of the alveolar walls and lymphocytic infiltration around the bronchioles were observed in mice and rats from microbiologically contaminated facilities. Cryptosporidial oocysts were observed in the gastric pits of only conventionally-housed mice and rats. Helicobacter spp. infection was also detected in 1 of 24 feces DNA samples in mice and 9 of 40 feces DNA samples in rats by PCR in 2003, but they were not Helicobacter hepaticus. This paper describes bacteriological, parasitological, and virological examinations of the animals. (+info)
Quarantine for SARS, Taiwan.
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During the 2003 outbreak of severe acute respiratory syndrome (SARS) in Taiwan, >150,000 persons were quarantined, 24 of whom were later found to have laboratory-confirmed SARS-coronavirus (SARS-CoV) infection. Since no evidence exists that SARS-CoV is infective before the onset of symptoms and the quarantined persons were exposed but not symptomatic, we thought the quarantine's effectiveness should be investigated. Using the Taiwan quarantine data, we found that the onset-to-diagnosis time of previously quarantined confirmed case-patients was significantly shortened compared to that for those who had not been quarantined. Thus, quarantine for SARS in Taiwan screened potentially infective persons for swift diagnosis and hospitalization after onset, thereby indirectly reducing infections. Full-scale quarantine measures implemented on April 28 led to a significant improvement in onset-to-diagnosis time of all SARS patients, regardless of previous quarantine status. We discuss the temporal effects of quarantine measures and other interventions on detection and isolation as well as the potential usefulness of quarantine in faster identification of persons with SARS and in improving isolation measures. (+info)
Osler and the infected letter.
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The spread of infectious agents through the mail has concerned public health officials for 5 centuries. The dissemination of anthrax spores in the US mail in 2001 was a recent example. In 1901, two medical journals reported outbreaks of smallpox presumably introduced by letters contaminated with variola viruses. The stability and infectivity of the smallpox virus are reviewed from both a historical (anecdotal) perspective and modern virologic studies. Bubonic plague was the contagious disease that led to quarantines as early as the 14th century in port cities in southern Europe. Later, smallpox, cholera, typhus, and yellow fever were recognized as also warranting quarantine measures. Initially, attempts were made to decontaminate all goods imported from pestilential areas, particularly mail. Disinfection of mail was largely abandoned in the early 20th century with newer knowledge about the spread and stability of these 5 infectious agents. (+info)
Sentinel surveillance for international Shigella by a quarantine station in Japan.
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The Japanese quarantine system monitors incoming passengers to detect imported pathogens at international airports. At one airport, we found that 74% of 13 315 travellers returning with diarrhoea had visited only one country before entering Japan. On the basis of our results, we hypothesized that the international distribution and potential source of bacterial strains could be inferred by analysing strains isolated from travellers returning to Japan. In order to demonstrate the potential for this system, we randomly selected five Shigella sonnei strains and examined their restriction fragment length polymorphism patterns. One set of strains appeared to be closely related, while three sets, isolated from travellers who visited different countries were possibly related. These results suggest that international distributions and potential sources of S. sonnei may be inferred by monitoring isolates from passengers arriving at a Japanese quarantine station. (+info)
Containing pandemic influenza at the source.
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Highly pathogenic avian influenza A (subtype H5N1) is threatening to cause a human pandemic of potentially devastating proportions. We used a stochastic influenza simulation model for rural Southeast Asia to investigate the effectiveness of targeted antiviral prophylaxis, quarantine, and pre-vaccination in containing an emerging influenza strain at the source. If the basic reproductive number (R0) was below 1.60, our simulations showed that a prepared response with targeted antivirals would have a high probability of containing the disease. In that case, an antiviral agent stockpile on the order of 100,000 to 1 million courses for treatment and prophylaxis would be sufficient. If pre-vaccination occurred, then targeted antiviral prophylaxis could be effective for containing strains with an R0 as high as 2.1. Combinations of targeted antiviral prophylaxis, pre-vaccination, and quarantine could contain strains with an R(0) as high as 2.4. (+info)