Showing papers by "Keiji Fukuda published in 1999"
TL;DR: A more sensitive microneutralization assay is developed to detect antibodies to avian influenza in humans and is being used for the seroepidemiologic investigations of the avian H5N1 influenza outbreak.
Abstract: From May to December 1997, 18 cases of mild to severe respiratory illness caused by avian influenza A (H5N1) viruses were identified in Hong Kong. The emergence of an avian virus in the human population prompted an epidemiological investigation to determine the extent of human-to-human transmission of the virus and risk factors associated with infection. The hemagglutination inhibition (HI) assay, the standard method for serologic detection of influenza virus infection in humans, has been shown to be less sensitive for the detection of antibodies induced by avian influenza viruses. Therefore, we developed a more sensitive microneutralization assay to detect antibodies to avian influenza in humans. Direct comparison of an HI assay and the microneutralization assay demonstrated that the latter was substantially more sensitive in detecting human antibodies to H5N1 virus in infected individuals. An H5-specific indirect enzyme-linked immunosorbent assay (ELISA) was also established to test children’s sera. The sensitivity and specificity of the microneutralization assay were compared with those of an H5-specific indirect ELISA. When combined with a confirmatory H5-specific Western blot test, the specificities of both assays were improved. Maximum sensitivity (80%) and specificity (96%) for the detection of anti-H5 antibody in adults aged 18 to 59 years were achieved by using the microneutralization assay combined with Western blotting. Maximum sensitivity (100%) and specificity (100%) in detecting anti-H5 antibody in sera obtained from children less than 15 years of age were achieved by using ELISA combined with Western blotting. This new test algorithm is being used for the seroepidemiologic investigations of the avian H5N1 influenza outbreak.
827 citations
TL;DR: The possible effects of the next influenza pandemic in the United States and the economic impact of vaccine-based interventions are estimated and a net savings to society is projected if persons in all age groups are vaccinated.
Abstract: We estimated the possible effects of the next influenza pandemic in the United States and analyzed the economic impact of vaccine-based interventions. Using death rates, hospitalization data, and outpatient visits, we estimated 89,000 to 207,000 deaths; 314,000 to 734,000 hospitalizations; 18 to 42 million outpatient visits; and 20 to 47 million additional illnesses. Patients at high risk (15% of the population) would account for approximately 84% of all deaths. The estimated economic impact would be US$71.3 to $166.5 billion, excluding disruptions to commerce and society. At $21 per vaccinee, we project a net savings to society if persons in all age groups are vaccinated. At $62 per vaccinee and at gross attack rates of 25%, we project net losses if persons not at high risk for complications are vaccinated. Vaccinating 60% of the population would generate the highest economic returns but may not be possible within the time required for vaccine effectiveness, especially if two doses of vaccine are required.
665 citations
TL;DR: Exposure to live poultry (by visiting either a retail poultry stall or a market selling live poultry) in the week before illness began was significantly associated with H5N1 disease, and travel, eating or preparing poultry products, recent exposure to persons with respiratory illness, including persons with known influenza A (H5n1) infection, were not associated withH5N 1 disease.
Abstract: In May 1997, a 3-year-old boy in Hong Kong died of a respiratory illness related to influenza A (H5N1) virus infection, the first known human case of disease from this virus. An additional 17 cases followed in November and December. A case-control study of 15 of these patients hospitalized for influenza A (H5N1) disease was conducted using controls matched by age, sex, and neighborhood to determine risk factors for disease. Exposure to live poultry (by visiting either a retail poultry stall or a market selling live poultry) in the week before illness began was significantly associated with H5N1 disease (64% of cases vs. 29% of controls, odds ratio, 4.5, P=.045). By contrast, travel, eating or preparing poultry products, recent exposure to persons with respiratory illness, including persons with known influenza A (H5N1) infection, were not associated with H5N1 disease.
284 citations
TL;DR: One H5 antibody-positive household contact provided evidence that human-to-human transmission of the avian virus may have occurred through close physical contact with H5N1-infected patients, and social exposure to case patients was not associated with H 5N1 infection.
Abstract: The first documented outbreak of human respiratory disease caused by avian influenza A (H5N1) viruses occurred in Hong Kong in 1997. The kinetics of the antibody response to the avian virus in H5N1-infected persons was similar to that of a primary response to human influenza A viruses; serum neutralizing antibody was detected, in general, >/=14 days after symptom onset. Cohort studies were conducted to assess the risk of human-to-human transmission of the virus. By use of a combination of serologic assays, 6 of 51 household contacts, 1 of 26 tour group members, and none of 47 coworkers exposed to H5N1-infected persons were positive for H5 antibody. One H5 antibody-positive household contact, with no history of poultry exposure, provided evidence that human-to-human transmission of the avian virus may have occurred through close physical contact with H5N1-infected patients. In contrast, social exposure to case patients was not associated with H5N1 infection.
240 citations
64 citations
TL;DR: The collaborative planning process has been the development of new working relationships and partnerships among several agencies at the state, local and national levels that will improve the collective ability to rapidly investigate and control public health threats in the 21st century.
Abstract: In the US, planning for the next influenza pandemic is occurring in parallel at the national, state and local levels. Certain issues, such as conducting surveillance and purchasing pandemic vaccine, require co-ordination at the national level. However, most prevention and control actions will be implemented at the state and local levels, which vary widely in terms of population demographics, culture (e.g. rural versus urban) and available resources. In 1995, a survey by the Council of State and Territorial Epidemiologists (CSTE) found that only 29 (59%) states perceived a need to develop a specific influenza pandemic plan for their jurisdiction. Since then, the process of developing state and local plans has gained considerable momentum. Integration of these efforts with the national planning process has been facilitated by: (1) the mutual involvement of state and federal staff in both processes; (2) the sharing of draft documents; (3) the ongoing occurrence of local and national co-ordinating meetings; (4) the provision of financial resources by the federal government. So far, approximately 12 states either have drafted or begun drafting a state and local influenza pandemic plan. One of the benefits of the collaborative planning process has been the development of new working relationships and partnerships among several agencies at the state, local and national levels. Such efforts will improve our collective ability to rapidly investigate and control other emerging or re-emerging public health threats in the 21st century, be it a bioterrorist event, pandemic influenza, or any other catastrophic health event.
39 citations