145 research outputs found

    Reflections on The Global Influenza Surveillance and Response System (GISRS) at 65 Years: An Expanding Framework for Influenza Detection, Prevention and Control

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142476/1/irv12511_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142476/2/irv12511.pd

    Influenza: Quantifying morbidity and mortality

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    Because of their dramatic impact, morbidity and mortality associated with influenza have been recognized since et lent the time of Elizabeth I of England. Excess mortality has been documented since 1889, and the infamous 1918 outbreak confirmed that influenza was truly one of the last major plagues. Despite the clear recognition of large clusters of influenza activity, it is still difficult to quantify precisely the total impact of influenza morbidity and mortality, since laboratory confirmation is required for exact diagnosis. Many methods have been developed to provide estimates of the mortality associated with Influenza. These methods are usually predicated on establishing expected baseline rates of mortality. Deaths in excess of these rates are then calculated--and attributed to the circulating influenza virus. In this way, groups et high risk of mortality have been defined as the elderly and those with chronic conditions. Special-risk groups, such as those in institutions, have also been identified. The quantification of morbidity has required different approaches, and here community and family studies have made major contributions. In contrast to mortality, morbidity is most pronounced in children and Young adults, and the diseases, although self-limited, are offen quite severe. Although the site of the outbreaks varies, influenza infection can be documented annually. Thus, each year must be considered an influenza year.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26677/1/0000221.pd

    Effectiveness of Inactivated Influenza Vaccine Among Nursing Home Residents During an Influenza Type A (H3N2) Epidemic

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111257/1/j.1532-5415.1999.tb04574.x.pd

    EFFECT OF NEURAMINIDASE ANTIBODY ON HONG KONG INFLUENZA

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    The relation between antineuraminidase antibody (A.N.) and natural influenza infection in 1968 was investigated in the community of Tecumseh, Michigan. The outbreak was caused by Hong Kong influenza virus, which contained a new haemagglutinin antigen (H3), while the neuraminidase antigen (N2) was more closely related to that of Asian viruses circulating since 1957. In the study group of two hundred and seventy-four randomly selected adults (aged 20-45), titres of N2 neuraminidase antibody were detected in a hundred and fifteen (42%) serum samples collected before the outbreak. Influenza infection during the course of the outbreak was identified serologically. The frequency of infection decreased significantly at increasing levels of pre-existing A.N. antibody. In those subjects who were not protected from infection, A.N. antibody significantly suppressed the clinical expression of infection. It is concluded that antibody against the neuraminidase of the influenza virus prevented or modified infection in a situation in which haemagglutinin antibody had no effect.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33917/1/0000183.pd

    Maximum likelihood estimation of influenza vaccine effectiveness against transmission from the household and from the community

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142449/1/sim7558_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142449/2/sim7558.pd

    Vaccines and Antiviral Drugs in Pandemic Preparedness

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    Controlling a pandemic with vaccine and antiviral drugs will require a coordinated international approach to determine how the least amount of virus can immunize the largest segment of a population

    Human coronaviruses and other respiratory infections in young adults on a university campus: Prevalence, symptoms, and shedding

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145532/1/irv12563.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145532/2/irv12563_am.pd

    HAI and NAI titer correlates of inactivated and live attenuated influenza vaccine efficacy

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    Abstract Background High hemagglutination inhibition (HAI) and neuraminidase inhibition (NAI) titers are generally associated with reduced influenza risk. While repeated influenza vaccination reduces seroresponse, vaccine effectiveness is not always reduced. Methods During the 2007-2008 influenza season, a randomized, placebo-controlled trial (FLUVACS) evaluated the efficacies of live-attenuated (LAIV) and inactivated influenza vaccines (IIV) among healthy adults aged 18-49 in Michigan; IIV vaccine efficacy (VE) and LAIV VE against influenza disease were estimated at 68% and 36%. Using the principal stratification/VE moderation framework, we analyzed data from this trial to assess how each VE varied by HAI or NAI responses to vaccination observed for vaccinated individuals and predicted counterfactually for placebo recipients. We also assessed how each VE varied with pre-vaccination/baseline variables including HAI titer, NAI titer, and vaccination history. Results IIV VE appeared to increase with Day 30 post-vaccination HAI titer, albeit not significantly (p=0.20 and estimated VE 14.4%, 70.5%, and 85.5% at titer below the assay lower quantification limit, 512, and 4096 (maximum)). Moreover, IIV VE increased significantly with Day 30 post-vaccination NAI titer (p=0.040), with estimated VE zero at titer 10 and 92.2% at highest titer 640. There was no evidence that fold-change in post-vaccination HAI or NAI titer associated with IIV VE (p=0.76, 0.38). For LAIV, there was no evidence that VE associated with post-vaccination or fold-rise HAI or NAI titers (p-values >0.40). For IIV, VE increased with increasing baseline NAI titer in those previously vaccinated, but VE decreased with increasing baseline NAI titer in those previously unvaccinated. In contrast, for LAIV, VE did not depend on previous vaccination or baseline HAI or NAI titer. Conclusions: Future efficacy trials should measure baseline and post-vaccination antibody titers in both vaccine and control/placebo recipients, enabling analyses to better elucidate correlates of vaccine- and natural-protection. Trial registration: ClinicalTrials.gov NCT00538512. October 1, 2007.https://deepblue.lib.umich.edu/bitstream/2027.42/149182/1/12879_2019_Article_4049.pd

    Human coronaviruses and other respiratory infections in young adults on a university campus: Prevalence, symptoms, and shedding

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    BACKGROUND: The prevalence, symptom course, and shedding in persons infected with the 4 most common human coronaviruses (HCoV)-229E, HKU1, NL63, and OC43 are poorly described. OBJECTIVES: We estimate their prevalence and associated symptoms among college students identified via a social network study design. PATIENTS/METHODS: We collected 1-3 samples (n = 250 specimens) from 176 participants between October 2012 and January 17, 2013: participants with acute respiratory infection (ARI; cough and body aches or chills or fever/feverishness) and their social contacts. Virus was detected using RT-PCR. RESULTS: 30.4% (76/250) of specimens tested positive for any virus tested, and 4.8% (12/250) were positive for 2 or more viruses. Human coronaviruses (HCoVs [22.0%; 55/250]), rhinovirus (7.6%; 19/250), and influenza A (6.4%; 16/250) were most prevalent. Symptoms changed significantly over time among ARI participants with HCoV: the prevalence of cough and chills decreased over 6 days (P = .04, and P = .01, respectively), while runny nose increased over the same period (P = .02). HCoV-NL63 was the most frequent virus detected 6 days following symptom onset (8.9%), followed by rhinovirus (6.7%). CONCLUSIONS: During a 3-month period covering a single season, HCoVs were common, even among social contacts without respiratory symptoms; specific symptoms may change over the course of HCoV-associated illness and were similar to symptoms from influenza and rhinovirus
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