Patricia A. Clark

Bio: Patricia A. Clark is an academic researcher from Michigan Department of Community Health. The author has contributed to research in topics: Immunoglobulin M & Evolution of influenza. The author has an hindex of 3, co-authored 4 publications receiving 2361 citations.

Antigenic and Genetic Characteristics of Swine-Origin 2009 A(H1N1) Influenza Viruses Circulating in Humans

Abstract: Since its identification in April 2009, an A(H1N1) virus containing a unique combination of gene segments from both North American and Eurasian swine lineages has continued to circulate in humans. The lack of similarity between the 2009 A(H1N1) virus and its nearest relatives indicates that its gene segments have been circulating undetected for an extended period. Its low genetic diversity suggests that the introduction into humans was a single event or multiple events of similar viruses. Molecular markers predictive of adaptation to humans are not currently present in 2009 A(H1N1) viruses, suggesting that previously unrecognized molecular determinants could be responsible for the transmission among humans. Antigenically the viruses are homogeneous and similar to North American swine A(H1N1) viruses but distinct from seasonal human A(H1N1).

Enzyme-Linked Immunosorbent Assays Using Recombinant Envelope Protein Expressed in COS-1 and Drosophila S2 Cells for Detection of West Nile Virus Immunoglobulin M in Serum or Cerebrospinal Fluid

Abstract: Humans infected with West Nile virus (WNV) develop immunoglobulin M (IgM) antibodies soon after infection. The microtiter-based assays for WNV IgM antibody detection used by most state public health and reference laboratories utilize WNV antigen isolated from infected Vero cells or recombinant envelope protein produced in COS-1 cells. Recombinant antigen produced in COS-1 cells was used to develop a WNV IgM capture enzyme immunoassay (EIA). A supplementary EIA using WNV envelope protein expressed in Drosophila melanogaster S2 cells was also developed. Both assays detected WNV IgM in the sera of experimentally infected rhesus monkeys within approximately 10 days postinfection. Human sera previously tested for WNV IgM at a state public health laboratory (SPHL) were evaluated using both EIAs. Among the sera from 20 individuals with laboratory-confirmed WNV infection (i.e., IgM-positive cerebrospinal fluid [CSF]) that were categorized as equivocal for WNV IgM at the SPHL, 19 were IgM positive and one was negative by the new EIAs. Of the 19 IgM-positive patients, 15 were diagnosed with meningitis or encephalitis; the IgM-negative patient was not diagnosed with neurological disease. There was 100% agreement between the EIAs for the detection of WNV IgM. CSF samples from 21 individuals tested equivocal for WNV IgM at the SPHL; all 21 were positive in both bead assays, and 16 of these patients were diagnosed with neurological disease. These findings demonstrate that the new EIAs accurately identify WNV infection in individuals with confirmed WNV encephalitis and that they exhibit enhanced sensitivity over that of the microtiter assay format.

Reducing length of stay for patients undergoing transcatheter aortic valve replacement using a prescreening approach

Abstract: Supplemental Digital Content is Available in the Text. ABSTRACT Background: As transcatheter aortic valve replacement (TAVR) becomes a preferred treatment option for patients with aortic valve stenosis, and demand for TAVR increases, it is imperative that length of stay (LOS) is reduced while maintaining safety and effectiveness. Local Problem: As TAVR procedures have become less invasive and more streamlined, current protocols have not been updated to reflect today's postprocedure requirements. Methods: The next-day discharge (NDD) protocol was established using available literature. A convenience sample was evaluated for NDD protocol inclusion during aortic multidisciplinary team conference using predetermined inclusion and exclusion criteria. Length of stay for NDD protocol participants was compared with LOS from a retrospective convenience sample of patients undergoing TAVR in the time frame mirroring NDD protocol initiation of the year prior. Interventions: Patients meeting inclusion criteria were enrolled in the NDD protocol with a goal of discharge to home on postprocedural day 1 by 2:00 p.m. The NDD protocol included preprocedure expectation setting, prescheduled same-day postprocedure imaging, and discharge priority on postprocedure day 1. Results: There is a significant difference in LOS between the NDD eligible retrospective and prospective groups. The prospective group has a significantly lower LOS than the retrospective group (M = 1.6 vs 2.1, respectively; p = .0454). Conclusions: An NDD protocol can help reduce LOS after TAVR in appropriately selected patients. Further protocol revision will be required to optimize LOS outcomes.

“Bioinformatics” 특집을 내면서

Abstract: BIOE 402. Medical Technology Assessment. 2 or 3 hours. Bioentrepreneur course. Assessment of medical technology in the context of commercialization. Objectives, competition, market share, funding, pricing, manufacturing, growth, and intellectual property; many issues unique to biomedical products. Course Information: 2 undergraduate hours. 3 graduate hours. Prerequisite(s): Junior standing or above and consent of the instructor.

Origins and evolutionary genomics of the 2009 swine-origin H1N1 influenza A epidemic.

Abstract: In March and early April 2009, a new swine-origin influenza A (H1N1) virus (S-OIV) emerged in Mexico and the United States. During the first few weeks of surveillance, the virus spread worldwide to 30 countries (as of May 11) by human-to-human transmission, causing the World Health Organization to raise its pandemic alert to level 5 of 6. This virus has the potential to develop into the first influenza pandemic of the twenty-first century. Here we use evolutionary analysis to estimate the timescale of the origins and the early development of the S-OIV epidemic. We show that it was derived from several viruses circulating in swine, and that the initial transmission to humans occurred several months before recognition of the outbreak. A phylogenetic estimate of the gaps in genetic surveillance indicates a long period of unsampled ancestry before the S-OIV outbreak, suggesting that the reassortment of swine lineages may have occurred years before emergence in humans, and that the multiple genetic ancestry of S-OIV is not indicative of an artificial origin. Furthermore, the unsampled history of the epidemic means that the nature and location of the genetically closest swine viruses reveal little about the immediate origin of the epidemic, despite the fact that we included a panel of closely related and previously unpublished swine influenza isolates. Our results highlight the need for systematic surveillance of influenza in swine, and provide evidence that the mixing of new genetic elements in swine can result in the emergence of viruses with pandemic potential in humans.

Prevention and control of seasonal influenza with vaccines: recommendations of the Advisory Committee on Immunization Practices (ACIP), 2009.

Abstract: This report updates the 2009 recommendations by CDC's Advisory Committee on Immunization Practices (ACIP) regarding the use of influenza vaccine for the prevention and control of influenza (CDC. Prevention and control of influenza: recommendations of the Advisory Committee on Immunization Practices [ACIP]. MMWR 2009;58[No. RR-8] and CDC. Use of influenza A (H1N1) 2009 monovalent vaccine---recommendations of the Advisory Committee on Immunization Practices [ACIP], 2009. MMWR 2009;58:[No. RR-10]). The 2010 influenza recommendations include new and updated information. Highlights of the 2010 recommendations include 1) a recommendation that annual vaccination be administered to all persons aged >or=6 months for the 2010-11 influenza season; 2) a recommendation that children aged 6 months--8 years whose vaccination status is unknown or who have never received seasonal influenza vaccine before (or who received seasonal vaccine for the first time in 2009-10 but received only 1 dose in their first year of vaccination) as well as children who did not receive at least 1 dose of an influenza A (H1N1) 2009 monovalent vaccine regardless of previous influenza vaccine history should receive 2 doses of a 2010-11 seasonal influenza vaccine (minimum interval: 4 weeks) during the 2010--11 season; 3) a recommendation that vaccines containing the 2010-11 trivalent vaccine virus strains A/California/7/2009 (H1N1)-like (the same strain as was used for 2009 H1N1 monovalent vaccines), A/Perth/16/2009 (H3N2)-like, and B/Brisbane/60/2008-like antigens be used; 4) information about Fluzone High-Dose, a newly approved vaccine for persons aged >or=65 years; and 5) information about other standard-dose newly approved influenza vaccines and previously approved vaccines with expanded age indications. Vaccination efforts should begin as soon as the 2010-11 seasonal influenza vaccine is available and continue through the influenza season. These recommendations also include a summary of safety data for U.S.-licensed influenza vaccines. These recommendations and other information are available at CDC's influenza website (http://www.cdc.gov/flu); any updates or supplements that might be required during the 2010-11 influenza season also will be available at this website. Recommendations for influenza diagnosis and antiviral use will be published before the start of the 2010-11 influenza season. Vaccination and health-care providers should be alert to announcements of recommendation updates and should check the CDC influenza website periodically for additional information.

Hospitalized patients with 2009 H1N1 influenza in the United States, April-June 2009.

Abstract: BACKGROUND During the spring of 2009, a pandemic influenza A (H1N1) virus emerged and spread globally. We describe the clinical characteristics of patients who were hospitalized with 2009 H1N1 influenza in the United States from April 2009 to mid-June 2009. METHODS Using medical charts, we collected data on 272 patients who were hospitalized for at least 24 hours for influenza-like illness and who tested positive for the 2009 H1N1 virus with the use of a real-time reverse-transcriptase-polymerase-chain-reaction assay. RESULTS Of the 272 patients we studied, 25% were admitted to an intensive care unit and 7% died. Forty-five percent of the patients were children under the age of 18 years, and 5% were 65 years of age or older. Seventy-three percent of the patients had at least one underlying medical condition; these conditions included asthma; diabetes; heart, lung, and neurologic diseases; and pregnancy. Of the 249 patients who underwent chest radiography on admission, 100 (40%) had findings consistent with pneumonia. Of the 268 patients for whom data were available regarding the use of antiviral drugs, such therapy was initiated in 200 patients (75%) at a median of 3 days after the onset of illness. Data suggest that the use of antiviral drugs was beneficial in hospitalized patients, especially when such therapy was initiated early. CONCLUSIONS During the evaluation period, 2009 H1N1 influenza caused severe illness requiring hospitalization, including pneumonia and death. Nearly three quarters of the patients had one or more underlying medical conditions. Few severe illnesses were reported among persons 65 years of age or older. Patients seemed to benefit from antiviral therapy.