flu
[Optical immunoassay test for rapid detection of influenza A and B viruses: an evaluation]

[Article in Japanese]

Mitamura K, Sugaya N, Shimizu H, Nirasawa M, Takahashi K, Hirai Y, Takeuchi Y.

Department of Pediatrics, Nippon Kokan Hospital.

The optical immunoassay test (FLU OIA, BioStar, USA) for rapid detection of influenza A and B viral antigens was compared with viral isolation in cell culture. A total of 103 respiratory specimens were tested on 75 pediatric patients with acute respiratory illnesses. Influenza viruses were recovered in 40 specimens (type A: 5, Type B: 35). FLU OIA demonstrated 80.0% sensitivity and 68.8% specificity for nasopharyngeal aspirates and 36.7% sensitivity and 83.9% specificity for throat swabs. We also tested FLU OIA, retrospectively, using 78 supernatant samples from pediatric patients with influenza A virus infection frozen after cell culture. FLU OIA demonstrated 91.4% sensitivity and 92.3% specificity for nasopharyngeal aspirates and 50.0% sensitivity and 91.7% specificity for throat swabs diluted in viral transport media. Nasopharyngeal aspirates showed higher sensitivity than throat swabs for detection of influenza virus by FLU OIA. We believe this rapid test kit is useful for the detection of influenza A and B viruses.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10565124&dopt=Abstract flu, flu medicine, tamiflu



flu
Comparison of four clinical specimen types for detection of influenza A and B viruses by optical immunoassay (FLU OIA test) and cell culture methods.

Covalciuc KA, Webb KH, Carlson CA.

BioStar, Inc., Boulder, Colorado 80301, USA.

Although laboratory diagnosis of respiratory viruses has been widely studied, there is a relative insufficiency of literature examining the impact of specimen type on the laboratory diagnosis of influenza A and B. In a clinical study comparing the FLU OIA test with 14-day cell culture, clinical specimens from nasopharyngeal swabs, throat swabs, nasal aspirates, and sputum were obtained from patients experiencing influenza-like symptoms. A total of 404 clinical specimens were collected from 184 patients. Patients were defined as influenza positive if the viral culture of a specimen from any sample site was positive. Patients were defined as influenza negative if the viral cultures of specimens from all sample sites were negative. By this gold standard, culture and FLU OIA test results for each sample type were compared. For each of the four specimen types, the viral culture and FLU OIA test demonstrated equal abilities to detect the presence of influenza A or B virus or viral antigen. Sputum and nasal aspirate samples were the most predictive of influenza virus infection. Throat swabs were the least predictive of influenza virus infection, with both tests failing to detect influenza virus in nearly 50% of the throat samples studied.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10565916&dopt=Abstract flu, flu medicine, tamiflu



flu
Common colds. Reported patterns of self-care and health care use.

Vingilis E, Brown U, Hennen B.

Population and Community Health Unit, University of Western Ontario in London. evingili julian.uwo.ca

OBJECTIVE: To describe the self-reported prevalence and patterns of self-care and health care use for colds and flu. DESIGN: Using the expert panel method, a questionnaire was developed to explore self-care practices, attitudes, pharmaceutical use, and health care use for a range of cold and flu symptoms. SETTING: London and Windsor, Ont. PARTICIPANTS: Using a random-digit-dialing survey method, 210 residents were interviewed between November and December 1993. Of 1484 telephone numbers called, 1179 calls were ineligible. Two hundred ten questionnaires were completed for 305 eligible respondents. MAIN OUTCOME MEASURES: Demographic data, typical self-care practices, actual practice during respondents' last cold, opinions on appropriate practices, and knowledge of how to treat colds. RESULTS: Self-care was respondents' treatment of choice, and most respondents use over-the-counter drugs. Prescription drug use was low. Only 1% reported seeing a physician for their last cold. As the number of symptoms increased, however, reported use of over-the-counter drugs and calls or visits to doctors increased. CONCLUSIONS: Results are congruent with other studies showing that the health care practices of most respondents are consistent with low use of the health care system and high levels of self-care for colds and flu.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10587772&dopt=Abstract flu, flu medicine, tamiflu



flu
Unusual cervical spinal cord toxicity associated with intra-arterial carboplatin, intra-arterial or intravenous etoposide phosphate, and intravenous cyclophosphamide in conjunction with osmotic blood brain-barrier disruption in the vertebral artery.

Fortin D, McAllister LD, Nesbit G, Doolittle ND, Miner M, Hanson EJ, Neuwelt EA.

Department of Neurology, Oregon Health Sciences University, Portland 97201, USA.

BACKGROUND AND PURPOSE: When the clinical and radiologic characteristics of an unusual cervical spinal cord complication of intra-arterial (IA) chemotherapy with blood brain-barrier (BBB) disruption in the vertebral circulation are documented. Seven cases are reported and analyzed in search of a pathophysiologic explanation. METHODS: We retrospectively identified 94 patients who received a total of 380 standardized regimens of IA carboplatin, IA or IV etoposide phosphate, and IV cyclophosphamide infusion in conjunction with osmotic BBB disruption of the vertebral artery. We describe seven of those patients in whom unexpected neck pain developed followed by neurologic symptoms primarily in the upper extremities. RESULTS: The symptoms correlated with MR abnormalities (T1 hypointensity, T2 hyperintensity, and unusual contrast enhancement) in the cervical spinal cord, usually involving the gray matter. The neurologic deficits and MR changes were generally transient. One patient who received a flu vaccination 48 hours before the chemotherapy incurred progressive myelitis and expired. CONCLUSION: The pathophysiology of this complication is probably multifactorial but may be related to vascular streaming and an atypical inflammatory toxic reaction to carboplatin and etoposide. The complication has not recurred during a 6-month period following modification of the protocol.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10588099&dopt=Abstract flu, flu medicine, tamiflu



flu
Diagnosing influenza: the value of clinical clues and laboratory tests.

Hulson TD, Mold JW, Scheid D, Aaron M, Aspy CB, Ballard NL, Boren N, Gregory ME, Truong TC.

Westbrook Family Physicians, 1208 W. 15th St, Edmond, OK 73013, USA.

OBJECTIVE: Our goal was to determine the utility of clinical clues, white blood cell (WBC) and differential counts, and a rapid antigen test for differentiating influenza from coexistent infectious diseases during influenza epidemics. STUDY DESIGN: Data were collected during 3 consecutive influenza outbreaks over a 2-year period. The information collected included date of onset, symptoms, vaccine status, WBC and differential counts, ZstatFlu test (ZymeTx, Oklahoma City, Ok), and influenza culture. Using culture positivity as the criterion for influenza diagnosis, we compared cases with noncases on each variable independently and by logistic regression. Receiver operating characteristic curves were plotted for WBC count, ZstatFlu, and their combination in an effort to determine the most useful diagnostic strategy. POPULATION: We included consecutive patients presenting to a family practice office with fever, cough, sore throat, myalgia, and/or headache during flu season. OUTCOMES MEASURED: The outcomes were sensitivity, specificity, and other measures of test accuracy. RESULTS: Culture-positive cases could not be reliably distinguished from those that were culture negative using symptoms or vaccination status. Both WBC count and ZstatFlu results discriminated fairly well, and their combination did somewhat better. Differential counts were not helpful. WBC counts above 8000 were associated with a low probability of influenza. The sensitivity and specificity of the ZstatFlu were 65% and 83%, respectively. CONCLUSIONS: Our data suggest that symptoms and vaccine status do not reliably identify patients with influenza. Use of WBC counts and the ZstatFlu test can be helpful. The sequence, combination, and criteria for use of these tests depend on tradeoffs between undertreatment of influenza cases and the overtreatment of noninfluenza cases, and the cost and benefit projections for individual patients.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11742606&dopt=Abstract flu, flu medicine, tamiflu



flu
It'll only hurt a second? Microeconomic determinants of who gets flu shots.

Mullahy J.

Department of Preventive Medicine, University of Wisconsin-Madison, 537O5, USA. jmullahy facstaff.wisc.edu

Appreciating how the propensity to be immunized against the flu depends on individual characteristics and environments is essential for policies regarding influenza control to be formulated sensibly. To this point, the literature has offered little documentation on the determinants of influenza immunization. Beyond epidemiology, there are important economic issues that must be addressed to understand this form of preventive care. One concerns the relationship between labour supply and immunization propensity: While it is relatively costly (in terms of time costs) for workers to obtain immunizations, workers also have relatively more to lose from being ill with the flu. Another concern not generally appreciated is the extent to which individuals' perceived risks of infection may affect their propensities to be immunized. The paper also attempts to shed light on these issues. The analysis uses data from the 1991 National Health Interview Survey. Immunization propensity displays expected patterns by age and health status, while the results with respect to race, household structure, income and insurance are somewhat more surprising and/or novel. The estimated labour supply and perceived risk effects suggest that some aspects of the economics of preventive care generally not considered in empirical work are important and merit further consideration.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10082140&dopt=Abstract flu, flu medicine, tamiflu