Showing papers by "Donald E. Low published in 1988"

25- to 30-nm virus particle associated with a hospital outbreak of acute gastroenteritis with evidence for airborne transmission

Abstract: Between November 1 and 22, 1985, an outbreak of acute, nonbacterial gastroenteritis occurred in a 600-bed hospital in Toronto, Ontario, Canada. Illness in 635 of 2,379 (27%) staff was characterized by fatigue, nausea, diarrhea, and vomiting and had a median duration of 24-48 hours. The finding of virus-like particles measuring 25-30 nm in six stool specimens and low rates of seroresponse to Norwalk virus (3/39) and Snow Mountain agent (1/6) suggest that a Norwalk-like virus was responsible for the outbreak. The outbreak was of abrupt onset and high incidence, affecting 79 people in a single day. No common food or water exposure could be identified. The attack rate was greatest (69%) for staff who had worked in the Emergency Room. Of 100 patients and their companions who visited the Emergency Room on November 11-12 for unrelated problems, 33 (33%) developed gastroenteritis 24-48 hours after their visit, versus 0 of 18 who visited the Emergency Room on November 8 (p less than 0.001). An analysis of housekeepers who worked at least once during the period from November 9-13, which included those who became ill during the period of November 9-14, showed that the risk of becoming ill was four times greater for those who visited or walked through the Emergency Room than for those who did not (p = 0.028). These data are consistent with the possibility of the airborne spread of a virus.

Evaluation ofa New LatexTestanda New EnzymeImmunoassay forDetermination ofRubella Immunity

Abstract: A new enzyme immunoassay (Rubenostika; OrganonTeknika, Turnhout, Belgium), a new latex agglutination test(Rubalex; OrionDiagnostica, Espoo, Finland), andthree other accepted methods forthedeterminationofrubella immunity were compared witha standard hemagglutination inhibition assay.Of224serum samples tested, 54(24%)were nonreactive and24(11%)were lowtitered. Allprocedures were veryspecific (94to100%).Rubenostika was theleast sensitive method(88%), andRubalex was themostsensitive (98%). Thehemagglutination inhibition (HAI) assayisconsidered thestandard methodforthedetection ofrubella antibodies (6,9).However, other lesstedious andmore rapid procedures havebeenfound tobeacceptable alternatives tothe HAIassayforrubella immunity screening. Rapidmethods that havebeendeveloped forrubella serology testing include enzyme immunoassay (1,2,5,8,13), latex agglutination (2, 3,5,7,10-13), passive hemagglutination (2,4,9),fluorescenceimmunoassay (1,4,9),andradioimmunoassay (4,9). Thepurposeofthis study was toevaluate five rapid commercial tests, including a new enzyme immunoassay (Rubenostika; Organon Teknika, Turnhout, Belgium) anda new latex agglutination procedure (Rubalex; OrionDiagnostica, Espoo,Finland), andcompare themwitha standard HAI assayforthedetermination ofrubella immunity. A total of224serum samples were tested byallmethods. Theserahadbeensubmitted forthedetermination ofrubella immunity, frozen at -70°C,andthawedonce prior to testing. Sera were selected toinclude 54(24%)nonimmune specimens and24(11%)samples withlowtiters ofantibody (1:8 to1:16) asdetermined byHAIassay.Usingthese sera, we evaluated two commercial enzyme immunoassay kits (Rubenostika, Organon; Rubazyme, AbbottLaboratories, NorthChicago, 111.), two latex agglutination procedures (Rubalex, Orion; Rubascan, BBL Microbiology Systems, Cockeysville, Md.),anda rapid passive hemagglutination procedure (Rubaquick; Abbott), andcompared themwith a standard HAIassay(RubeHIT; Behring, Marburg, Federal Republic ofGermany). TheHAIassaywas donefollowing pretreatment ofsera withkaolin, using reagents, controls, andstabilized human O erythrocytes supplied bythemanufacturer. Serathat were positive only atatiter of1:8byHAIassaywere retitrated to ensure thatthis was nota false-positive reaction. Forall otherprocedures, sera were tested without pretreatment, using reagents andcontrols supplied bythemanufacturer, according totheinstructions ofthemanufacturer. Latex agglutination withRubascan was donebyusing seradiluted 1:10, asrecommended bythemanufacturer toapproximate thelevel ofsensitivity obtained withHAI assaymethods, andalsobyusing undiluted serum samples. Alltests were doneblind; serawere coded, andcomparative results were unknownuntil thetabulation ofalldata. Thesensitivity, specificity, andpositive andnegative predictive values were