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The nasopharyngeal culture in acute otitis media
Abstracts of literature
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gonorrhoea should receive a course of treatment as for established gonorrhoea. Other methods of gonorrhoea prevention in those at risk include education, genital hygiene (undefined), antisepsis and above all the use of the condom. THE NASOPHARYNGEALCULTURE IN ACUTE OTITIS MEDIA Schwartz, R., Rodriguez, W. J., Mann, R., Khan, W. and Ross, S. (1979). Journal of the American Medical Association, 241, 2170. The bacteria responsible for acute otitis media are rarely isolated as tympanocentesis is not routinely performed and treatment, therefore, tends to be 'best informed guess'. It seems logical to culture the nasopharynx, which is presumably the reservoir for middle ear pathogens. The authors investigated the relationship of nasopharyngeal culture compared to middle ear fluid culture simultaneously obtained on myringotomy. Two hundred and fifty-five children (mean age 34 months) were studied and overall there was a 72 per cent prediction rate for middle ear pathogens if the nasopharyngeal swab was plated immediately, and semiquantitative methods for bacterial counts were employed when reading the plates. The technique was most useful if 25 pe r cent or more of the colonies from nasopharyngeal cultured yielded a single pathogen; the technique was of additional use in predicting ampicillinresistant Haemoph~lus influenzae and g r o u p A streptococci as causative organisms of acute otitis media. However false positives did occur; in 16 out of 52 (30 per cent) where nasopharyngeal cultures were read as normal a pathogen was recovered from the middle earl In 20 out of 27 (74 per cent) of nasopharyngeal cultures of ampicillin-resistant Haemophilus influenzae the middle ear fluid revealed the same organism. No ampicillin-resistant organisms were isolated from the middle ear in the absence of a nasopharyngeal isolate. Thus it seems that this technique will confirm infection with resistant organisms. It is not necessarily of predictive value; one suspects that in many patients with resistant organisms tympanic perforation and other complications would occur before the nasopharyngeal culture results were available. Myringotomy was performed on children entering this study; it is debatable whether this procedure is of use or alters the early and most important therapeutic decisions. PROPAGATION OF HUMAN HEPATITIS A VIRUS IN CELL CULTURE I N VITRO (40422) Provost, P. J. and Hilleman M. R. (1979). Proceedings ofthe Society for Experimental Biology and Medicine, 160, 213.
Human hepatitis A virus has defied reliable in vitro propagation for more than half a century. In this paper the authors describe the first definitive proof of serial propagation in cell cultures obtained from marmoset liver ceils. The virus was also serially propagated in kidney cells from foetal rhesus monkies. Employing virus obtained from infected marmoset serum and liver it was demonstrated that viral propagation in marmoset liver cultures appear to be limited to cells resembling hepatocytes: virus was not detected in other cell types. Replication and unequivocal identification of virus in cell culture was verified by detection of antigen using immunofluorescent, radioimmunoassay, blocking immunofluorescent and serum neutralisation techniques (including tests performed with sera from human cases of hepatitis A). This propagation of hepatitis A virus is important for three reasons. (1) it provides a means of detecting human hepatitis A virtus, (2) it provides a means for preparing virus and derived antigens for use in serological tests, and (3) it provides a source of virus and antigen for vaccine preparation. (The authors had previously described elsewhere their preparation of an inactivated virus vaccine which induced antibody and protected against subsequent challenge with hepatitis A virus.) However, at present marmoset liver cell cultures do not abolish the need for in vivo cultures of hepatitis A virus.
387
gonorrhoea should receive a course of treatment as for established gonorrhoea. Other methods of gonorrhoea prevention in those at risk include education, genital hygiene (undefined), antisepsis and above all the use of the condom. THE NASOPHARYNGEALCULTURE IN ACUTE OTITIS MEDIA Schwartz, R., Rodriguez, W. J., Mann, R., Khan, W. and Ross, S. (1979). Journal of the American Medical Association, 241, 2170. The bacteria responsible for acute otitis media are rarely isolated as tympanocentesis is not routinely performed and treatment, therefore, tends to be 'best informed guess'. It seems logical to culture the nasopharynx, which is presumably the reservoir for middle ear pathogens. The authors investigated the relationship of nasopharyngeal culture compared to middle ear fluid culture simultaneously obtained on myringotomy. Two hundred and fifty-five children (mean age 34 months) were studied and overall there was a 72 per cent prediction rate for middle ear pathogens if the nasopharyngeal swab was plated immediately, and semiquantitative methods for bacterial counts were employed when reading the plates. The technique was most useful if 25 pe r cent or more of the colonies from nasopharyngeal cultured yielded a single pathogen; the technique was of additional use in predicting ampicillinresistant Haemoph~lus influenzae and g r o u p A streptococci as causative organisms of acute otitis media. However false positives did occur; in 16 out of 52 (30 per cent) where nasopharyngeal cultures were read as normal a pathogen was recovered from the middle earl In 20 out of 27 (74 per cent) of nasopharyngeal cultures of ampicillin-resistant Haemophilus influenzae the middle ear fluid revealed the same organism. No ampicillin-resistant organisms were isolated from the middle ear in the absence of a nasopharyngeal isolate. Thus it seems that this technique will confirm infection with resistant organisms. It is not necessarily of predictive value; one suspects that in many patients with resistant organisms tympanic perforation and other complications would occur before the nasopharyngeal culture results were available. Myringotomy was performed on children entering this study; it is debatable whether this procedure is of use or alters the early and most important therapeutic decisions. PROPAGATION OF HUMAN HEPATITIS A VIRUS IN CELL CULTURE I N VITRO (40422) Provost, P. J. and Hilleman M. R. (1979). Proceedings ofthe Society for Experimental Biology and Medicine, 160, 213.
Human hepatitis A virus has defied reliable in vitro propagation for more than half a century. In this paper the authors describe the first definitive proof of serial propagation in cell cultures obtained from marmoset liver ceils. The virus was also serially propagated in kidney cells from foetal rhesus monkies. Employing virus obtained from infected marmoset serum and liver it was demonstrated that viral propagation in marmoset liver cultures appear to be limited to cells resembling hepatocytes: virus was not detected in other cell types. Replication and unequivocal identification of virus in cell culture was verified by detection of antigen using immunofluorescent, radioimmunoassay, blocking immunofluorescent and serum neutralisation techniques (including tests performed with sera from human cases of hepatitis A). This propagation of hepatitis A virus is important for three reasons. (1) it provides a means of detecting human hepatitis A virtus, (2) it provides a means for preparing virus and derived antigens for use in serological tests, and (3) it provides a source of virus and antigen for vaccine preparation. (The authors had previously described elsewhere their preparation of an inactivated virus vaccine which induced antibody and protected against subsequent challenge with hepatitis A virus.) However, at present marmoset liver cell cultures do not abolish the need for in vivo cultures of hepatitis A virus.