An article published in the January issue of JAMA Ophthalmology (formerly Archives of Ophthalmology) describe a sensitive and specific point-of-care test that can help clinicians quickly and easily reach a diagnosis for adenoviral conjunctivitis.
The test uses direct sampling microfiltration and is based on lateral flow technology, similar to a home pregnancy test. The test producse visual results, with a blue control line and, if positive, a red test line.
The article evaluates the adenovirus test (AdenoPlus, Rapid Pathogen Screening Inc), which detects the most common cause of viral conjunctivitis. Adenovirus-associated conjunctivitis may lead to significant ocular morbidity and is associated with substantial healthcare costs.
Researchers led by Robert Sambursky, MD, a cornea specialist at the Manatee Sarasota Eye Clinic and Laser Center in Sarasota, Florida, compared this recently US Food and Drug Administration–cleared second-generation test with traditional gold standard tests.
"Ophthalmologists and optometrists that have access to a slit lamp biomicroscope and who should be the experts are somewhere between 25% to 60% accurate at making a differentiation between a viral and bacterial disease...and that impacts treatment," Dr. Sambursky told Medscape Medical News.
For the multicenter trial, the researchers recruited 128 patients (76 females, 52 males) with a clinical diagnosis of acute viral conjunctivitis in a prospective, sequential manner within 7 days of developing a red eye. Patients ranged in age from 5 to 90 years, with a mean duration of symptoms among patients from each center of between 2.8 and 3.7 days.
Tear samples were collected with the test device as well as for testing by viral cell culture with confirmatory immunofluorescence assay (CC-IFA) and for polymerase chain reaction (PCR). If either CC-IFA or PCR were positive, the patient was considered definitively positive for adenoviral conjunctivitis. If both were negative, the patient was considered negative for adenoviral infection. The AdenoPlus test, which requires only 10 minutes to develop after sample collection, was read by an independent healthcare professional masked to the clinical examination results.
High Sensitivity and Specificity
Of the 128 patients, 36 were positive by either CC-IFA or PCR. Cell culture has been the traditional definitive test for adenovirus infection. "Compared to [that] gold standard, AdenoPlus has a 90% sensitivity and a 96% specificity," Dr. Sambursky said. "When you actually compare it to PCR, that specificity goes up to about 98% and still maintains a good sensitivity in the mid-80s." Compared with CC-IFA, the test had a positive predictive value of 88% and a negative predictive value of 97%. Compared with PCR, the positive predictive value was 94% and the negative predictive value was 95%.
"[T]he rapidity is a major advantage" of the new test, Dr. Sambursky said. Making a diagnosis early allows withholding inappropriate antibiotics from patients with viral disease instead of treating them empirically, thereby reducing the potential for developing antibiotic resistance, complications, and toxicities. "[N]ot treating is as important as treating effectively," he noted.
Stephanie Marioneaux, MD, a cornea specialist in private practice in Chesapeake, Virginia, and an expert spokesperson from the American Academy of Ophthalmology, commended the trial for comparing AdenoPlus with the gold standard tests, which "are so burdensome, and they are not readily available to your average clinician," she told Medscape Medical News. "[W]hereas this now makes the test much more widely accessible." She noted that the researchers used appropriate patient eligibility criteria, a wide age range of patients, and masked examiners.
Dr. Marioneaux said the test "will add a lot to the clinician's ability to rapidly diagnose something that is extremely contagious and is often very difficult to diagnose." Getting infected patients out of the office quickly is an advantage, she said, because the virus is highly contagious and can persist on surfaces for weeks.
The test uses direct sampling microfiltration and is based on lateral flow technology, similar to a home pregnancy test. The test producse visual results, with a blue control line and, if positive, a red test line.
The article evaluates the adenovirus test (AdenoPlus, Rapid Pathogen Screening Inc), which detects the most common cause of viral conjunctivitis. Adenovirus-associated conjunctivitis may lead to significant ocular morbidity and is associated with substantial healthcare costs.
Researchers led by Robert Sambursky, MD, a cornea specialist at the Manatee Sarasota Eye Clinic and Laser Center in Sarasota, Florida, compared this recently US Food and Drug Administration–cleared second-generation test with traditional gold standard tests.
"Ophthalmologists and optometrists that have access to a slit lamp biomicroscope and who should be the experts are somewhere between 25% to 60% accurate at making a differentiation between a viral and bacterial disease...and that impacts treatment," Dr. Sambursky told Medscape Medical News.
For the multicenter trial, the researchers recruited 128 patients (76 females, 52 males) with a clinical diagnosis of acute viral conjunctivitis in a prospective, sequential manner within 7 days of developing a red eye. Patients ranged in age from 5 to 90 years, with a mean duration of symptoms among patients from each center of between 2.8 and 3.7 days.
Tear samples were collected with the test device as well as for testing by viral cell culture with confirmatory immunofluorescence assay (CC-IFA) and for polymerase chain reaction (PCR). If either CC-IFA or PCR were positive, the patient was considered definitively positive for adenoviral conjunctivitis. If both were negative, the patient was considered negative for adenoviral infection. The AdenoPlus test, which requires only 10 minutes to develop after sample collection, was read by an independent healthcare professional masked to the clinical examination results.
High Sensitivity and Specificity
Of the 128 patients, 36 were positive by either CC-IFA or PCR. Cell culture has been the traditional definitive test for adenovirus infection. "Compared to [that] gold standard, AdenoPlus has a 90% sensitivity and a 96% specificity," Dr. Sambursky said. "When you actually compare it to PCR, that specificity goes up to about 98% and still maintains a good sensitivity in the mid-80s." Compared with CC-IFA, the test had a positive predictive value of 88% and a negative predictive value of 97%. Compared with PCR, the positive predictive value was 94% and the negative predictive value was 95%.
"[T]he rapidity is a major advantage" of the new test, Dr. Sambursky said. Making a diagnosis early allows withholding inappropriate antibiotics from patients with viral disease instead of treating them empirically, thereby reducing the potential for developing antibiotic resistance, complications, and toxicities. "[N]ot treating is as important as treating effectively," he noted.
Stephanie Marioneaux, MD, a cornea specialist in private practice in Chesapeake, Virginia, and an expert spokesperson from the American Academy of Ophthalmology, commended the trial for comparing AdenoPlus with the gold standard tests, which "are so burdensome, and they are not readily available to your average clinician," she told Medscape Medical News. "[W]hereas this now makes the test much more widely accessible." She noted that the researchers used appropriate patient eligibility criteria, a wide age range of patients, and masked examiners.
Dr. Marioneaux said the test "will add a lot to the clinician's ability to rapidly diagnose something that is extremely contagious and is often very difficult to diagnose." Getting infected patients out of the office quickly is an advantage, she said, because the virus is highly contagious and can persist on surfaces for weeks.
Many times a patient would wonder why on other occasions, conjunctivitis occur more often than usual. Trust that once a member of the household contracts one, the rest of the family will get it too.
ReplyDeleteEddie Perez