Can Rapid Viral Testing Reduce Unnecessary Antibiotic Use?

Adults with an acute respiratory illness or fever who had rapid point-of-care testing (POCT) for viruses had a higher percentage of either a single dose of antibiotics or a course of less than 48 hours compared with those receiving standard care, according to a new trial published in the Lancet Respiratory Medicine.¹

Acute respiratory infections are the third most common cause of death worldwide.² Recent studies show that viruses are detected by molecular testing in 40% to 50% of adults hospitalized for acute respiratory infections.³ However, physicians prescribe antibiotics to most patients hospitalized with an acute respiratory illness,¹ and overuse and misuse of antibiotics significantly contribute to bacterial resistance and continue to be a threat to global health.⁴

The diagnostic uncertainty of microbial etiology contributes to the practice of antibiotic overuse and missuse.¹ Recently, a rapid molecular testing platform for respiratory viruses has been developed with accuracy comparable to that of laboratory polymerase chain reaction testing.

Nathan Brendish, MBBS, MRCP, and colleagues from the University Hospital Southampton, United Kingdom, sought to determine whether employing a rapid point-of-care molecular testing platform for viruses would reduce unnecessary antibiotic use, improve influenza detection, or reduce hospital length of stay.

The authors performed an open-label RCT enrolling adults presenting to the emergency department or acute medical unit of a large UK hospital with an acute respiratory illness and/or fever (≤7 days). The study was performed during the winter months and included 362 patients receiving molecular POCT for respiratory viruses and 358 receiving standard care (control group) with laboratory polymerase chain reaction viral testing performed at the discretion of the physician.

Results for the primary outcome revealed 84% of the patients received antibiotics in the POCT group compared with 83% in the control group (not significant). However, many of the patients received antibiotics before randomization or POCT results. Therefore, the authors performed a post hoc analysis of patients who received antibiotics after randomization and POCT results. In this subgroup analysis, 61 (51%) of 120 patients in the POCT group received antibiotics compared with 107 (64%) of 167 in the control group (difference, −13.2%; 95% CI, −24.8% to −1.7%; P =.0289).

Antibiotics given for less than 48 hours were significantly higher in the POCT group (50/301; 17%) compared with in the control group (26/294; 9%), for a difference of 7.8% (95% CI, 2.5%-13.1%; P =.0047). Importantly, recent evidence suggests this type of early discontinuation is associated with a reduced risk for drug resistance.⁵

All patients in the POTC group were tested for viruses (with 45% testing positive) compared with 45% in the control group (with 15% testing positive), for a difference of 30.0% (95% CI, 23.3%-36.8%; P <.0001). There was also a significant difference in average turnaround time for physicians to see the results of their testing (2.3 vs 37.1 hours; P <.0001) in the POCT compared with in the control groups, respectively.

The average length of hospital stay was shorter in the POTC group, at 5.7 days, compared with in the control group, at 6.8 days (difference, −1.1; 95% CI, −2.2 to −0.3; P =.0443).

In addition, the appropriate use of neuraminidase inhibitors in influenza-positive patients was more common, at 91%, in the POTC group compared with 65% in the control group (P =.0026).

No significant differences in adverse outcomes were found between the groups.

The authors concluded by drawing attention to the need for further research, and if reproduced, “routine molecular POTC testing for viruses should be introduced into diagnostic pathways for acute respiratory illness in adults presenting to the hospital during the winter months.”

References

1. Brendish NJ, Malachira AK, Armstrong L, et al. Routine molecular point-of-care testing for respiratory viruses in adults presenting to hospital with acute respiratory illness (ResPOC): a pragmatic, open-label, randomised controlled trial. Lancet Respir Med. 2017;5:401-411. doi: 10.1016/S2213-2600(17)30120-0
2. Naghavi M, Wang H, Lozano R, et al. Global, regional, and national age-sex specific all-cause and cause-specific mortality for 240 causes of death, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet. 2015;385:117-171. doi: 10.1016/S0140-6736(14)61682-2
3. Clark TW, Medina MJ, Batham S, Curran MD, Parmar S, Nicholson KG. Adults hospitalized with acute respiratory illness rarely have detectable bacteria in the absence of COPD or pneumonia; viral infection predominates in a large prospective UK sample. J Infect. 2014;69:507-515. doi: 10.1016/j.jinf.2014.07.023
4. Paterson IK, Hoyle A, Ochoa G, Baker-Austin C, Taylor NG. Optimising antibiotic usage to treat bacterial infections. Sci Rep. 2016;6:37853. doi: 10.1038/srep37853
5. Raman K, Nailor MD, Nicolau DP,  Aslanzadeh J, Nadeau M, Kuti JL. Early antibiotic discontinuation in patients with clinically suspected ventilator-associated pneumonia and negative quantitative bronchoscopy cultures. Crit Care Med. 2013;41:1656-1663. doi: 10.1097/CCM.0b013e318287f713