Antibiotic practice patterns with procalcitonin levels in patients with acute lower respiratory tract infection

OBJECTIVES

Procalcitonin (PCT) testing is FDA approved to guide antibiotic therapy in patients with lower respiratory tract infection (LRTI). However, its utilization and impact on real-world antibiotic prescribing behavior are unknown. We investigated the rate of PCT testing to evaluate an association between initial PCT level and antibiotic prescription patterns for patients with suspected LRTI within a large integrated health system.

STUDY DESIGN

Retrospective cohort study.

METHODS

A retrospective cohort study (January 1, 2016, through December 31, 2017) was performed in patients 18 years and older who were hospitalized with LRTI and had a PCT measurement. Antibiotic changes were noted before and 36 hours after initial PCT results. Antibiotic concordance was determined using a PCT cutoff value of 0.25 mcg/L. Concordance was defined as (1) patients received antibiotics after a PCT of at least 0.25 mcg/L resulted or (2) antibiotics were withheld after a PCT less than 0.25 mcg/L resulted.

RESULTS

PCT testing occurred in 18% of hospitalized patients with LRTI. Among 1606 patients, antibiotic concordance with PCT results was 55%. Among the discordant population, 77% of patients received antibiotics in the setting of a low PCT level compared with 23% who did not receive antibiotics at a high PCT level. There were no statistical differences between LRTI types between patients with PCT-discordant and PCT-concordant care.

CONCLUSIONS

Within a real-world environment of patients hospitalized with LRTI, PCT testing was low and the PCT levels did not appear to influence antibiotic prescribing behavior. Our findings suggest that clinicians continue to prioritize clinical judgment over initial PCT levels when prescribing antibiotics for suspected LRTIs.

Two cases of uveitis associated with severe transaminitis during a Rickettsia typhi outbreak in Los Angeles County

Purpose

To report the clinical presentation, multimodal imaging, and management of two patients with Rickettsia typhi infection who presented with transaminitis and bilateral uveitis.

Observations

We report two cases of murine typhus-associated uveitis in the setting of a Rickettsia typhi outbreak in Los Angeles County. In case 1, a 29-year-old Hispanic female presented with scotoma of the right eye and bilateral floaters after 2 weeks of persistent fevers, maculopapular rash, and arthralgia. Clinical examination and optical coherence tomography (OCT) revealed vitreous cell and scattered white spots in both eyes at the level of the inner retina, and a cotton wool spot inferiorly in the left eye. Multiple hyperautofluorescent spots were seen on widefield fundus autofluorescence (FAF). Retinal vascular leakage and optic disc hyperfluorescence were visualized on widefield fluorescein angiography (FA). These findings were concerning for a white dot syndrome (WDS). The patient was started on oral prednisone 30 mg daily. Serologic testing during the convalescent phase returned positive for R. typhi infection and she was started on doxycycline. 3 weeks later, she reported complete resolution of scotoma and significant improvement of bilateral floaters.

In the second case, a 42-year-old Hispanic male presented with sudden bilateral increased floaters and blurry vision after 12 days of persistent fever and headache. Clinical examination revealed trace flare with 1+ cell in the anterior chamber, 1+ vitreous cell, and multiple white dots in both eyes at the level of the inner retina. FAF showed scattered hyperautofluorescent spots in both eyes. FA demonstrated late retinal vascular leakage with bilateral hyperfluorescent optic discs. He was started on oral prednisone 40mg, prednisolone acetate 1% drops, and cyclopentolate 1% drops daily. 2 weeks later, serologic titers returned positive for murine typhus and he was started on doxycycline with gradual taper off of steroids. He subsequently had complete resolution of floaters, blurry vision, and the inner retinal white spots.

Conclusions and Importance

Murine typhus-associated uveitis may present with scotoma and increased floaters in the setting of persistent fevers and transaminitis, with pre- or inner retinal white spots seen on fundus examination. Ophthalmologists may aid in prompt diagnosis and initiation of antibiotic therapy, which can shorten the course of the disease and in turn, reduce the risk of severe complications.

Performance of Treponemal Tests for the Diagnosis of Syphilis

BACKGROUND

Treponemal immunoassays are increasingly used for syphilis screening with the reverse sequence algorithm. There are few data describing performance of treponemal immunoassays compared to traditional treponemal tests in patients with and without syphilis.

METHODS

We calculated sensitivity and specificity of 7 treponemal assays: (1) ADVIA Centaur (chemiluminescence immunoassay [CIA]); (2) Bioplex 2200 (microbead immunoassay); (3) fluorescent treponemal antibody absorption test (FTA-ABS); (4) INNO-LIA (line immunoassay); (5) LIAISON CIA; (6) Treponema pallidum particle agglutination assay (TPPA); and (7) Trep-Sure (enzyme immunoassay [EIA]), using a reference standard combining clinical diagnosis and serology results. Sera were collected between May 2012-January 2013. Cases were characterized as: (1) current clinical diagnosis of syphilis: primary, secondary, early latent, late latent; (2) prior treated syphilis only; (3) no evidence of current syphilis, no prior history of syphilis, and at least 4 of 7 treponemal tests negative.

RESULTS

Among 959 participants, 262 had current syphilis, 294 had prior syphilis, and 403 did not have syphilis. FTA-ABS was less sensitive for primary syphilis (78.2%) than the immunoassays or TPPA (94.5%-96.4%) (all P ≤ .01). All immunoassays were 100% sensitive for secondary syphilis, 95.2%-100% sensitive for early latent disease, and 86.8%-98.5% sensitive in late latent disease. TPPA had 100% specificity.

CONCLUSIONS

Treponemal immunoassays demonstrated excellent sensitivity for secondary, early latent, and seropositive primary syphilis. Sensitivity of FTA-ABS in primary syphilis was poor. Given its high specificity and superior sensitivity, TPPA is preferred to adjudicate discordant results with the reverse sequence algorithm over the FTA-ABS.

1348. Mycobacterium Chimera Infection Following Cardiac Surgery: A Review of a Large Cohort of Cases in the United States

Background

Methods

Results

Conclusion

Disclosures

240. The Clinical Utility of Molecular Testing in the Diagnosis and Management of Infectious Diseases: Plasma-based Next-Generation Sequencing (PNGS)

Background

Molecular diagnostic tests can provide microbiologic results rapidly and with greater sensitivity than traditional methods. However, these tests come with considerable costs, so thoughtful diagnostic stewardship is essential to ensure that resources and outcomes are optimized. We sought to evaluate the impact of PNGS testing on patient management.

Methods

From February 2017 to January 2019, physicians in our group ordered 164 PNGS tests (Karius, Redwood City CA) on 125 patients. A retrospective chart review was performed to determine the clinical indication and utility of the test.

Results

The assay failure rate was 4.9% (8/164). Positive (pos) results were noted in 34% (53/156), of which 23 (43.4%) represented false pos results; 28 were true pos (52.8%) but 2 were unnecessary (also had pos blood cultures). The most common reason for testing was to assess for Mycobacterium chimera (Mc) infection, representing 94 of 156 (60.3%) tests. Of the 21 patients with known Mc, only 10/21 had pos initial tests (47.6%); if patients with Mc localized to the sternum were excluded (8 patients), 76.9% with deep organ involvement had pos initial tests. Five patients with deep Mc infection had persistently pos results while on therapy; 4 of these had not had surgery; 1 was 6 months s/p valve replacement for Mc. The next most common indication was to r/o endocarditis in 18/156 (11.5%) and had an impact in 8/18 (44.4%), including 4 patients whose PNGS result identified a likely pathogen in culture negative endocarditis (CNE). Of the 62 tests done for non-Mc patients, 33.9% (21/62) were useful for management decisions. Among patients who eventually had a diagnosis made but had negative PNGS results included patients with Whipple’s (1), CNS infection (2), and fungal infections (5).

Conclusion

Overall, only 17.9% (28/156) of tests yielded true pos results. The most common reason was to evaluate for Mc infection. PNGS did not detect Mc in patients with proven local disease and was pos in >75% with deep/disseminated disease. However, a negative result did not exclude significant Mc infection. Repeat testing can be considered if clinical suspicion is high but should not be done before standard blood cultures are negative. While more than 60% of the non-Mc tests were not clinically useful, there was modest added utility where infection is high on the differential especially patients with CNE.

Disclosures

All authors: No reported disclosures.

A probable case of West Nile virus transfusion transmission

BACKGROUND

Transfusion-transmitted West Nile virus (WNV) infection is infrequent as a result of minipool (MP) and individual-donation (ID) nucleic acid testing (NAT) of blood donations. ID-NAT is triggered on the basis of local WNV activity identified by MP-NAT.

STUDY DESIGN AND METHODS

A 78-year-old male patient who was treated for cardiac disease received 14 blood components from 30 donors in August 2016. He was discharged 7 days after aortic valve replacement and coronary bypass surgery, but was re-admitted on Day 12 with symptoms of viral infection, and eventually was diagnosed with aseptic meningitis. The patent died on Day 51.

RESULTS

The patient was positive for WNV-immunoglobulin M (IgM) antibodies in his cerebrospinal fluid on Day 14 and was positive for WNV-IgM (on Days 14 and 16) and WNV-IgG antibodies (on Day 16) in his serum. All associated donations were nonreactive by MP-NAT or ID-NAT. However, one MP-NAT was noted to have an elevated (but negative) signal-to-cutoff ratio, and one donor from that MP was subsequently found positive for WNV-IgM and IgG antibodies; the donor was diagnosed with a WNV-like viral syndrome that had an onset 3 to 5 days postdonation. The donor's plasma was transfused 12 days before the patient's onset of WNV-meningoencephalitis. Conversion to ID-NAT was triggered for the region 7 days after the implicated donation, which was associated with the region's first human WNV case.

CONCLUSION

Despite the possibility of mosquito-borne transmission, this was considered to be a case of transfusion-transmitted WNV infection from an MP-NAT-nonreactive donation collected just before triggering conversion to ID-NAT; a rare event recognized once in 84 million donations.

Cytomegalovirus sinusitis complicated by orbital apex syndrome in an immunocompromised host

Sinusitis in immunocompromised patients can be caused by a wide variety of pathogens, primarily bacterial and fungal in nature. Tissue invasion can extend into the orbital apex and result in ophthalmoplegia and blindness. We report the first histologically proven case, to our knowledge, caused by cytomegalovirus infection.

Hepatitis B testing and vaccination among adults with sexually transmitted infections in a large managed care organization

Data on viral hepatitis B (HBV) testing and vaccination in primary care settings among persons at sexual risk for HBV infection have been sparse. We examined rates and factors associated with HBV serologic testing and vaccination rates in adults infected with sexually transmitted infections. We conducted a retrospective cohort study of adults diagnosed with chlamydia, gonorrhea, or syphilis in Kaiser Permanente Southern California in 2008-2011. The vaccine series initiation was examined in subjects who were tested susceptible. The 90-day hepatitis B surface antigen (HBsAg) testing rate was 28.1% in 15 357 adults. Testing rates increased through the study period. Only 8.8% of patients received both HBsAg and hepatitis B surface antibody tests to determine prior exposure and susceptibility to HBV. Among those who were tested susceptible, 116 (10.6%) subjects initiated the vaccine series. In multivariable logistic regression analysis, the odds of receiving testing was inversely associated with female sex, black race, other/unknown race, or having prespecified chronic comorbidities. In survival analysis, adults aged 25-34 years and ≥55 years were more likely to initiate hepatitis B vaccine series compared with those aged 18-24 years. There are missed opportunities in HBV testing and vaccination in primary care. Implementation of provider decision-making support tools in the electronic medical record system may potentially improve hepatitis B testing and vaccination rates.