Diagnostic value of the molecular detection of Sarcoptes scabiei from a skin scraping in patients with suspected scabies

Scabies is a highly contagious parasitic disease associated with long-term residence in nursing homes, and it is a public health burden worldwide. However, atypical skin manifestations are frequent and the widely used diagnostic test based on microscopic examinations has limited sensitivity. We evaluated the diagnostic value of polymerase chain reaction (PCR) from skin scraping in patients with suspected scabies. Adult patients with suspected scabies, unrelated diseases or healthy volunteers were enrolled at a tertiary hospital, in Seoul, South Korea, from December 2017 through October 2018. We classified participants based on the consensus criteria established by the International Alliance for the Control of Scabies in 2018; confirmed (microscopic mite detection), clinical (scabies burrow or typical lesions with two history features including itch and close contact with scabies patients), suspected scabies (typical lesion with one history feature or atypical lesion with two history features), or no scabies. PCR was performed on the skin scrapings to target the cytochrome c oxidase subunit 1 (cox1) gene of Sarcoptes scabiei. A total of 47 participants, 33 with suspected scabies, 10 with unrelated diseases, and 4 healthy volunteers were enrolled. Of the 33 patients, 22 were classified as confirmed scabies, 2 as clinical scabies, 6 as suspected scabies, and 3 as no scabies. The sensitivities of the microscopic examination were 100%, 92%, and 73% in confirmed scabies; confirmed and clinical scabies; and confirmed, clinical, and suspected scabies, respectively (p = 0.006). The sensitivities of PCR were 86%, 83%, and 80% in confirmed scabies; confirmed and clinical scabies; and confirmed, clinical, and suspected scabies, respectively (p = 0.59). The specificity of the scabies PCR in the no scabies control was 100% (95% CI = 80–100).PCR testing for scabies may be helpful in the improvement of sensitivity for the diagnosis of scabies by clinical criteria.

Scabies occasionally presents in atypical forms causing a delay in diagnosis, which can lead to the outbreaks in residential and nursing care for elderly people. We hypothesized that polymerase chain reaction (PCR) detection of Sarcoptes scabiei DNA directly has higher sensitivity than microscopic examination. Recently, clinical consensus criteria have been proposed by the International Alliance for the Control of Scabies (IACS) to overcome the low sensitivities of conventional diagnostic tests for scabies. We thus evaluated the diagnostic capability of in-house real-time PCR for the diagnosis of scabies from skin scraping in subjects with suspected scabies and with unrelated disease according to the criteria of the IACS. We found that the diagnostic sensitivity of scabies PCR maintained between 86% and 80% as the level of diagnostic certainty by the IACS criteria decreased, while the diagnostic sensitivity of microscopic examinations decreased from 100% to 73% as the level of diagnostic certainty by the IACS criteria decreased. Our data suggested that our in-house scabies PCR test was a useful adjunct in the improvement for the diagnosis of scabies by the consensus criteria.

Effect of glenohumeral stabilization exercises combined with scapular stabilization on shoulder function in patients with shoulder pain: A randomized controlled experimenter-blinded study

BACKGROUND

Shoulder stabilization exercises consisted of a glenohumeral stabilization and scapular stabilization. No studies have been assessed the superiority of shoulder stabilization until now.

OBJECTIVE

To compare the effect of a glenohumeral stabilization exercise (GSE) combined with a scapular stabilization exercise (SSE) on changes in shoulder function in patients with shoulder painMETHODS: Shoulder stability, scapular alignment, pain, muscle power, and range of motion (ROM) were measured before and after the intervention in both groups.

RESULTS

Forty subjects with shoulder pain were randomly assigned to an experimental or control group. GSE in the experimental group (n= 20) resulted in significantly better shoulder stability (P= 0.020, from 9.00 ± 6.90 score to 14.25 ± 8.58) and pain intensity (P= 0.042, 7.40 ± 2.44 score to 4.60 ± 2.06) compared to SSE in the controls (n= 20). However, no significant effects were observed for scapular symmetric alignment including the angles of inferior scapular distance (P= 0.555) and inferior scapular height difference (P= 0.770), muscle power including shoulder flexion (P= 0.942) and shoulder abduction (P= 0.551), or ROM including shoulder flexion (P= 0.852) and shoulder abduction (P= 0.622).

CONCLUSION

This study suggests that GSE positively affects shoulder stability and pain control in patients with shoulder pain, probably through a centralization effect on the shoulder mechanism.

Combined IFN-γ and TNF-α release assay for differentiating active tuberculosis from latent tuberculosis infection

OBJECTIVES

The IFN-γ-release assay (IGRA) cannot differentiate active tuberculosis (TB) from latent TB infection (LTBI). We hypothesized that the TNF-α-release assay (TARA) combined with IGRA might discriminate active TB from not active TB without LTBI.

METHODS

Adult patients with suspected TB, and with unrelated diseases such as herpes zoster as controls, were enrolled in an intermediate TB-burden country. Patients with confirmed or probable TB were regarded as active TB, and patients with not active TB were further classified as those having not active TB with and without LTBI based on IGRA results. The IGRA and TARA by using ELISPOT assays were performed on peripheral mononuclear cells.

RESULTS

Thirty six patients with active TB and 53 patients including 18 not active TB with LTBI and 35 not active TB without LTBI were finally included. The sensitivity and specificity of the IGRA for those patients found to have active TB were 94% (CI, 80-99) and 66% (CI 52-78), respectively. Combining the IGRA and the TARA substantially increased the specificity for active TB (93%, CI, 82-98; P = 0.001) compared with the IGRA only, without compromising sensitivity (89%, CI, 73-96; P = 0.67).

CONCLUSIONS

Combining the IGRA and TARA appears to be useful for diagnosing active TB.

Kinetics of viral load and cytokines in severe fever with thrombocytopenia syndrome

•

SFTS viremia persists until week 3 from the day of symptom onset.

•

The concentrations of inflammatory cytokines are elevated in SFTS patients.

•

IFN-α, IL-10, and IP-10 are associated with the initial cytokine storm.

Background

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease in China, Japan, and Korea, which is characterized by high fever, thrombocytopenia, and high mortality. It is hypothesized that a cytokine storm plays an important role in the pathophysiology of SFTS. However, limited data have been published on the detailed kinetics of the viral load and cytokine profiles throughout the course of this disease.

Objectives

We investigated the patterns of changes in cytokines and viral load in SFTS patients.

Study design

During the admission period of patients, RNA was extracted from plasma and quantified by reverse transcription polymerase chain reaction. In addition, cytokine bead arrays were performed for the 18 cytokines and chemokines selected for testing.

Results

The median time from admission to the negative conversion of SFTS viremia was 17.0 days. When censored patients were found to be negative for viral load at discharge, the median duration of viral shedding was 13.0 days (95% CI, 5.4–20.6). Interferon (IFN)-α, interleukin (IL)-10, and IFN-γ-induced protein (IP)-10 concentrations significantly increased in the early course of disease and then decreased during the hospital stay. However, the concentrations of tumor necrosis factor-α, IL-1β, IL-12p40, IL-13, IL-17A, Regulated on Activation and Normally T-cell Expressed and Secreted (RANTES), and vascular endothelial growth factor (VEGF) increased during the late course of disease. Initial IP-10 levels during hospital days 1–4 were the most significantly correlated with initial viral load (r = 0.88, P < .01).

Conclusion

SFTS viremia persisted until weeks 2–3 and was highly correlated with initial plasma IP-10 levels. In addition, IFN-α, IL-10, and IP-10 were associated with the initial cytokine storm in SFTS.