Kikuchi-Fujimoto Disease Following COVID-19 Infection in a 7-Year-Old Girl: A Case Report and Literature Review.

The coronavirus disease 2019 (COVID-19) symptoms in children are relatively mild and often do not require treatment. Nonetheless, complications caused by the immune response to COVID-19 in children are possible and diverse. We present the case of a 7-year-old girl with persistent fever and lymphadenopathy arising from SARS-CoV-2 infection, diagnosed with Kikuchi-Fujimoto Disease (KFD) on lymph node biopsy. KFD is a rare benign disease, clinically characterized by fever and tender cervical lymphadenopathy affecting posterior cervical lymph nodes. We also reviewed six previously reported cases of COVID-19-associated KFD that occurred in school-aged children and compared them with the present case. The clinical course of COVID-19-associated KFD was similar to that of previous reports of KFD with a favorable prognosis. This is the first report of a school-aged child developing KFD following SARS-CoV-2 infection. KFD should be considered when approaching patients with hyperinflammatory states who present with prolonged fever and cervical lymphadenopathy after COVID-19.

Evaluation of a Novel Immunochromatographic Assay Using Monoclonal Antibodies against the Matrix Protein of Human Metapneumovirus.

BACKGROUND: The aim of this study was to determine the sensitivity and specificity of a novel immunochromatographic (IC) assay (APD1806) using monoclonal antibodies against the matrix (M) protein of human metapneumovirus (hMPV) for detection of hMPV from nasopharyngeal swab samples based on the results of real-time RT-PCR. METHODS: Nasopharyngeal swab samples taken from 189 patients aged 0 - 5 years who were suspected of having respiratory tract infections associated with hMPV were used in this study. The samples were tested both by the IC assay and by real-time RT-PCR for detection of hMPV. RESULTS: The sensitivity and specificity of the IC assay for detection of hMPV were 88.8% (95/107) and 92.7% (76/82), respectively. CONCLUSIONS: The IC assay using monoclonal antibodies against the M protein of hMPV is an accurate and fast assay that is suitable as a diagnostic tool for hMPV infection. The optimal timing of the IC assay is 12 hours or more after the onset of fever due to hMPV infection.

P1 gene of Mycoplasma pneumoniae isolated from 2016 to 2019 and relationship between genotyping and macrolide resistance in Hokkaido, Japan.

We characterized 515 Mycoplasma pneumoniae specimens in Hokkaido. In 2013 and 2014, the p1 gene type 1 strain, mostly macrolide-resistant, was dominant and the prevalence of macrolide resistance was over 50 %. After 2017, the p1 gene type 2 lineage, mostly macrolide-sensitive, increased and the prevalence of macrolide resistance became 31.0 % in 2017, 5.3 % in 2018 and 16.3 % in 2019.

Clinical effectiveness of four neuraminidase inhibitors (oseltamivir, zanamivir, laninamivir, and peramivir) for children with influenza A and B in the 2014-2015 to 2016-2017 influenza seasons in Japan.

The clinical effectiveness of four neuraminidase inhibitors (NAIs) (oseltamivir, zanamivir, laninamivir, and peramivir) for children aged 0 months to 18 years with influenza A and B were investigated in the 2014-2015 to 2016-2017 influenza seasons in Japan. A total of 1207 patients (747 with influenza A and 460 with influenza B) were enrolled. The Cox proportional-hazards model using all of the patients showed that the duration of fever after administration of the first dose of the NAI was shorter in older patients (hazard ratio = 1.06 per 1 year of age, p < 0.001) and that the duration of fever after administration of the first dose of the NAI was shorter in patients with influenza A infection than in patients with influenza B infection (hazard ratio = 2.21, p < 0.001). A logistic regression model showed that the number of biphasic fever episodes was 2.99-times greater for influenza B-infected patients than for influenza A-infected patients (p < 0.001). The number of biphasic fever episodes in influenza A- or B-infected patients aged 0-4 years was 2.89-times greater than that in patients aged 10-18 years (p = 0.010), and the number of episodes in influenza A- or B-infected patients aged 5-9 years was 2.13-times greater than that in patients aged 10-18 years (p = 0.012).

Altered myocardial flow reserve and endothelial function late after Kawasaki disease.

OBJECTIVES: Coronary arterial lesions after Kawasaki disease (KD) may cause coronary endothelial dysfunction as the result of intimal hypertrophy. Our purpose was to assess myocardial flow reserve (MFR) and endothelial function in various myocardial regions after KD by using positron emission tomography. STUDY DESIGN: Twenty-seven patients, 17.2 +/- 3.2 years of age, who had KD at 1.9 +/- 1.4 years, and 12 normal healthy subjects, 26.5 +/- 3.4 years of age, were evaluated by means of myocardial blood flow (MBF) with (15)O-water positron emission tomography. MFR was estimated by MBF changes under adenosine triphosphate infusion and endothelial function by MBF changes under cold pressor testing. The left ventricle was divided into three coronary territories. Ten stenotic regions, 20 aneurysmal regions, 30 regressed aneurysmal regions, and 21 regions without coronary arterial lesions were compared with 36 control regions of the normal volunteers. RESULTS: MBF at rest was similar in each region. Hyperemic blood flow and MFR in each region after KD was significantly lower than those in the regions of normal volunteers. MBF during cold pressor testing was significantly reduced in each region after KD, as compared with no change in the control regions. CONCLUSIONS: Our study indicates impaired MFR and endothelial function regardless of coronary artery status after KD.

Assessment of coronary function in children with a history of Kawasaki disease using (15)O-water positron emission tomography.

BACKGROUND: Coronary abnormalities after Kawasaki disease (KD) may be associated with endothelial dysfunction due to intimal hypertrophy. The purpose of this study was to evaluate myocardial flow reserve (MFR) and endothelial function in regressed aneurysmal regions after KD. Methods and Results- Subjects were 12 patients aged 16.0+/-2.6 years who suffered from KD at 1.7+/-1.5 years and 12 normal subjects aged 26.5+/-3.4 years. MFR and endothelial function were estimated, respectively, by changes in myocardial blood flow (MBF) during ATP infusion and by that during cold pressor test using (15)O-water positron emission tomography. Data from 24 regressed aneurysmal regions were compared with those from the corresponding regions (n=36) in the control group. Although the MBF at rest in the regressed aneurysmal regions was similar to that in controls, the MBF at a hyperemic state induced by ATP infusion in the regressed aneurysmal regions was significantly lower than that in the control regions. Therefore, the MFR in regressed aneurysmal regions was significantly lower than that in controls (3.53+/-0.95 versus 4.60+/-1.14; P<0.05). MBF at rest and during the cold pressor test did not change in the control regions, but it was significantly reduced in regressed aneurysmal regions. The ratio of MBF during the cold pressor test to MBF at rest was significantly lower in regressed aneurysmal regions than in control regions (0.67+/-0.15 versus 1.00+/-0.15; P<0.05). CONCLUSIONS: MFR and endothelial function are often impaired in regressed aneurysmal regions after KD, and tomography enables the noninvasive evaluation of coronary function.