ABSTRACT
Japanese spotted fever (JSF) is an emerging acute febrile natural infectious disease caused by the neglected zoonotic pathogen Rickettsia japonica. Here we reported a 64-year-old female patient who initially presented to the local hospital with an intermittent fever of unknown origin (FUO). A systemic, evident edema and eschar on the skin of the patient's upper limb was observed. The patient was diagnosed with critical Rickettsia japonica bloodstream infection by Q-mNGS and treated with doxycycline, as well as symptomatic treatments. Unfortunately, the patient passed away as a result of complications of septic shock and multiple organ and acute respiratory failure. Delayed treatment resulting from the nonspecific clinical symptoms in the early stages of infection can lead to fatal complications. Q-mNGS is an emerging pathogen detection method with the advantages of comprehensive detection, high accuracy and sensitivity and should be promoted and applied by clinicians.
Japanese spotted fever is an emerging infectious disease caused by the bacteria Rickettsia japonica. The onset of symptoms in patients is very sudden once infected. Here, we reported a 64-year-old female patient who experienced recurrent fever with an unknown cause. The patient was diagnosed with Rickettsia japonica infection after testing and received antibiotic treatment. However, delays in treatment led to continuous worsening of the condition and ultimately death. We emphasize the value of early, broader testing in the diagnosis of rare infections to detect infection early.
ABSTRACT
Objectives: To assess antibody responses to an inactivated SARS-CoV-2 vaccine in individuals aged 50 and older. Methods: We conducted a post-market cross-sectional seroepidemiology study. We recruited 4,632 vaccinated individuals aged 50 and older, measured their total serum SARS-CoV-2-specific antibody (TA), and collected correlates. The primary outcome was the geometric mean titer (GMT) of TA, and the secondary outcome was the decline of TA with age. Univariate, bivariate, and multivariate analyses were used to examine the associations of the TA GMT with age, and trend analyses were used to test whether their associations were significant. Results: All participants had a detectable TA, which was generally at a low level across all age groups. The TA GMT (95% CI) in AU/mL was 3.05 (2.93, 3.18); the corresponding arithmetic mean (95% CI) was 17.77 (16.13, 19.42) in all participants and 4.33 (3.88, 4.84), 3.86 (3.49, 4.28), 3.24 (2.92, 3.59), 2.77 (2.60, 2.96), and 2.65 (2.48, 2.83) in the age groups of 50-54, 55-59, 60-64, 65-74, and 75 years or older, respectively. The TA GMT decreased with age with a P trend < 0.001. The TA GMT was significantly lower in those with hypertension or diabetes compared to those with neither. Conclusion: The inactivated SARS-CoV-2 vaccine is effective in individuals aged 50 and older. This is the first study that has found an inverse dose-response relationship between ages and the low-level TAs. Older people, especially those with chronic diseases, should get the SARS-CoV-2 vaccine, and their vaccination frequency, dose, and method may need to be different from those of younger people.