Background:Q fever endocarditis,a chronic illness caused by Coxiella burnetii,can be fatal if misdiagnosed or left untreated.Despite a relatively high positive rate of Q fever serology in healthy individuals in the mainland of China,very few cases of Q fever endocarditis have been reported.This study summarized cases of Q fever endocarditis among blood culture negative endocarditis (BCNE) patients and discussed factors attributing to the low diagnostic rate.Methods:We identified confirmed cases of Q fever endocarditis among 637 consecutive patients with infective endocarditis (IE) in the Peking Union Medical College Hospital between 2006 and 2016.The clinical findings for each confirmed case were recorded.BCNE patients were also examined and each BCNE patient's Q fever risk factors were identified.The risk factors and presence of Q fever serologic testing between BCNE patients suspected and unsuspected of Q fever were compared using the Chi-squared or Chi-squared with Yates' correction for continuity.Results:Among the IE patients examined,there were 147 BCNE patients,of whom only 11 patients (7.5％) were suspected of Q fever and undergone serological testing for C.burnetii.Six out of 11 suspected cases were diagnosed as Q fever endocarditis.For the remaining136 BCNE patients,none of them was suspected of Q fever nor underwent relevant testing.Risk factors for Q fever endocarditis were comparable between suspected and unsuspected patients,with the most common risk factors being valvulopathy in both groups.However,significantly more patients had consulted the Infectious Diseases Division and undergone comprehensive diagnostic tests in the suspected group than the unsuspected group (100％ vs.63％,P =0.03).Conclusions:Q fever endocarditis is a serious yet treatable condition.Lacking awareness of the disease may prevent BCNE patients from being identified,despite having Q fever risk factors.Increasing awareness and guideline adherence are crucial in avoiding misdiagnosing and missed diagnosing of the disease.

BACKGROUND AND PURPOSE: Additional folic acid (FA) treatment appears to have a neutral effect on reducing vascular risk in countries that mandate FA fortification of food (e.g., USA and Canada). However, it is uncertain whether FA therapy reduces stroke risk in countries without FA food fortification. The purpose of this study was to comprehensively evaluate the efficacy of FA therapy on stroke prevention in countries without FA food fortification. METHODS: PubMed, EMBASE, and clinicaltrials.gov from January 1966 to August 2016 were searched to identify relevant studies. Relative risk (RR) with 95% confidence interval (CI) was used as a measure of the association between FA supplementation and risk of stroke, after pooling data across trials in a random-effects model. RESULTS: The search identified 13 randomized controlled trials (RCTs) involving treatment with FA that had enrolled 65,812 participants, all of which stroke was reported as an outcome measure. After all 13 RCTs were pooled, FA therapy versus control was associated with a lower risk of any future stroke (RR, 0.85; 95% CI, 0.77 to 0.95). FA alone or combination of FA and minimal cyanocobalamin (≤0.05 mg/day) was associated with a lower risk of future stroke (RR, 0.75; 95% CI, 0.66 to 0.86) whereas combination of FA and cyanocobalamin (≥0.4 mg/day) was not associated with a lower risk of future stroke (RR, 0.95; 95% CI, 0.86 to 1.05). CONCLUSIONS: FA supplement reduced stroke in countries without mandatory FA food fortification. The benefit was found mostly in patients receiving FA alone or combination of FA and minimal cyanocobalamin.
Folic Acid ; Food, Fortified ; Humans ; Outcome Assessment (Health Care) ; Stroke ; Vitamin B 12