一個呼吸的距離

http://www.clinicalmicrobiologyandinfection.com/article/S1198-743X(16)30025-8/fulltext

歐洲微生物與感染症醫學會建議的C. difficile (困難梭菌)的診斷建議更新：

檢體選擇Sample selection

• 不建議只限於特定的醫師要求。We recommend that CDI testing should not be limited to samples with a specific physician's request. (Strong recommendation, high-quality evidence) 
• 3歲以上的病人，要送不成形便。We suggest that at least all submitted unformed stool samples from patients 3 years or older should be tested for CDI. (Weak recommendation, low-quality evidence) 
• 3歲以下則建議在醫師的要求下再送。We suggest to limit testing of samples from children under age 3 to samples with a physician's request only. (Weak recommendation, low-quality evidence) 
• 成形便不建議送檢CDI (除非是paralytic ileus)。Formed stool samples should not be tested for CDI (except in case of paralytic ileus). (Good practice statement)
•  若ileus, 可用rectal swab來送檢。In patients suspected of ileus, a rectal swab can be used for (toxigenic) culture, NAAT or GDH EIA. (Strong recommendation, moderate-quality evidence)

檢查流程 Testing protocol 

• CDI的診斷需合併臨床與檢查結果；治療CDI是靠臨床診斷，即便所有的檢查都是陰性。The diagnosis of CDI should be based on clinical signs and symptoms in combination with laboratory tests. Decision for treatment for CDI is a clinical decision and may be justified even if all laboratory tests are negative. (Good practice statement) 
• 在好發區，不建議單用一種檢查就決定之。We recommend against the use of a single rapid test as a standalone test due to inadequate PPV in an endemic situation. (Strong recommendation, moderate-quality evidence) 
• 建議用2階診斷流程，如下圖。We recommend the use of a 2-step algorithm (Fig. 3(A)). (Strong recommendation, moderate-quality evidence) 
• This algorithm should start with either NAAT or GDH EIA. Samples with a negative first test result can be reported as negative. (Strong recommendation, moderate-quality evidence) 
• Samples with a positive first test result should be tested further with a toxin A/B EIA. Samples with a positive second test results can be reported as CDI-positive. (Strong recommendation, moderate-quality evidence) 
• An alternative algorithm is to screen samples with both a GDH and toxin A/B EIA (Fig. 3(B)). Samples with concordant positive or negative results can be reported as such. Samples with a negative GDH result but positive for toxin need to be retested as this is an invalid result. (Strong recommendation, moderatequality evidence) 
• Samples with a positive first test result and negative second test result (Fig. 3(A)) and samples with a GDH-positive test result but negative toxin A/B test result (Fig. 3(B)) may represent samples with CDI or C. difficile carriage and may optionally be tested with TC or NAAT (if not performed yet). (Weak recommendation, moderate-quality evidence) 
• We recommend to perform TC and molecular typing of recovered isolates in case of outbreak situations. (Good practice statement)

(Recommended algorithms for CDI testing. (a) GDH or NAATeTox A/B algorithm. (b) GDH and Tox A/BeNAAT/TC algorithm. CDI, Clostridium difficile infection; GDH, glutamate dehydrogenase; NAAT, nucleic acid amplification test; TC, toxigenic culture; Tox A/B, toxin A/B; EIA, enzyme immunoassay)