TABLE 4.

Summary of clinical and laboratory data of cases showing false-positive results in PCR and/or latex agglutination tests by using strict criteria

Patient no.	Final diagnosis	Sex, age (yr)	Prior antibiotic therapy	Diagnostic method	Sputum Gram staina	LAb	PCR
1	C. pneumoniae infection	Male, 79	Oral amoxicillin	IgM (+) and high IgG titers	MOF	ND	+
2	E. coli infection	Male, 84	No	TNA culture	ND	−	+
3	Aspiration pneumonia	Male, 83	No	TNA and blood culture	ND	−	+
4	C. pneumoniae infection	Male, 72	No	IgM (+) and high IgA titers	ND	+	−
5	C. pneumoniae infection	Male, 59	Intramuscular penicillin-procaine	Seroconversion	ND	+	−
6c	C. pneumoniae infection	Male, 63	Oral roxithromycin	IgM (+) and high IgG titers	GPDC	+	−
7c	Pneumonia of unknown etiology	Male, 66	No		SR	+	+
8c	Pneumonia of unknown etiology	Male, 39	No		ND	+	+
9c	Pneumonia of unknown etiology	Male, 77	Oral ciprofloxacin		GPDC	ND	+
10c	Pneumonia of unknown etiology	Male, 79	No		GPDC	−	+
11c	Pneumonia of unknown etiology	Male, 76	No		GPDC	−	+
12	Pneumonia of unknown etiology	Male, 71	Oral erythromycin		ND	−	+
13	Pneumonia of unknown etiology	Male, 66	No		ND	−	+
14	Pneumonia of unknown etiology	Female, 84	No		ND	−	+
15	Pneumonia of unknown etiology	Male, 25	Oral amoxicillin		SR	+	−
16	Pneumonia of unknown etiology	Male, 59	No		SR	+	−

^aMOF, mixed oral flora; ND, not done; SR, specimen rejected because of poor quality; GPDC, gram-positive diplococci. 

^bLA, latex agglutination. 

^cCases considered as true positive in the analysis with the expanded criteria.