TABLE 6.

Outstanding issues concerning Plesiomonas gastroenteritis

Type of study	Information from studies:
	Before 2000	Current
Case reports	<10 well-described case reports or series of case reports	Only one case since 2000 (103)
Case-controlled investigations	One study through 2000 (5)	Four studies through 2000 (see Table 3); two with positive findings, one with negative findings, one with equivocal findings
Outbreaks	P. shigelloides not clearly shown to cause outbreak of gastroenteritis (5)	At least 11 outbreaks described, including 1 since 2000; several with good epidemiologic data (see Table 4); several more anecdotally described in the literature
Immune response	Data from a CDC study not supportive (100); several case reports more supportive (8, 131)	No new data
Histopathology	Good histopathology from a few selected case reports (131, 135)	No new data
Pathogenicity	No well-described enteropathogenic mechanisms (8)	Some now described but poorly characterized (see Pathogenicity section)