Plaque reduction neutralization antibody test does not accurately predict protection against dengue infection in Ratchaburi cohort, Thailand

Table 1 Pre-existing PRNT50 titer and subsequent dengue infection in subjects with low titer (<90) to subsequent infecting serotype

Subject code	PRNT50 titer (Feb 2006)					Date of illness	Clinical diagnosis	ELISA test result^a	Serotype isolated
Subject code	D1	D2	D3	D4	JE	Date of illness	Clinical diagnosis	ELISA test result^a	Serotype isolated
03-146	<10	<10	<10	<10	155	11/10/2006	DF	Secondary	D1
05-119	<10	<10	<10	<10	235	9/6/2006	Pharyngitis	Secondary	D1
05-181	<10	<10	<10	<10	<10	21/8/2006	DF	Primary	D1
05-310	10	<10	167	<10	250	21/4/2006	DF	Secondary	D1
07-479	<10	<10	<10	<10	29	23/7/2006	DF	Secondary	D1
07-383	13	<10	<10	<10	<10	10/9/2006	DF	Primary	D1
04-276	13	<10	<10	<10	<10	13/3/2006	DF	Primary	D1
05-357	40	29	27	<10	303	10/10/2006	Bronchitis	Secondary	D1
05-002	50	<10	<10	<10	396	25/11/2006	DF	Secondary	D1
03-097	75	1134	24	20	1307	7/10/2006	DF	Secondary	D1
05-339	<10	<10	<10	<10	503	28/8/2006	Pharyngitis	Secondary	D2
04-322	17	<10	<10	<10	165	9/11/2006	DF	Secondary	D3
04-325	<10	<10	<10	<10	685	23/10/2006	DHF gr2	Secondary	D3
02-189	<10	10	12	<10	<10	6/7/2006	DF	Primary	D3
01-227	49	<10	<10	<10	590	19/2/2006	Pharyngitis	Secondary	D4
01-254	12450	3348	32	<10	78	28/2/2006	AGE	Secondary	D4
01-384	<10	<10	<10	<10	92	19/12/2006	Pharyngitis	Secondary	D4
06-164	210	540	12040	21	76	30/8/2006	DF	Secondary	D4
01-124	228	135	516	39	28	31/3/2006	DF	Secondary	D4
05-257	3141	194	272	41	726	15/10/2006	Common cold	Secondary	D4
01-224	195	2901	220	50	802	9/3/2006	DHF gr1	Secondary	D4
05-378	6238	2204	676	75	43	28/7/2006	DF	Secondary	D4

^aELISA result showed either primary or secondary infection.
AGE: acute gastroenteritis; D: dengue virus; DF: dengue fever; DHF: dengue hemorrhagic fever; gr: grade; JE: Japanese encephalitis virus; PRNT50: 50% plaque reduction neutralization.

ISSN: 1743-422X