Bulletin of the World Health Organization

A cohort study to assess the new WHO Japanese encephalitis surveillance standards

Tom Solomon, Thi Thu Thao, Penny Lewthwaite, Mong How Ooi, Rachel Kneen, Nguyen Minh Dung, Nicholas White

Volume 86, Number 3, March 2008, 178-186

Table 3. Clinical diagnosis, initial AES classification and final AES classification for 149 children and 231 adults with suspected infections of the central nervous system

Clinical diagnostic group^a	Etiology^b	AES on admission?				Final case classification for patients with AES^c
		No		Yes
		Children	Adults	Children	Adults
Encephalitis	JEV	6	0	35	9	Laboratory-confirmed JE
	Dengue	0	0	2	1	AES – other agent
	Rabies	0	0	1	1	AES – other agent
	Unknown^d	1	0	7	30	AES – unknown
	ADEM (post rabies vaccination)	0	0	0	2	AES – unknown
Encephalopathy	Dengue (DF or DHF)	0	0	2	5	AES – other agent
	Typhoid	0	0	3	4	AES – other agent
	Malaria	0	0	2	3	AES – other agent
	Leptospirosis	0	0	0	1	AES – other agent
	Unknown	0	0	7	38	AES – unknown
	Sepsis – other	0	0	1	11	AES – other agent
Pyogenic meningitis	Culture positive	5	2	1	14	AES – other agent
	Culture negative	5	5	7	17	AES – unknown
	JEV^e	1	0	0	0	N/A
Tuberculous meningitis		1	10	7	28	AES – unknown
Aseptic meningitis	JEV	4	0	0	0	N/A
	Mumps	0	1	0	0	N/A
	Unknown	1	5	0	0	N/A
Meningitis – fungal		0	2	0	1	AES – other agent
Meningism	JEV	2	0	0	0	N/A
	Assoc with pneumonia	2	0	1	0	AES – unknown
	Assoc with other viral illness	2	2	0	0	N/A
Myelitis	JEV	6	0	0	0	N/A
	Dengue	1	1	0	0	N/A
	Unknown	2	0	2	1	AES – unknown
Abscess		2	2	0	5	AES – other agent
Guillain-Barré syndrome		6	0	1	0	AES – unknown
Complex febrile convulsion		0	0	12	0	AES – unknown
Tense fontanelle		6	0	1	0	AES – unknown
Non-infectious cause		0	1	4	29	AES – other agent
Total		52	32	96	200

ADEM, acute disseminated encephalomyelitis; AES, acute encephalitis syndrome; DF, dengue fever; DHF, dengue haemorrhagic fever; JE, Japanese encephalitis; JEV, Japanese encephalitis virus; N/A, not applicable.^a Clinical diagnostic group was based on the initial clinical and (cerebrospinal fluid) CSF findings.^b Etiology is that determined after investigations were completed.^c Laboratory-confirmed JE patients meet AES case definition on admission; AES – other agent, if an alternative agent or non-infectious cause was identified; AES – unknown, if no definite cause identified.^d One JEV-negative child presented with fever, focal neurological signs, but no loss of consciousness and had encephalitis diagnosed on computed tomography.^e One child with a neck stiffness, and extensor plantars, had a CSF white-cell count of 200/ml, 55% neutrophils, a glucose ratio of 53% and protein of 63.5 mg/dl was diagnosed clinically as having pyogenic meningitis, but CSF bacterial cultures were negative, and the CSF was positive for JEV IgM antibody.