Table 1. Demographic characteristics and clinical and laboratory features of 22 patients with dengue-associated hemophagocytic lymphohistiocytosis that were identified at four referral hospitals in Puerto Rico during January 2008 through June 2013.

Case no.	Age (years)	Sex	Duration of fever (days)	Duration of hospitalization (days)	Method of dengue diagnosis	Infecting DENV	Highest measured serum ferritin (μg/L)	Hemophagocytosis seen in bone marrow?
1	0.5	M	8	57	rRT-PCR, MAC ELISA	DENV-1	8,266	Yes
2	0.8	M	5	70	rRT-PCR, MAC ELISA	DENV-1	22,203	Yes
3	0.9	M	5	18	rRT-PCR	DENV-1	19,994	NP
4	0.9	F	7	18	rRT-PCR, MAC ELISA	DENV-1	38,920	No
5	1.1	F	11	19	rRT-PCR	DENV-1	12,269	Yes
6	9	F	12	63	rRT-PCR	DENV-1	53,158	Yes
7	15	M	15	11	rRT-PCR	DENV-1	16,800	NP
8	17	M	3	12	rRT-PCR	DENV-1	60,300	NP
9	17	F	10	15	rRT-PCR	DENV-1	5,210	NP
10	0.2	F	7	10	rRT-PCR, MAC ELISA	DENV-4	9,899	NP
11	0.2	M	6	20	rRT-PCR, MAC ELISA	DENV-4	522,000	No
12	0.4	M	8	60	rRT-PCR, MAC ELISA	DENV-4	27,861	NP
13	0.6	F	6	8	rRT-PCR	DENV-4	44,202	Yes
14	0.6	F	6	17	rRT-PCR	DENV-4	18,789	No
15	7.9	F	8	40	rRT-PCR, MAC ELISA	DENV-4	9,076	No
16	12	F	10	11	rRT-PCR	DENV-4	9,270	NP
17	15	F	9	30	rRT-PCR, MAC ELISA	DENV-4	49,400	Yes
18	0.2	M	7	9	MAC ELISA	UNK	6, 526	No
19	0.6	M	10	10	MAC ELISA	UNK	4,834	NP
20	16	F	11	27	MAC ELISA	UNK	754	No
21	16	M	13	29	MAC ELISA	UNK	16,500	Yes
22	17	M	25	71	MAC ELISA	UNK	77,377	Yes

Abbreviations: DENV = dengue virus; F = female; M = male; rRT-PCR = real-time reverse transcriptase-polymerase chain reaction; MAC ELISA = IgM antibody capture enzyme linked immunosorbent assay; UNK = unknown; NP = not performed