Dengue Virus Type 2, Puerto Rico | CDC EID

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Volume 17, Number 1–January 2011
Research
Endurance, Refuge, and Reemergence of Dengue Virus Type 2, Puerto Rico, 1986–2007

Kate L. McElroy,1 Gilberto A. Santiago,1 Niall J. Lennon, Bruce W. Birren, Matthew R. Henn,1 and Jorge L. Muñoz-Jordán1 Comments to Author
Author affiliations: Centers for Disease Control and Prevention, San Juan, Puerto Rico (K.L. McElroy, G.A. Santiago, J.L. Muñoz-Jordán); and Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA (N.J. Lennon, B.W. Birren, M.R. Henn)

Suggested citation for this article

Abstract
To study the evolution of dengue virus (DENV) serotype 2 in Puerto Rico, we examined the genetic composition and diversity of 160 DENV-2 genomes obtained through 22 consecutive years of sampling. A clade replacement took place in 1994–1997 during a period of high incidence of autochthonous DENV-2 and frequent, short-lived reintroductions of foreign DENV-2. This unique clade replacement was complete just before DENV-3 emerged. By temporally and geographically defining DENV-2 lineages, we describe a refuge of this virus through 4 years of low genome diversity. Our analyses may explain the long-term endurance of DENV-2 despite great epidemiologic changes in disease incidence and serotype distribution.

Epidemic dengue fever (DF) and the emergence of dengue hemorrhagic fever (DHF) in the Americas are associated with increased endemicity and cocirculation of the 4 dengue virus (DENV) serotypes, 1–4 (1). These increases have been particularly evident in Puerto Rico, where transmission increased during the past 25 years (2–4). The first DHF epidemics in the Americas occurred in the 1980s and were caused by the Asian/American genotype of DENV-2, then new to the region, which rapidly replaced the American genotype (5–7). This replacement has been linked to a potential to cause higher viremia and severe illness (8–10). Introduction of DENV-3 in the mid 1990s and increased human population and travel further fostered larger and more frequent DF and DHF epidemics in the region (11–13).

Although all 4 DENV serotypes circulate on the island, DENV-2 circulated continuously for 25 years. Previously, a partial sequence analysis from 74 DENV-2 isolates collected in Puerto Rico during 7 years throughout a 14-year period (1987–2001) showed a DENV-2 lineage evolving through a series of turnover events (14). A lineage replacement in 1994 appeared to be associated with a foreign virus but only 3 other reintroductions were found, all linked to the 1998 epidemic, the largest in Puerto Rico history (14). This was a turning point in the epidemiology of dengue, with DENV-2 (and DENV-1 and -4) rapidly declining during the expansion of DENV-3. However, transmission of DENV-2 persisted at low levels during 1999–2003 and increased thereafter. This serotype turnover offers new opportunities to study the evolution of DENV-2. Our analysis illustrates the genetic composition and population diversity of DENV-2 throughout 22 consecutive years of sampling in Puerto Rico and may explain the evolutionary resilience and long-term establishment of this virus.

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Suggested Citation for this Article

McElroy KL, Santiago GA, Lennon NJ, Birren BW, Henn MR, Muñoz-Jordán JL. Endurance, refuge, and reemergence of dengue virus type II, Puerto Rico, 1986–2007. Emerg Infect Dis [serial on the Internet]. 2011 Jan [date cited].
http://www.cdc.gov/EID/content/17/1/64.htm

DOI: 10.3201/eid1701.100961



1These authors contributed equally to this article.

Comments to the Authors

Please use the form below to submit correspondence to the authors or contact them at the following address:

Jorge L. Muñoz-Jordán, Centers for Disease Control and Prevention, 1324 Calle Cañada, San Juan, PR 00920, USA; email: jmunoz@cdc.gov