Date Published: March 19, 2015
Publisher: Public Library of Science
Author(s): Luis Angel Villar, Diana Patricia Rojas, Sandra Besada-Lombana, Elsa Sarti, Olaf Horstick. http://doi.org/10.1371/journal.pntd.0003499
Abstract: A systematic literature review was conducted to describe the epidemiology of dengue disease in Colombia. Searches of published literature in epidemiological studies of dengue disease encompassing the terms “dengue”, “epidemiology,” and “Colombia” were conducted. Studies in English or Spanish published between 1 January 2000 and 23 February 2012 were included. The searches identified 225 relevant citations, 30 of which fulfilled the inclusion criteria defined in the review protocol. The epidemiology of dengue disease in Colombia was characterized by a stable “baseline” annual number of dengue fever cases, with major outbreaks in 2001–2003 and 2010. The geographical spread of dengue disease cases showed a steady increase, with most of the country affected by the 2010 outbreak. The majority of dengue disease recorded during the review period was among those <15 years of age. Gaps identified in epidemiological knowledge regarding dengue disease in Colombia may provide several avenues for future research, namely studies of asymptomatic dengue virus infection, primary versus secondary infections, and under-reporting of the disease. Improved understanding of the factors that determine disease expression and enable improvement in disease control and management is also important.
Partial Text: Dengue disease is the most prevalent arthropod-borne viral disease in humans and is caused by any one of four serologically related, but antigenically distinct dengue virus serotypes (DENV-1, -2, -3 or -4). The primary vector for viral transmission is the Aedes aegypti (Linnaeus) mosquito. Dengue disease is a rapidly increasing public health priority with a global distribution. Resource-poor countries are particularly vulnerable to transmission of dengue disease , and it is present in urban and suburban areas in the Americas, eastern Mediterranean, western Pacific, South-East Asia and mainly rural areas in Africa . Since 1997, symptomatic dengue disease has been categorized by the World Health Organization (WHO) as: undifferentiated fever, dengue fever (DF) and dengue haemorrhagic fever (DHF) . DHF was further classified into four severity grades, with grades III and IV being defined as dengue shock syndrome (DSS). However, a new classification was proposed by the WHO in 2009 based on levels of severity: non-severe dengue disease with or without warning signs, and severe dengue disease, which encompasses DHF and DSS .
A Literature Review Group, comprised of epidemiology and dengue specialists, developed a protocol based on previous literature surveys and analyses . The protocol reflects the preferred reporting items of systematic literature reviews and meta-analyses (PRISMA) guidelines  and details well-defined methods to search, identify and select relevant research, and predetermined inclusion criteria to guide study selection. The review protocol was registered on PROSPERO, an international database of prospectively registered systematic reviews in health and social care managed by the Centre for Reviews and Dissemination, University of York on 18 May 2012 (CRD42012002294): http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42012002294/. Papers, theses, dissertations, reports, statistical tables, official web sites and grey materials (e.g., lay publications) were identified using an inclusive search strategy. A heterogeneous group of articles with respect to data selection and classification of cases was anticipated. As these would not be methodologically comparable, a meta-analysis was not planned.
Searches identified 225 relevant citations, following the initial removal of duplicates and papers not matching the study criteria 63 papers were evaluated. Of these 33 were excluded after detailed review of the publication because on further examination data collection occurred outside the search criteria date range, they contained little epidemiological data relevant to the study objectives or because they provided similar but less extensive data to that provided by sources already included and thus provided insufficient information to be included in the review. Some studies were excluded for more than one of these reasons. Consequently, 30 dengue-related sources were included (Fig. 1, S2 Table), of which, 14 and 16 sources were published in English and Spanish, respectively. There were 18 journal articles and three conference presentations/abstracts. The majority of these publications (n = 8) provided analysis of national surveillance data, providing dengue case counts, with some characterization by disease severity, geographic region, and serotype. Six were cross-sectional studies usually limited to specific geographic regions. Only two prospective studies were identified, four studies were phylogenetic studies and one was a disease awareness survey. The remaining 9 sources were recommended and accessed by members of the LRG and comprised surveillance reports, statistical tables (n = 8) and data reported in the text book ‘Dengue en Colombia: epidemiología de la reemergencia a la hiperendemia (Dengue in Colombia: epidemiology of hyperendemic re-emergence’ .
This systematic literature review is one of a series conducted within a similar timeframe in selected countries of the Americas and Asia. The series serves to provide an overview of the changeable epidemiology of DF and severe dengue disease across a broad geographical area over a decade or more.
Dengue disease is a serious public health priority in Colombia and control of the disease has been difficult. The period from 2000 to 2011 has been characterized by a stable ‘baseline’ annual number of DF cases, punctuated by major outbreaks in 2001–2003 and 2010. Between 2000 and 2010, there was a general increase in the annual number of DHF cases, but this was followed by a considerable decrease in 2011. Conversely, the case fatality rate, which was generally lower during 2000–2009 than in the 1990s, began to increase in 2010 and showed a large increase in 2011. The geographical spread of dengue disease cases showed a steady increase between 2000 and 2010, with most of the country affected by the 2010 outbreak. During the review period, the majority of dengue disease cases in Colombia occurred among those <15 years of age, with the highest incidence in 2009 among infants <1 year of age. Overall, there is a lack of definitive evidence to characterize the links between DENV serotype, genotype or subtype with the incidence or severity of dengue disease in Colombia. Source: http://doi.org/10.1371/journal.pntd.0003499