Epidemiology of Dengue in the Western Pacific Region
By S.K. Lam, T. Pang T. Umenai

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SK lam, T Pang and T Umenai

Introduction

00000000Dengue virus is probably the most important virus transmitted to man by arthropods. Although reliable data are not available, it can be assumed that dengue fever (DF) and dengue haemorrhagic fever (DHF) are leading causes of hospitalization and death among children in Asia.

00000000Classical dengue fever was first recognized more than two centuries ago when, in 1776, epidemics were recorded in Java and Egypt. Siler it al(1) believed that dengue originated in 'tropical America' as opposed to claims of Mattingly2( who believed that it originated in South-East Asia. However, it was a few years later that Rush have the first accurate clinical description of true dengue when an outbreak occurred in Philadelphia in 1780(1,3). In the 19th and 20th centuries, extensive outbreaks were reported from tropical and sub-tropical areas on all continents and from many sub-continents and islands in the South Pacific and the Caribbean. Epidemics were reported in the Southern United States (1920, 1922), Australia (1925 - 1926, 1942 and 1954 - 1955), South Africa (1926 - 1927), Greece (1927 - 1928) and Japan (1942 - 1945).

00000000In Queensland the first outbreak of dengue haemorrhagic fever/dengue shock syndrome DHF/DSS might have occurred in 1877 but it was not recognized as such until later. DHF outbreaks were also recorded in refugee-swollen Athens and Piraeus(4). In Bangkok, children were hospitalized with DHF/DSS-like syndromes during every rainy season from 1950 - 1965(5). DHF/DSS cases were recognized in South-East Asia after the 'Philippines haemorrhagic fever' in 1953 and the 'Thai Haemorrhagic Fever' in 1958. In 1956 alone at least 1000 children with haemorrhagic fever were hospitalized in Manila and, from some of these cases, Hammon et al.(6) recovered dengue 2, 3 and 4 viruses.

00000000The increase in the incidence of dengue may be attributed to two important factors, namely, the rapid growth and urbanization of people in the tropics and the increased frequency and speed of human travel. Unlike other arthropod-borne viruses, dengue virus does not require a non-human host, and transmission from man to man by mosquitoes occurs freely in urban settings.

00000000The early history of dengue epidemics in southern Asia followed the invasion by Aedes aegypti and its spread. Dengue infection has occurred widely throughout the Western Pacific region except in areas climatically unsuitable for the vectors.

00000000Data concerning DF/DHF in countries of the Western Pacific vary from scanty to good, according to the country. This may be a reflection of the importance of the disease as a public health problem or of the interest in the disease as such. In this review, we have tried to collate the most recent data available to us on the epidemiology of dengue in the Western Pacific region.