Research on Dengue Spreading Pattern in Sri Lankan Urban Cities

Research on creating a knowledge base on history of dengue in Sri Lankan urban cities

Introduction

Dengue viruses are mosquito-borne viruses that have plagued people for centuries. Starting in the middle of the 20th century, large-scale urbanization and increasing human populations in tropical parts of the world created conditions especially favorable for dengue transmission. These changes led to the current global dengue pandemic, which is characterized by a dramatic increase in dengue infections and an expanding geographic distribution of both the viruses and the mosquito vector.

The pattern of dengue changed in Sri Lanka after 1989, with an exponential increase in the incidence of DHF which is known as dengue hemorrhagic fever. Before this, DHF was rare, despite circulation of more than one dengue virus serotype. Subsequently, the pattern of the severe type of disease changed and regular epidemics of DHF have since been reported. Because of increase in DHF in 2004, a major epidemic of dengue infection occurred in Sri Lanka, which accounted for 15 457 cases and 88 deaths.

The problem

During the past few years, the characteristics of dengue in Sri Lanka appear to have changed. For instance, a decade ago, children were predominantly affected, but in recent years, clinicians have seen increasing numbers of adult dengue patients, with significant morbidity, and increasing numbers of adult deaths due to dengue. Similar trends are seen in some South Asian, South-East Asian and South

American countries. The rise in the incidence of dengue among Sri Lankan adults adversely affects the country’s developing economy and also its health planning. The situation has been compounded by the general lack of systematically collected information on the natural history of dengue in Sri Lanka. This lack often leads health planners and clinicians to base their decisions regarding resource allocation and clinical management on personal experiences rather than on tangible evidence. For instance, if somebody carries out a survey of the opinions of at least 50 consultant physicians and pediatricians on the management of dengue found widely varying views and practices by both the groups. The usage of platelet and plasma transfusions used as a treatment for dengue is not based on any specific guidelines. Hence there is a need for a database of systematically collected information on the natural history of dengue in Sri Lanka.

Research Questions

• What is the