The number of dengue fever cases in Sri Lanka are up significantly in 2017, in fact, it is three-and-a-half times more than the average number of cases for the same period between 2010 and 2016.
Through July 17, the Ministry of Health reports 93,322 dengue cases, including 250 deaths to date.
Based on surveillance data, dengue cases peaked in June 2017, coinciding with the South-West monsoon rains which commenced in late May.
Approximately 43% of cases were reported from the Western Province. The areas most affected include Colombo (20, 472), Gampaha (13, 567) and Kurunegala (5,745).
Preliminary laboratory results have identified dengue virus serotype 2 (DENV-2) as the circulating strain in this outbreak.
Dengue is a viral infection transmitted by the bite of an infected mosquito. There are four closely related but antigenically different serotypes of the virus that can cause dengue (DEN1, DEN 2, DEN 3, DEN 4).
- Dengue Fever (DF) – marked by an onset of sudden high fever, severe headache, pain behind the eyes, and pain in muscles and joints. Some may also have a rash and varying degree of bleeding from various parts of the body (including nose, mouth and gums or skin bruising).Dengue has a wide spectrum of infection outcome (asymptomatic to symptomatic). Symptomatic illness can vary from dengue fever (DF) to the more serious dengue hemorrhagic fever (DHF).
- Dengue Hemorrhagic Fever (DHF) – is a more severe form, seen only in a small proportion of those infected. DHF is a stereotypic illness characterized by 3 phases; febrile phase with high continuous fever usually lasting for less than 7 days; critical phase (plasma leaking) lasting 1-2 days usually apparent when fever comes down, leading to shock if not detected and treated early; convalescence phase lasting 2-5 days with improvement of appetite, bradycardia (slow heart rate), convalescent rash (white patches in red background), often accompanied by generalized itching (more intense in palms and soles), and diuresis (increase urine output).
- Dengue Shock Syndrome (DSS) — Shock syndrome is a dangerous complication of dengue infection and is associated with high mortality. Severe dengue occurs as a result of secondary infection with a different virus serotype. Increased vascular permeability, together with myocardial dysfunction and dehydration, contribute to the development of shock, with resultant multiorgan failure.