The number of dengue fever cases in Sri Lanka has topped 50,000 before the end of May, according to Ministry of Health data.

An Aedes aegypti mosquito prepares to bite a human. Image/USDA
An Aedes aegypti mosquito prepares to bite a human.

Through May 24,  the Ministry’s Epidemiology Unit has reported 52,015 cases. During the first five months of 2016, Sri Lanka saw less just over 19,000 cases, a little more than a third of the cases.

The Regional Director of Health Service (RDHS) of Colombo has reported the most cases year to date with 11,431. Gampaha was the second hardest hit region with 7673.

According to one Sri Lankan news source, 130 dengue related fatalities have been reported.

Officials fear the situation could get worse during the monsoon season.

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.