OFFICIALS WARN OF HIGHER RISK OF DEVELOPING SEVERE DENGUE, WITH TWO SEROTYPES CURRENTLY IN CIRCULATION IN SAINT LUCIA.
Over the last few weeks, the Ministry of Health and Wellness has continued to provide updates to the public on the significant increases in trends of dengue viral infection. These increasing trends now constitute an outbreak. This means the numbers currently being reported exceed the numbers expected, and as such this warrants an immediate and targeted response.
As of the week of Aug 9 to 15, there have been 168 confirmed cases of dengue infection. The hospitalization rate is at 46 percent while the case fatality rate remains at zero. Thirty-eight percent of reported cases were between the ages of 5 to 13 years. Even more concerning is the fact that both serotypes two and three of dengue are in circulation in Saint Lucia. While most of the reported cases are concentrated in the northern, central and eastern regions of the island, some cases have also been reported in the south and west of the island to a lesser extent.
The public health impact of managing a dengue outbreak combined with adjusting to the new normal amid the COVID-19 pandemic will place a strain on the already stretched healthcare services. The direct economic cost of treatment, hospitalization and prevention, as well as the indirect costs such as loss of productivity related to absences, disability or death and the effects on tourism is of concern to an already fragile economy. The Ministry of Health and Wellness therefore solicits the usual cooperation of the public in dealing with this emerging public health threat.
Dengue fever is one of the most prevalent arboviral infections worldwide. It is mosquito-borne, which means that it is transmitted by a mosquito---usually the female Aedes egypti and to a lesser extent the Aedes albopictus. These are the same mosquitoes that are responsible for transmitting chikungunya, yellow fever and zika. The mosquito lives in urban habitats and breeds mostly in manmade containers. It is a daytime feeder, with its peak biting periods in the early mornings, and on evenings before sunset.
Dengue is widespread throughout the tropics with local variations of risk influenced by rainfall, temperature, humidity and unplanned rapid urbanization. Dengue is also endemic to Saint Lucia which means that there is continued local transmission throughout the year.
However, we see spikes at certain points during the year, usually during the rainy season which facilitates breeding of the mosquito. There are four distinct serotypes of the virus. Recovery from infection is believed to be lifelong, however, cross-immunity t other serotypes is only temporary. After recovering from the first dengue infection, and individual is protected from the remaining three dengue serotypes for about two to three months, which means it is possible for in individual to be infected twice during the year. Secondary infections by other serotypes increase the risk of developing severe dengue.
Dengue viral disease has an incubation period of four to 10 days after the bite of an infected mosquito. About 75 percent of dengue infections are asymptomatic or produce a very mild febrile illness. Persons with mild dengue may present with skin rash, nausea, vomiting, usually pain behind the eyes, and muscle and joint pain. In its more severe form, persons may progress to bleeding from the gums or nose, vomiting of blood and passing blood in the stool. They may also experience severe abdominal pain and excessive vomiting, which may lead to dehydration. About five percent of infections progress to the severe form of dengue.
There is no specific treatment or vaccine for dengue virus infection. Dengue fever cannot be transmitted from one person to another and requires the presence of the mosquito. Prevention and control therefore involves elimination of the mosquito.