As the 2017 rainy season cranks up, ideal breeding conditions for disease-carrying mosquitoes will be coming to a peak, increasing the risks of an epidemic of dengue fever in the lakeshore region.
Statistics indicate that 2016 was a record year for dengue infections in the Lake Chapala, with 240 confirmed cases registered by health authorities in the municipality of Chapala and high incidences also detected in other lakeshore communities.
The Chapala government and the local branch of Jalisco’s Health Ministry are expected to launch a community dengue prevention campaign within the next few weeks. The program will involve encouraging residents to get rid of household junk and open containers that collect stagnant water where the mosquitoes reproduce, as well as neighborhood fumigation patrols to eradicate the insects.
Dengue is caused by any one of four different but related types of virus. It is transmitted from sick persons to healthy individuals by the Aedes aegypti mosquito. The genus is distinguished from other kinds of mosquitoes by white stripes on its legs and a distinctive lyre-shaped marking on the thorax.
Symptoms of dengue commonly begin with the sudden onset of a high fever occurring four to seven days after infection. The disease is sometimes referred to as “breakbone fever” because it causes intense joint and muscle aches along with extreme fatigue. Other symptoms include swollen lymph nodes, headache (especially severe pain behind the eyes), a red rash on the body, increased skin sensitivity, nausea and vomiting. Blood testing is required to confirm diagnosis.
There is no specific treatment for the illness, which normally lasts for a week or more, provided there are no complications. Patients require bed rest and sufficient intake of fluids to prevent dehydration. Acetaminophen is usually prescribed to relieve fever and discomfort.
A more severe form of the disease — dengue hemorrhagic fever — can lead to internal bleeding, shock and death. Early symptoms are similar to those of common dengue, but after several days the patient becomes irritable, restless and sweaty. It usually strikes people who have previously suffered dengue and are later infected with a different type of the virus.
Aside from eliminating potential mosquito breeding habitat at home, personal protection measures to reduce the risk of infection include the use of bug repellents, insecticides, appropriate clothing, window screens and bedroom netting to limit exposure to insect bites.
A new vaccine that works against four types of the dengue virus was introduced in Mexico last September by the pharmaceutical outfit Sanofi Pasteur. Sold under the commercial name Dengvaxia, the product is apparently available only from private sources. The recommended prophylactic strategy requires three applications of the vaccination at six-month intervals over a full year, at a cost of around 1,500 pesos per dose.