Dengue Fever – Symptoms and Prevention
October 18, 2012 The city of La Paz has announced an aggressive spray program in the hopes of averting an outbreak of Dengue fever. Fumigation by malathion will be increased in the evening hours in select neighborhoods. In the past public announcements of neighborhoods to be sprayed has appeared in advance on the radio and newspapers, but this isn't much use to gringos who are espanol illiterate. Following the double hurricane hit in 2003 Dengue reached near epidemic proportions in Baja Sur.
Residents have been urged in the media to clean up standing water in their yards, to make sure their tanacos (water cisterns) are bug proof . In the past the city has handed out little packets of sterilizer for these cisterns, of which nearly every home in La Paz has at least one. A couple of tablespoons of unscented bleach will also sanitize the tanks, but using bottle water following either treatment is recommended.
Again, this action is to avert an outbreak of Dengue following the wettest summer in La Paz in 26 years. Although Dengue is not usually fatal, the malaria like symptoms are no fun at all.
ORIGINAL STORY: Every year, following the rains, it is important to clear your property of standing water and drain puddles. The cities usually issue a small packet of chemicals to sanitize tanaco (water cisterns) to prevent the spread of the disease. Dengue usually runs in 7 year cycles and it has been 7 years since the last serious outbreak in Baja Sur. Dengue is a mosquito-borne infection which, in recent years, has become a major international public health concern.
Care should be taken to avoid contracting mosquito bites. Infection rates are still very low, affecting less than 0.1% of the population, this is in comparison with 2003, following Hurricanes Ignacio and Marty, when the outbreak reach epidemic proportions in many parts of Baja California Sur. Spraying operations are now active in many parts of the city of La Paz and surrounding suburbs. One death has been reported in greater La Paz. Mulegue had significant concerns with Dengue following the flooding of TS Julio in late August.
Although a serious disease, the mortality rate is very low, about 1% and it poses the greatest threat to the very young, elderly and those under treatment for other diseases which may compromise the bodies ability to resist infection.
Dengue is found in many tropical sub-tropical regions in Mexico and around the world, predominantly in urban and semi-urban areas. Dengue viruses are transmitted by infected Aedes mosquitoes, (Aedes albopictus) which are most active during the day but can be found out at night. There is no truth to the rumor that only a species of daytime mosquito carry the virus. The Asian Tiger Mosquito is denoted by the black and gray stripes on the abdomen and is know for its ability to bite quickly, more quickly that it can be swatted away.
There are four variations of Dengue fever, and you can only contract each version once, as the body develops antibodies to the virus. Unfortunately, as anyone who has had any of the varieties will tell you, once is enough. There are no medications for the disease, antibiotics are ineffective and may only prevent secondary infections and further reduce the bodies ability to combat the disease. Hospitalization can be required and intravenous fluids administered to prevent dehydration, a major threat of the infection.
The first reported epidemics of Dengue occurred in 1779-1780 in Asia, Africa, and North America. The near simultaneous occurrence of outbreaks on three continents indicates that these viruses and their mosquito vector have had a worldwide distribution in the tropics for more than 200 years.
A pandemic of dengue began in Southeast Asia after World War II and has spread around the globe since then. Epidemics caused by multiple serotypes (hyperendemicity) are more frequent, the geographic distribution of dengue viruses and their mosquito vectors has expanded, and DHF has emerged in the Pacific region and the Americas. In Southeast Asia, epidemic DHF first appeared in the 1950s, but by 1975 it had become a frequent cause of hospitalization and death among children in many countries in that region
The city of La Paz distributes packets of pesticides beginning late each summer, following our torrential rains, to homeowners and encourages removal of any standing water. The standing water is a key link in the development of the mosquito responsible for transmission of the disease. Night time spray trucks have been seen throughout the city in an effort to contain the adult mosquito. Dengue is usually most prevalent in northern hemisphere tropical areas from late June to mid October.
The classic symptoms of Dengue Fever include a high fever that may last from 5 to 7 days; intense headache; eye, joint and muscle pain; and a rash. The rash typically begins on the arms or legs three to four days after the beginning of the fever. Symptoms can range widely in severity. Significant symptoms usually resolve within 1 to 2 weeks, but like the diseases' relative Malaria, lethargia and some other symptoms can revisit the victim for months.
Dengue Hemorrhagic Fever is the most serious form of this illness. Individuals with Dengue Hemorrhagic Fever experience blood clotting problems which result in bleeding and shock (extremely low blood pressure). Hospitalization is usually required.
Dengue Fever is diagnosed by clinical symptoms and by specific blood tests.
There is no curative treatment for Dengue Fever. If there are no complications, recovery will occur within 1 to 2 weeks. Hospital care with intravenous fluids is usually necessary for individuals with the more serious Dengue Hemorrhagic Fever.
An individual infected with Dengue Fever is not directly infectious to other individuals except through sharing of blood contaminated needles. Untreated individuals, if bitten by Dengue Fever-capable mosquitoes, could infect a small number of mosquitoes. These could transmit Dengue Fever if they subsequently bite another human at least 1 to 2 weeks later, depending upon environmental conditions.
The best tactic to prevent Dengue is to avoid being bitten by mosquitoes. This includes sleeping in areas screened from mosquitoes, wearing long sleeves and pants, and using mosquito repellents and insecticides.
There is no vaccine which can prevent Dengue Fever, however such vaccines are in development.
Alternate Names: Breakbone Fever, Dengue-Like Disease, O'nyong-Nyong Fever