Dengue Fever – Symptoms and Prevention
Updated Nov 10, 2014 Dengue Fever runs in 7 year cycles for an unknown reason and this year, in conjunction with the abundant rains, has brought out a heavier than normal season of this common, but rarely fatal tropical disease.
In the week ending November 10 new cases were down 44% in Baja California Sur.
Dengue has been prevalent since July of this year and significant control measures, including aerial spraying have been in place since early September across Baja California Sur.
Dengue fever is also present in Mazatlan, Puerto Vallarta and points further south. The state of Jalisco reported 107 new cases in the week proceeding with a total of just over 1100, mostly in coastal communities. The state of Sonora reported 1114 cases so far this year. The Pacific state of Nayarit reported just over 1000 cases, down significantly from the previous year, due to an aggressive clean up campaign.
Final medical testing is underway on a vaccine for Dengue, which may be available as soon as the second half of 2015. The French drug maker Sanofi Pasteur intends to ask to release the vaccine in several endemic countries next year, the company said in a statement. The new vaccine has proven about 95% effective in clinical trials.
Dengue is a common tropical afflicton and although rarely fatal, hospitalizes more than half a million people world wide each year. There are four strains of Dengue, including the most serious, Hemoragic Fever, and you can only get Dengue once for each strain.
The Federal Health Ministry said the lack of citizen participation to keep yards clean and avoid places where water can accumulate in puddles or dirty water is a factor to increase cases of dengue.
"I have always said, that the reduction of cases at par and is proportional to the participation of the community, as a community and private institutions become involved it decrease dengue cases by the same proportion." said Garcia, Federal Minister of Health.
Local health officials announced that the number of new cases in the last week dropped dramatically over the previous week. But they also advised that the cooler weather will not end the out break, as La Paz never receives a 'killing frost' to eliminate the mosquito population. what is happening is that since the end of the rainy season, breeding grounds for the mosquito are drying up. In the past seven days an additional 171 new cases were reported, that is down dramatically from 306 last week and 478 new cases in the preceding week.
Although Dengue is a very 'uncomfortable' thing to have, it is less fatal than even common influenza. There have been no deaths attributed to the disease in Baja California Sur during this outbreak.
According to the State Health Secretary the Dengue outbreak has had the most reported cases in La Paz, with approximately a total of 2,446 in the peninsula's largest city. Cabo San Lucas is in second place with 497 total cases. The sparely populated region of Comondu is in third place with 401, and Mulege with 175 and Loreto weighing in at around 116 cases. These numbers do not reflect those that did not seek medical attention, the Federal Health Minister speculated that about 30% more cases are unreported.
The total number of cases reported in Baja California Sur since the beginning of the outbreak in July now stands at 3, 635. Of all the reported cases only 82 have shown symptoms of the most aggressive and painful version, Hemorrhagic Fever.
Cases of Dengue as a percentage of population: Updated 11/10/14
La Paz 1.2%
Los Cabos 0.4%
Loreto & Mulege about 0.7%
The good news is, that the end of the suspect season is nearly upon us. Mosquito populations diminish significantly as the weather cools in November.
Care should be taken to avoid contracting mosquito bites. Infection rates are still very low, this is in comparison with 2003, following Hurricanes Ignacio and Marty, when the outbreak reach epidemic proportions in many parts of Baja California Sur.
Dengue Hemorrhagic Fever is the most serious of the four strains of the disease and a only a handful this strain have been treated in Los Cabos in this time around.
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.
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.
Second Generation story from 2010: 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.
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. The disease can be very debilitating, incapacitating the sufferer during the early stages and robbing the victim of energy for many weeks to follow.
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 unusual 1975 outbreak was particularly virulent in Southeast Asia and that year was the 5th leading cause of infectious death of children under 10 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. Antibiotic treatments are usually only applied to the Hemorrhagic version to prevent secondary infection. Antibiotics have little or no effect of the disease itself.
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