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Prevent Dengue and Preserve the Environment. By Judith Eve Lipton, MD Playa Potrero, Costa Rica. What is Dengue Fever?. Dengue Fever is a viral disease that affects people all over the world. It is caused by an arbovirus that is transmitted by the bite of a certain species of mosquito.
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Prevent Dengue and Preserve the Environment By Judith Eve Lipton, MD Playa Potrero, Costa Rica
What is Dengue Fever? • Dengue Fever is a viral disease that affects people all over the world. • It is caused by an arbovirus that is transmitted by the bite of a certain species of mosquito. • Only people get Dengue Fever, and only one genus of mosquito carries it. Therefore it may be considered to be a contagious disease with a mosquito vector.
What does all that mean? • What is a virus? A virus is a small package of DNA or RNA that cannot live by itself. • A virus hijacks other cells, and makes them make new viruses. • An “arbovirus” is an “arthropod transmitted virus.” • An arthropod is an animal which has an external skeleton, a jointed body, and jointed legs. A mosquito, flea, or tick.
What is a vector? A Vector is something that carries things:
Aedes aegyptiOur Enemy! The Vector! Look at those stripes:
How about Dengue? • Dengue Fever is caused by a virus that contains RNA. • It is spread from mosquitos to people and back again. • No other animals get Dengue Fever. • The name of the mosquito is Aedes aegypti • More than 15,000 people got Dengue Fever in Costa Rica in 2012.
Aedes aegypti in Costa Rica • A campaign to eradicate Aedes aegypti began in 1948 • Costa Rica was declared free of Aa in 1961 • It came back in 1971 in Puntarenas, and was eliminated in 1973 • The country was free of Aa in 1987 • The Aedes mosquitos came back in 1992, and have been present ever since.
Dengue has increased 300% since 1960. Why? Increased population Increased urbanization Increased international travel Global warming
Guanacaste is hit hard • There are 400% more cases of Dengue Fever in Guanacaste now than in 2009. • Normal community programs of spraying and fumigation have not worked. • Random spraying and fogging kill animals that eat mosquitos. • We need new methods to prevent Dengue.
What does Dengue Feel Like? • “Bone break fever” – the worst pain you have ever felt in your whole life, all over your body • High fever • Severe headache • A Rash • Vomiting and diarrhea • For 2-7 days. No fun at all! • This occurs 4-10 days after the mosquito bite
Can it get worse? YES! • Dengue Hemorrhagic Fever can be fatal. • It includes all of the pain and problems as regular Dengue, plus • Easy bruising • Low platelets (blood cells that cause clotting) • Low blood pressure, drowsiness • Difficulty breathing • Organ Failure • Swelling in arms, legs, brain, and belly
How does a Doctor Diagnose Dengue? Clinical Signs of Dengue Are: High Fever Pain all over Low white blood cell count High hematocrit (red blood cells) +low platelets (clotting cells) Vomiting, liver enlargement Rash Sleepiness or restlessness Swelling in the feet and hands
How does a doctor prove Dengue? To prove a person has Dengue Fever, a laboratory has to analyze blood. Low platelets, high hematocrit, and low white blood cell count are easy tests Elevated IgG and IgM are important But PCR (polymerase chain reaction), viral antibodies and specific antibodies (ELISA) are proof.
In Costa Rica, Dengue Must Be Proven and Reported According to the Health Department, anybody with signs of Dengue Fever should have blood tests, including serotyping. The blood tests may be gotten at private clinics or the EBAIS clinics in Brasilito or Matapalo Just platelets or a low white count are not enough Serotyping or PCR are necessary The government of Costa Rica has the means to do these important tests.
Antibodies don’t show up until after Day 5, but they can be measured even weeks after a Dengue infection.
Dengue is a Reportable Disease, like TB or AIDS Why? Because it is spread from infected mosquitos to healthy people, and then from infected people to healthy mosquitos. People and mosquitos are the problem!
Treatment of Dengue Rest, indoors, in a place with good screens Fluids, hydration Tylenol or tramadol are ok for pain Aspirin, Motrin, Aleve and other NSAIDS are not ok. “NSAIDS” are non-steroidal anti-inflammatory drugs. They inhibit blood clotting and may make Dengue worse.
Go to the hospital if • You are getting very dizzy or have severe headaches • You are bleeding • Your urine decreases a lot • Your behavior changes dramatically
What can we do? Protect our bodies Protect our homes Kill the baby mosquitos Kill the adults if we can Protect the animals that eat mosquitos or mosquito babies
Protect our bodies • Aedes aegypti mosquitos feed at dawn and dusk. Stay indoors in well screened areas at these times. • Wear long sleeved shirts and pants and socks • Consider using DEET, citronella, soy oil or other chemical repellants • Consider buying mosquito repellant clothing with DEET or permethrin
Protect our Homes • Female mosquitos like to lay their eggs in fresh water inside houses. They like dog bowls, fish tanks, flower pots, and toilets. • Go through your house and remove every single thing that collects water. • Empty your pet dishes every day and give them fresh water • Fix the screens, or add new ones
Kill the larvae in standing water:All you need is a little cooking oil
Mosquito Dunks Kill Larvaemade with Bt-israelensisa bacteria harmless to the environment
Protect our Yards Eliminate all standing water. Do not leave buckets of water outside for pets Consider eliminating ponds or fountains Put plenty of chlorine in swimming pools, especially in rainy season Do not allow old tires or other junk in the yard.
What does not work • No specific vaccines yet • No specific anti-virals yet • Broadcast fumigation causes a short drop in numbers of mosquitos, but increased numbers later because natural predators are killed. • Spraying indoor walls does not work, because the mosquito larvae live in water.
