Mosquito larvae hatch from the eggs when the containers fill with water, in many cases after a rainfall. The larvae are aquatic, meaning that they live in the water and feed on microorganisms found in the water. Larvae go through developmental stages in which they molt, or shed their skin, three times. These larval stages are called the first to fourth instars. When a larva is a fully grown fourth instar, it undergoes metamorphosis into a new form called a pupa, the "cocoon" stage for the mosquito.
This stage of the mosquito's life is also aquatic. After two days, the fully developed adult mosquito forms and breaks through the skin of the pupa. The adult mosquito is able to fly and is no longer aquatic. It has a terrestrial habitat. What happens if there is no rain? Aedes aegypti mosquitoes have adapted so that their eggs can survive dry conditions for several months. If eggs are laid in a dry container, new mosquitoes only develop when the container is filled with water.
This adaptation has made it very difficult to eliminate mosquito populations completely. In many areas of the world, dengue outbreaks occur every year during the rainy season, when conditions are perfect for mosquito breeding. Dengue can pose a particular threat in highly populated regions because epidemics are more likely where there are large numbers of people in contact with large numbers of mosquito vectors than in more isolated areas.
In countries in the equatorial zone that experience tropical monsoon seasons — such as Indonesia, India, Brazil, Thailand, Sri Lanka, and Myanmar — dengue epidemics are a serious public health problem. Alameda County Mosquito Abatement District. Centers for Disease Control and Prevention. Dengue Virus Net. Aedes aegypti Kuno, G. Rodhain, F. Aa Aa Aa. Dengue Transmission. The risk of contracting dengue infection has increased dramatically since the s.
This upward trend is due to increases in long-distance travel, population growth and urbanization, lack of sanitation, ineffective mosquito control, and increases in the surveillance and official reporting of dengue cases.
Dengue is an endemic disease, which means that it occurs regularly, in tropical regions of the world. The disease is endemic in more than one hundred countries in Africa, the Americas, Asia, the Caribbean, and the Pacific. How does dengue spread, and how is this disease transmitted to humans? How Does Dengue Spread? Aedes Mosquitoes. Figure 1: Aedes aegypti. Aedes aegypti is the principal vector responsible for dengue transmission. How Is Dengue Transmitted to Humans? Figure 2: Dengue transmission.
The dengue virus is spread through a human-to-mosquito-to-human cycle of transmission. Dengue Mosquito Life Cycle. Figure 3: Aedes aegypti life cycle. Female Aedes aegypti commonly lay eggs on the inner walls of artificial containers. The dengue virus is spread through a human-to-mosquito-to-human cycle of transmission, with the mosquito Aedes aegypti as the primary vector. These mosquitoes live near humans in tropical and subtropical regions of the world.
Female Aedes aegypti become dengue vectors after feeding on the blood of a person infected with the dengue virus. Infected mosquitoes continue to transmit dengue with each blood meal for the rest of their lives. Aedes aegypti have a complex life cycle that includes aquatic and terrestrial stages. These mosquitoes lay their eggs inside containers, and new Aedes aegypti hatch when the containers are filled with water.
Dengue poses the greatest risk in highly populated regions with rainy seasons where there are large populations of Aedes aegypti with a high degree of contact between the mosquitoes and humans. The symptoms normally pass after about 1 week, although you may feel tired and slightly unwell for several weeks afterwards. Call NHS or see your GP if you develop a fever or flu-like symptoms up to 2 weeks after visitng an area where the dengue virus is found.
Go to a doctor or hospital if you develop symptoms while travelling or living in an area where dengue is common. There's little a doctor can do to help you recover, but it's important to get a proper diagnosis in case there's another cause of your symptoms.
You may need a blood test to confirm that you have dengue. There's no cure or specific treatment for dengue. You can only relieve the symptoms until the infection has gone. You should start to feel better after about 1 week, although it may be a few weeks before you feel your normal self again. Get medical advice if your symptoms don't improve. Mosquitoes in the UK do not spread dengue. Cases in the UK usually happen to people who recently travelled to an area where the virus is common.
Use the NHS Fit for Travel destination guide to find out if dengue is a risk in a country you're planning to visit. Dengue is spread by infected mosquitoes, usually the Aedes aegypti and Aedes albopictus varieties. These mosquitoes bite during the day, usually early in the morning or in the early evening before dusk.
They're often found near still water in built-up areas, such as in wells, water storage tanks or in old car tyres. There are four types of the dengue virus. Dengue Tests: How to Diagnose Dengue Fever The most common dengue fever tests are the dengue antigen test and the dengue antibody test. Currently, it is common practice for physicians to use a combination of the following dengue tests blood tests to diagnose this disease: Dengue molecular test Dengue PCR test : this test is used to confirm the diagnosis of a suspected dengue case.
The dengue PCR test may be used after 72 hours of initial symptom onset. Dengue virus antigen detection test NS1 test : High concentrations of the NS1 antigen are found during the first dengue phase.
In addition, it is found in both patients with their first dengue infection, as well as patients with a subsequent re-infection. This antigen can be found from the first day of illness onset. Thus, this test can be performed after day one of symptom onset, and up to day seven of symptom onset. Dengue antibody test IgM and IgG Dengue serologic test : our immune system reacts against this infection and produces enough IgM antibodies to be detected after 3 to five days from fever onset.
On the other hand, IgG antibodies are produced after 14 days of fever onset and remain in our body for life. Dengue Hemorrhagic Fever Treatment Similarly to the above-mentioned instance, treatment for dengue hemorrhagic fever consists of staying at home, getting plenty of rest, staying hydrated, and managing fever.
How to Prevent Dengue Dengue fever can be prevented by preventing and stopping the reproduction of the Aedes aegypti mosquito. Moreover, by following these recommendations we can prevent dengue fever: Wash frequently with soap-buckets, tanks, and cisterns, as well as any item that can serve to store water. Cover household items that can hold or contain water.
Throw away junk and maintain your house junk-free. Always keep your house and its surroundings clean and tidy. Invest in a screen for your windows and doors.
Use protective clothing such as long-sleeve shirts and pants. You can use insecticides that are effective against mosquitoes. Use mosquito repellent all over your body. Avoid high-risk areas where dengue is known to be prevalent. If I have Dengue Fever, when should I seek medical care?
Profuse vomiting. Breathing difficulty. Bleeding in gums, nose, in your vomit, or your stool. If, on the other hand, you have dengue fever without symptoms or with mild symptoms, you should keep to the following instructions: Stay at home.
Get plenty of rest. Do not take aspirin or ibuprofen. Always keep yourself hydrated; drink lots of water and electrolytes. Frequently Asked Questions about dengue. How do dengue symptoms begin to develop? When is the dengue season in Mexico? Which type of dengue is more dangerous? Therefore, if you develop any of these symptoms after having a fever, go to your nearest hospital: Stomach pain.
Bleeding in nose or gums. Blood presence in vomit or stool. A feeling of being exhausted or irritated. Can dengue be cured?
Can I take Aspirin when I have a dengue infection? Can I get dengue fever if I am pregnant? Is there a vaccine for dengue fever?
Dengue Fever Vaccine. Who is the dengue fever vaccine for? In addition, the WHO recommends that this vaccine should only be used to persons with confirmed prior dengue virus infections.
This is very important because people who receive the dengue vaccine and have not been previously infected with dengue may be at risk of developing hemorrhagic dengue if they get dengue after getting vaccinated with Dengvaxia. The dengue vaccine is given as a three-dose series on a 0, 6, and month schedule. Is the dengue fever vaccine effective Dengue Vaccine efficacy? The dengue vaccine proved to be effective in randomized trials. Accordingly, its efficacy during this trial was that of What are the common side effects of the dengue vaccine?
Common side effects of the dengue vaccine include headaches, muscle pains, and pain in the site of injection. What is the cost of the dengue fever vaccine? How long does the dengue fever vaccine last? Although there is no definitive information about how long you will be protected from this disease after getting the dengue vaccine, we do know several things.
First, the vaccine is most effective once 28 days have passed from the day you get your vaccine. Second, we know that you will be protected from a dengue infection for at least three years, and perhaps even longer. What is the difference between Dengue, Zika, and Chikungunya?
Nausea and vomit. Feeling weak. Nose bleeds or gum bleeds. High fever. Back pain. Intolerance to light. Muscle pain. Red and white dots in skin. Severe joint pain in hands and feet. Red dots on the skin. Conjunctivitis Beginning of symptoms 2 — 7 days after the mosquito bite. Complications Dengue hemorrhagic fever. May cause damage to main organs such as lungs, heart, liver, etc.
Neurologic complications. Muscle weakness. No frequent complications. Sometimes intense pain for months or even years.
Treatment For mild symptoms: Lots of rest, hydration, fever management with Paracetamol. Medication for pain management. Treatment depends on symptoms. In general, rest, hydration, and pain management. Basilio Badillo Puerto Vallarta.
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