Dengue Fever

Dengue fever is a painful, debilitating mosquito borne disease caused by any one of four closely related dengue viruses. These viruses are related to the viruses that cause West Nile infection and yellow fever.

An estimated 400 million dengue infections occur worldwide each year, with about 96 million resulting in illness. Most cases occur in tropical areas of the world, with the greatest risk occurring in the Indian sub continent, Southeast Asia, Southern China, Taiwan, the Pacific Islands, the Caribbean (except Cuba and the Cayman Islands), Mexico, Africa, Central and South America (except Chile, Paraguay, Argentina)

Dengue fever is transmitted by the bite of an Aedes mosquito infected with a dengue virus. Its peak biting periods are early morning and before dusk. The mosquito becomes infected when it bites a person with dengue virus in their blood. It cant spread directly from one person to another person.

Transmission of Dengue virus

Symptoms of Dengue fever usually begin four to six days after infection and last for up to 10 days, and may include sudden high fever, severe headaches, pain behind the eyes, severe joint and muscle pain, fatigue, nausea, vomiting, skin rash which appear two to five days after the onset of fever,mild bleeding such as nose bleeding, bleeding gums or easy bruising.

Sometimes symptoms are mild and can be mistaken for those of flu or another viral infection. Younger children and person who have never had the infection before tend to have have milder cases than older children and adults. However, serious problems can develop. These include dengue hemorrhagic fever, a rare complication characterized by high fever, damage of lymph and blood vessels, bleeding from the nose and gums, enlargement of the liver, and failure of the circulatory system. The symptoms may progress to massive bleeding, shock and death. This is called dengue shock syndrome (DSS).

People with weakened immune systems as well as those with a second or subsequent dengue infection are believed to be at greater risk for developing dengue hemorrhagic fever.

Doctors can diagnose dengue infection with a blood test to check for the virus or antibodies to it.

There is no specific medicine to treat dengue infection, If you think you may have dengue fever, you should use pain relievers with acetaminophen and avoid medicines with aspirin, which could worsen bleeding, You should also rest, drink plenty of fluids and see your doctor. If you start to feel worse in the first 24 hours after your fever goes down, you should get to a hospital immediately to be checked for complications.

The best way to prevent the disease is to prevent bites by infected mosquitoes, particularly if you are living in or travelling to a tropical area. This involves protecting yourself and making efforts to keepk the mosquito population down.

To protect yourself
Use mosquito repellents, even indoors
When outdoors, wear long sleeved shirts and long pants tucked into socks
When indoors, use air conditioning if available
Make sure window and door screens are secure and free of holes. If sleeping areas are not screened or air conditioned, use mosquito nets
If you have symptoms of dengue, speak to your doctor

To reduce the mosquito population, destroy the mosquito breeding grounds and spray insecticide in the affected areas. These include old tires, cans. or flower pots that collect rain. Regularly change the water in outdoor bird baths and pet's water dishes.

If someone in your home gets dengue fever, be especially vigilant about efforts to protect yourself and other family members from mosquitoes. Mosquitoes that bite the infected family member could spread the infection to others in your home.

Discoverer of penicillin Alexander Fleming warned against its overuse and the risk of resistant microorganisms as early as 1945, in his Nobel Prize lecture

"The time may come when penicillin can be bought by anyone in the shops. Then there is the danger that the ignorant man may easily underdose himself and by exposing his microbes to non-lethal quantities of the drug make them resistant.

Here is a hypothetical illustration. Mr. X has a sore throat. He buys some penicillin and gives himself, not enough to kill the streptococci but enough to educate them to resist penicillin. He then infects his wife. Mrs. X gets pneumonia and is treated with penicillin. As the streptococci are now resistant to penicillin the treatment fails. Mrs. X dies. Who is primarily responsible for Mrs. X's death? Why Mr. X whose negligent use of penicillin changed the nature of the microbe.

Moral: If you use penicillin, use enough"

Sir Alexander Fleming shared the Nobel Prize in Physiology or Medicine in 1945 with Howard Florey and Ernst Boris Chain for his discovery of the world's first antibiotic substance benzylpenicillin (Penicillin G) from the mould Penicillium notatum in 1928. He also discovered the enzyme lysozyme in 1923.

Fleming's Nobel Lecture reached from here:Nobel Lecture by Sir Alexander Fleming on December 11, 1945

'Breakthrough' in malaria fight

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Australian scientists have identified a potential treatment to combat malaria.

Researchers in Melbourne believe their discovery could be a major breakthrough in the fight against the disease.
The malaria parasite produces a glue-like substance which makes the cells it infects sticky, so they cannot be flushed through the body.
The researchers have shown removing a protein responsible for the glue can destroy its stickiness, and undermine the parasite's defence.
The malaria parasite - Plasmodium falciparum - effectively hijacks the red blood cells it invades, changing their shape and physical properties dramatically.
Among the changes it triggers is the production of the glue-like substance, which enables the infected cells to stick to the walls of the blood vessels.
This stops them being pased through the spleen, where the parasites would usually be destroyed by the immune system.
Painstaking tests
The Australian team developed mutant strains of P. falciparum, each lacking one of 83 genes known or predicted to play a role in the red cell remodeling process.
Systematically testing each one, they were able to show that eight proteins were involved in the production of the key glue-like substance.
Removing just one of these proteins stopped the infected cells from attaching themselves to the walls of blood vessels.
Professor Alan Cowman, a member of the research team at the Walter and Eliza Hall Institute of Medical Research, said targeting the protein with drugs - or possibly a vaccine - could be key to fighting malaria.
"If we block the stickiness we essentially block the virulence or the capacity of the parasite to cause disease," he said.
Malaria is preventable and curable, but can be fatal if not treated promptly. The disease kills more than a million people each year. Many of the victims are young children in sub-Saharan Africa.