Definition Of Avian Influenza

Definition of Avian influenza Swine Flu FAQ Slideshow

Avian influenza: Also called fowl plague, avian flu, and bird flu. A highly contagious viral disease with up to 100% mortality in domestic fowl. Caused by influenza A virus subtypes H5 and H7. All types of birds are susceptible to the virus but outbreaks occur most often in chickens and turkeys. The infection may be brought by migratory wild birds which can carry the virus but show no signs of disease. Humans are only rarely affected. Type A influenza viruses can infect several animal species aside from birds, including pigs, horses, seals and whales. Birds are an especially important species because all known subtypes of influenza A viruses circulate among wild birds, which are the natural hosts for influenza A viruses. Avian influenza viruses do not usually directly infect humans or circulate among humans. Influenza A viruses can be divided into subtypes on the basis of their surface proteins - hemagglutinin (HA) and neuraminidase (NA). There are 15 known H subtypes. While all subtypes can be found in birds, only 3 subtypes of HA (H1, H2 and H3) and two subtypes of NA (N1 and N2) are known to have circulated widely in humans. The symptoms in humans range from typical influenza-like symptoms (with fever, cough, sore throat and muscle aches) to eye infections, pneumonia, acute respiratory distress, viral pneumonia, and other severe and life-threatening complications. Studies to date suggest that the prescription medications approved for human influenza strains would be effective in preventing avian influenza infection in humans. All influenza viruses have the potential to change. It is possible that an avian influenza virus could change so that it could infect humans and could spread easily from person to person. Because these viruses do not commonly infect humans, there is little or no immune protection against them in the human population. If an avian virus were able to infect people and gain the ability to spread easily from person to person, an influenza pandemic, a global outbreak, could begin. Past influenza pandemics have led to high levels of illness, death, social disruption and economic loss. There were 3 pandemics in the 20th century; the Spanish flu (1918-19), Asian flu (1957-58), and Hong Kong flu (1968-69). All of them spread worldwide within a year of being detected.

Definition of Dengue fever Dengue fever: An acute mosquito- borne viral illness of sudden onset that usually follows a benign course with headache, fever, prostration, severe joint and muscle pain, swollen glands (lymphadenopathy) and rash. The presence (the "dengue triad") of fever, rash, and headache (and other pains) is particularly characteristic of dengue. Dengue fever is endemic throughout the tropics and subtropics. It goes by other names including breakbone or dandy fever. Victims of dengue often have contortions due to the intense joint and muscle pain. Hence, the name "breakbone fever." Slaves in the West Indies who contracted dengue were said to have "dandy fever" because of their postures and gait.

Definition of Malaria Malaria: An infectious disease caused by protozoan parasites from the Plasmodium family that can be transmitted by the sting of the Anopheles mosquito or by a contaminated needle or transfusion. Falciparum malaria is the most deadly type. The symptoms of malaria include cycles of chills, fever, sweats, muscle aches and headache that recur every few days. There can also be vomiting, diarrhea, coughing, and yellowing (jaundice) of the skin and eyes. Persons with severe falciparum malaria can develop bleeding problems, shock, kidney and liver failure, central nervous system problems, coma, and die. The treatment of malaria is with oral or intravenous medications, including chloroquine, mefloquine (Larium), or atovaquone/proguanil (Malarone). Malaria transmission occurs primarily between dusk and dawn because of the nocturnal feeding habits of Anopheles mosquitoes. One should therefore take protective measures to reduce contact with mosquitoes, especially during these hours. These measures include remaining in well-screened areas, using mosquito nets, and wearing clothes that cover most of the body. Additionally, one should have insect repellent for use on exposed skin. The most effective repellent against a wide range of vectors is DEET (N,N-diethylmetatoluamide), an ingredient in many commercially available insect repellents. The actual concentration of DEET varies widely among repellents. DEET formulations as high as 50% are recommended for both adults and children >2 months of age. Travelers not staying in well-screened or air-conditioned rooms are advised to use a pyrethroid-containing flying-insect spray in living and sleeping areas during the evening and nighttime hours. They should sleep under insecticide-treated bed nets. Bed nets are more effective if they are treated with permethrin or deltamethrin insecticide; bed nets may be purchased that have already been treated with insecticide. Among the many names for malaria are ague, jungle fever, marsh or swamp fever, and paludism.