5 of the Most Common Infectious Diseases
Thursday, November 25, 2010
An infectious disease is a disease caused by bacterial, viral, fungal or protozoan infection. The diseases can be spread from one person to another or from animals to humans. Infectious diseases kill more people worldwide than any other single cause. Vaccines, proper hand washing and medicines can help prevent infections. Here is a list of 5 of the Most Common Infectious Diseases:
Meningitis
Meningitis is an inflammation of the membranes and cerebrospinal fluid that covers the brain and spinal cord, known collectively as the meninges. The inflammation can be caused by an infection with bacteria, viruses, fungi, parasites or other microorganisms and in rare cases by certain drugs. Symptoms of meningitis can appear suddenly and often include stiff neck, high fever, severe headaches, nausea, vomiting, confusion, sleepiness and difficulty waking up. In infants, symptoms are less specific and can include irritability, loss of appetite and fever.
The disease can be life-threatening and result in coma, shock and death.There are several types of meningitis, such as acute bacterial meningitis, viral meningitis, chronic meningitis and aseptic meningitis. The treatment depends on the type of meningitis. Usually, the most serious and deadly type is acute bacterial meningitis as it develops very quickly in a matter of hours or days. Some forms of bacterial meningitis are preventable with vaccinations such as: Meningococcal conjugate vaccine, Pneumococcal conjugate vaccine, Haemophilus influenzae type b vaccine and Pneumococcal polysaccharide vaccine.
Rotavirus
Rotavirus is the most common cause of viral gastroenteritis worldwide and of severe diarrhea among infants and young children. Almost 600,000 children die annually from complications of the rotavirus. There are five species of rotavirus: A, B, C, D, and E; rotavirus A causes more than 90% of infections. Almost every child 5 years and younger at some point will be infected with rotavirus at least once, but with each infection, immunity develops.
The disease is characterized by vomiting, dry or sticky mouth, abdominal pain, diarrhea and fever and has an incubation period of two days. The symptoms may last from three to eight days. If left untreated it can lead to dehydration and death. Rotavirus is highly contagious and it spreads through fecal-oral route of transmission (children can transmit the virus when they forget to wash their hands after using the toilet or before eating). The treatment consists of increased fluid intake to prevent dehydration and about one in 40 children needs hospitalization for intravenous fluid. Outbreaks of rotavirus A are common among hospitalized infants and young children attending day care centers. The main way to prevent rotavirus is through vaccination. There are two available vaccines: Rotarix and RotaTeq.
Measles
Measles also known as Rubeola is a highly contagious respiratory infection caused by a virus, a paramyxovirus of the genus Morbillivirus. It is spread through respiration, coughing, sneezing and direct contact with infected nasal or throat secretions. The virus can remain contagious and active in the air or for up to two hours. An infected person can transmit the disease from four days prior to the onset of the rash to four days after the rash erupts. The initial symptoms include: fever (it can rise as much as 40°C - 104°F), cough, runny nose (coryza), red eyes (conjuctivitis) and loss of appetite. Two to four days after the onset of initial symptoms the characteristic rash begins to develop starting on the face and spreading to the torso and then arms and legs.
"Koplik spots", small grayish spots on the inside of the cheek, can also develop, but are not often seen as they usually disappear within a day. As the rash begins to clear up the skin can shed in some cases. Measles is usually a mild disease, but complications can occur, ranging from diarrhea to pneumonia and encephalitis. There is no specific medical treatment and the virus has to run its course. Children are usually immunized by the age of 18 months through the MMR (Measles-Mumps-Rubella) vaccine. Sadly in less developed countries, where vaccines are not available and complications appear due to unsanitary conditions and inadequate care, Measles is the main cause of death among young children.
Japanese Encephalitis
Japanese Encephalitis is a disease that is spread to humans by infected mosquitoes. The Japanese encephalitis virus is a virus from the family Flaviviridae and is closely related to St. Louis encephalitis and West Nile virus. The disease is more prevalent in rural areas in East and Southeast Asia and is the leading cause of viral encephalitis in Asia. Annually, between 30.000 and 50.000 cases are being reported. The vast majority of infections are asymptomatic, only 1 in 250 infections develops into encephalitis. Japanese encephalitis has an incubation period of 5 to 15 days and the virus initially propagates at the site of the bite and in regional lymph nodes.
The onset of the disease is marked by severe rigor marks and in some cases fever, vomiting and headaches. Symptoms that develop during the acute encephalitic stage include neck stiffness, hemiparesis (weakness in one half of the body), high fever (ranging between 38°C and 41°C), cachexia (loss of weight, muscle atrophy, fatigue, weakness and loss of appetite), convulsions, disorientation, coma and paralysis. About 1 in 4 cases of severe infections with encephalitis results in death. Most symptomatic infections occur in young children and elderly people. Japanese encephalitis vaccine can prevent the disease, but is not 100% effective precautions to avoid mosquito bites must also be taken.
Pneumonia
Pneumonia is an an inflammatory condition of the lung which is usually caused by bacteria, viruses, or fungi. It can also be caused by a fungal infection, yeast infection and trauma. People afflicted by pneumonia initially have symptoms of a cold : sneezing, sore throat, cough, followed by a high fever, nausea, headaches, vomiting, chills and a cough with sputum production. In rare cases, skin color may become dusky or purplish (cyanosis) due to blood being poorly oxygenated. If left untreated pneumonia can develop serious complications such as empyema, pleural effusion, lung abscess, acute respiratory distress syndrome, respiratory failureand sepsis.
These complications can lead to death. Pneumonia can affect people in all parts of the world. It is a major cause of death among all age groups and is the leading cause of death in children and the elderly living in low income countries. More cases occur during autumn and winter. The disease occurs more often in males than in females. People with underlying conditions such as cystic fibrosis, Alzheimer's disease, AIDS, cancer, emphysema and tobacco smoking are more at risk and more likely to develop pneumonia more than once.





































