There are two main types of influenza virus, Types A and B. The influenza A and B viruses that routinely spread in people (human influenza viruses) are responsible for seasonal flu epidemics each year. Influenza A viruses can be broken down into sub-types depending on the genes that make up the surface proteins. Over the course of a flu season, different types (A & B) and subtypes (influenza A) of influenza circulate and cause illness. Influenza outbreaks have apparently occurred since atleast the Middle Ages. In the elderly, in infants, and in people with chronic diseases, influenza is associated with especially high mortality.

Infection is the invasion of an organism's body tissues by disease causing agents, their growth, and the reaction of host tissues to these organisms and the toxins they produce. Pediatric infections are caused by infectious agents including viruses, viroid’s, prions, bacteria, nematodes such as parasitic roundworms and pinworms, arthropods such as ticks, mites, fleas, and lice, fungi such as ringworm, and other macro parasites such as tapeworms and other helminths. Specific medications used to treat pediatric infections include antibiotics, antivirals, antifungals, antiprotozoal, and anthelminthic.

Vaccines save lives by protecting people against infectious diseases such as polio, measles, Influenza and viral hepatitis. But recently, particularly in the Northwest, people have delayed or refused vaccination because of safety fears, leading to local outbreaks of potentially deadly diseases like whooping cough. Kaiser Permanente Washington is working to protect communities by continually improving the safety and effectiveness of vaccines.

Infectious diseases prevention and control is helpful to prevent the transmission of infectious diseases. Sexually Transmitted Infection control efforts have increasingly been defined in relation to HIV programme priorities that are funded, implemented and evaluated independently of other STI control efforts. STI control is a public health outcome, measured as reduced incidence and prevalence, achieved by implementing strategies composed of multiple synergistic interventions. 

Parasites are animals or plants which must live on or in another plant or animal to survive (go on living). There are several parasites in the environment and when they get into a person's body, his/her health can be affected. Some parasites enter the body by way of contaminated food or water and some live on the skin and the hair. Examples of parasites include stomach and gut worms (threadworm, hookworm),skin mites (scabies), hair and body lice (head lice and crab lice), protozoa (Giardia).

Fungal diseases are usually caused by common fungi found in our environment, including the soil, plants, trees, and even on our skin and other parts of the body. Symptoms of fungal infection depend on the type and location in the body. Fungal infections may be mild, manifesting as rashes or mild respiratory problems. However, some diseases may be severe and can cause serious complications and death. Here in this article we list common diseases, including causes, symptoms and treatment options for each condition.

There are obviously many other human diseases caused by viruses. Indeed, many professional medical books are devoted exclusively to this topic. A few notable examples that have garnered the attention of the public health community and the population at large include: -- Zika: a virus spread primarily by mosquitoes that can cause birth defects -- MERS-CoV: the virus responsible for Middle East respiratory syndrome, a potentially deadly respiratory infection -- Ebola: virus spread through contact with infected body fluids that can causes an often fatal illness called Ebola hemorrhagic fever -- HIV: virus responsible for acquired immunodeficiency syndrome (AIDS) -- Hepatitis C: virus that typically establishes long-term infection of the liver, and is the leading cause of liver transplants and liver cancer in the U.S.

Viruses cause a wide array of skin infections. Herpes simplex viruses (HSV) cause some of the most common skin infections. HSV type 1 tends to cause vesicles in the mouth and on the lips, commonly known as cold sores or fever blisters. HSV type-2 tends to cause genital herpes. According to the Cleveland Clinic, 85 percent of the population has blood test evidence of exposure to HSV-1, even if they never had symptoms. The varicella virus causes chickenpox, an illness characterized by itchy fluid-filled bumps on the skin that eventually rupture and scab over. The varicella virus also causes shingles, which is a reactivation of the virus years after the initial bout of chickenpox. Another group of viruses, the human papillomaviruses (HPV), cause warts. Warts are a very common skin infection and can affect any skin surface. The feet, hands and face are frequently affected by common warts or plantar wart. Genital warts are the most common sexually transmitted infection. Among women, genital warts caused by certain types of HPV can predispose to cervical cancer. The HPV vaccine protects against these cancer-causing types of HPV.

Several viruses can infect the central nervous system, which consists of the brain and spinal cord. For example, enteroviruses and herpes viruses can cause meningitis and encephalitis. According to an October 2014 article published in the "The Neurohospitalist," other viral causes of central nervous system infections are emerging, including West Nile virus, Japanese encephalitis virus, human parechoviruses and Chikungunya virus. Meningitis is an inflammation of the tissue surrounding the brain and spinal cord. Encephalitis is an inflammation of the brain tissue itself. The symptoms of these central nervous system infections overlap and can include fever, headache, neck stiffness and light sensitivity. Mental status changes are common, including confusion, mood instability, extreme lack of energy and possibly coma. Seizures occur in some people with meningitis or encephalitis.

Several types of viruses cause viral gastroenteritis, commonly called the stomach flu. This common illness, characterized by diarrhea, nausea and vomiting, is caused by many different viruses, but not the influenza virus. According to a June 2012 "American Family Physician" article, viruses cause 75 to 90 percent of acute gastrointestinal disease in children. Rotavirus is the most common cause of viral gastroenteritis among children. Norovirus is the leading cause of viral gastroenteritis outbreaks. Other viruses that cause the stomach flu include adenovirus, calicivirus and astrovirus. Most cases of viral gastroenteritis clear on their own within 2 to 4 days, but dehydration may require medical treatment.

A variety of viruses cause different types of respiratory infections. Rhinovirus, coronavirus and adenovirus are the leading causes of the common cold. Influenza viruses infect the upper respiratory system and sometimes spread to the lungs causing pneumonia. Another virus called the respiratory syncytial virus (RSV) causes a respiratory infection called bronchiolitis in infants and toddlers. The symptoms of bronchiolitis include dry cough, rapid breathing and wheezing, a high-pitched sound sick children make when exhaling.

Viruses are very tiny germs. They are made of genetic material inside of a protein coating. Viruses cause familiar infectious diseases such as the common cold, flu and warts. They also cause severe illnesses such as HIV/AIDS, smallpox, and Ebola. Viruses are like hijackers. They invade living, normal cells and use those cells to multiply and produce other viruses like themselves. This can kill, damage, or change the cells and make you sick. Different viruses attack certain cells in your body such as your liver, respiratory system, or blood.

Infectious diseases kill more people worldwide than any other single cause. Infectious diseases are caused by germs. Germs are tiny living things that are found everywhere - in air, soil and water. People can get infected by touching, eating, drinking or breathing something that contains a germ. Germs can also spread through animal and insect bites, kissing and sexual contact. Vaccines, proper hand washing and medicines can help prevent infections. They are caused by pathogenic microorganisms such as bacteria, virus, parasites and fungi. Germs can be spread by direct or indirect contact. Zoonotic diseases example Anthrax are transmittable diseases of animals that can cause disease when transmitted to humans. 

Rare diseases caused by causative agents rather than genetic or environmental factors. A rare disease is any disease that affects a small percentage of the population. In some parts of the world, an orphan disease is a rare disease whose rarity means there's a lack of a market large enough to gain support and resources for discovering treatments for it, except by the government granting economically advantageous conditions to creating and selling such treatments. Orphan drugs are ones so created or sold.

Most healthy people’s immune systems kill or contain TB infection without developing symptoms. Latent TB infection is an asymptomatic and non-transmissible form of TB. Hepatitis is an inflammation of the liver. There are 5 main hepatitis viruses, referred to as types A, B, C, D and E. Twin studies of tuberculosis (TB) and chronic hepatitis B virus (HBV) infection identified a strong host genetic component to individual variability in disease susceptibility. Short-course chemotherapy containing rifampicin and isoniazid in combination has proved to be highly effective in the treatment of tuberculosis, but one of its adverse effects is hepatotoxicity. An estimated 49 million lives were saved through TB diagnosis and treatment between 2000 and 2015.

It is necessary a medical expert to shield people among his or her clinical workplace follow. This responsibility isn't restricted to patients, but rather, includes clinical staff and alternative guests moreover. Each from a structural Associate in nursing purposeful purpose of read there are ample opportunities for infection to be transmitted in a workplace setting. Infectious agents aren't solely unfold person-to-person, however may also be unfold indirectly through inanimate objects called fomites, and also the room of a clinical workplace follow could also be a supply for several communicable diseases. As such, protecting mechanisms should be in situ, not solely in direct patient management however in handling of the clinical workplace setting moreover. These infection bar and management best practices for physicians aren't meant to exchange a physician’s best clinical judgement, however can assist physicians with their clinical office-based follow. Some elements are derived from legislation and laws, and can state in specific terms what physicians ought to or mustn't do.

Most common maternal infections like UTIs, skin and respiratory tract infections are usually not serious problems during pregnancy, although some genital infections like bacterial vaginosis and genital herpes affect labor or choice of delivery method. Thus, the main issue is usually use and safety of antimicrobial drugs. Give antibacterials to pregnant patients only when there is strong evidence of a bacterial infection and only if benefits of treatment outweigh risk, which varies by trimester.

Infectious disease affects us all. Human diseases have a profound effect in countries across the world, causing premature deaths and disability. Diseases in plants and animals act as barriers to economic development and also threaten ecosystems.

Infectious diseases are disorders caused by organisms — such as bacteria, viruses, fungi or parasites. Many organisms live in and on our bodies. They're normally harmless or even helpful, but under certain conditions, some organisms may cause disease. Some infectious diseases can be passed from person to person. Some are transmitted by bites from insects or animals. And others are acquired by ingesting contaminated food or water or being exposed to organisms in the environment. Therapy or treatment is the attempted remediation of a health problem, usually following a diagnosis.

Gene therapy is being investigated as an alternative cure for a extensive range of infectious diseases that are not acquiescent to standard clinical management. Gene therapy holds considerable potential for the treatment of both hereditary genetic disorders and infectious diseases. Gene therapy for infectious diseases requires the introduction of genes designed to specifically inhibit the gene expression or function of gene products, such that the replication of the infectious agent is blocked. In addition to this intracellular intervention, gene therapy may be used to intervene in the spread of the infectious agent at the extracellular level. This could be achieved by sustained expression in vivo of a secreted inhibitory protein or by stimulation of a specific immune response.