query: medical_specialty amoebiasis
supports: Infection is the invasion of an organism's body tissues by disease-causing agents, their multiplication, and the reaction of host tissues to these organisms and the toxins they produce. Infectious disease, also known as transmissible disease or communicable disease, is illness resulting from an infection.
  Infections are caused by infectious agents including viruses, viroids, prions, bacteria, nematodes such as parasitic roundworms and pinworms, arthropods such as ticks, mites, fleas, and lice, fungi such as ringworm, and other macroparasites such as tapeworms and other helminths. Malaria is a mosquito-borne infectious disease affecting humans and other animals caused by parasitic protozoans (a group of single-celled microorganisms) belonging to the "Plasmodium" type. Malaria causes symptoms that typically include fever, fatigue, vomiting, and headaches. In severe cases it can cause yellow skin, seizures, coma, or death. Symptoms usually begin ten to fifteen days after being bitten. If not properly treated, people may have recurrences of the disease months later. In those who have recently survived an infection, reinfection usually causes milder symptoms. This partial resistance disappears over months to years if the person has no continuing exposure to malaria.
  The disease is most commonly transmitted by an infected female "Anopheles" mosquito. The mosquito bite introduces the parasites from the mosquito's saliva into a person's blood. The parasites travel to the liver where they mature and reproduce. Five species of "Plasmodium" can infect and be spread by humans. Most deaths are caused by "P. falciparum" because "P. vivax", "P. ovale", and "P. malariae" generally cause a milder form of malaria. The species "P. knowlesi" rarely causes disease in humans. Malaria is typically diagnosed by the microscopic examination of blood using blood films, or with antigen-based rapid diagnostic tests. Methods that use the polymerase chain reaction to detect the parasite's DNA have been developed, but are not widely used in areas where malaria is common due to their cost and complexity.
  The risk of disease can be reduced by preventing mosquito bites through the use of mosquito nets and insect repellents, or with mosquito control measures such as spraying insecticides and draining standing water. Several medications are available to prevent malaria in travellers to areas where the disease is common. Occasional doses of the combination medication sulfadoxine/pyrimethamine are recommended in infants and after the first trimester of pregnancy in areas with high rates of malaria. Despite a need, no effective vaccine exists, although efforts to develop one are ongoing. The recommended treatment for malaria is a combination of antimalarial medications that includes an artemisinin. The second medication may be either mefloquine, lumefantrine, or sulfadoxine/pyrimethamine. Quinine along with doxycycline may be used if an artemisinin is not available. It is recommended that in areas where the disease is common, malaria is confirmed if possible before treatment is started due to concerns of increasing drug resistance. Resistance among the parasites has developed to several antimalarial medications; for example, chloroquine-resistant "P. falciparum" has spread to most malarial areas, and resistance to artemisinin has become a problem in some parts of Southeast Asia.
  The disease is widespread in the tropical and subtropical regions that exist in a broad band around the equator. This includes much of Sub-Saharan Africa, Asia, and Latin America. In 2015, there were 214 million cases of malaria worldwide resulting in an estimated 438,000 deaths, 90% of which occurred in Africa. Rates of disease have decreased from 2000 to 2015 by 37%, but increased from 2014 during which there were 198 million cases. Malaria is commonly associated with poverty and has a major negative effect on economic development. In Africa, it is estimated to result in losses of US$12 billion a year due to increased healthcare costs, lost ability to work, and negative effects on tourism. A liver abscess is a pus-filled mass inside the liver. Common causes are abdominal infections such as appendicitis or diverticulitis due to haematogenous spread through the portal vein. Irritable bowel syndrome (IBS) is a group of symptomsincluding abdominal pain and changes in the pattern of bowel movements without any evidence of underlying damage. These symptoms occur over a long time, often years. It has been classified into four main types depending on if diarrhea is common, constipation is common, both are common, or neither occurs very often (IBS-D, IBS-C, IBS-M, or IBS-U respectively). IBS negatively affects quality of life and may result in missed school or work. Disorders such as anxiety, major depression, and chronic fatigue syndrome are common among people with IBS.
  The causes of IBS are not clear. Theories include gutbrain axis problems, small intestinal bacterial overgrowth, genetic factors, food sensitivity, and gut motility problems. Onset may be triggered by an intestinal infection, or stressful life event. IBS is a functional gastrointestinal disorder. Diagnosis is based on signs and symptoms in the absence of worrisome features. Worrisome features include onset at greater than 50 years of age, weight loss, blood in the stool, or a family history of inflammatory bowel disease. Other conditions that may present similarly include celiac disease, microscopic colitis, inflammatory bowel disease, bile acid malabsorption, and colon cancer.
  There is no cure for IBS. Treatment is carried out to improve symptoms. This may including dietary changes, medication, probiotics, and counseling. Dietary measures include increasing soluble fiber intake, a gluten free diet, or a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP). The medication loperamide may be used to help with diarrhea while laxatives may be used to help with constipation. Antidepressants may improve overall symptoms and pain. Patient education and a good doctorpatient relationship are an important part of care.
  About 10 to 15% of people in the developed world are believed to be affected by IBS. It is more common in South America and less common in Southeast Asia. It is twice as common in women as men and typically occurs before age 45. The condition appears to become less common with age. IBS does not affect life expectancy or lead to other serious diseases. The first description of the condition was in 1820 while the current term "irritable bowel syndrome" came into use in 1944.
  Classification.
  IBS can be classified as either diarrhea-predominant (IBS-D), constipation-predominant (IBS-C), or with alternating stool pattern (IBS-A) or pain-predominant. In some individuals, IBS may have an acute onset and develop after an infectious illness characterized by two or more of: fever, vomiting, diarrhea, or positive stool culture. This postinfective syndrome has consequently been termed "postinfectious IBS" (IBS-PI). Rotavirus is the most common cause of diarrhoeal disease among infants and young children. It is a genus of double-stranded RNA viruses in the family "Reoviridae". Nearly every child in the world is infected with rotavirus at least once by the age of five. Immunity develops with each infection, so subsequent infections are less severe; adults are rarely affected. There are eight species of this virus, referred to as A, B, C, D, E, F, G and H. "Rotavirus A", the most common species, causes more than 90% of rotavirus infections in humans. Cholera is an infection of the small intestine by some strains of the bacterium "Vibrio cholerae". Symptoms may range from none, to mild, to severe. The classic symptom is large amounts of watery diarrhea that lasts a few days. Vomiting and muscle cramps may also occur. Diarrhea can be so severe that it leads within hours to severe dehydration and electrolyte imbalance. This may result in sunken eyes, cold skin, decreased skin elasticity, and wrinkling of the hands and feet. The dehydration may result in the skin turning bluish. Symptoms start two hours to five days after exposure.
  Cholera is caused by a number of types of "Vibrio cholerae", with some types producing more severe disease than others. It is spread mostly by unsafe water and unsafe food that has been contaminated with human feces containing the bacteria. Undercooked seafood is a common source. Humans are the only animal affected. Risk factors for the disease include poor sanitation, not enough clean drinking water, and poverty. There are concerns that rising sea levels will increase rates of disease. Cholera can be diagnosed by a stool test. A rapid dipstick test is available but is not as accurate.
  Prevention involves improved sanitation and access to clean water. Cholera vaccines that are given by mouth provide reasonable protection for about six months. They have the added benefit of protecting against another type of diarrhea caused by "E. coli". The primary treatment is oral rehydration therapythe replacement of fluids with slightly sweet and salty solutions. Rice-based solutions are preferred. Zinc supplementation is useful in children. In severe cases, intravenous fluids, such as Ringer's lactate, may be required, and antibiotics may be beneficial. Testing to see which antibiotic the cholera is susceptible to can help guide the choice.
  Cholera affects an estimated 35 million people worldwide and causes 58,000130,000 deaths a year as of 2010. While it is currently classified as a pandemic, it is rare in the developed world. Children are mostly affected. Cholera occurs as both outbreaks and chronically in certain areas. Areas with an ongoing risk of disease include Africa and south-east Asia. While the risk of death among those affected is usually less than 5%, it may be as high as 50% among some groups who do not have access to treatment. Historical descriptions of cholera are found as early as the 5th century BC in Sanskrit. The study of cholera by John Snow between 1849 and 1854 led to significant advances in the field of epidemiology. Lactose intolerance is a condition in which people have symptoms due to the decreased ability to digest lactose, a sugar found in milk products. Those affected vary in the amount of lactose they can tolerate before symptoms develop. Symptoms may include abdominal pain, bloating, diarrhea, gas, and nausea. These typically start between half and two hours after drinking milk or eating milk products. Severity depends on the amount a person eats or drinks. It does not cause damage to the gastrointestinal tract.
  Lactose intolerance is due to not enough of the enzyme lactase in the small intestines to break lactose down into glucose and galactose. There are four types: primary, secondary, developmental, and congenital. Primary lactose intolerance is when the amount of lactase decline as people age. Secondary lactose intolerance is due to injury to the small intestine such as from infection, celiac disease, inflammatory bowel disease, or other diseases. Developmental lactose intolerance may occur in premature babies and usually improves over a short period of time. Congenital lactose intolerance is an extremely rare genetic disorder in which little or no lactase is made from birth.
  Diagnosis may be confirmed if symptoms resolve following eliminating lactose from the diet. Other supporting tests include a hydrogen breath test and a stool acidity test. Other conditions that may produce similar symptoms include irritable bowel syndrome, celiac disease, and inflammatory bowel disease. Lactose intolerance is different from a milk allergy. Management is typically by decreasing the amount of lactose in the diet or taking lactase supplements. Those affected are usually able to drink at least one cup of milk without developing significant symptoms, with greater amounts tolerated if drunk with a meal or throughout the day.
  The number of people with lactose intolerance is unknown. The percentage of the population that has a decrease in lactase as they age is less than 10% in Northern Europe and as high as 95% in parts of Asia and Africa. Onset is typically in late childhood or adulthood. The ability to digest lactose into adulthood is believed to have developed among some human populations in the last 10,000 years.  Nitazoxanide is a broad-spectrum antiparasitic and broad-spectrum antiviral drug that is used in medicine for the treatment of various helminthic, protozoal, and viral infections. It is indicated for the treatment of infection by "Cryptosporidium parvum" and "Giardia lamblia" in immunocompetent individuals and has been repurposed for the treatment of influenza. Nitazoxanide has also been shown to have "in vitro" antiparasitic activity and clinical treatment efficacy for infections caused by other protozoa and helminths; emerging evidence suggests that it possesses efficacy in treating a number of viral infections as well. Giardia lamblia, also known as Giardia intestinalis, is a flagellated parasite that colonizes and reproduces in the small intestine, causing giardiasis. The parasite attaches to the epithelium by a ventral adhesive disc, and reproduces via binary fission. Giardiasis does not spread via the bloodstream, nor does it spread to other parts of the gastrointestinal tract, but remains confined to the lumen of the small intestine. "Giardia" trophozoites absorb their nutrients from the lumen of the small intestine, and are anaerobes. If the organism is split and stained, its characteristic pattern resembles the familiar "smiley face" symbol. Chief pathways of human infection include ingestion of untreated sewage, a phenomenon particularly common in many developing countries; contamination of natural waters also occurs in watersheds where intensive grazing occurs. Peritonitis is an inflammation of the peritoneum, the thin tissue that lines the inner wall of the abdomen and covers most of the abdominal organs. Peritonitis may be localized or generalized, and may result from infection (often due to perforation of the intestinal tract as may occur in abdominal trauma or inflamed appendix) or from a non-infectious process. Amoebiasis , also known as amebiasis or entamoebiasis , is an infection caused by any of the amoebas of the Entamoeba group . Symptoms are most common upon infection by Entamoeba histolytica . Amoebiasis can present with no , mild , or severe symptoms . Symptoms may include abdominal pain , mild diarrhoea , bloody diarrhea or severe colitis with tissue death and perforation . This last complication may cause peritonitis . People affected may develop anemia due to loss of blood . Invasion of the intestinal lining causes amoebic bloody diarrhea or amoebic colitis . If the parasite reaches the bloodstream it can spread through the body , most frequently ending up in the liver where it causes amoebic liver abscesses . Liver abscesses can occur without previous diarrhea . Cysts of Entamoeba can survive for up to a month in soil or for up to 45 minutes under fingernails . It is important to differentiate between amoebiasis and bacterial colitis . The preferred diagnostic method it through faecal examination under microscope , but requires a skilled microscopist and may not be reliable when excluding infection . Increased white blood cell count is present in severe cases , but not in mild ones . The most accurate test is for antibodies in the blood , but it may remain positive following treatment . Prevention of amoebiasis is by separating food and water from faeces and by proper sanitation measures . There is no vaccine . There are two treatment options depending on the location of the infection . Amoebiasis in tissues is treated with either metronidazole , tinidazole , nitazoxanide , dehydroemetine or chloroquine , while luminal infection is treated with diloxanide furoate or iodoquinoline . For treatment to be effective against all stages of the amoeba may require a combination of medications . Infections without symptoms do not require treatment but infected individuals can spread the parasite to others and treatment can be considered . Treatment of other entamoeba infections apart from E. histolytica is not needed . Amoebiasis is present all over the world . About 480 million people are infected with E. histiolytica and this results in the death of between 40,000 -- 110,000 people every year . E. dispar is more common in certain areas and symptomatic cases may be fewer than previously reported . The first case of amoebiasis was documented in 1875 and in 1891 E. histiolytica was identified resulting in the terms amoebic dysentery and amoebic liver abscess . Further evidence from the Philippines in 1913 found that upon ingesting cysts of E. histiolytica volunteers developed the disease . It has been known since 1903 that at least one species of non-disease causing entamoeba exist , but it was first formally recognized by the WHO in 1997 . In addition to the recognized E. dispar evidence shows there is likely another species of E. moshkovskii as well . The reason these species have n't been differentiated until recently may be because they look very similar . Diarrhea, also spelled diarrhoea, is the condition of having at least three loose or liquid bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin with loss of the normal stretchiness of the skin and irritable behaviour. This can progress to decreased urination, loss of skin color, a fast heart rate, and a decrease in responsiveness as it becomes more severe. Loose but non-watery stools in babies who are breastfed, however, may be normal.
  The most common cause is an infection of the intestines due to either a virus, bacteria, or parasite; a condition known as gastroenteritis. These infections are often acquired from food or water that has been contaminated by stool, or directly from another person who is infected. It may be divided into three types: short duration watery diarrhea, short duration bloody diarrhea, and if it lasts for more than two weeks, persistent diarrhea. The short duration watery diarrhea may be due to an infection by cholera, although this is rare in the developed world. If blood is present it is also known as dysentery. A number of non-infectious causes may also result in diarrhea, including hyperthyroidism, lactose intolerance, inflammatory bowel disease, a number of medications, and irritable bowel syndrome. In most cases, stool cultures are not required to confirm the exact cause.
  Prevention of infectious diarrhea is by improved sanitation, clean drinking water, and hand washing with soap. Breastfeeding for at least six months is also recommended as is vaccination against rotavirus. Oral rehydration solution (ORS), which is clean water with modest amounts of salts and sugar, is the treatment of choice. Zinc tablets are also recommended. These treatments have been estimated to have saved 50 million children in the past 25 years. When people have diarrhea it is recommended that they continue to eat healthy food and babies continue to be breastfed. If commercial ORS are not available, homemade solutions may be used. In those with severe dehydration, intravenous fluids may be required. Most cases; however, can be managed well with fluids by mouth. Antibiotics, while rarely used, may be recommended in a few cases such as those who have bloody diarrhea and a high fever, those with severe diarrhea following travelling, and those who grow specific bacteria or parasites in their stool. Loperamide may help decrease the number of bowel movements but is not recommended in those with severe disease.
  About 1.7 to 5 billion cases of diarrhea occur per year. It is most common in developing countries, where young children get diarrhea on average three times a year. Total deaths from diarrhea are estimated at 1.26 million in 2013  down from 2.58 million in 1990. In 2012, it was the second most common cause of deaths in children younger than five (0.76 million or 11%). Frequent episodes of diarrhea are also a common cause of malnutrition and the most common cause in those younger than five years of age. Other long term problems that can result include stunted growth and poor intellectual development. Anemia, also spelled anaemia, is usually defined as a decrease in the total amount of red blood cells (RBCs) or hemoglobin in the blood. It can also be defined as a lowered ability of the blood to carry oxygen. When anemia comes on slowly, the symptoms are often vague and may include feeling tired, weakness, shortness of breath or a poor ability to exercise. Anemia that comes on quickly often has greater symptoms, which may include confusion, feeling like one is going to pass out, loss of consciousness, or increased thirst. Anemia must be significant before a person becomes noticeably pale. Additional symptoms may occur depending on the underlying cause.
  There are three main types of anemia: that due to blood loss, that due to decreased red blood cell production and that due to increased red blood cell breakdown. Causes of blood loss include trauma and gastrointestinal bleeding, among others. Causes of decreased production include iron deficiency, a lack of vitamin B12, thalassemia, and a number of neoplasms of the bone marrow. Causes of increased breakdown include a number of genetic conditions such as sickle cell anemia, infections like malaria, and certain autoimmune diseases. It can also be classified based on the size of red blood cells and amount of hemoglobin in each cell. If the cells are small, it is microcytic anemia. If they are large, it is macrocytic anemia while if they are normal sized, it is normocytic anemia. Diagnosis in men is based on a hemoglobin of less than 130 to 140 g/L (13 to 14 g/dL), while in women, it must be less than 120 to 130 g/L (12 to 13 g/dL), Further testing is then required to determine the cause.
  Certain groups of individuals, such as pregnant women, benefit from the use of iron pills for prevention. Dietary supplementation, without determining the specific cause, is not recommended. The use of blood transfusions is typically based on a person's signs and symptoms. In those without symptoms, they are not recommended unless hemoglobin levels are less than 60 to 80 g/L (6 to 8 g/dL). These recommendations may also apply to some people with acute bleeding. Erythropoiesis-stimulating medications are only recommended in those with severe anemia.
  Anemia is the most common disorder of the blood, affecting about a quarter of the people globally. Iron-deficiency anemia affects nearly 1 billion. In 2013, anemia due to iron deficiency resulted in about 183,000 deaths  down from 213,000 deaths in 1990. It is more common in females than males, among children, during pregnancy, and in the elderly. Anemia increases costs of medical care and lowers a person's productivity through a decreased ability to work. The name is derived from "", meaning "lack of blood", from - "an-", "not" +  "haima", "blood". Appendicitis is inflammation of the appendix. Symptoms commonly include right lower abdominal pain, nausea, vomiting, and decreased appetite. However, approximately 40% of people do not have these typical symptoms. Severe complications of a ruptured appendix include widespread, painful inflammation of the inner lining of the abdominal wall and sepsis.
  Appendicitis is caused by a blockage of the hollow portion of the appendix. This is most commonly due to a calcified "stone" made of feces. Inflamed lymphoid tissue from a viral infection, parasites, gallstone, or tumors may also cause the blockage. This blockage leads to increased pressures in the appendix, decreased blood flow to the tissues of the appendix, and bacterial growth inside the appendix causing inflammation. The combination of inflammation, reduced blood flow to the appendix and distention of the appendix causes tissue injury and tissue death. If this process is left untreated, the appendix may burst, releasing bacteria into the abdominal cavity, leading to severe abdominal pain and increased complications.
  The diagnosis of appendicitis is largely based on the person's signs and symptoms. In cases where the diagnosis cannot be made based on the person's history and physical exam, close observation, radiographic imaging and laboratory tests can be helpful. The two most common imaging tests used are an ultrasound and computed tomography (CT scan). CT scan has been shown to be more accurate than ultrasound in detecting acute appendicitis. However, ultrasound may be preferred as the first imaging test in children and pregnant women because of the risks associated with radiation exposure from CT scans.
  The standard treatment for acute appendicitis is surgical removal of the appendix. This may be done by an open incision in the abdomen (laparotomy) or through a few smaller incisions with the help of cameras (laparoscopy). Surgery decreases the risk of side effects or death associated with rupture of the appendix. Antibiotics may be equally effective in certain cases of non-ruptured appendicitis. It is one of the most common and significant causes of severe abdominal pain that comes on quickly worldwide. In 2013 about 16 million cases of appendicitis occurred. This resulted in 72,000 deaths globally. In the United States, appendicitis is the most common cause of acute abdominal pain requiring surgery. Each year in the United States, more than 300,000 people with appendicitis have their appendix surgically removed. Reginald Fitz is credited with being the first person to describe the condition in 1886. Hyperthyroidism is the condition that occurs due to excessive production of thyroid hormone by the thyroid gland. Thyrotoxicosis is the condition that occurs due to excessive thyroid hormone of any cause and therefore includes hyperthyroidism. Some, however, use the terms interchangeably. Signs and symptoms vary between people and may include irritability, muscle weakness, sleeping problems, a fast heartbeat, heat intolerance, diarrhea, enlargement of the thyroid, and weight loss. Symptoms are typically less in the old and during pregnancy. An uncommon complication is thyroid storm in which an event such as an infection results in worsening symptoms such as confusion and a high temperature and often results in death. The opposite is hypothyroidism, when the thyroid gland does not make enough thyroid hormone.
  Graves' disease is the cause of about 50% to 80% of the cases of hyperthyroidism in the United States. Other causes include multinodular goiter, toxic adenoma, inflammation of the thyroid, eating too much iodine, and too much synthetic thyroid hormone. A less common cause is a pituitary adenoma. The diagnosis may be suspected based on signs and symptoms and then confirmed with blood tests. Typically blood tests show a low thyroid stimulating hormone (TSH) and raised T or T. Radioiodine uptake by the thyroid, thyroid scan, and TSI antibodies may help determine the cause.
  Treatment depends partly on the cause and severity of disease. There are three main treatment options: radioiodine therapy, medications, and thyroid surgery. Radioiodine therapy involves taking iodine-131 by mouth which is then concentrated in and destroys the thyroid over weeks to months. The resulting hypothyroidism is treated with synthetic thyroid hormone. Medications such as beta blockers may control the symptoms, and anti-thyroid medications such as methimazole may temporarily help people while other treatments are having effect. Surgery to remove the thyroid is another option. This may be used in those with very large thyroids or when cancer is a concern. In the United States hyperthyroidism affects about 1.2% of the population. It occurs between two and ten times more often in women. Onset is commonly between 20 and 50 years of age. Overall the disease is more common in those over the age of 60 years. Malnutrition or malnourishment is a condition that results from eating a diet in which nutrients are either not enough or are too much such that the diet causes health problems. It may involve calories, protein, carbohydrates, vitamins or minerals. Not enough nutrients is called undernutrition or undernourishment while too much is called overnutrition. Malnutrition is often used specifically to refer to undernutrition where there is not enough calories, protein, or micronutrients. If undernutrition occurs during pregnancy, or before two years of age, it may result in permanent problems with physical and mental development. Extreme undernourishment, known as starvation, may have symptoms that include: a short height, thin body, very poor energy levels, and swollen legs and abdomen. People also often get infections and are frequently cold. The symptoms of micronutrient deficiencies depend on the micronutrient that is lacking.
  Undernourishment is most often due to not enough high-quality food being available to eat. This is often related to high food prices and poverty. A lack of breastfeeding may contribute, as may a number of infectious diseases such as: gastroenteritis, pneumonia, malaria, and measles, which increase nutrient requirements. There are two main types of undernutrition: protein-energy malnutrition and dietary deficiencies. Protein-energy malnutrition has two severe forms: marasmus (a lack of protein and calories) and kwashiorkor (a lack of just protein). Common micronutrient deficiencies include: a lack of iron, iodine, and vitamin A. During pregnancy, due to the body's increased need, deficiencies may become more common. In some developing countries, overnutrition in the form of obesity is beginning to present within the same communities as undernutrition. Other causes of malnutrition include anorexia nervosa and bariatric surgery.
  Efforts to improve nutrition are some of the most effective forms of development aid. Breastfeeding can reduce rates of malnutrition and death in children, and efforts to promote the practice increase the rates of breastfeeding. In young children, providing food (in addition to breastmilk) between six months and two years of age improves outcomes. There is also good evidence supporting the supplementation of a number of micronutrients to women during pregnancy and among young children in the developing world. To get food to people who need it most, both delivering food and providing money so people can buy food within local markets are effective. Simply feeding students at school is insufficient. Management of severe malnutrition within the person's home with ready-to-use therapeutic foods is possible much of the time. In those who have severe malnutrition complicated by other health problems, treatment in a hospital setting is recommended. This often involves managing low blood sugar and body temperature, addressing dehydration, and gradual feeding. Routine antibiotics are usually recommended due to the high risk of infection. Longer-term measures include: improving agricultural practices, reducing poverty, improving sanitation, and the empowerment of women.
  There were 793 million undernourished people in the world in 2015 (13% of the total population). This is a reduction of 216 million people since 1990 when 23% were undernourished. In 2012 it was estimated that another billion people had a lack of vitamins and minerals. In 2013, protein-energy malnutrition was estimated to have resulted in 469,000 deathsdown from 510,000 deaths in 1990. Other nutritional deficiencies, which include iodine deficiency and iron deficiency anemia, result in another 84,000 deaths. In 2010, malnutrition was the cause of 1.4% of all disability adjusted life years. About a third of deaths in children are believed to be due to undernutrition, although the deaths are rarely labelled as such. In 2010, it was estimated to have contributed to about 1.5 million deaths in women and children, though some estimate the number may be greater than 3 million. An additional 165 million children were estimated to have stunted growth from malnutrition in 2013. Undernutrition is more common in developing countries. Certain groups have higher rates of undernutrition, including womenin particular while pregnant or breastfeedingchildren under five years of age, and the elderly. In the elderly, undernutrition becomes more common due to physical, psychological, and social factors. Influenza, commonly known as "the flu", is an infectious disease caused by an influenza virus. Symptoms can be mild to severe. The most common symptoms include: a high fever, runny nose, sore throat, muscle pains, headache, coughing, and feeling tired. These symptoms typically begin two days after exposure to the virus and most last less than a week. The cough, however, may last for more than two weeks. In children, there may be nausea and vomiting, but these are not common in adults. Nausea and vomiting occur more commonly in the unrelated infection gastroenteritis, which is sometimes inaccurately referred to as "stomach flu" or "24-hour flu". Complications of influenza may include viral pneumonia, secondary bacterial pneumonia, sinus infections, and worsening of previous health problems such as asthma or heart failure.
  Three types of influenza viruses affect people, called Type A, Type B, and Type C. Usually, the virus is spread through the air from coughs or sneezes. This is believed to occur mostly over relatively short distances. It can also be spread by touching surfaces contaminated by the virus and then touching the mouth or eyes. A person may be infectious to others both before and during the time they are showing symptoms. The infection may be confirmed by testing the throat, sputum, or nose for the virus. A number of rapid tests are available; however, people may still have the infection if the results are negative. A type of polymerase chain reaction that detects the virus's RNA is more accurate.
  Frequent hand washing reduces the risk of infection because the virus is inactivated by soap. Wearing a surgical mask is also useful. Yearly vaccinations against influenza are recommended by the World Health Organization for those at high risk. The vaccine is usually effective against three or four types of influenza. It is usually well tolerated. A vaccine made for one year may not be useful in the following year, since the virus evolves rapidly. Antiviral drugs such as the neuraminidase inhibitor oseltamivir, among others, have been used to treat influenza. Their benefits in those who are otherwise healthy do not appear to be greater than their risks. No benefit has been found in those with other health problems.
  Influenza spreads around the world in a yearly outbreak, resulting in about three to five million cases of severe illness and about 250,000 to 500,000 deaths. In the Northern and Southern parts of the world outbreaks occur mainly in winter while in areas around the equator outbreaks may occur at any time of the year. Death occurs mostly in the young, the old and those with other health problems. Larger outbreaks known as pandemics are less frequent. In the 20th century three influenza pandemics occurred: Spanish influenza in 1918, Asian influenza in 1958, and Hong Kong influenza in 1968, each resulting in more than a million deaths. The World Health Organization declared an outbreak of a new type of influenza A/H1N1 to be a pandemic in June 2009. Influenza may also affect other animals, including pigs, horses and birds. Diverticulitis is a digestive disease in which pouches within the large bowel wall become inflamed. Symptoms typically include lower abdominal pain of a sudden onset. Onset however may also occur over a few days. In North America and Europe pain is usually on the left side, while in Asia it is often on the right. There may also be fever, nausea, diarrhea or constipation, or blood in the stool. Repeated attacks may occur.
  The cause is uncertain. Risk factors may include obesity, lack of exercise, smoking, a family history of the disease, and nonsteroidal anti-inflammatory drugs (NSAIDs). The role of dietary fibre is unclear. Having pouches in the large intestine that are not inflamed is known as diverticulosis. Inflammation occurs in between 10% and 25% at some point in time and is due to a bacterial infection. Diagnosis may be made by blood tests, CT scan, colonoscopy, or lower gastrointestinal series. The differential diagnosis includes irritable bowel syndrome.
  While avoiding nuts and seeds has historically been recommended, an association between eating these foods and diverticulitis has not been found, and therefore, avoiding these foods is no longer recommended. Mesalazine and rifaximin appear useful for preventing attacks in those with diverticulosis. For mild diverticulitis, antibiotics by mouth and a liquid diet is recommended. For severe cases intravenous antibiotics, hospital admission, and complete bowel rest may be recommended. Probiotics are of unclear use. Complications such as abscess formation, fistula formation, and perforation of the colon may require surgery.
  The disease is common in the Western world and uncommon in Africa and Asia. In the Western world about 35% of people have diverticulosis while it affects less than 1% of those in rural Africa. The disease becomes more frequent with age being particularly common in those over the age of 50. It has also become more common in all parts of the world. In 2003 in Europe it resulted in about 13,000 deaths. Costs associated with diverticular disease are around $2.4 billion a year in the United States as of 2013.
  Signs and symptoms.
  People typically have left lower quadrant abdominal pain of sudden onset. There may also be fever, nausea, diarrhea or constipation, and there may be blood in the stool.
candidates: infection infectious disease surgery
answer: infectious disease