Clinical age and immunity Mumps is found worldwide. In the absence of vaccination against mumps there are between 100 and 1,000<unk> s per 100,000 people each year, i.e. 0.1% to 1.0% of the population are infected each year. The number of<unk> s peaks every 2–5 years, with incidence highest in children 5–9 years old. According to seroconversion surveys done prior to the start of mumps vaccination, a sharp increase in mumps antibody levels at age 2–3 was observed. Furthermore, 50% of 4–6 year olds, 90% of 14–15 year olds, and 95% of adults had tested positive to prior exposure to mumps, indicating that nearly all people are eventually infected in unvaccinated populations. Prior to the start of vaccination, mumps accounted for ten percent of meningitis<unk> s and about a third of encephalitis<unk> s. Worldwide, mumps is the most common<unk>  of inflammation of the salivary glands. In children, mumps is the most common<unk>  of deafness in one ear in<unk> s when the inner ear is damaged. Asymptomatic infections are more common in adults, and the rate of asymptomatic infections is very high, up to two-thirds, in vaccinated populations. Mumps vaccination has the effect of increasing the average age of the infected in vaccinated populations that have not previously experienced a mumps outbreak. While infection rates appear to be the same in males and females, males appear to experience symptoms and complications, including neurological involvement, at a higher rate than females. Symptoms are more severe in adolescents and adults than in children. Settings of outbreaks It is common for outbreaks of mumps to occur. These outbreaks typically occur in crowded spaces where the virus can spread from person to person easily, such as schools, military barracks, prisons, and sports clubs. Since the introduction of vaccines, the frequency of mumps has declined dramatically, as have complications<unk> d by mumps. The epidemiology in countries that vaccinate reflects the number doses administered, age at vaccination, and vaccination rates. If vaccine coverage is insufficient, then herd immunity may be unobtainable and the average age of infection will increase, leading to an increase in the prevalence of complications. Risk factors include age, exposure to a person with mumps, compromised immunity, time of year, travel history, and vaccination status. Mumps vaccination is less common in developing countries, which consequently have higher rates of mumps.<unk> s peak in different seasons of the year in different regions. In temperate climates,<unk> s peak in winter and spring, whereas in tropical regions no seasonality is observed. Additional research has shown that mumps increases in frequency as temperature and humidity increase. The seasonality of mumps is thought to be<unk> d by several factors: fluctuation in the human immune response due to seasonal factors, such as changes in melatonin levels; behavior and lifestyle changes, such as school attendance and indoor crowding; and meteorological factors such as changes in temperature, brightness, wind, and humidity.
medical cause of Pancreatitis
symptom of Gallbladder cancer
symptom of Pancreatic cancer
symptom of Primary biliary cholangitis
symptom of Liver cancer
symptoms of Primary biliary cholangitis
complications of Gallstone
medical cause of Ascites