A population pyramid, also called an age pyramid or age picture is a graphical illustration that shows the distribution of various age groups in a population (typically that of a country or region of the world), which forms the shape of a pyramid when the population is growing.
Hand, Foot, and Mouth Disease Symptoms & Signs. The symptoms of hand, foot, and mouth disease are typically mild and occur mainly in children during the spring and fall seasons. Symptoms can include fever, malaise, decreased appetite, and sore throat. A rash is characteristic of this viral disease.
A fever and sore throat are usually the first symptoms of hand, foot, and mouth disease. The characteristic blisters and rashes show up later, usually one or two days after the fever begins. Hand, foot, and mouth disease is often caused by a strain of coxsackievirus, most commonly coxsackievirus A16. The coxsackievirus is part of a group of viruses called Enteroviruses. In some cases, other types of Enteroviruses can cause hand, foot, and mouth disease. Viruses can be easily spread from person-to-person.