Typhoid is not common in countries with good sanitation and clean water. For example, scientists think that there are only 400 cases a year in the United States. In 2015, 12.5 million new cases worldwide were reported. For example, in the Indian subcontinent, typhoid is one of the most common diseases because of poor sanitation and lack of basic hygiene.In that case, typhoid fever is common in children of the one to 15 years age group.