A few synonyms for the term "pest house" include plague house, fever hospital, isolation ward, contagious disease hospital and infectious disease hospital. These terms are often used to describe medical facilities that were built to quarantine contagious patients in the past. However, today's modern hospitals are equipped with advanced isolation rooms and infection control practices, which make these types of specialized wards unnecessary. In the 19th and early 20th centuries, pest houses were common and played a vital role in controlling the spread of infectious diseases such as smallpox and tuberculosis. Today, most of these historic pest houses are either abandoned or have been converted into museums or unique living spaces.