Cluster diagram of a medium-sized molecular tuberculosis cluster. Each symbol represents a patient. The symbols are placed on a timeline according to the month of specimen collection. Triangles denote patients with smear-positive pulmonary tuberculosis (TB), circles patients with smear-negative pulmonary TB, and squares patients with extrapulmonary TB. Grey coloured symbols indicate patients with Yugoslavian ethnicity, and for simplicity, all cases with other background have uncoloured symbols. (Origins included Netherlands in 4 persons, Surinam or Netherlands Antilles in 7, Morocco in 5, Indonesia in 3, India in 1, and Turkey in 1). Cases with a number are culture-confirmed; cases with a letter are culture-negative cases epidemiologically linked to the cluster. Lines between cases indicate that cases know each other (see also Results). Note: The diagram can be made with different coloured symbols for ethnic background. Instead of symbols, bars could be used to show the duration of symptoms of infectious TB patients.