[Tuberculosis outbreak in 13 people in Saxony-Anhalt: indications of an infection chain by spoligotyping].

BACKGROUND

In Germany the number of new tuberculosis incidents continues to decline slightly. Cases of illnesses are often diagnosed late, due to the uncharacteristic course of tuberculosis. The success in environment investigations by health authorities in finding incidents within one infection chain depends on the compliance of patients among other factors. Tuberculosis occurs especially in groups with social disadvantages. In this population segment the identification of contact persons of a patient with infectious tuberculosis presents difficulties. Moreover, identifying the source of infection is frequently not successful. For these reasons, additional infections and sicknesses are caused. The cultural pathogen proof, including type differentiation and resistance testing, continues to be the "gold standard" in tuberculosis diagnostics and is required for the examination of outbreaks. Molecular methods for fine typification of isolated bacterial strains and their subsequent comparison constitute an important tool in the infection epidemiology investigation of incident clustering.

OBJECTIVE AND METHOD

The objective of this work is the description of a tuberculosis infection chain in Saxony-Anhalt, which was discovered by means of a molecular biological method. The conservative method represents the environment investigations for the expedient selection of contact persons. The investigations always take 2 directions in the process. On the one hand, it is searched for the still unknown source of infection. On the other hand, persons are to be identified, who have been infected before the diagnosis became known. The diagnostics for contact persons includes besides the lung X-ray checkup exam, the Mendel Mantoux tuberculin skin test (THT), sputum tests and the Interferon Gamma (INF-γ) tests (IGRA). In described case, the molecular biological method of spoliogotyping was employed as additional instrument. Therein, fingerprint maps of the patients' tuberculosis strings were created and compared. Infection chains resulting from the environment investigations were thereby secured.

RESULTS

We report on a tuberculosis outbreak in a district of the state of Saxony-Anhalt, which occurred in the time from June 2007 to May 2010. As result of the environment investigations, an infection chain of 13 ill patients (77% ♂, 23% ♀) was identified. In 11 cases the correlation of the infection chain was proven by spoligotyping (9 ♂, 2 ♀). 2 cases (1 ♂, 1 ♀) without verification of the pathogen cannot be attributed on basis of the epidemiological correlations.