Travel-associated malaria in the Rhine-Main area: An evaluation of the cases diagnosed at the Institute for Laboratory Medicine, Microbiology and Infection Control at the Northwest Medical Centre in Frankfurt/Main, Germany, from 2003 to 2022

In the Rhine-Main area, a dynamic region with numerous travellers and newcomers from several countries, travel-associated malaria is of particular relevance. However, there are few publications in Germany regarding imported malaria on the regional level. The goal of this research was to provide new insights on the epidemiological and clinical characteristics of travel-associated malaria in Frankfurt am Main and the Rhine-Main area. For this purpose, the malaria cases diagnosed between 2003 and 2022 at the Institute for Laboratory Medicine, Microbiology and Infection Control (Northwest Medical Centre, Frankfurt am Main) were evaluated. The results were then compared with the national surveillance data of the Robert Koch Institute. A total of 44 malaria cases were diagnosed at the Institute for Laboratory Medicine. Half of the cases were diagnosed during the last six years of the study period. Most of the patients (63.6%) were between 20 and 49 years old. The gender ratio was nearly balanced (52.3% male, 47.7% female). The most common pathogen was Plasmodiumfalciparum (84.1%). Most of the infections were acquired in Africa. A particularity were the two cases of airport-associated malaria. Of the 23 patients with data on country of origin, 21 were of foreign origin. Nine of the ten people with information on chemoprophylaxis did not use chemoprophylaxis or only took it irregularly. 54.5% of the people with details on reasons for travel were visiting friends and relatives. There were 17 complicated malaria cases, all caused by Plasmodiumfalciparum. People over 45 years were significantly more likely to experience severe disease. In terms of medication, there was an increasing trend in the use of artemether/lumefantrine. The findings showed many consistencies with the German surveillance data, but there were also deviations, like the gender distribution and the trend in case numbers during the COVID-19 pandemic. This study provides important insights into travel-related malaria in the Rhine-Main area. Increased research on the regional level can reveal regional differences, identify opportunities for improvement in patient care, and raise malaria awareness among medical staff and travellers.