For re-entry of the donors after the deferral period, testing for antibodies or by NAT might be reliable and cost-effective. more expensive. A general pathogen inactivation for all blood components (whole blood) promises to be a long-term, sustainable solution for both known and unknown pathogens. Transfusion medicine therefore eagerly awaits such a system. Key Words:Blood safety, Malaria, Dengue virus, Chagas disease,Babesia == Introduction == Since the HIV-1 blood scandal in the mid-1980s, the main concern of patients before receiving a blood transfusion is the risk of acquiring a transfusion-transmitted infection. Currently in Germany, the residual risk of suffering a transfusion-related HCV or HIV-1 infection is extremely low: approximately 1:11 million and 1:4.3 million, respectively [1]. Further reduction of these residual risks with regard to transfusion-transmitted infections is a major goal for transfusion medicine. Next to optimised donor selection programmes, the introduction of nucleic acid amplification technologies (NAT) [2,3] into blood donor screening has been a major reason for the improvement of blood BMS-813160 safety and the reduction of the diagnostic window period to a minimum of 4-6 days for HCV and 6-10 days for HIV-1 [4,5,6]. With the reduction of the residual transfusion-transmitted risks of the three major transfusion-relevant viruses (HBV, HCV and HIV-1), the activities of transfusion medicine have shifted to reducing the risks posed by bacterial contamination, especially in platelet components [7]. Due to fatal septic reactions after the transfusion of platelet components at the end of their shelf-life (day 5 after donation), the maximum shelf-life of these components was reduced to 4 days in Germany in 2008 [8]. Nevertheless, shelf-life reduction was not able to prevent every case of serious bacterial transmission. In addition, due to new screening strategies with rapid bacterial detection methods, like Bactiflow [9,10] and 16S and 23S rDNA NAT [11,12,13], the introduction of pathogen reduction methods [14,15,16,17,18] is a promising option to cover the bacterial contamination risk in the near future. Other pathogens, likePlasmodiumspp. [19], dengue virus [20],Trypanosoma cruziandBabesiaspp., could be transmitted by blood components and become more relevant in their BMS-813160 endemic regions as well as to travellers in non-endemic regions. DNMT1 This manuscript summarises the current situation for these four emerging pathogens with respect to their BMS-813160 global and regional relevance for Germany and the opportunities to prevent these infections. == Emerging Infections == == Malaria Infections == Malaria parasites are mainly transmitted by bites fromAnophelesmosquitoes. Each year, more than 1 million people die from malaria [21,22]. Approximately 50% are children under 5 years of age. About 90% of all infected people live in Africa. Five pathogens are relevant for human infections:Plasmodium falciparum,Plasmodium vivax,Plasmodium ovale,Plasmodium malariaeandPlasmodium knowlesi[23]. The most harmful pathogen isPlasmodium falciparum. The symptoms of malaria include high recurring-to-periodic fever, chills, dysfunction of the gastrointestinal tract and cramps. Children have a much higher risk of dying from malaria [24]. The lifecycle ofPlasmodiumspp. is separated into two parts: one part is located in the primary hosts (mosquitoes) with sexual reproduction, and a second in hosts like humans with asexual reproduction. After a mosquito bite, sporozoites migrate along blood vessels and infect liver cells (hepatocytes) where asexual reproduction occurs (tissue schizogony). Merozoites release into the blood and are able to infect new red blood cells and also initiate asexual reproduction (blood BMS-813160 schizogony). Other merozoites continue to develop into immature gametocytes. These gametocytes are re-transmitted again into mosquitoes, build ookinetes in the mosquito gut and develop zygotes. From the ookinete, new sporozoites will migrate into salivary glands of the mosquito and can infect another host with the next bite. Since only female mosquitoes feed on blood cells, only they are responsible for the transmission of malaria [25]. Aside from transmission by mosquitoes, malaria pathogens can also be transmitted by blood components [26]. Although all blood components should be tested for malaria in endemic countries in sub-Saharan Africa (SSA), most blood components are not tested [27]. This can be explained by several reasons. On the one hand, most malaria tests are not sensitive enough to detect BMS-813160 a low level of parasites. On the other hand, some African countries, like Benin, have a prevalence of malaria in blood donors of more than 30% [28]. If all infected blood donors were rejected, the blood supply could not be maintained in these countries. In Germany, donors travelling to regions at risk for malaria transmission are deferred from donating blood for 6 months after their return. According to the German guidelines, people born in regions endemic for malaria or who have lived.