[The re-introduction of malaria in the Pontine Marshes and the Cassino district during the end of World War II. Biological warfare or global war tactics?].

After the fall of the Fascist regime on September 8, 1943, Italy was split into two parts: (i) the Southern regions where the King Victor Emanuel III and the military general staff escaped was under the control of English-American allied armies, and (ii) the northern regions comprising Lazio, Tuscany, Umbria, and Marche still under the control of the Germans. The German Wehrmacht, after suffering several defeats on Southern lines, established a new strengthened line of defence called the Gustav line, located south of Rome and crossing in the western portion the recently-drained Pontine Marshes. In his book published in 2006, Frank Snowden hypothesised that occupying German armies in 1943 had initiated a programme of re-flooding the Pontine plain as a biological warfare strategy to re-introduce malaria infection in the territories south of Rome, Such a plan was intended (i) to slow down the advance of English-American forces, and (ii) to punish Italians who abandoned their former allies. Other authors, including Annibale Folchi, Erhard Geissler, and Jeanne Guillemin, have disputed this hypothesis based on an analysis of recently-uncovered archive documents. What is not disputed is that the flooding of the Pontine and Roman plains in 1943 contributed to a severe malaria epidemic in 1944, which was associated with exceptionally high morbidity and mortality rates in the afflicted populations. Herein, we critically evaluate the evidence and arguments of whether the Wehrmacht specifically aimed to spread malaria as a novel biological warfare strategy in Italy during the Second World War. In our opinion, evidence for specific orders to deliberately spread malaria by the German army is lacking, although the strategy itself may have been considered by Nazis during the waning years of the war.