Captain LaFleur was a Belgian military medical officer in East Africa, under the command of Colonel Mathieu. In December 1916, LaFleur was assigned to be the doctor on the expedition across from the Belgian camp in German East Africa to Cape Lopez to pick up a shipment of machine guns, mortars and howitzers needed for the taking of Tabora.
At the Ubangi village that had been killed by disease, LaFleur stated that it was smallpox that had killed them, leaving only the Ubangi boy alive. While Boucher suspected smallpox when the soldiers began to get ill, Lafleur diagnosed the men as having yellow fever.
When Defense alerted Boucher that the boy was in the camp, LaFleur could not prove that the boy was not a health risk to the soldiers, and so Boucher ordered that the boy be left behind.
Near the end of December, LaFleur himself was taken ill with the disease, and died on Christmas Day. He was buried in a mass grave in the jungle, the first of the Belgians to die on the expedition.