For instance, the poliovirus outbreak in Syria, Israel and Egypt, caused by related strains can be traced back to Pakistan.
War and insurgency provide the ideal conditions for bacteria and viruses to take hold, so it is little surprise that polio has become entrenched in Pakistan and Afghanistan. The dreaded disease has now re-emerged in the Middle East and Africa. Consequently, poliovirus continues to circulate in northern Nigeria, igniting a further outbreak in war-torn Somalia and the wider Horn of Africa.
But, mass movement of troops and refugees also spreads infectious disease. Many civil wars in Africa have been accompanied by the swell in infectious diseases, such as HIV.
The impact of infection during war can be traced back to the depths of time.
From the BBC, Chronicles of contagion:
165 AD: Roman soldiers returning from the Parthian war spark the Antonine Plague (probably smallpox) that ravishes the Roman Empire.
1155: Emperor Barbarossa contaminates drinking water by disposing human corpses in wells in Italy.
1618-48: The Thirty Years War. Typhus fever caused by a bacterium spread through the feces of blood-sucking lice was rampant and lead to the cancellation of some battles.
1763: British settlers give two blankets and a handkerchief from a smallpox hospital to two visiting Native American chiefs.
1805-14: The Napoleonic wars. Typhus fever wreaked havoc, killing more French soldiers than the war effort itself.
1853-56: Crimean war. British forces are decimated by cholera outbreaks.
1870-71: Franco-Prussian war. A particularly aggressive form of smallpox virus, originating in France, was introduced into Prussia by French prisoners of war incarcerated in camps. This spread through the civilian population, but not to the Prussian soldiers - they had been protected.
1914-18: World War I. Across the world the influenza pandemic kills millions. In Russia, peace was followed by widespread famine and a constant flow of refugees blighted by cholera, dysentery, malaria, typhoid and typhus.
1939-45: World War II. The Japanese poison more than 1,000 Chinese wells with cholera and typhus and drop plague-infested fleas.
2011: The CIA was reported to have established fake vaccination programs in Pakistan to secure DNA samples during the "war on terror" and the search for Osama Bin Laden. The ensuing mistrust has hampered legitimate polio vaccine programs.
2012-13: Environmental samples test positive for the presence of poliovirus in Egypt, Israel, the West Bank and the Gaza Strip and cases of polio reported in Syria.
May 2013: WHO report on the isolation of wild poliovirus from a young girl in Somalia, which had been polio-free since 2007.
Why do people fight? For what they believe is right? Considering the dignity with which Nelson Mandela conducted his campaign for equal rights in South Africa, I'm wondering if peaceful protest would work just as well. At least it would deny disease a chance of spreading.