As several countries around the world continue to record alarming COVID-19 cases, many continue to question how Malta managed to keep numbers low.
Malta had a minuscule number of active coronavirus cases until last week, when a cluster of cases linked to a weekend party led to a spike in numbers. There were 26 active COVID-19 cases as of Monday morning.
The health authorities say the “success” was a result of prompt decisions and a good healthcare system coupled with the public’s effort in following rules.
But consultant respiratory physician Martin Balzan, while recognising what he says is “Malta’s high level of preparedness”, has another theory centred around a minuscule sandfly that has been in and around southern Europe for thousands of years.
In a paper published in international scientific journal Medical Hypotheses last week, Balzan notes that the significantly lower numbers in southern Europe corresponded “very closely” with the geographical distribution of sandflies in the area.
The sandfly carries a virus that causes a disease known as the Sicilian fever, a non-fatal influenza-like illness.
Exposure to such infections through many generations may have helped the development of natural immunity to novel viruses carrying animal DNA such as COVID-19, by evolutionary survival of the fittest across many generations, Balzan believes.
The physician explains how historically, the Sicilian fever transmitted through sandflies had been recorded in American, British and German troops during the war yet locals were “practically unaffected”, reflecting what he says is a degree of “innate immunity”.
Noting this theory is merely a hypothesis that has yet to be formally researched, Balzan told Times of Malta the fact that similar trends were reported by the various countries despite them having different public health systems and procedures made his hypothesis more likely.
Like Malta, Sicily, Cyprus, Greece and Croatia all had very similar low numbers per capita, he said.
“Differences in public health measures, and healthcare delivery can only partly explain the difference,” he said.
To date, sandflies have not been shown to carry coronaviruses.
To confirm whether his theory is right, Balzan believes blood studies comparing antibodies of local phleboviruses (viruses transmitted by the sandfly) in COVID-19 patients with individuals exposed to the novel coronavirus who remained asymptomatic and healthy controls could “give an indication of cross-immunity”.