After the Crimean War, soldiers of the British Army stationed in Malta began to suffer from an illness that nobody could explain. Such was the severity of the fever that the average hospital stay for sufferers was 90 days, but could be anything up to two years. Around two percent of British Army cases of Mediterranean fever, also known as Malta fever, ended in fatality, and this figure was much higher for the general population.

With recent discoveries having identified the causes of diseases such as typhoid and diphtheria, Sir David Bruce, a British military surgeon who initially served in Malta in 1884, was inspired to hunt for the microbes behind Mediterranean fever. In 1887, Bruce discovered that the organism Micrococcus melitensis was responsible for the debilitating symptoms in those afflicted.

In 1904 Bruce began to call for an investigation to discover the route by which this bacterium was infecting sufferers – still a mystery to doctors in the region – in an attempt to find a cure. Maltese scientist Dr Themistocles Zammit was already working on the problem, and was convinced the disease was spread by insects. Bruce notified the Royal Society of Zammit’s research, and thus the Mediterranean Fever Commission of 1904-1906 was born. Headed by Bruce, the Commission’s membership also included Zammit, Major William Horrocks, Staff-Surgeon Ernest Shaw and Dr Ralph Johnstone.

 

David Bruce (seated, centre) and the other members of the Mediterranean Fever Commission, ca. 1907, from Sir David Bruce (1855-1931) and Mary, Lady Bruce, OBE (d. 1931): personal papers in the care of the Wellcome Library. Wellcome Images (L0022610), Creative Commons

 

Nobody first dealing with Mediterranean fever would have expected that the route for infection was via the milk of the Maltese goat. Indeed, Surgeon Captain Matthew Louis Hughes wrote a book, published in 1897, in which he claimed milk could not be the causal agent, and even recommended it as a treatment! But eventually, perhaps in part due to a shortage of monkeys to experiment on, Zammit proved that the milk of the Maltese goat was indeed the major route by which Micrococcus melitensis was infecting the British Army and the Maltese population with Mediterranean fever.

 

‘Goat-herd milking, Malta’ by David Bruce, ca. 1907, from the RAMC Muniment Collection in the care of the Wellcome Library, Wellcome Images (RAMC 1242 ‘D’). Creative Commons: https://wellcomeimages.org/indexplus/image/L0020991.html

 

In 1906 the use of goat’s milk by the British Army was banned completely; between 1900 and 1906 there had been 3,631 cases of Mediterranean fever in the British Army but by 1907 there were only 21. However, this did not prevent cases in the Maltese population, where the disease continued to be widespread, and it was not until 2005 that Malta was finally Mediterranean fever-free.

However successful the Mediterranean Fever Commission, there were controversies over who had discovered what. Shaw claimed that he, and not Zammit, had been the first to find that goat’s milk was the means of transmission, but Bruce rebuffed his claims and insisted that the work of the Commission as a whole, rather than individual successes, had led to the breakthrough. To further confuse matters, Bruce, in his later reports about the Commission, began to leave out the names of the key players until it was widely assumed that he had been solely responsible for the key discovery. In 1920 K F Meller suggested that Malta fever be renamed Brucellosis and indeed, when first researching this blog, I was under the impression that the ‘goat milk question’ had been resolved by Bruce alone! Whether this action was intentional or not we may never know…

Further information about the Mediterranean Fever Commission, including correspondence from Royal Society staff regarding the progress of the investigation and the publication of reports, plus the Committee Minutes of the Tropical Diseases Committee of the Royal Society (CMB/50, CMB/51 and CMB/52), can be found in the archives of the Royal Society.