The Poliomyelitis Epidemic in Malta 1942–3

During the period November 1942 to February 1943 there was an epidemic of anterior poliomyeitis in the islands of Malta and Gozo. There were 483 cases in all, 426 civilians and 57 men in the services. The incidence fell most heavily on Maltese children under five years of age (82 per cent.); 61 persons over the age of 20 years were affected, and of these only four were Maltese, the remainder, the service cases, being from the United Kingdom. The mortality rate was high in the services (19·3 per cent.) and low among the civilians (3·5 per cent. +), the chief cause of death being respiratory paralysis. That the virus was an indigenous strain was suggested by the following facts: Poliomyelitis has been endemic in Malta for many years, though the annual number of notifications has always been small, and there has never before been an outbreak that could be described as an epidemic.The disease affected civilians first.There was no evidence that the virus had been brought in by men in the services.The adult Maltese were almost completely unaffected, and there were no cases among Maltese soldiers.Although all service personnel, apart from the Maltese, came from the United Kingdom where poliomyelitis is endemic, they were severely affected; the case incidence was 2·5 per 1,000, the mortality rate much higher than that of the native children, and the residual disability among the survivors considerable. There were several unusual circumstances: Great overcrowding, which seemed to play little part in promoting spread of the disease.Lack of food and vitamins, which also appeared irrelevant.The use of sewage in certain parts of Malta for manuring of crops. If it could be assumed that the excreta of a considerable number of persons harboured the virus, then the disease might have been spread by contamination of the water supply or of crops. Such evidence as is available suggests that the water was not contaminated, and it is unlikely that the crops were. It is tolerably certain that the disease was not spread by flies.Dried milk was distributed to both islands, especially to children and to men in the services. It was, however, impossible to trace any connexion between the distribution of this article of food and the geographical incidence of cases of poliomyelitis.