The Common Nature of Epidemics, and their relation to climate and civilization

by Southwood Smith

“Stagnant water had settled in great quantity at the back of the town, to which was joined great heat in the weather.”

Dr King says:—

“The information received on the island in 1846, fully corroborated what is stated in the above extracts, the periodical rains, contrary to what usually happens, did not set in till late in September. In October, November, and December the winds were light and variable, with frequent calms, and the weather became in consequence extremely sultry and oppressive. The grass and green crops were nearly destroyed by the long previous drought, and what little appeared after the rains was devoured by the locusts, which visited the island in greater numbers this year than was ever known to be the case before.”

Though Dr M‘William, on his inspection of the island with a view to ascertain the true cause of the pestilence, took no notice of any of these premonitory signs of its approach, Sir William Burnett was fully aware of their signification, and calls special attention to one of the most important of them in his Report to the Lords of the Admiralty.

“I beg to lay before their Lordships,” he says, “an extract of a letter from the Governor-General of the Cape de Verd Islands, and likewise extracts of letters from Mr Macaulay and the British Consul, residents on the island of Boa Vista, distinctly showing the very remarkable state of the weather preceding the attack of the inhabitants of the island, which very important circumstance in a case of this kind I regret to observe Dr M‘William has omitted to take any particular notice of.”

The event foreshadowed by these occurrences rapidly followed. As early as the middle of September a few cases of unusually malignant fever broke out, but, as has been already stated, the first case that attracted public attention occurred on the 12th of October; a few others followed during the remainder of this month; a still greater number broke out in the beginning of November, and the epidemic came to its height in the latter half of November, continuing to prevail throughout December, and recurring for several months in the following year.

As in epidemic outbreaks in general, so in this instance, individual or sporadic cases occurred some time before the appearance of the epidemic in its true and proper form. On minute inquiry, it was discovered that one if not two cases occurred as early as the 14th of September (Pathi), another on the 20th of September (Roque), and a third on the 21st of September (Agostinho): no other cases, at least none that attracted attention, appeared to have occurred until the one already mentioned (Gallinha), on the 12th of October. These sporadic cases all occurred in the ordinary localities of epidemic disease, and among individuals belonging to the classes that usually furnish its first and chief victims.

At Boa Vista, in addition to other proofs of the presence of a stagnant and pestilential atmosphere, there was the evidence derived from the prevalence of unusual sickness and mortality among domestic animals.

“That the common air,” says Dr King, “which was inhaled by every living thing on the island was in an epidemic condition in the months of October, November, and December of both years, is sufficiently demonstrated by the simultaneous occurrence of universal sickness and great mortality among the cattle (including horses, cows, mules, donkeys, and goats) at the very time that fever was raging among the inhabitants. And, further, there was this remarkable coincidence, that after an interval of some months and the disappearance of the disease both in man and beast, the same fever broke out again in the towns and villages about the rainy season of the following year, and was again accompanied by the same murrain among the cattle, which in the two seasons proved fatal to two-thirds of the whole stock of the island.”

These considerations afford all the evidence which the nature of the case admits of, that the sickness which affected the island on this occasion arose, not from the landing of the sick of the “Eclair,” but from climatic and endemic causes.