The conditions that produce mosquitoes seem to be the same as the conditions that produce malaria, and, in any case, it is these that must be attacked, no matter whether Lady Anopheles be proved innocent or in any measure guilty. The mysteries that
surround the subject, the occasional outbursts of disease when areas have been drained, the usual method of improvement, the occasional betterment of health when the reverse process of flooding has taken place, may possibly be explained by the law of subsoil water. Dr. Charles Creighton writes in his History of Epidemics in Britain (p. 278): “According to that law, the dangerous products of fermentation arise from the soil when the pores of the ground are either getting filled with water after having been long filled with air, or are getting filled with air after having been long filled with water. It is the range of the fluctuation in the ground-water, either downwards or upwards, that determines the risk to health.”
However, far be it from me to descant upon the mysterious causes of malaria. My object is only to try to prove the unwisdom of rivetting attention upon the anopheline mosquito. Deductions as to her innocence may be drawn from the accusations endeavoring to prove her guilty. We are told how noticeable among troops the difference in fever rate has been between those that slept on shore and those that remained on board ship in malarious districts. But as the mosquito is free to come aboard too, how does that statement tell against her? I remember a host of such insect invaders on the Sydney, the French mail boat, when anchored at feverish Saigon. We carried a shipload away with us, and when out at sea they feasted on me to such an extent that I arrived at Singapore looking as though stricken with a rash, but otherwise none the worse for their greediness.
Again I was scarred for a long period after the venomous attacks of mosquitoes and sandflies combined at Kuala Klang, on the Malay coast, in its old days of fever, before it started a new sanitary career under the name of Port Swettenham. Yet these myriad bites produced fever of no sort, although I was at that time pronounced a malarial subject. I did not remain in Kuala Klang long enough to be affected by its unhealthiness; but, had Lady Anopheles been justly blamed, the terrible biting I underwent should have taken effect, irrespective of my removal. On the contrary, my own experience of fever was connected entirely with locality and never with mosquitoes. Intermittent fever, the genuine article, with its burnings, its icings, its whole programme
of miseries, had me constantly in its grip during residence at a particular house in Kuala Lumpur, the Capital of the Federated Malay States. My one compensation was freedom from mosquito bites. When I left that abode, fever left me, and soon after mosquitoes began to feed on me again with infinite relish. What matter? It was a proof of sound blood, freedom from that worse scourge, malaria!
To turn from the personal to what is far more important, the general, let us consider the Medical Reports from that haunt of malaria, the Malay Peninsula.
The year 1911 in the Federated Malay States held the unpleasant distinction of being particularly malarious. The mosquito theorists explained as cause a great influx of, often, unhealthy coolies from India, and much clearing of land, which distributed the mosquitoes, and drove them into the houses and among the inhabitants. But, if mosquitoes be culpable, why should this same year have also been particularly unhealthy in regard to most diseases, phthisis excepted? Yet the Medical Report for 1912 shows that, concomitantly with a fall in malaria, 1,010 fewer cases of dysentery were this year treated in hospital. There were 77 notified cases of smallpox, as against 286 in 1911; 29 cases of cholera, as against 620; and 5,676 cases of beri-beri, as against 6,402. The greater prevalence of disease in general in 1911 surely shows that the causes for its specific forms must be deeper seated than mere insect bites. Yet so dominating is the fashion to rivet attention on such factors as these that fundamental troubles, even when known, appear often to be unheeded.
The F. M. S. Medical Report for 1912 provides a good instance, taken from the portion dealing with the Institute for Medical Research, Kuala Lumpur.
On page 25 it states that the occurrence of several cases of bubonic plague in and near Kuala Lumpur rendered it advisable to consider the possibility of the disease appearing as an epidemic and measures to avert such a calamity. A short paragraph refers to reported cases of plague, and then follow nearly four pages devoted to rats. Toward the bottom of the fourth page come the pregnant words: “Nearly 50 per cent. of the plague-infected rats came from the small stretch of Ampang
Street, about 150 yards long.” The short description of this small area surely reveals a source of danger. “At the back of most of the houses there is a kitchen or bathing-place from which an open brick drain, covered with planks, runs through the house to the front of the shop and under the pavement of the five-foot way into one open drain at the side of the street. The plank covering of the house-drain is usually buried beneath sacks of grain or other heavy articles, so that the drain is not often cleaned. The open cement street-drain forms a convenient highway for rats, which can readily gain access to the house by the unprotected house-drains leading into it. Some eighty yards away the main drain empties into the Klang River, here a shallow and muddy stream with irregular, foul banks covered with reeds, rank grass and collections of garbage.” Now, who could expect rats to keep well in the vicinity of such a drain “not often cleaned,” and such a river, “shallow and muddy,” with “foul banks covered with collections of garbage”? Surely gratitude is due to the rodents, who, being nearer the level of the bad conditions, get ill first, and thus give human beings a fair warning of the sickness likely also to be their due, unless surroundings are made healthy for all animals, four-legged and two-legged. Yet, actually the Report has not a commentary upon these palpable ills, and, though it has by no means exhausted itself on the subject of rats, proceeds to vary the topic with fleas, the meteorological conditions that affect these high-jumpers, and the uses of guinea-pigs as flea-traps. The results of searching questions to medical men on the subject of flea bites are even given. “Of eighteen who replied one stated that he had never been bitten by a flea in his life” (p. 31). Most people must wish they were equally lucky. But not a single mention again of the uncleaned drains and the river choked with garbage during the course of pages all the more diverting because intended so seriously.