Prevention Of Malaria.

Medical Science Holds Out Hopes by Discovery of New Remedies.

Specially Written for “The Pacific Islands Monthly,” by a Medical Practitioner ,

MALARIA is an enemy to be reckoned with in many parts of the Pacific.

Except by personal prophylaxis, the problem of its prevention has never been thoroughly tackled in our South Sea possessions, and judging from the enormous cost of draining swamp areas and destroying all breed ing spots, it seems likely that the ano pheles mosquito will hold its own.

Although such large scale attempts at prevention are always advisable where the cost is not prohibitive, a new method of personal prophylaxis has been introduced, and we believe that this journal, by making the method known, may do incalculable good to those who are obliged to live in mal arious districts. That it will not en tirely replace official measures to render certain districts healthier is in stanced by the present non-malarious state of Samarai, the port of Eastern Papua. Many years ago, all breeding places and swampy spots in that island were dealt with, and now malaria fever is a thing of the past in Samarai.

Malaria is caused by the injection into the blood of a parasite—the sporo zoite —by the bite of an infected mos quito. From the presence of these parasites spring the well-known mani festations of the disease. In course of time, the young parasites turn into a stage of their history which is very resistant to quinine.

For nearly a generation now, quinine has been used as a preventive of ma laria, under the impression that a suf ficient quantity of the drug circulating in the blood would attack and kill the parasites. This is now proved to be erroneous; quinine does not actually destroy the sporozoites, and even less the parasites in their advanced stage, though it does inhibit the attacks or fever and ague that follow infection.

Consequently, the daily or weekly doses of quinine which were at one time believed to protect the individual are better left alone. In fact, they may actually be harmful, by accustoming the sporozoites to the action of the drug in small doses.

Quinine for prevention is now re placed by a new synthetic compound called Plasmoquine, which is of Con tinental origin, and by no means a new discovery. French scientists, from the first, declared its efficiency in the pre vention and treatment of malaria; but British physicians, who are more in clined to caution, required very definite proof before advocating its substitution for quinine in prevention.

This is now forthcoming. The re sults of carefully-controlled experi ments, carried out at an English hos pital, were published recently in The Lancet, and prove conclusively that plasmoquine actually killed sporozoites introduced into the blood of volunteers who had been inoculated by malarious mosquitoes. Thus the drug is a definite preventive of the disease.

We need not go into the details of these experiments beyond saying that

they were conducted with the greatest care and were tested at every stage by means of “controls.” The primary ob ject in carrying them out was to dis cover if there was any known drug which would kill the sporozoites of malaria fever in the human blood, in all, seven substances were tried out, but only Plasmoquine emerged success fully.

No doubt, readers in the islands are more interested in the practical appli cation of these researches to them selves than in mere academic state merits of their value. Plasmoquine is easily obtainable, and a small dose taken every day is confidently believed to offer protection against infection, not only to newcomers to a malarious district, but to old hands who already harbour parasites.

In Guatemala, physicians attached to the United Fruit Company have freed hundreds of natives from the most re sistant type of parasite, and herein one discerns, it may be, the beginning of the end of this devastating disease.

The efficiency of the drug is en hanced by the addition of a little quinine, and the two drugs are com bined in tabloid form for prophylactic use.

We do not advocate self-drugging, without preliminary advice from a medical man, as Plasmoquine has proved itself occasionally to be a little uncertain and even dangerous in its action —enough to put one on one’s guard. What we do advise is that every man, woman and child who is exposed to frequent infection of ma laria by mosquitoes, write to the nearest doctor and obtain a supply of the drug, together with full instruc tions how to use it.