XVIII. PUBLIC HEALTH AND HYGIENE

WALTER WYMAN *

WORLD MOVEMENTS OF EPIDEMIC DISEASES

ed rodents exist, the disease is continuously propagated and thus remains endemic in the affected area. Under these circumstances, the conditions permitting a recrudescence of the disease among human beings are ever present.

The ease of intercommunication connection, it is well to emphasize which characterizes modern civiliza- that, even though the disease may tion greatly facilitates the spread of apparently die out in any infected epidemic diseases. Were it not for community, as long as plague-infectthe constant vigilance of sanitary authorities and the prompt enforcement of suppressive and eradicative measures, it would be difficult to form an adequate idea of the devastation which would result from their dissemination. As it is, the havoc wrought by diseases of this character throughout the world is sufficiently impressive, and suggests forcibly the results which would have followed their unrestrained extension.

PLAGUE

Endemic Centers.-Plague is believed to be permanently endemic in certain localities in Central Asia. Although some of the most destructive epidemics in history have been due to this disease, prior to 1894 it had long been absent from the civilized world. Subsequent to that date, it began to appear again in various places which probably derived their infection from the endemic areas mentioned. Since its reappearance, its spread has been gradual, but continuous, with the result that the disease is now pandemic. In this way numerous secondary foci have been established in which the rodent as well as the human population in in

Distribution of Human Cases.During the past year human cases have been reported in the following countries throughout the world: Arabia, Azores, Brazil, British Egyptian Sudan, Chili, China, Ecuador, Egypt, England, German East Africa, Great Britain, Hawaii, India, Indo-China, Japan, Java, Mauritius, Morocco, New Caledonia, New Zealand, Persia, Peru, Portugal, Portuguese East Africa, Russia, Siam, Straits Settlements, Trinidad, Tunis, Turkey in Asia, United States, Venezuela and Zanzibar.

England.-Four cases of pneumonic plague were reported at Freston, in East Suffolk, in Oct., 1910. It also appears that, during the winters of 1906-7 and 1909-10 there had been outbreaks of a disease, not recognized at the time, but which, in the light of a retrospective diagnosis, seems possibly to have been plague. As a result of the diagnosis of human plague, an examination of the rodents of the locality was begun and

a number of infected rats and rab

bits were discovered.

Up to the present time it has not been possible to ascertain precisely how the disease was introduced, but, in view of the extensive commercial relations of the British Empire with

plague-infected

countries, it is populations of certain Chinese vilthought that the infection was lages were completely exterminated. brought by rats arriving on grainladen vessels from such countries. CEREBRO-SPINAL MENINGITIS The report on this outbreak states that there are grounds for believing that plague has been endemic in Suffolk for several years. Plague-infected rats have also been found along the waterfront, in the neighborhood of the docks, in London, but it is not known how far investigation has developed the extent of the rodent infection.

Manchuria. An unusual and virulent outbreak of the pneumonic type of plague occurred in Manchuria, and, to a lesser extent, in the contiguous provinces during the early part of the year. The disease was first observed at Manchouli by Russian railway officials, in the persons of two Chinese ill with pneumonic symp; toms. One died during the night and the diagnosis of plague was made by the post mortem appearances and bacteriological examination. The following day nine Chinese were found dead of the disease. With a rapidity unusual for plague, the disease spread until, by March 29, 1911, 42,756 deaths from the disease had been reported in Manchuria. The infection was so virulent that there were few instances of recovery.

Greece.--A well-marked epidemic of cerebro-spinal meningitis occurred in Greece. The disease is said to have been first observed in that country in 1843, but up to 1868 only sporadic cases of the disease occurred. A marked outbreak was then observed, during the winter of 18689, after which a gradual subsidence were reported from time to time. was noted, although isolated cases Since the year 1881, however, the disease seems to have been more or less endemic, with marked recrudescences in the winter and spring months. In Nov., 1910, an epidemic broke out in Athens and, from that point, invaded the whole country. The height of the epidemic was reached in Feb., 1911, and was then followed by a vent the importation of the disease gradual subsidence. In order to preto America, officers of the Public Health and Marine Hospital Service were stationed in Greece during the spring and summer.

YELLOW FEVER

Plague is believed to be endemic in During 1911.-During the past year Manchuria in a rodent, the tarbagan, there have been no cases of yellow a species of marmot, which is hunted fever reported in the United States, for its fur. As the first cases were and no severe epidemic of the disease observed among tarbagan hunters, has been recorded in any other counthis animal is thought to be the source of the Manchurian epidemic. It may be noted, in this connection. that while, in all probability, the bubonic type of the disease results from the transmission of plague from ro dents to man, through the agency of fleas, the pneumonic type, with equal probability, is directly transmitted from man to man.

In Fuchiatien, Manchuria, 1,100 bodies of persons dead from plague were burned on Jan. 30, 1911, 350 on Feb. 1, and 2,100 on Feb. 3. A large number of houses in which cases had occurred, were also burned, including one entire section of the town. According to the available accounts of the Manchurian epidemic. instances are narrated where the

try. This is doubtless the fruit of the precise knowledge now possessed of the modes of transmission of the disease and the increased attention paid to specific methods by which its dissemination is prevented. The disease, however, has been present at some time during the year in Brazil, Ecuador, Central America, Mexico, the West Indies, and Africa, and in October a case was reported from Honolulu in a quarantine guard who had been stationed on the steamship Hongkong Maru after arrival from Manzanillo, Mexico, with a convalescent aboard.

Endemic Centers.-It has recently been shown that yellow fever has existed on the West African Coast for years, and has been one of the prime

causes of mortality among foreign ments, Sumatra and Turkey. Among residents on the African Gold Coast. the insular possessions of the United Hitherto the disease has been con- States, it has been present in the founded with malarial fever and oth- Philippine Islands and a small outer diseases. The disease is endemic break occurred at Honolulu. in Western Africa, and the native Russia. Epidemics of cholera have population is largely immune. There been occurring in Russia for several are excellent grounds for believing years, except in the winter months. that the disease has been present in In 1908, 17,000 deaths from this disWestern Africa for at least the last ease were officially reported, and in century. The natives who have grad-1909, 28,000. In 1910, from May 8 ually acquired immunity, suffer but to Nov. 16, 216,796 cases with 100,little, but the white population fur- 982 deaths occurred. The disease nish many victims. Nevertheless, then became quiescent during the the outbreaks have not been exten- winter, but reappeared in the spring sive by reason of the small number with the result that from April 21 of non-immune white residents in to Sept. 11, 1911, 1,045 cases with any of the foci where the infection 579 deaths were reported. is endemic.

CHOLERA

Italy. On Aug. 17, 1910, cholera was reported present in the provinces of Bari and Foggia. The infection is thought to have been importCholera seems to be endemic in ed by a band of Russian gypsies certain portions of Asia, from which from Batum, who landed at Brindisi it spreads periodically to other por- and proceeded by rail to Trani, the tions of Asia and occasionally to place which has been regarded as other parts of the world. In this the primary focus of the epidemic. way temporary endemic foci are es- There is considerable doubt as to tablished which endure for a period whether any of the party was actudepending upon the local, climatic ally ill, but it has been determined and sanitary conditions and the that they washed clothes in vessels eradicative measures employed. For used in drawing water from a well. several years past, cholera has been In due course of time cases of a disendemic in Russia, and small local- ease appeared, which were at first ized outbreaks have made their ap- reported as "grave gastro-intestinal pearance in other countries in disturbances." Later the correct Europe. During 1911 there have diagnosis of cholera was made. been outbreaks in the following The disease gradually spread to European countries: Austro-Hun- the south and eastern parts of Italy gary, Bulgaria, France, Germany, and invaded Sicily, where it conGreece, Roumania, Servia and Tur- tinued prevalent until the winter key, besides being present in epidemic form in Italy.

months. The epidemic subsided in Jan., 1911, but reappeared in June. In Asia the disease has been pres- The resulting epidemic has been far ent in Arabia, China, Ceylon, Fed- more extensive than that of the preerated Malay States, India, Indo- ceding year. Up to Nov. 1, 14,803 China, Japan, Java, Korea, Man- cases with 5,661 deaths were rechuria, Persia, Siam, Straits Settle- corded.

EPIDEMIC AND INFECTIOUS DISEASES IN THE UNITED STATES

PLAGUE

California. During 1911 plague among the ground squirrels in California continued to be found, and three human cases were reported during the year, one in Contra Costa County, one in Alameda County and the other in San Joaquin County.

The source of the infection, in all

probability, was infected ground squirrels.

Suppressive Measures.-Since the important observation was made by Blue in 1908 that not only rats but ground squirrels (Citellus), in the case of California, serve as extrahuman hosts for plague, the plague

suppressive measures in the United States have been conducted on the following plan:

1. The destruction of known foci of rodent infection.

2. The determination of new and hitherto unknown foci of infection in order to ascertain at the earliest possible moment, its entire extent. 3. The general eradication of squirrels.

of Nevada, Arizona and Oregon, with the result that new foci of infection have been found in Merced County. Originally a total of 12 counties were found to be infected, and during the past year the infection has been found only in 9 counties. The area of infection has therefore apparently been lessened.

The principle which has been fol lowed in the eradication of squirrel The first two steps in this plan of plague has been as follows: the escampaign were undertaken by the tablishment of squirrel-free zones Public Health and Marine Hospital around infected areas, thus confining Service, and the third in coöperation the infection, followed by the exwith the state of California under termination of the rodents in the the direction of the same Service. areas isolated in this manner. A The chief efforts were directed toward discovering new foci of rodent infection and toward creating squirrel-free zones around the cities of San Francisco, Oakland, Alameda, Berkeley and vicinity.

summary of the work in plague eradication shows that the following results have been accomplished:

of

1. Through the maintenance squirrel-free zones the re-infection of cities has been prevented.

been

2. The infected areas are believed to have been definitely delimited. 3. Plague has apparently eradicated from three counties, San Francisco, Los Angeles and San Luis Obispo.

Rodent Extermination. Further investigations were also made with a view of ascertaining whether the rats of the communities in question still remained free from plague infection. As a result of the latter investigation, no cases of plague, human or 4. In addition to the counties inrodent, have been found to have orig- vestigated during the previous year, inated in the cities of San Francisco, 22 additional counties in California, Oakland, Berkeley or Alameda in the 1 in Oregon and 3 in Nevada have past year. By reason of the accom- been scrutinized with negative repanying sanitary inspection, enforce-sults. ment of rat-proofing ordinances, the

5. Possible routes by which infecdestruction or efficient protection of tion could spread to the East have all substances serving as a source been found by reason of the discovof food for rats, the rodent popula-ery of ground squirrels in certain of tion of San Francisco has been re- the passes of the Sierra Nevada duced and maintained at the lowest Mountains. level ever reached.

During the fiscal year 1911, in the cities of San Francisco, Oakland, and Berkeley, 126,303 rats were trapped, of which 115,257 were examined and none found plague infected. In Los Angeles 23,761 squirrels were killed, of which 21,932 were examined and found negative for plague. In addition to the examination of rats, 126,125 ground squirrels were killed and examined, of which 55 were found to be plague infected. The total number of rodents examined was 219,

655.

6. Incidentally the sanitary condition of the cities in which plaguesuppressive measures have been applied, has been materially improved.

7. By the destruction of squirrels on a large scale, not only is the establishment of endemic foci of plague being averted but great economic benefits, also, have resulted to farmers, ranchers and land owners.

Seattle, Wash.-Plague-suppressive measures were directed, as in the past, against the rodent population. No plague-infected rats were found until Aug. 26, 1911, when one was found, followed by two others on Sept. 21 and 22. Additional suppressive measures were at once insti

Results. The investigation for the detection of new foci of rodent plague has been extended to embrace 45 counties of California and parts tuted.

CHOLERA

New York. In Sept., 1910, one case, and in November, three cases of cholera were apprehended on two ships arriving at the New York quarantine station. No other cases of cholera arrived until June, 1911. On June 6, a passenger died of cholera on board the steamship Berlin four days out of Naples. In all, from June 14 to Aug. 15, 1911, 23 cases of cholera developed either on board ships from cholera-infected ports, while en route, or among immigrants and members of their crews while detained at quarantine.

5. The further detention under medical supervision at quarantine at the port of arrival, of all passengers from infected ports.

6. The supplementary medical inspection at immigrant stations of all aliens released from quarantine.

7. The notification of state health officers and, in the case of large cities, such as New York, Chicago, and Philadelphia, of the municipal health officers of the names and ultimate destination of passengers from infected areas, en route to the territory under their supervision.

Cholera Carriers.-In addition to the precautions just enumerated, one In addition to these, one case de- other means of protection was added, veloped at Brooklyn, N. Y., and one which, in view of its employment for at Auburn, N. Y. Both of these cases the first time on so extended a scale, occurred in recently arrived immi- warrants a reference in somewhat grants who had been under observa- greater detail. It has been shown tion at quarantine for at least seven days. One case developed on Staten Island, N. Y., in the person of an employee of the quarantine station, one case in New York City in an alien who had come from Boston, Mass., a few days previously, and one case in Boston in a woman who quarantine measures previously dehad been associated with recently arrived immigrants. In addition to the above, 27 cholera-bacillus carriers were apprehended on arrival at New York.

Special Measures of Exclusion.-At no time during the past 25 years has the danger of the introduction of cholera in epidemic form into the United States been so imminent, in view of the pandemicity of the disease in Europe and the constant westward tide of immigration.

The following line of defense was adopted:

1. The isolation and detention, under careful medical observation for a period of five days of all prospective passengers at infected ports of foreign embarkation.

2. The disinfection of personal effects.

3. The destruction of all food stuffs and beverages found in the possession of passengers.

that persons from cholera-infected zones, although exhibiting no sign of disease, may harbor the germs of cholera in their intestinal tracts, and thus be the means of introducing the disease into non-infected territory. From this it is evident that the

scribed, while insuring the detection of suspicious cases of illness, are powerless to detect the bacillus carrier.

The additional precaution has been therefore adopted of detaining passengers from infected ports until it had been determined by bacteriological examination which of them if any, were carriers of the disease. Upon the discovery of a bacillus carrier such person is detained at quarantine and not allowed to proceed until it has been determined bacteriologically that he no longer harbors cholera germs. By the observance of this precaution, intercourse with cholera-infected countries may still be maintained and yet a degree of protection secured which, in former years could be obtained only by the prohibition of all commercial relations.

By this method the 27 carriers mentioned above have been detected 4. The careful medical supervision at ports of arrival in the United of all passengers en route for the States. The examination for cholera United States, together with the bacillus carriers among immigrants prompt isolation and subsequent re- to America, has been instituted by port of all illness observed. the Italian authorities, and, at Pa