Germany and in Austria-Hungary, and the disease was present to a less extent in the various Balkan States, in Russia, Italy, and Greece. One vessel reporting a suspicious death on voyage arrived at Savannah, Ga., quarantine station from an infected port of North Africa. Bacteriological examination of ship's personnel was made without discovering any trace of cholera infection, and the vessel was permitted to enter without further detention.

Bacteriological examinations were performed on Filipino passengers from Manila destined to Hawaii. As a result 12 carriers of the cholera vibrio were found and refused passage.

PLAGUE.

Plague as occurring in numerous ports having commercial relations with the United States was reported in a very wide area. The disease prevailed practically throughout all of Peru, in the ports of Chile, in Ecuador (more especially Guayaquil), Buenos Aires, and the seaports of Brazil, in Cuba, in the Azores, in Japan, South Africa, Greece, India, Indo-China, Hongkong, and Shanghai, Japan, and the Malay Archipelago, the Philippine Islands excluded. Its widespread prevalence necessitated strict supervision of incoming vessels and incoming cargo from such places, including the fumigation of ships for the destruction of rodents.

In July, 1915, there was reported a case of human plague in Habana. This was the last case of the third epidemic of human plague which occurred in Habana during the years 1912, 1914, and 1915. Owing to the irregular results of bacteriological examinations of rodents in Cuba, it is questionable as to whether the infection has been eliminated at the present time. Notwithstanding the elapse of 11 months from the last indication of the infection, it is borne in mind that an interval of 18 months extended between plague cases in 1912 and the subsequent reappearance of the infection in 1914, during which time it was generally accepted that the infection remained latent in Habana without any manifestation of its presence. As the result of the fumigation of a vessel arriving at New Orleans quarantine station from India, via ports of England and France, plague infection was found among the rats destroyed. It is believed that this incident would be of more frequent occurrence were it practicable to obtain all the rats destroyed by fumigation. This, however, is impossible on many ships because of their being loaded with cargo, which precludes any thorough search for dead rodents, or because the vessel departs from quarantine before the fumes sufficiently clear from the compartments to permit of search. The above-mentioned ship had a clean bill of health and presented no evidence of being infected; and yet had it not been fumigated, introduction of plague infection into an American port would probably have resulted.

The problem of preventing the introduction of plague seems to have reduced itself to a large extent to the systematic, periodic fumigation of all vessels for the purpose of making them as nearly rodent-free as possible this with the supervision and treatment, if necessary, of cargo from known plague-infected localities.

YELLOW FEVER.

Yellow fever was reported from Mexico, Guayaquil, and Brazil. Several cases originating in Colombia were held at the quarantine station on the Panama Canal Zone. The service officer detailed for the inspection of the Mexican ports on the Gulf reported fatal cases in several localities, strikingly like yellow fever as to symptoms, although diagnosed by the local sanitary officials as "icteria," "malaria," or "gastroenteritis." Yellow fever, as such, was reported from one Mexican port in May, 1916, and later on developed in other ports of that country. The utmost precautions were therefore observed to prevent the introduction of yellow fever into the ports of the United States. Means were found, however, to facilitate shipping from some of those ports by the requirement of loading at sea and nonintercourse between vessel and shore. The large increase in the number of refugees from Mexico to the United States which occurred in the spring of 1916 very greatly taxed the facilities of the quarantine stations at the Southern ports of the United States.

Acting Asst. Surg. Stewart reports that yellow fever is probably endemic in Venezuela, but that owing to its continued presence in that country the nonimmune number of persons is so small that an epidemic of yellow fever seems improbable from the lack of infectible material. It is not improbable that in certain sections of Mexico and South America the same condition exists, the occurrence of any noticeable number of yellow-fever cases being dependent upon the introduction of persons susceptible to the disease.

TYPHUS FEVER.

Typhus infection, while chiefly menacing the United States from the border country of Mexico, was also considered a source of danger from its prevalence in various south European localities, as a very severe epidemic ravaged the Balkan States, and the disease occurred to a less degree in Russia, Italy, Spain, and practically all European nations.

SMALLPOX.

Smallpox is practically pandemic, its occurrence in greater or less degree being reported from all countries.

TYPHUS FEVER ON THE MEXICAN BORDER.

A very fatal type of typhus fever has been known to exist in Mexico for many years, but as heretofore the infection was confined to the higher altitude of the central section and chiefly prevailed during the colder months, its extension to the border and coast cities was assumed to be improbable because of unfavorable climatic or other natural conditions. Following the disordered conditions in that southern Republic, however, and largely attended by neglected sanitation and abnormal and unusual troop and refugee movements, typhus fever overflowed its former boundaries and cases commenced to be observed in the border and coast cities of Mexico. Aside from the increased travel from the interior toward the border of Mexico, the neglect of personal hygiene and lowered body resistance that

accompanies destitution may also have been a factor in the increased prevalence of the disease amongst the lower-class Mexicans.

The presence of typhus in American territory along the border first became known on December 14, 1915, when three cases were reported from Laredo, Tex. Senior Surg. C. C. Pierce was immediately ordered to take charge of service operations on the border and remained on that duty until May 15, 1916. Asst. Surg. E. W.. Scott was also ordered to duty at Laredo to take charge of service operations at that place, being assisted in his work by Acting Asst. Surg. H. J. Hamilton. During the month of June, 1916, Surg. B. J. Lloyd was ordered to the border and has been continued in charge of service operations in that section.

The problem of applying any effective preventive measures was a difficult one. The overland extension of typhus had not been anticipated, and the quarantine equipment at the border points of entry was inadequate. To this handicap there was added the inability to confine incoming travel to the ports of entry. The Rio Grande is easily forded in places, and clandestine crossing for the purpose of evading the customs and immigration laws of the United States has always been common. The imposition of quarantine restrictions has a tendency to increase this illegal practice. Senior Surg. Pierce, however, was able to secure fairly effective means of preventing the introduction of typhus with the cooperation of the local Mexican officials in the border cities, the inspection force of the United States Immigration Service, and the officials of the Texas State Board of Health. The cooperation extended by these Federal services and the State officials of Texas was cordial, and the results obtained were as satisfactory as could be expected considering the multifold obstacles that are inevitably present in any overland quarantine system.

Disinfection plants were found in the Mexican towns of Piedras Niegras, Juarez, and Nuevo Laredo, and at Senior Surg. Pierce's solicitation such equipment was repaierd, bathing facilities added, and vermin-infested persons and personal effects were treated under the supervision and with the assistance of service representatives. At Matamoros a dry-heat disinfector was installed for the treatment of vermin-infested articles, and the same object was attained at Roma, Rio Grande, and other smaller places by the immersion of such articles in gasoline. Reliance was placed on the application of gasoline or a mixture of coal oil and vinegar for the destruction of body lice on incoming travelers.

The ideal system of prevention would have involved the treatment of persons and their effects for the destruction of vermin, and the detention of travelers to complete the period of incubation of typhusi. e., 12 days-but the latter procedure was rendered impracticable because of the enormous financial expense and the increased incentive to travelers for evading any and all restrictions by resorting to clandestine crossing. The facilities for illegal entry that existed along the Texas-Mexico border are greatly increased along the border of Arizona and New Mexico, where not even a river interposes an obstacle to the crossing of the boundary line. The maintenance of detention camps would probably have intailed the daily care and subsistence of some 50,000 persons, and the measure was dismissed as impracticable.

Another feature that has increased the difficulty of enforcing an efficient quarantine is the large amount of local traffic. Juarez, Mexico, and El Paso, Tex., are practically one city, the Rio Grande River dividing the two, and the same description applies to Laredo, Tex., and Nuevo Laredo, Mexico, as also to Brownsville, Tex., and Matamoros, Mexico, and various other border cities. A great many persons live on one side of the boundary and have their occupation in the opposite town, this necessitating one or more daily trips. Considering all things, the situation was a difficult one.

At one period refugee Mexicans poured into the American cities in such vast numbers as to cause grave anxiety amongst the local authorities, and request was made of the bureau to have invoked the authority of the act of 1893, prohibiting all incoming travel. Fortunately, however, it was found possible to avoid such extreme action. Admission was refused to all sick persons. Reliance, however, was placed on the requirement that all incoming travelers should be free from vermin, both as to person and effects. With this condition accomplished the potential transmission and extension of the infection was prevented, even though the traveler might be in the incubative stage and later on develop symptoms; the nontransmission, of course, being dependent on the person's continued noninfestation by lice. It is possible, of course, that there may be means for the extension of typhus infection other than by insects, but this means of conveyance has been the only one considered. In view of the many thousands of travelers that have entered the United States from Mexico, it speaks well for the method employed that thus far there have been only 104 cases in the State of Texas, 11 cases in Arizona, and 8 cases in New Mexico. These figures are not accurate but are approximately correct. Of these totals a very considerable number of cases acquired their infection in louse-infested Mexican colonies located in the various American communities on the border. At the end of the fiscal year the case incidence of the disease had diminished to a negligible number, but apprehension is felt as to a possible recrudescence during the coming winter. Plans have been made and partially carried into effect, for the installation of adequately equipped quarantine stations on American soil, containing provision for steam sterilization of personal effects, cyanide-gas chambers, bathing facilities, and accommodations for delousing infested persons. Surg. Lloyd has supervision of all service quarantine procedures along the border, and is especially engaged in organizing quarantine facilities of a more permanent type than have previously existed. Senior Surg. Pierce reports, in detail, as follows:

For the past year typhus fever prevailed extensively throughout Mexico, especially in the States of Guanajuata, Jalisco, Queretaro, Michoacan, San Luis Potosi, Aguascalientes, Puebla, the Federal District, Zacatecas, and southern Coahuila. Upon my arrival at Laredo, shortly after the reporting of cases in that city on December 14, arrangements were made with the Mexican officials at Nuevo Laredo, Mexico, opposite Laredo, Tex., whereby an abandoned French steam chamber of large size was repaired and put into commission for sterilizing clothing and personal effects of passengers arriving from Mexico. Shower baths were installed at the disinfection station thus established, and male and female service attendants were nominated for duty in connection with the operation of the plant. Since the equipment of the disinfection station, all passengers from Mexico, corresponding to the steerage class on vessels, are required, upon arrival at the border, to go to the plant from the railroad station. There they remove their clothing and take a bath; while bathing, their clothing,

other wearing apparel, and bedding is disinfected with steam under pressure to destroy vermin. Those that are infested with head lice have their hair clipped short, and all are required to wash their heads in gasoline, or a mixture of vinegar and kerosene oil. After a thorough cleansing of the person, the sterilized clothing is returned and the passengers leave for American territory, with a certificate signed by the service attendant, who is on duty at all times while the disinfecting plant is in operation.

Similar arrangements were soon made at Piedras Negras, opposite Eagle Pass, Tex., and during March, 1916, at Juarez, opposite El Paso. At Matamoros, opposite Brownsville, Tex., no steam chamber was available. At this place a hot-air oven of large size was designed by the officer in charge of the border quarantine and the officer at Brownsville for disinfecting clothing. In this oven a temperature of 300° F. can be secured in 20 minutes. This apparatus is cheap and gives satisfactory results, but would not be applicable for stations where a large amount of disinfection is necessary. This is because there is no pressure inside the apparatus, therefore no power of penetration, so that clothing must be laid out on racks and not thrown in, tied in bundles.

A similar hot-air apparatus was made and installed at Hidalgo, Tex. New ports of entry were also established at Rio Grande City and Roma, Tex., as it was reported that persons were crossing at these two places, presumably to avoid quarantine and immigration inspection. Acting assistant surgeons were assigned to duty at these stations, where disinfection of clothing is accomplished by boiling or by submerging in gasoline, as but few passengers require treatment at these ports.

The ports of entry of Arizona were inspected and recommendations made to closely inspect all immigrants for body lice and to remand those infested until they had freed themselves of vermin. No disinfection arrangements were made at the Arizona ports nor at Del Rio, Tex., as the immigrants arriving at those places do not come from badly infected areas on account of the railroad facilities into Mexico from those places.

Some of the cases reported at El Paso developed among recent arrivals before the establishment of the disinfection plant at Juarez. The infection there was controlled by the joint action of two service officers and the State, county, and city health officials, with the cooperation of the county supervisors, the mayor, and council of El Paso. In suppressing typhus in El Paso a systematic campaign was carried on by the officials mentioned to free all persons from body vermin. A house-to-house canvass was made among the Mexican laborers and their families by male and female employees of the city and county. All persons were made to undress, wash their heads in vinegar and kerosine, bathe, and to immediately boil their clothing, all such measures being accomplished under supervision. This was repeated once each week for several successive weeks.

The chief difficulty encountered in enforcing quarantine against arrivals from Mexico is due to the fact that illegal entry can easily be made into the States from Mexico all along the Mexican border. The Rio Grande is shallow most of the year, and numerous fords exist where persons may cross. Many small boats operate as ferries, often in an illegal manner.

The economic and political conditions in Mexico at present are such as to cause large numbers of Mexicans seeking a livelihood to make every effort to enter the United States. Many of these persons are without funds upon arrival at the border and are therefore frequently refused entry by the Immigration Service. Naturally those so refused attempt to enter clandestinely. To prevent this, so far as possible, representations were made to the Immigration Bureau, as a result of which a large force of additional guards was temporarily engaged to suppress illegal entries. Considerable assistance was also secured from the military authorities along certain sections. of the border and from local and State officials in Texas. To completely patrol the Mexican border would require thousands of guards and is impracticable on account of the enormous expense that would be involved.

The officer in charge of border quarantine from January until late in May, 1916, conferred with the local authorities in many of the border towns, both in Mexico and the States, with a view of getting the local prison, cheap lodging houses, charitable institutions, and the hovels of the poor in better sanitary condition and their occupants freed from body vermin. Various railroad companies were requested to cooperate by requiring vermin destruction in the section camps and in the box cars used as barracks for laborers, and to compel those living in these places to boil their blankets, sheets, etc., and underclothing 63887°-H. Doc. 1493, 64-2-8