CHAPTER Vll (Part 5)

examination and by the periodicity of relapses. Malta fever was excluded by agglutination tests, dengue by the absence of a rash, and influenza by the absence of bronchial catarrh, a lower degree of prostration and the periodic relapses. Malaria and relapsing fever were excluded by the absence of parasites in the blood. The disease can be transmitted experimentally by the whole blood (haemolized) but not by the serum. The method of transmission in nature is unknown. The following indicate approximately the incubation and segrega- tion periods of some infectious diseases. Authorities differ on such figures. Usual number of days Incubation Isolation Cholera 3 to 6 12 Chicken pox 4 to i6 20 Diphtheria i to lo 12 * Erysipelas 1 to 5 12 Influenza 3 to 4 5 Measles 8 to 14 10 Mumps 4 to 25 21 Plague 2 to 8 21 Rubella 7 to 18 10 Scarlet fever. 1 to 21 40 Trench fever 6 lo 2 2 ? two succes- sive negative cultures CAMP DISEASES 1 89 Usual number of days Incubation Isolation f Typhoid fever 10 to 14 23 - three nega- tive succes- sive weekly cultures Typhus fever 5 to 20 14 Yellow fever 3 to 5 5 or 6 DISEASES CAUSED BY EXPOSURE Trench Feet. — A condition common among soldiers who serve in the trenches is known as trench feet. The most important causes are cold and wet, in combination. Pressure is an aggravating factor but probably not a cause. Cold and wet, causing a rapid loss of heat, cause first a local vasoconstriction, leading to defective circula- tion through the feet and then to vasomotor paresis passing on to paralysis with consequent haemostasis, oedema and gangrene. . Pressure aggravates the trouble. The onset is gradual, the feet feel cold and eventually lose sensa- tion. Pain, except the discomfort associated with cold feet, is not complained of at first. Later, as the feet begin to swell there is pain around the ankles, occasionally extending up to the calves. If boots are removed at this time the feet swell immediately and it is impossible to replace the boots. The pathology of the condition is similar to that of Reynaud^s disease. Two varieties are recog- nized, the red and the white. The majority of the cases resemble the former but in some the foot is dead white. This is believed to be a precursor of the congested type as the foot eventually assumes that appearance. On admission to hospital the feet are usually in all stages of lividity from a pink blush to a dead black gangrenous appearance. They are greatly swollen, the skin is covered with bullous eruptions, containing a blood-stained fluid. The discoloration is often sharply demarcated at the mid-tarsal joint. The feet are cold. In mild cases there is oedema over the tarsus with Uttle discoloration. Often the only color change is a light pink flush, on the ball of the great toe and the tips of the toes. There is a patchy anaesthesia. In the white cases the foot is stone cold, dead white and has lost sensation. Gangrene rarely followed even the severe cases, except that a igO FIELD HYGIENE AND SANITATION superficial sloughing occurs. Pain increases at night, is aggravated by warmth, and extends up to the leg. It persists long after the circulation has been restored, and the feet appear healthy. Men whose feet are greatly swollen and appeal gangrenous complain of little pain. In some cases there is great tenderness of the soles of the feet after acute symptoms have disappeared. The condition is treated by elevating the feet, powdering with boracic acid and wrapping in absorbent cotton, which is changed twice a day. Massage, twice daily, when it can be borne, gives good results. Painting with iodine appeared to benefit certain neurotic cases. Pain was treated by morphine. Other agents were unsatisfactory. Foot drill is highly beneficial to convalescents. Recurrences upon exposure are frequent. Feet and foot gear should be inspected before the troops enter the trenches. Shoes should be roomy and well greased at intervals. The jimction of sole and upper especially should be attended to in order to prevent rotting of the seams. Before entering the trenches the feet and legs should be anointed with sH to 4 oz. of a 5 to 10 per cent, ointment of salt and lard or whale-oil. Rubber boots are much used. Trenches should be drained if possible or provided with fascines of brushwood. Constant care of the feet is necessary. Men should be encouraged to stamp their feet, move the toes, and exercise generally. Wash- ing the feet should be encouraged. Lukewarm water containing half an ounce of mustard to the gallon should be employed. Dried socks should be put on and the shoes dried when possible. The legs should be kept elevated when at rest. Ftost Bite. — Severe frost bite causing loss of feet or hands has been quite common in the trenches. Among its causes in addition to cold are: dampness, high winds, nervous exhaustion, over indulgence in alcohol and lack of proper rest, food, and physical exercise. To prevent it winter clothing should be distributed systematically. Garments should be loose and the circulation unimpeded by light equipments. The foot gear is most important. Soldiers in the trenches should unlace their leggins frequently and move and rub their feet briskly. The face is protected with a hood, the hands with woolen mittens. Feet, legs and hands, as well as the ears, nose and chin, are to be rubbed with a specially pre- CAMP DISEASES 191 pared ointment containing ten per cent, of salt. When glasses are worn the metallic parts which come in contact with the skin are covered. Inmiobility and inertia must be carefully guarded against, especially in the case of sentinels, whose posts should be sheltered from the wind. They should be relieved frequently during the night. They must be cautioned against standing still and yielding to drowsiness. Forty-eight hours should be the limit of service in the trenches. Alcohol is strictly forbidden in the Italian service except small quantities of light wine. Medical officers establish aid stations near the advanced posts, in order to treat without delay soldiers who show evidences of succumbing to cold, i.e., by drowsiness. Hot bouillon and coffee are served to sentries on coming off duty and if necessary the patient is sent to the rear. In extreme cases he must be treated at the aid station by artificial respiration, massage and cardiac stimulation. Hot applications are to be avoided in every case of frost bite. No alcohol is given. Blisters are emptied and great care is exercised to avoid infection and subsequent gangrene. In every case of frost bite with skin lesions, anti-tetanus serum is injected. Gas Poisoning. — ^Information on this subject is of a confidential character and can not now be noted here.