Cold spongings, provided the patient is not disturbed by being moved, are of value for the insomnia. Phenacetine may be given for the relief of the headache and backache. It is rarely necessary to give morphine.
During convalescence tonics are indicated and if there is any condition where a good wine is of value, it is in this, to counteract the terrible depression. It has been suggested that adrenal insufficiency may account for the asthenic, protracted convalescence and from this standpoint adrenalin has been recommended.
DENGUE-LIKE FEVERS
Phlebotomus or Pappataci Fever
Etiology and Epidemiology.—This fever, which is often called three-day fever, on account of its running its course in this period, is caused by a filterable virus. This virus only seems to be in the blood of the patient’s peripheral circulation during the first twenty-four hours of the illness, blood abstracted toward the end of the second day and injected into a well person failing to reproduce the disease.
If the blood is filtered through a Pasteur candle F, the filtrate will set up an attack just as well as the unfiltered blood, in this respect being like dengue and yellow fever. Couvy reports having found spirochaetes in the blood 3 hours and 24 hours after the onset.
The transmitting agent is a moth midge, Phlebotomus papatassii. This midge, as is true of the psychodid family, to which it belongs, is very hairy. It has long slender legs and narrow wings. The proboscis is as long as the head and the lancets project beyond the labium.
The female alone bites, which act takes place chiefly at night; cool, moist, shady places, away from sleeping rooms, being preferred in the day time. The insect is a persistent, vicious feeder, difficult to escape from, as mosquito nets offer no protection. It takes from six to eight days after feeding on a patient in the first day of the fever before the midge is capable of transmitting the disease, this being in accordance with the twelve-day developmental period in the mosquito, that holds for yellow fever. Doerr thinks that the pappataci virus may be transmitted hereditarily by the insect to the egg.
At present, of the genera of the three families of midges, only Phlebotomus is known to transmit disease. P. papatasii transmits phlebotomus fever in the Balkans. P. minutus is the host at Aden. Another species, P. perniciosus, can transmit the disease. These moth midges are 2 mm. in length and have the body densely covered with long yellow hairs. The second longitudinal vein has three distinct branches. The antennae have 16 restricted joints and the proboscis is as long as the head. The species of Phlebotomus are separated by slight variations in wing venation, palpal lengths, etc., thus the second segment of palpi of P. papatasii is a little longer than the third one, while with P. perniciosus these segments are of equal lengths. In P. minutus the second segment is only half the length of the third. The insect lays about 40 eggs in damp dark places. The period of metamorphosis from egg to insect is about one or two months, according to temperature.
Phlebotomus larvae die out in dry soil and very wet earth is unfavorable. Moderate moisture and protection from light seem necessary for their development. The remains of dead insects also seem to make good breeding places. It is in cracks of old damp brick or stone walls that the female most often deposits her eggs. Caves are also selected.
Blood seems necessary for the fertilization of the eggs but lizard blood seems more common in the stomach of P. minutus than human blood. They have also been observed to feed on other reptilian bloods. The female insect has been kept alive in captivity up to forty-six days.