Report on the occurrence of exanthematous typhus of murine or endemic type in São Paulo

Abstract

After reviewing several of the main works that contribute for the perfect individualization of the nosological entity known as murinus or endemic typhus the A.reports himself to the efforts made. in 1932-1934 by medical researchers in São Paulo trying to isolate the endemic virus from rats caught in the same city in whose suburban areas appeared, since 1929, the first cases of "exanthematic typhus of São Paulo". In a further review of the works on this subject, done in South America, the A. met the report of cases lately obseI'ved in Venezuela. Out of patients from the city of São Paulo the A. tried, since 1932, to isolate other types of exanthematic virus without being successfuI. However the A. says that he has obtained positive Weil-Felix reaction, sometimes in high dilution title, from the blood of patients living in the country towns af the State of São Paulo. ln a few of these patients the reaction became stronger as the disease went on; most of these cases had a benign evolution, sometimes resembling grippe. The A. suggests that such cases might perhaps be related to the possible existence of the murinus typhus in those country towns or again it might be related to a more benign, more rural and more diffuse variety of the exanthematic typhus of São Paulo, such as happens with the "Rocky Mountain spotted fever" of the United States. Moreover he says that in the State of Minas Gerais there have been reported walking cases of local exanthematic typhus. The A. studied in 1940, in the city of São Paulo, four cases of probable endemic or murinus typhus. Such cases were studied from the epidemiological, clinical, sorological, experimental and immunological point of view. Out of the from patients reported three of themw ere rat catcher of the Public Health Dpt. and the last one was in the bag business near the big Stores of food products, almost in the heart of the city. Clinically all the four patients presented all the symptoms generally met with in the endemic typhus: malaise; headache, pain ln the legs, shilvering, anorexia, fever, sudoresis, injected conjuntivae, photofobia and exhaustion. The fever remained between 38,5° and 40°C. for about six days and the total febrile time was from 13-16 days. Some of the patients presented a slight exanthem in the lateral and anterior portion of the thorax and middle portion of the arm. This eruption lasted a few days; it appeared during the febril e period and disappeared before the fever did. All paatients recovered. The Weil-Felix reaction of the four patients became stronger in the course of the disease. Two guinea-pigs inocu1ated with the blood of two patients had de1ayed reaction and did not present the typica1 thermic curve; but other guinea-pigs serially inoeulated showed scrotal reaction which however disappeared with the fever leaving no sequalae. The A. could not do the crossed immunity test because he lost the viruses in the first few serial inoculations. Two guinea-pigs which reacted thermical1y against the blood of two patients got well, but again reacted when inoculated with the São Paulo virus. Such fact shows although unilateraly that the first virus did not yeild immmunity against the second one probably because they were of different types. The A. thinks that these are the first few probab1e cases of murinus or endemic typhus observed in São Paulo and perhaps in Brazil. He prefers to call it "probable" at 1east until he can obtain new samp1es of viruses from local patients or rats for more detailed studies. The search for the virus in rats is already in course.