Serological Evidence on the European Type of Typhus Fever in China

Abstract

Fletcher and Lesslar 1 described what they called tropical typhus from the Federated Malay States. By using several strains of B. proteus × for the Weil-Felix test they showed that, though clinically the same, urban cases gave a positive agglutination with the X₁₉ (Warsaw) strain while those from rural districts gave positive tests only with the Kingsbury strain. Spencer and Maxcy 2 using the variants of X₁₉, X₂, and X_k (Kingsbury) found that the sera of patients with endemic typhus invariably agglutinated to a high titre the X₁₉ strain, but possessed no appreciable group agglutinins for other strains. With Rocky Mountain spotted fever, however, X₁₉ organisms were agglutinated significantly only in a minority of cases and to a lower titre than in endemic typhus; moreover, agglutinins for X₂ and X_k were also found in a considerable proportion of these cases. Felix and Rhodes 3 have recently studied more extensively the sera of patients with typhus and typhus-like diseases from various parts of the world and confirmed the above findings. There seems no doubt that some endemic diseases clinically simulating typhus give positive Weil-Felix reactions with the X_k strain to high or low titres, but not with the usual X₁₉ strain, while still others give negative tests with any known strain. Felix and Rhodes propose to consider the various forms of typhus and typhus-like diseases as serological types of typhus. According to them the typhus nature of those diseases which give negative Weil-Felix reactions but otherwise are typhus-like may later be proved when corresponding types or variants of B. proteus × are isolated.