• Mediterranean spotted fever;
  • Rickettsia conorii;
  • Portugal;
  • Israeli tick typhus

Abstract: Mediterranean spotted fever (MSF), endemically present, is associated with a low mortality and morbidity in Portugal. Etiological agents are Malish and Israeli tick typhus strains of Rickettsia conorii. In the last few years severe forms of MSF have emerged, with patients presenting atypical symptoms, major neurological manifestations, and multiorgan involvement, who have required intensive care facilities. Advanced age, underlying chronic disease, and delay of appropriate treatment are bad prognostic factors. In the acute phase of diagnosis, serological studies are delayed, inconclusive, and often unhelpful. A definitive diagnosis can only be made using isolation or molecular biology which can establish and clearly identify agents. Using evidence-based case reports, clinical and laboratory data were evaluated from patients with severe or fatal MSF observed in Garcia da Orta Hospital-Almada. Of the eight reference cases, four died, three in an acute fulminant stage. Of the survivors, four presented atypical involvement: ocular inoculation, massive gastric hemorrhage, acute respiratory disease (ARDS), and necrotizing vasculitis. Diagnosis by isolation of the agent was made in two cases, by immunohistochemistry in three, and by the indirect fluorescent antibody test (IFA) in three others. Israeli tick typhus and Malish R. conorii strains were isolated once each in fatal cases. In early stages, diagnosis continues to be clinical and patients should start appropriate therapy without delay if clinical suspicion of rickettsiosis arises to prevent poor outcome. Patients ranged in age from 39 to 71 years (mean 60), APACHE II ranged from 15 to 38 points and TISS 28 was between 24 and 46 points. In reported cases severity of disease was not obviously related to the usual comorbidities. Accelerated clinical course may not suggest classical MSF. Another relevant factor was prior prescription of an inappropriate antibiotic that contributed to misleading clinical features. The reported complications and atypical manifestations illustrate well the diversity of this disease.