Predictive Factors for Fatal Tick‐Borne Spotted Fever in Brazil

Abstract

In Brazil, two pathogenic Rickettsia species have been identified causing tick-borne spotted fever (SF). The aetiological agent Rickettsia rickettsii causes serious illness, particularly in the south-eastern region of the country. Moreover, the Rickettsia sp. strain Atlantic Rainforest cause milder clinical manifestations in south-eastern, south and north-east regions. This study has sought to analyse predictive factors for fatal SF. A case-control study was performed using disease notification records in Brazil. The cases included were individuals with laboratory confirmation and fatal progression of SF, while the controls included individuals with SF who were cured. A total of 386 cases and 415 controls were identified (1 : 1.1), and the cases and controls were similar in age. The factors identified as being protective against death were reported presence of ticks (odds ratio [OR], 0.60; 95% confidence interval [CI], 0.41-0.88), residing in urban areas (OR, 0.47, 95% CI, 0.31-0.74) and presenting lymphadenopathy (OR, 0.43; 95% CI, 0.23-0.82). Males exhibited a greater chance of death (OR, 1.57; 95% CI, 1.13-2.18), as did patients who were hospitalized (OR, 10.82; 95% CI, 6.38-18.35) and who presented hypotension or shock (OR, 10.80; 95% CI, 7.33-15.93), seizures (OR, 11.24; 95% CI, 6.49-19.45) and coma (OR of 15.16; 95% CI, 8.51-27.02). The study demonstrates the severity profile of the SF cases, defined either as the frequency of hospitalization (even in cases that were cured) or as the increased frequency of the clinical complications typically found in critical patients. Opportune clinical diagnosis, a careful evaluation of the epidemiological aspects of the disease and adequate care for patients are determining factors for reducing SF fatality rates.

Epidemiology of capybara-associated Brazilian spotted fever

“…In contrast, a highly virulent strain prevails in Central and South America, which has been linked to the higher fatality rates of BSF, when compared to RMSF [1]. In addition, the greatest fatality of BSF is also evidenced by its neglected status in Brazil, such as the unavailability in the country of parenteral doxycycline, considered the first-choice medication to treat severe BSF or RMSF presenting vomiting or altered mental status [2, 3].…”

Muerte inesperada por rickettsiosis: implicaciones médico-legales y epidemiológicas

“…La fmmr es un padecimiento febril exantemático agudo, caracterizado por vasculitis con infiltrado perivascular linfocitario, variados signos y síntomas, y manifestaciones de un cuadro clínico grave, que puede ser letal sin tratamiento oportuno [7,11]. Cuando el cuadro clínico está avanzado, se ha descrito que el riesgo de muerte es mayor entre varones hospitalizados que presentan hipotensión, convulsiones y coma [11].…”

“…La fmmr es un padecimiento febril exantemático agudo, caracterizado por vasculitis con infiltrado perivascular linfocitario, variados signos y síntomas, y manifestaciones de un cuadro clínico grave, que puede ser letal sin tratamiento oportuno [7,11]. Cuando el cuadro clínico está avanzado, se ha descrito que el riesgo de muerte es mayor entre varones hospitalizados que presentan hipotensión, convulsiones y coma [11]. Las descripciones Al terminar la necropsia, en la valoración de los datos clínicos y de los hallazgos macroscópicos se consideró que podía tratarse de un caso de rickettsiosis, motivo por el cual se tomaron y enviaron muestras de hígado para análisis molecular al de los casos con desenlace fatal presentan un cuadro clínico similar al nuestro, salvo en la ausencia del exantema.…”

Tick-Borne-Associated Illnesses in the Pediatric Intensive Care Unit

“…34 Critically ill patients can develop hypotension, shock, renal failure, seizure, stupor, coma, encephalitis, hemorrhagic manifestations, noncardiogenic pulmonary edema, or acute respiratory distress syndrome. 35 When this occurs, they are five times more likely to succumb to this illness due to airway compromise, hypoxemia, and hemodynamic instability. 35…”

“…35 When this occurs, they are five times more likely to succumb to this illness due to airway compromise, hypoxemia, and hemodynamic instability. 35…”