The Rickettsioses

Abstract

Rickettsia are small, obligately intracellular Gram negative bacilli. They are distributed among a variety of hematophagous arthropod vectors and cause illness throughout the world. Rickettsioses present as an acute undifferentiated febrile illness and are often accompanied by headache, myalgias, and malaise. Cutaneous manifestations include rash and eschar, which both occur at varying incidence depending on the infecting species. Serology is the mainstay of diagnosis, and the indirect immunofluorescence assay is the test of choice. Reactive antibodies are seldom present during early illness, so testing should be performed on both acute-and convalescent-phase sera. Doxycycline is the treatment of choice.

<p>Clinical Features, Laboratory Characteristics and Prognostic Factors of Severity in Patients with Rickettsiaceae at Two Military Hospitals, Northern Vietnam</p>

“…8 In the National Hospital for Tropical Diseases, Rickettsioses account for one-third of acute undifferentiated fevers with the mortality rate of 5.4% between 2015 and 2017. 9 It is of great challenge to diagnosis Rickettsioses because of the variable clinical manifestations with the typical eschar, rash or lymphadenopathy are not always presented; [10][11][12] complications such as pneumonitis, and meningoencephalitis vary from one disease to another. 10,12,13 Therefore, it is easy to misdiagnose accompanied by complications and higher mortality.…”

“…9 It is of great challenge to diagnosis Rickettsioses because of the variable clinical manifestations with the typical eschar, rash or lymphadenopathy are not always presented; [10][11][12] complications such as pneumonitis, and meningoencephalitis vary from one disease to another. 10,12,13 Therefore, it is easy to misdiagnose accompanied by complications and higher mortality. 12 According to CDC, estimated case fatality rate of Rickettsial infection can be up to 5% to 10% 14 and delayed treatment beyond the fifth day of illness is the single most important predictor of fatal outcome.…”

“…10,12,13 Therefore, it is easy to misdiagnose accompanied by complications and higher mortality. 12 According to CDC, estimated case fatality rate of Rickettsial infection can be up to 5% to 10% 14 and delayed treatment beyond the fifth day of illness is the single most important predictor of fatal outcome. 15 Misdiagnosis and treatment persist among healthcare providers even in the United State.…”

Epidemiology of zoonotic tick-borne diseases in Latin America: Are we just seeing the tip of the iceberg?

“…After the first description of Rickettsia rickettsii in North America in the first half of the twentieth century, this species also was recognized as a human pathogen in Latin America 9 . Currently, R. rickettsii rickettsiosis is the most important and deadly TBDs in México, Panamá, Colombia, Brazil, and Argentina, where is transmitted to humans by different ticks’ species as Rhipicephalus sanguineus , Amblyomma mixtum , A. patinoi , A. sculptum , A. aureolatum , and A. tonelliae 9, 10 . Unfortunately, only in Brazil, this disease is of officially mandatory reporting 9 .…”

“…Unfortunately, only in Brazil, this disease is of officially mandatory reporting 9 . Moreover, in the last years, other rickettsiae have been pointed as emerging pathogenic species, causing febrile rickettsiosis ( R. parkeri and R. massiliae ) or asymptomatic/mild illness ( R. amblyommatis ) 9, 10 . Currently, R. parkeri , transmitted by A. ovale , A. tigrinum , and A. triste , is the main agent relate to eschar-associated rickettsiosis in Brazil, Argentina and Uruguay 11– 13 .…”