Rocky Mountain Spotted Fever Case Study
Rocky Mountain Spotted Fever
Rickettsia rickettsia was named after the first person who discover Rocky Mountain Spotted fever, Howard Taylor Ricketts. The unicellular aerobic gram negative non-motile, non-spore forming, coccobacilli bacterium are 0.3-0.5 x 0.8-2.0 um. It is in the family Rickettsiaceae and order Rickettsiales of the α-Proteobacteria. It is a unicellular microorganism that lacks a distinct nucleus and membrane- bound organelles, while it is a three-layered cell wall and its outer membrane is mainly composed of lipopolysaccharides. It can be stained using the Machiavello, Giernsa, and Gimenea methods. R. rickettsia is a dangerous pathogen as it dwells in an arthropod tissue and causes a terrible disease when transmitted to vertebrates. …show more content…
Most cases are sporadic, although bunches are seen occasionally. Some of this might be due to better awareness, or to the adoption of a new, less stringent, case definition in surveillance. Infections with other organisms have been included in the statistics for RMSF. To this, the reporting category was changed to “Spotted Rickettsioses (including RMSF)” in 2010.Before effective treatments were available, up to 63-87% of the cases in some parts of the U.S. and 75-80% of the cases in Brazil were fatal. Mortality from this disease has decreased steadily in the U.S. With modern antibiotics and supportive care, it was estimated to be approximately3% (range 3-5%) between 1981 and 1998, and decreased to1.4% (range 0.7–2.9%) in 1997–2002. The reason for the further decrease to 1.4% is not known, although some authors speculate that it might be related to the accidental inclusion of other diseases under “Rocky Mountain spotted fever.” Geographical variations in disease severity have been reported, both within North America, and in comparisons between North and South America. In one region of Brazil, severe cases are common, and the average case fatality rate was 39% during 1995–2004. In contrast, the clinical course is milder, and the case fatality rate lower, in another part of Brazil. Geographical differences might becaused by the virulence of local strains of R. rickettsii, differences in treatment, or the distribution of other Rickettsia that can be confused with R. rickettsii. Treatment of
Rickettsia rickettsia was named after the first person who discover Rocky Mountain Spotted fever, Howard Taylor Ricketts. The unicellular aerobic gram negative non-motile, non-spore forming, coccobacilli bacterium are 0.3-0.5 x 0.8-2.0 um. It is in the family Rickettsiaceae and order Rickettsiales of the α-Proteobacteria. It is a unicellular microorganism that lacks a distinct nucleus and membrane- bound organelles, while it is a three-layered cell wall and its outer membrane is mainly composed of lipopolysaccharides. It can be stained using the Machiavello, Giernsa, and Gimenea methods. R. rickettsia is a dangerous pathogen as it dwells in an arthropod tissue and causes a terrible disease when transmitted to vertebrates. …show more content…
Most cases are sporadic, although bunches are seen occasionally. Some of this might be due to better awareness, or to the adoption of a new, less stringent, case definition in surveillance. Infections with other organisms have been included in the statistics for RMSF. To this, the reporting category was changed to “Spotted Rickettsioses (including RMSF)” in 2010.Before effective treatments were available, up to 63-87% of the cases in some parts of the U.S. and 75-80% of the cases in Brazil were fatal. Mortality from this disease has decreased steadily in the U.S. With modern antibiotics and supportive care, it was estimated to be approximately3% (range 3-5%) between 1981 and 1998, and decreased to1.4% (range 0.7–2.9%) in 1997–2002. The reason for the further decrease to 1.4% is not known, although some authors speculate that it might be related to the accidental inclusion of other diseases under “Rocky Mountain spotted fever.” Geographical variations in disease severity have been reported, both within North America, and in comparisons between North and South America. In one region of Brazil, severe cases are common, and the average case fatality rate was 39% during 1995–2004. In contrast, the clinical course is milder, and the case fatality rate lower, in another part of Brazil. Geographical differences might becaused by the virulence of local strains of R. rickettsii, differences in treatment, or the distribution of other Rickettsia that can be confused with R. rickettsii. Treatment of