Rocky Mountain spotted fever in the United States, 1993-1996.

Abstract

Abstract. During 1993 through 1996, 2,313 cases of Rocky Mountain spotted fever (RMSF) were reported to the Centers for Disease Control and Prevention (CDC) by 42 states and the District of Columbia through the National Electronic Telecommunications System for Surveillance (NETSS). During this same interval, 1,752 case report forms (CRFs) were submitted to CDC and 1,253 (70%) of the cases were categorized as confirmed RMSF by laboratory testing. On the basis of analyses performed with NETSS data, the average annual RMSF incidence during 1993-1996 was 2.2 cases per million persons; the incidence rose from 1.8 in 1993 to 3.3 per million persons in 1996. Incidence for confirmed cases was highest among children 5-9 years of age (3.7 per million) and lowest among individuals older than 70 years of age (1.4 per million). The south Atlantic region accounted for the largest proportion of confirmed cases (52%). The case-fatality rate was highest among persons 70 years of age and older (9.0%) and lowest among adults 40-49 years of age (0.6%).

Diagnosis and Management of Tickborne Rickettsial Diseases: Rocky Mountain Spotted Fever and Other Spotted Fever Group Rickettsioses, Ehrlichioses, and Anaplasmosis — United States

“…SFG rickettsiosis, ehrlichiosis, and anaplasmosis are nationally notifiable in the United States. Cases have been reported in each month of the year, although most cases are reported during April-September, coincident with peak levels of tick host-seeking activity (3)(4)(5)(9)(10)(11)(12)(13)(14). The distribution of tickborne rickettsial diseases varies geographically in the United States and approximates the primary tick vector distributions, making it important for health care providers to be familiar with the regions where tickborne rickettsial diseases are common.…”

“…During 2008-2012, 63% of reported SFG rickettsiosis cases originated from five states: Arkansas, Missouri, North Carolina, Oklahoma, and Tennessee (4). However, SFG rickettsiosis cases have been reported from each of the contiguous 48 states and the District of Columbia (4,9,12,14).…”

“…Although the recognition of a tick bite is helpful, unrecognized tick bites are common in patients who are later confirmed to have a tickborne rickettsial disease. A history of a tick bite within 14 days of illness onset is reported in only 55%-60% of RMSF cases (9,12,25) and 68% of ehrlichiosis cases (10). Therefore, absence of a recognized tick bite should never dissuade health care providers from considering tickborne rickettsial disease in the appropriate clinical context.…”

Rocky Mountain Spotted Fever in the United States, 2000–2007: Interpreting Contemporary Increases in Incidence

“…1,2 Rocky Mountain spotted fever has long been considered one of the most severe tick-borne rickettsial infections, with preantibiotic case-fatality rates reported as high as 65-80% in some case series [1][2][3][4] ;contemporary estimates from 1981 to 1998 placed modern case-fatality rates at around 3% of reported cases. 5,6 The disease causes fever, headache, abdominal pain, and rash in a majority of patients, and may also lead to complications such as encephalitis, acute respiratory distress syndrome, and coagulopathies. 1,2 Although most antibiotics are characteristically ineffective against R. rickettsii , tetracycylines offer excellent clinical results.…”

Absence of Rickettsia rickettsii and Occurrence of Other Spotted Fever Group Rickettsiae in Ticks from Tennessee

“…The vector typically attributed with RMSF transmission and maintenance in the southeastern United States is Dermacentor variabilis (the American dog tick), 1 although the widely distributed Rhipicephalus sanguineus (the brown dog tick), is also found in Tennessee 2 and has been shown to transmit the pathogen in other parts of the country. 3,4 Tennessee historically reports one of the highest incidence rates for RMSF in the United States, 5,6 which have rapidly increased in recent years. In 2008, 224 cases were reported to the Tennessee Department of Health (TDH), a 20% increase over 2007 and 120% increase over 2004.…”