Cluster of sylvatic epidemic typhus cases associated with flying squirrels, 2004-2006.

In February 2006, a diagnosis of sylvatic epidemic typhus in a counselor at a wilderness camp in Pennsylvania prompted a retrospective investigation. From January 2004 through January 2006, 3 more cases were identified. All had been counselors at the camp and had experienced febrile illness with myalgia, chills, and sweats; 2 had been hospitalized. All patients had slept in the same cabin and reported having seen and heard flying squirrels inside the wall adjacent to their bed. Serum from each patient had evidence of infection with Rickettsia prowazekii. Analysis of blood and tissue from 14 southern flying squirrels trapped in the woodlands around the cabin indicated that 71% were infected with R. prowazekii. Education and control measures to exclude flying squirrels from housing are essential to reduce the likelihood of sylvatic epidemic typhus.

Diagnosis and management of tickborne rickettsial diseases: Rocky Mountain spotted fever, ehrlichioses, and anaplasmosis--United States: a practical guide for physicians and other health-care and public health professionals.

Tickborne rickettsial diseases (TBRD) continue to cause severe illness and death in otherwise healthy adults and children, despite the availability of low cost, effective antimicrobial therapy. The greatest challenge to clinicians is the difficult diagnostic dilemma posed by these infections early in their clinical course, when antibiotic therapy is most effective. Early signs and symptoms of these illnesses are notoriously nonspecific or mimic benign viral illnesses, making diagnosis difficult. In October 2004, CDC's Viral and Rickettsial Zoonoses Branch, in consultation with 11 clinical and academic specialists of Rocky Mountain spotted fever, human granulocytotropic anaplasmosis, and human monocytotropic ehrlichiosis, developed guidelines to address the need for a consolidated source for the diagnosis and management of TBRD. The preparers focused on the practical aspects of epidemiology, clinical assessment, treatment, and laboratory diagnosis of TBRD. This report will assist clinicians and other health-care and public health professionals to 1) recognize epidemiologic features and clinical manifestations of TBRD, 2) develop a differential diagnosis that includes and ranks TBRD, 3) understand that the recommendations for doxycycline are the treatment of choice for both adults and children, 4) understand that early empiric antibiotic therapy can prevent severe morbidity and death, and 5) report suspect or confirmed cases of TBRD to local public health authorities to assist them with control measures and public health education efforts.

Rocky mountain spotted fever in the United States, 1997-2002.

The increased incidence of Rocky Mountain spotted fever (RMSF) in 1997-2002 compared with previous years may be related to enhanced awareness and reporting of RMSF as well as changes in human-vector interaction. However, reports on RMSF mortality underscore the need for physician vigilance in considering a diagnosis of RMSF for febrile individuals potentially exposed to ticks and stress the importance of treating such persons regardless of the presence of a rash.

Rocky Mountain spotted fever in the United States, 1997-2002.

Rocky Mountain spotted fever (RMSF) is the most commonly reported fatal tick-borne disease in the United States. During 1997-2002, 3,649 cases of RMSF were reported to the Centers for Disease Control and Prevention via the National Electronic Telecommunications System for Surveillance; 2,589 case report forms, providing supplemental information, were also submitted. The average annual RMSF incidence during 1997-2002 was 2.2 cases/million persons. The annual incidence increased during 1997-2002 to a rate of 3.8 cases/million persons in 2002. The incidence was lowest among persons aged<5 and 10-29 years, and highest among adults aged 60-69 years. The overall case-fatality rate was 1.4%; the rate peaked in 1998 at 2.9% and declined to 0.7% in 2001 and 2002. Children<5 years of age had a case-fatality rate (5%) that was significantly greater than the rates for age groups<60 years of age, except for that for 40-49 years of age. Continued national surveillance is needed to assess the effectiveness of prevention efforts and early treatment in decreasing severe morbidity and mortality associated with RMSF.

Reported gastrointestinal infections in the U.S. Air Force, 2000-2012.

During 2000-2012, U.S. Air Force Public Health Offices reported 3,429 cases of gastrointestinal infection (GI) diagnosed at Air Force medical treatment facilities. The four most commonly reported specific etiologies of GIs accounted for 86.7% of all GI cases (n=2,972). Salmonellosis accounted for 41.4% (n=1,420) of all cases. The next most commonly reported events were associated with Campylobacter infection, shigellosis, and giardiasis. The majority of GI cases were reported among dependents, most notably among those aged 0-5 years. Campylobacter infections represented a significantly larger proportion of GI reported from locations outside the continental United States (OCONUS) (n=222, 33.7%) compared to continental U.S. (CONUS) locations (n=363, 13.1%). CONUS locations reported higher proportions of salmonellosis, shigellosis, and giardiasis infections compared to OCONUS locations. Annual numbers of reported cases of GI peaked in 2002, declined to much lower numbers during 2004-2007, and then began to climb until the end of the surveillance period.

Reported vectorborne and zoonotic diseases, U.S. Air Force, 2000-2011.

During 2000-2011, U.S. Air Force Public Health Officers reported 770 cases of vectorborne and zoonotic diseases diagnosed at Air Force medical treatment facilities. Cases of Lyme disease accounted for 70 percent (n=538) of all cases and most cases of Lyme disease (57%) were reported from bases in the northeastern U.S. and in Germany. The annual numbers of reported Lyme disease cases were much higher during the last four years than earlier in the surveillance period. The next most commonly reported events were malaria (74 cases), Rocky Mountain spotted fever (RMSF) (41), Q fever (33), dengue (23), and leishmaniasis (20). These five infections and Lyme disease accounted for 95 percent of the reported conditions. Military service members accounted for a majority of the reported cases for most of the conditions, but family members and retirees accounted for most of the cases of Lyme disease and RMSF. Most reports of vectorborne and zoonotic diseases did not include mentions of recent travel.

Norovirus outbreak associated with person-to-person transmission, U.S. Air Force Academy, July 2011.

In July 2011, the U.S. Air Force School of Aerospace Medicine (USAFSAM) Epidemiology Consult Service investigated an ongoing outbreak of acute gastrointestinal (GI) illness--characterized by vomiting, nausea, diarrhea, and stomach cramps--that affected cadets and support personnel at a field training location at the U.S. Air Force Academy. Six outbreak-related stool specimens were confirmed by RT-PCR to be infected with norovirus, genogroup I. Overall, 290 cases (suspected and confirmed) of norovirus-related GI illness were recorded; the estimated attack rate among 1,359 cadets was 18%. The investigation suggested that norovirus was introduced into the field dining facility by one or more food service workers, possibly transmitted via common use serving utensils, and then further spread among cadets by person-to-person contact. Numbers of new cases sharply declined after ill cadets were segregated in separate tents for convalescence, and after all cadets moved from field billets (i.e., tents) to dormitories after completing the field training.