Rocky Mountain spotted fever

Infection agents of Didelphidae (Didelphimorphia) of Brazil: an underestimated matter in zoonoses research

Zoonoses are diseases or infections naturally transmissible from vertebrate animals to humans, and can be bacterial, viral or parasitic. The growth of urbanization, industrialization and the advance of agriculture and livestock facilitate the spread of infectious and parasitic agents from wild animals to the human population and to their domestic animals. Among the various reservoirs of zoonotic agents, we find that didelphid species, due to their high capacity for adaptation in urban environments, as an important study case. We reviewed the literature data on the pathogens, including with zoonotic potential of marsupial species occurring in Brazil, accounted for infections by agents that we categorized into Bacteria, Viruses, Protozoa, and Helminths. Aiming identifies possible knowledge gaps, we also surveyed the origin of studied samples and the institutions leading the researches on host didelphids. Among the hosts, the genus Didelphis in the cycles of these agents stands out. Moreover, we found that the majority of reported cases are in the Southeastern Brazil, mean the data from other Brazilian localities and didelphid species could be underestimated. Most studies took place in graduate programs of public research institutions, emphasizing the importance of the funding public research for the Brazilian scientific development.

Risk perceptions regarding ticks and Lyme disease: a national survey

BACKGROUND

Lyme disease (LD) is caused by the tickborne bacterium Borrelia burgdorferi and, in 2000, accounted for >90% of all reported cases of vectorborne illness in the United States. Aside from anecdotal and indirect evidence, little empirical evidence exists regarding what the U.S. public knows, says, or does about preventing LD.

OBJECTIVES

To examine knowledge, perceptions, and practices regarding prevention of tick bites and LD.

METHODS

In 1998, a random-digit-dial frame was used to collect a cross-sectional sample (n =1500) from the 48 coterminous states plus the District of Columbia, and an over-sample (n =250) from six states with the highest incidence of LD.

RESULTS

Forty percent of respondents reported doing something to avoid being bitten by ticks. Less than half (41%) used insect repellent. Ninety-two percent of those who had heard about LD stated their likelihood of ever getting the disease was </=50 on a 100-point scale (mean=29; standard deviation, 23.5). Being somewhat to very concerned about being bitten by ticks was strongly associated with taking preventive measures (odds ratio, 8.34; 95% confidence interval, 6.29-11.06).

CONCLUSIONS

Having seen ticks, being concerned about being bitten, perceiving insect repellent to be effective, having heard about LD, and knowing someone who had LD are the factors most predictive of specific tick-bite preventive behaviors (p <0.001). However, greater efforts are needed in promoting the effectiveness and safety of DEET-containing insect repellents.

Rocky Mountain spotted fever and pregnancy: a case report and review of the literature

The classic triad of fever, headache, and characteristic rash occurring 1 to 2 weeks after a tick bite in an endemic area should raise suspicions for Rocky Mountain spotted fever (RMSF). All providers with primary care responsibility for women should be familiar with the diagnosis and treatment of this illness. As a recent case illustrates, the diagnosis of Rocky Mountain spotted fever may be complicated by pregnancy. Several conditions of pregnancy have similar presentations to the initial, often nonspecific manifestations of RMSF. Although doxycycline is the recommended therapy for children and nonpregnant women, chloramphenicol remains the recommended therapy for women during pregnancy. The time of year, local prevalence, and patient's exposure history may be taken into account when deciding to treat during pregnancy. Vertical transmission of RMSF has not been documented in humans. Prevention of RMSF by avoidance of tick-infested areas or by the use of insect repellents and long clothing is recommended for all patients.

Doxycycline use for rickettsial disease in pediatric patients

BACKGROUND

Recent evidence suggests that despite potential side effects, doxycycline should be considered the drug of choice for children of all ages in whom a rickettsial disease is considered in the differential diagnosis of the illness. We hypothesized that doxycycline would be used infrequently for the treatment of suspected rickettsial disease. The objective of the investigation was to determine the initial antibiotic administered to children for whom rickettsial infection was considered likely.

METHODS

The study population consisted of 35 children evaluated at Texas Children's Hospital between 1987 and 1999 in whom rickettsial disease was a diagnostic consideration. Demographic information and clinical manifestations were assessed through a retrospective chart review.

RESULTS

Thirty children (86%) presented with fever, 21 (60%) with rash and 14 (40%) with headache, which are typical presenting symptoms for rickettsial diseases. Only 1 of 35 children (3%) was prescribed a tetracycline class antibiotic as initial empiric therapy. Eleven (31%) children received doxycycline during the hospital course. A total of 19 patients, or 54%, received an antimicrobial known to have efficacy in the treatment of rickettsial infection, usually at the suggestion of an infectious diseases consultant.

CONCLUSIONS

Even among children for whom rickettsial infection is a diagnostic consideration, doxycycline is not prescribed with the frequency that is indicated. Pediatric caregivers should have heightened awareness regarding the appropriate indications for doxycycline use in childhood.