ABSTRACT
Murine typhus is a febrile, fleaborne disease caused by infection with Rickettsia typhi bacteria. Cases can range from mild and nonspecific to fatal. We report 2 cases of murine typhus in Costa Rica, confirming the presence and circulation of R. typhi causing severe disease in the country.
Subject(s)
Rickettsia , Typhus, Endemic Flea-Borne , Animals , Mice , Humans , Typhus, Endemic Flea-Borne/diagnosis , Typhus, Endemic Flea-Borne/epidemiology , Typhus, Endemic Flea-Borne/microbiology , Costa Rica/epidemiology , Rickettsia typhi/geneticsABSTRACT
INTRODUCTION: Rickettsia typhi causes murine or endemic typhus, which is transmitted to humans primarily through flea bites contaminated with feces. Synanthropic and domestic animals also contribute to the infection cycle of R. typhi. Cases of murine typhus in humans were reported in the rural community of Bolmay, Yucatán, México, between 2007 and 2010. OBJECTIVE: To identify the presence of R. typhi and estimate the frequency of infection in dogs from Bolmay, México, a locality with previous reports of murine typhus in humans. MATERIALS AND METHODS: Whole blood samples were taken from 128 dogs. Total DNA was extracted for use in the polymerase chain reaction (PCR) to amplify fragments of the 17 kDa and omp B genes and confirms the presence of Rickettsia spp. The reaction products were sequenced, and alignment analysis was performed using the BLAST tool. RESULTS: The frequency of R. typhi infection in dogs was 5.5 % (7/128). The alignment identified 99% and 100% homology to the R. typhi 17 kDa and omp B genes, respectively. CONCLUSION: We confirmed the presence of R. typhi in dogs in the studied community but at a low frequency. However, there is potential risk of transmission to humans.
Subject(s)
Rickettsia Infections/epidemiology , Rickettsia typhi/chemistry , Siphonaptera/microbiology , Typhus, Endemic Flea-Borne/pathology , Animals , Dogs , Feces , Mexico , Polymerase Chain Reaction , Rickettsia Infections/microbiology , Rickettsia Infections/transmission , Rickettsia typhi/isolation & purification , Typhus, Endemic Flea-Borne/microbiology , Typhus, Endemic Flea-Borne/transmissionABSTRACT
Rickettsia typhi and R. felis are the etiological agents of murine typhus and flea-borne spotted fever, respectively. Both are emerging acute febrile zoonotic diseases for which fleas are vectors; they also have similar clinical characteristics and global distribution. In 2005, we identified the circulation of murine typhus in 6 towns within the mountainous coffee-growing area north of Caldas, Colombia. We now report the specific seroprevalence against R. typhi and R. felis, and associated risk factors in 7 towns of this province. The combined seroprevalence against the 2 flea-borne rickettsioses is the highest yet reported in the literature: 71.7% (17.8% for R. felis, 25.2% for R. typhi, and 28.7% for both). We also report a prospective analysis of 26 patients with a febrile illness compatible with rickettsioses, including murine typhus; 9 of these patients had a rickettsiosis. This supports our sero-epidemiological results and highlights the diagnostic complexity of febrile syndromes in this region.
Subject(s)
Insect Vectors/microbiology , Rickettsia Infections/epidemiology , Rickettsia felis/isolation & purification , Rickettsia typhi/isolation & purification , Siphonaptera/microbiology , Typhus, Endemic Flea-Borne/epidemiology , Adolescent , Adult , Aged , Animals , Colombia/epidemiology , Female , Humans , Male , Middle Aged , Prospective Studies , Rickettsia Infections/microbiology , Rickettsia felis/genetics , Rickettsia typhi/genetics , Risk Factors , Seroepidemiologic Studies , Typhus, Endemic Flea-Borne/microbiology , Young Adult , ZoonosesABSTRACT
A case of murine typhus in Yucatan was diagnosed in a child with nonspecific signs and symptoms. The finding of Rickettsia typhi increases the number of Rickettsia species identified in Yucatan and shows that studies are needed to determine the prevalence and incidence of rickettsioses in Mexico.