[Seroprevalence of risk factors associated with rickettsiosis (Rickettsia rickettsii) in humans in Baja California, Mexico].
BACKGROUND
Rickettsiosis caused by Rickettsia rickettsii is capable of infecting vertebrates, including humans. The symptoms are high fever, headache, myalgia, nausea, vomiting, abdominal pain, and cough. Mortality can be up to 30% in untreated patients.


OBJECTIVE
To prove the existence of rickettsiosis in Ensenada, Baja California, Mexico, because no human cases have been reported.


METHODS
This observational, cross-sectional, descriptive study included 384 samples of humans in Ensenada, Baja California. Antibodies against R. rickettsii were measured with the kit R. rickettsii ELISA(®) Helica Biosystems, Inc., adapted for use in humans using human IgG conjugate antibodies. To determine the sensitivity and specificity, 32 human samples were submitted to IFA. Specific primers were used for the molecular diagnosis of R. rickettsii in dogs and ticks.


RESULTS
The seroprevalence adjusted rickettsiosis in humans was 2.9% (95% CI: 0.8-5.3), seropositivity was not associated with sex, age, occupation, household, dogs, pet deworming program against ticks, the type of yard, and mobility of the dog between home and the street.


CONCLUSIONS
With substantial agreement of k between ELISA and IFA, it follows that the results of seroprevalence of this work are reliable.
Departamento de Pediatría e Infectología, Escuela de Ciencias de la Salud, Universidad Autónoma de Baja California, Ensenada, Baja California.
Jorge
J
Field-Cortazares
Instituto de Investigaciones en Ciencias Veterinarias, Universidad Autónoma de Baja California.
Angélica María
AM
Escárcega-Ávila
Instituto de Investigaciones en Ciencias Veterinarias, Universidad Autónoma de Baja California.
Gilberto
G
López-Valencia
Instituto de Investigaciones en Ciencias Veterinarias, Universidad Autónoma de Baja California.
Alberto
A
Barreras-Serrano
Instituto de Investigaciones en Ciencias Veterinarias, Universidad Autónoma de Baja California.
Luis
L
Tinoco-Gracia
D000818:Animals; D003430:Cross-Sectional Studies; D004283:Dog Diseases / Q000175:diagnosis* / Q000382:microbiology; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D008800:Mexico / Q000453:epidemiology; D025202:Molecular Diagnostic Techniques; D015203:Reproducibility of Results; D012284:Rickettsia rickettsii / Q000302:isolation & purification*; D012307:Risk Factors; D012373:Rocky Mountain Spotted Fever / Q000175:diagnosis / Q000453:epidemiology*; D012680:Sensitivity and Specificity; D016036:Seroepidemiologic Studies; D017282:Tick-Borne Diseases / Q000175:diagnosis* / Q000382:microbiology; D013987:Ticks / Q000382:microbiology