Febrile patients admitted to remote hospitals in Northeastern Kenya: seroprevalence, risk factors and a clinical prediction tool for Q-Fever.
Q fever in Kenya is poorly reported and its surveillance is highly neglected. Standard empiric treatment for febrile patients admitted to hospitals is antimalarials or penicillin-based antibiotics, which have no activity against Coxiella burnetii. This study aimed to assess the seroprevalence and the predisposing risk factors for Q fever infection in febrile patients from a pastoralist population, and derive a model for clinical prediction of febrile patients with acute Q fever.



Epidemiological and clinical data were obtained from 1067 patients from Northeastern Kenya and their sera tested for IgG antibodies against Coxiella burnetii antigens by enzyme-linked-immunosorbent assay (ELISA), indirect immunofluorescence assay (IFA) and quantitative real-time PCR (qPCR). Logit models were built for risk factor analysis, and diagnostic prediction score generated and validated in two separate cohorts of patients.



Overall 204 (19.1 %, 95 % CI: 16.8-21.6) sera were positive for IgG antibodies against phase I and/or phase II antigens or Coxiella burnetii IS1111 by qPCR. Acute Q fever was established in 173 (16.2 %, 95 % CI: 14.1-18.7) patients. Q fever was not suspected by the treating clinicians in any of those patients, instead working diagnosis was fever of unknown origin or common tropical fevers. Exposure to cattle (adjusted odds ratio [aOR]: 2.09, 95 % CI: 1.73-5.98), goats (aOR: 3.74, 95 % CI: 2.52-9.40), and animal slaughter (aOR: 1.78, 95 % CI: 1.09-2.91) were significant risk factors. Consumption of unpasteurized cattle milk (aOR: 2.49, 95 % CI: 1.48-4.21) and locally fermented milk products (aOR: 1.66, 95 % CI: 1.19-4.37) were dietary factors associated with seropositivity. Based on regression coefficients, we calculated a diagnostic score with a sensitivity 93.1 % and specificity 76.1 % at cut off value of 2.90: fever >14 days (+3.6), abdominal pain (+0.8), respiratory tract infection (+1.0) and diarrhoea (-1.1).



Q fever is common in febrile Kenyan patients but underappreciated as a cause of community-acquired febrile illness. The utility of Q fever score and screening patients for the risky social-economic and dietary practices can provide a valuable tool to clinicians in identifying patients to strongly consider for detailed Q fever investigation and follow up on admission, and making therapeutic decisions.
Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, 07743, Jena, Germany. John.Njeru@fli.bund.de.|Center for Infectious Diseases and Infection Control, Jena University Hospital, 07740, Jena, Germany. John.Njeru@fli.bund.de.|Centre for Microbiology Research (CMR), Kenya Medical Research Institute, P. O. Box 19464-00202, Nairobi, Kenya. John.Njeru@fli.bund.de.
J
J
Njeru
Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, 07743, Jena, Germany.
K
K
Henning
Center for Infectious Diseases and Infection Control, Jena University Hospital, 07740, Jena, Germany.
M W
MW
Pletz
Institute for Molecular Cell Biology, Center for Molecular Biomedicine, Friedrich Schiller University of Jena, 07745, Jena, Germany.
R
R
Heller
Center for Infectious Diseases and Infection Control, Jena University Hospital, 07740, Jena, Germany.|Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, 1090, Vienna, Austria.
C
C
Forstner
Centre for Microbiology Research (CMR), Kenya Medical Research Institute, P. O. Box 19464-00202, Nairobi, Kenya.
S
S
Kariuki
Institute of Infection and Global Health, University of Liverpool, Liverpool, UK.|International Livestock Research Institute (ILRI), Road, P.O. Box 30709-00100, Nairobi, Kenya.
E M
EM
Fèvre
Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, 07743, Jena, Germany.
H
H
Neubauer
D000293:Adolescent; D000328:Adult; D000818:Animals; D000942:Antigens, Bacterial / Q000097:blood; D002648:Child; D002675:Child, Preschool; D016997:Coxiella burnetii / Q000145:classification / Q000276:immunology / Q000302:isolation & purification*; D004269:DNA, Bacterial / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D000067565:Farmers / Q000706:statistics & numerical data; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007630:Kenya / Q000453:epidemiology; D058751:Livestock; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011778:Q Fever / Q000097:blood / Q000453:epidemiology* / Q000209:etiology; D060888:Real-Time Polymerase Chain Reaction; D012307:Risk Factors; D012680:Sensitivity and Specificity; D016036:Seroepidemiologic Studies
D000942:Antigens, Bacterial; D004269:DNA, Bacterial
Coxiella burnetii; Epidemiology; Kenya; Q fever; Seroprevalence