title: Detection of Salivary IgA Antibodies Against the HlyE Antigen as a Diagnosis of Typhoid Fever.
abstract: BACKGROUND
  The Salmonella typhi (S. typhi) haemolysin E protein (HlyE) has been shown to be a sensitive and specific antigen for the detection of typhoid fever through the detection of anti-HlyE antibodies in sera. Saliva can also be a useful diagnostic fluid as it also contains antibodies against bacterial pathogens.
  
  
  OBJECTIVE
  This study aims to evaluate the potential detection of salivary anti-HlyE antibodies as a diagnosis of typhoid fever.
  
  
  METHODS
  Saliva was collected from acute typhoid patients (n=16) who presented at Hospital Universiti Sains Malaysia with prolonged fever of more than five days and were positive for S. Typhi blood culture. Saliva was also collected from convalescent typhoid patients (n=11), patients with other febrile fevers (n=15), and from healthy individuals (n=25). An ELISA was developed to detect the presence of IgA antibodies against HlyE in the saliva of typhoid patients.
  
  
  RESULTS
  The acute typhoid group had a higher mean absorbance value of 1.496 compared to the convalescent typhoid (0.538), other febrile fevers (0.678), and healthy individuals (0.457) group.
  
  
  CONCLUSIONS
  This study demonstrated the utility of salivary anti-HlyE IgA antibody as a biomarker for the diagnosis of typhoid fever. Follow-up studies with a larger sample size will allow the optimization of the sensitivity and specificity of the assay. This non-invasive method can be useful for mass screening programs.
authors: PhD Student, Institute for Research in Molecular Medicine, Universiti Sains , Malaysia, 11800 Pulau Pinang, Malaysia .
authors: Kai Ling
authors: KL
authors: Chin
authors: PhD Student, School of Veterinary Medicine, Universiti Malaysia Kelantan , Kota Bharu, Kelantan, Malaysia .
authors: Nur Eliyana Mohd
authors: NE
authors: Redhuan
authors: Former Professor, Institute for Research in Molecular Medicine, Universiti Sains , Malaysia, 11800 Pulau Pinang, Malaysia .
authors: Prabha
authors: P
authors: Balaram
authors: Professor, Institute for Research in Molecular Medicine, Universiti Sains , Malaysia, 11800 Pulau Pinang, Malaysia .
authors: Kia Kien
authors: KK
authors: Phua
authors: Lecturer, Institute for Research in Molecular Medicine, Universiti Sains , Malaysia, 11800 Pulau Pinang, Malaysia .
authors: Eugene Boon Beng
authors: EB
authors: Ong
keywords: ELISA; Saliva; Salmonella