Assessment of Lymphocytosis in Patients with Pertussis in the Amhara Regional State, Ethiopia
Abstract Background: Pertussis is a severe and prolonged coughing disease caused by Bordetella pertussis. In 2014, an estimated 24.1 million pertussis cases, resulting in 160,700 deaths were reported worldwide. The aim of this study was to assess lymphocytosis in patients with pertussis in the Amhara Regional State, Ethiopia.Methods: An institution-based cross-sectional study was conducted among pertussis patients who met the clinical case definition for pertussis in the Amhara Regional State, Ethiopia. The study was conducted from July 2018 to February 2019 and nasopharyngeal swabs were collected from 321 participants, and samples were analyzed using real-time PCR. Blood specimens were collected from 321 study participant and total lymphocyte count was conducted using fully automated haematology analyzer.Results: One hundred nine study participants were positive for Bordetella species. Lymphocytosis was found in 15/109 (13.8%) of the PCR confirmed pertussis patients. Of those 15 PCR confirmed participants, 53.3% had lymphocytosis grading ‘high’ (>51%) followed by 20% ‘moderately high’ (>70%) and 26.7% had ‘very high’ (>85%). Amongst participants with lymphocytosis and PCR confirmed pertussis, 11/15 (73.3%) were less than 1 year old.Conclusions: This study revealed the importance of lymphocyte count in the diagnosis of pertussis. Thus, in combination with other laboratory tests, incorporation of lymphocyte count in pertussis suspected patients is recommended.