Date of Award


Document Type


Degree Name

Master of Medicine (MMed)

First Supervisor/Advisor

Dr. Samuel Nguku

Second Supervisor/Advisor

Proff. Rodney Adam

Third Supervisor/Advisor

Dr. Edward Nganga


Imaging and Diagnostic Radiology (East Africa)


Background: Community-acquired pneumonia (CAP) is a major cause of significant morbidity and mortality globally. The spectrum of causative organisms of CAP varies markedly with region as well as with the immune status of the patient. Chest radiography remains an important initial imaging modality in the diagnostic work-up of patients with CAP. Although previous studies have highlighted major trends and radiographic patterns of various causative organisms of CAP, there is a paucity of recent literature within Sub-Saharan Africa on these various radiographic patterns.

Objective: The primary objective of this study was to identify the association between the radiographic patterns of different etiologies of community-acquired pneumonia in patients admitted to the Aga Khan University Hospital, Nairobi (AKUHN).

Methods: Patients admitted to AKUHN with community-acquired pneumonia between May 2019 and March 2020 were recruited. A total of seventy-seven adults were enrolled in the study. The chest radiographs were reviewed retrospectively by two independent radiologists and the microbiology results were obtained to establish the etiology of pneumonia.

Results: A total of 71 out of the 77 chest radiographs had an infiltrate identified of which consolidation and ground glass infiltrates were most commonly identified. There was a significant association between the consolidation pattern of infiltrates and bacterial pneumonia (p < .05) and ground glass opacities and viral pneumonia (p < .05). The overall sensitivity of chest radiography in identifying an abnormality in patients with CAP is high at 93.5%, however, the sensitivity of consolidation for bacterial pneumonia was only 68.2% and the sensitivity for ground glass opacities for viral pneumonia was only 54.8%.

Conclusion: Our study found an association between consolidation and ground glass pattern of infiltrates with bacterial and viral etiologic agents respectively. However, the diagnostic capability of chest radiography in predicting the etiologic agent was limited due to the significant overlap of the patterns of infiltrates as well as the presence of more than one infiltrate. It should therefore not be used in isolation for this purpose. Rather, it should be combined with clinical presentation and microbiologic testing to determine the most likely etiology.

Included in

Radiology Commons