A Metagenomic Deep Sequencing Analysis of Infectious Conjunctivitis in Burkina Faso, Africa.

Abstract

Purpose : Burkina Faso, in West Africa, is one of many countries that experience frequent seasonal outbreaks of presumed infectious conjunctivitis of unknown etiology. This study leverages the hypothesis free diagnostic tool of metagenomic deep sequencing (MDS) to determine the local causes of infectious conjunctivitis

Methods : Inclusion criteria required acute conjunctivitis symptoms for less than 14 days. Sterile polyester applicators (Puritan) were used to swab the lower conjunctival fornix of each eye. All swabs were immediately placed in DNA/RNA-Shield (Zymo Research). Details of sequencing, library preparation, and bioinformatics analyses have been previously described.

Results : Samples were obtained from 19 participants. 47% were female. The average age was 9 years. Both eyes were affected in 15/19 cases (79%). The predominant ocular presenting symptom was purulent discharge, present in 17/19 (89%) cases. MDS identified a virus as the causative pathogen 53% (10/19) of cases. Bacterial pathogens were identified in 16% (3/19) of cases. A mixed bacterial and viral infection was noted in 2/19 (11%). Of the 10 viral etiologies identified, an adenoviral species was identified in 2 cases. This represents 20% of all viral pathogens and 11% of all cases. Other viruses identified as pathogenic include rhinovirus, influenza A and herpes viridae including herpes simplex virus (HSV), varicella zoster virus (VZV), Epstein Barr virus (EBV) and cytomegalovirus (CMV). The five bacteria identified as causative etiologies were Streptococcus pneumonia, Corynebacterium mastiditis, Moraxella catarrhalais, Neisseria meningititis, and Hemophilus influenza

Conclusions : Causative pathogens of patients presenting with acute, mostly purulent, clinically presumed infectious conjunctivitis in Burkina Faso are surprising. Adenoviridae were isolated in only two cases (11%). Bacterial pathogens only were identified in three cases. This study suggests that clinicians’ clinical suspicions of causative etiologies for infectious conjunctivitis may not be accurate. Similarly, classic teaching for what clinical findings predict which pathogen (viral vs bacterial) may need to be critically re-evaluated. Local surveillance with pathogen identification of seasonal and epidemic conjunctivitis outbreaks is necessary to determine definitive etiologies determine appropriate treatment strategies and inform region-specific public health initiatives.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.