%0 Journal Article %A Robert M R Butcher %A Oliver Sokana %A Kelvin Jack %A Eric Kalae %A Leslie Sui %A Charles Russell %A Joanna Houghton %A Christine Palmer %A Martin J Holland %A Richard T Le Mesurier %A Anthony W Solomon %A David C W Mabey %A Chrissy h. Roberts %T Active trachoma cases in the Solomon Islands have varied polymicrobial community structures but do not associate with individual non-chlamydial pathogens of the eye %D 2017 %R 10.1101/134213 %J bioRxiv %P 134213 %X Background Several non-chlamydial microbial pathogens are associated with clinical signs of active trachoma in trachoma endemic communities with a low prevalence of ocular Chlamydia trachomatis (Ct) infection. We observed a low prevalence of Ct in the Solomon Islands, therefore hypothesised that the high prevalence of active trachoma could be explained by a common non-chlamydial infection or by a dominant polymicrobial community dysbiosis.Methods We studied DNA from conjunctival swabs collected from 257 Solomon Islanders with active trachoma and 257 matched controls. Droplet digital PCR was used to test for Adenoviridae, Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus, coagulase-negative Staphylococcus and Streptococcus pneumoniae. Polymicrobial community diversity and composition were studied by sequencing of hypervariable regions of the 16S ribosomal ribonucleic acid gene in a subset of 54 cases and 53 controls.Results Although Ct was associated with active trachoma, the number of infections was low (cases: 3.9%, controls: 0.4%). Estimated prevalence (cases, controls) of each nonchlamydial infection was as follows: S. aureus (1.9%, 1.9%), Adenoviridae (1.2%, 1.2%), coagulase-negative Staphylococcus (5.8%, 4.3%), H. influenzae (7.4%, 11.7%), M. catarrhalis (2.3%, 4.7%) and S. pneumoniae (7.0%, 6.2%). There was no statistically significant association between clinical signs of trachoma and presence or load of any of the non-Ct infections that were assayed. Inter-individual variations in the conjunctival microbiome were characterised by differences in the levels of Corynebacterium, Proprionibacterium, Helicobacter and Paracoccus, but diversity and relative abundance of these specific genera did not differ between cases and controls.Discussion It is unlikely that the prevalent trachoma-like follicular conjunctivitis in the Solomon Islands has a dominant bacterial aetiology. Before implementing community-wide azithromycin distribution for trachoma, policy makers should consider that clinical signs of trachoma can occur without the involvement of any azithromycin-susceptible organism. %U https://www.biorxiv.org/content/biorxiv/early/2017/05/11/134213.full.pdf