# Impact of ocular microbiome, immune response and Chlamydiae on trachoma following MDA

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA, SAN FRANCISCO · 2023 · $798,995

## Abstract

PROJECT SUMMARY
Chlamydia trachomatis (Ct) is the leading cause of infectious blindness in the world today. The World Health
Organization (WHO) estimates that there are over 142 million people at risk of irreversible loss of sight. This
figure likely underestimates the true numbers as it is difficult to account for all communities that are affected
globally. The ocular disease caused by Ct is called trachoma and carries an annual price tag of approximately
$8 billion from lost productivity. The highest concentrations of this neglected disease include 37 countries in
Africa, the Middle East, Asia, and Central and South America along with Australia. Africa has over 89% of the
world’s known trachoma cases, reflecting a major region of health disparity. The WHO developed the SAFE
strategy to eliminate trachoma as a public health problem by the year 2020. SAFE stands for: Surgery to correct
in-turned eyelashes (known as Trachomatous Trichiasis or TT); Antibiotics to treat Ct; Facial cleanliness to
improve hygiene, and Environmental improvements to reduce transmission. The A part of SAFE includes Mass
Drug Administration (MDA) with azithromycin and has been used in many countries. Ten endemic or
hypoendemic countries have been validated by WHO as being trachoma free. However, 6 endemic and 38
hyperendemic countries have not, although they have received 5 to over 10 rounds of MDA. The highest burden
of disease is in Ethiopia and South Sudan where ~30-50% of children under 10 years of age have active
trachoma, and the reasons for this remain unclear. Trachoma as a public health concern will not be eliminated
until we understand why there is ongoing active trachoma following multiple rounds of MDA in hyperendemic
countries. Our unifying hypothesis, therefore, is that the natural history of trachoma is defined by the interaction
of the ocular microbiome, immune responses and pathogen populations (both Ct and non-Ct) that are influenced
by MDA. While there is a growing body of research on the ocular microbiome, few studies have evaluated
differences in microbiota composition between healthy and trachomatous eyes and none have looked at the
influence of Ct infection. We will employ metagenome shotgun sequencing (MSS) to understand healthy,
dysbiotic and chlamydial-associated microbiota in addition to immune responses and pathogen genomic
characteristics for a cohort residing in the trachoma hyperendemic Amhara Region of Ethiopia. We aim to: 1)
Examine Ct infections based on whole genome sequencing; 2) Identify taxonomic diversity and abundance of
ocular microbiota among subjects with and without Chlamydia and their association with trachomatous disease;
and 3) Determine host microbiota/immune response profiles associated with and without Chlamydia, and
develop models to predict trachoma post MDA. This work will naturally transition to improving chlamydial
diagnostics that utilize MSS methods, and developing interventions that, given the ineffective antibioti...

## Key facts

- **NIH application ID:** 10646357
- **Project number:** 5R01AI158527-02
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
- **Principal Investigator:** DEBORAH Anne DEAN
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2023
- **Award amount:** $798,995
- **Award type:** 5
- **Project period:** 2022-07-01 → 2027-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10646357

## Citation

> US National Institutes of Health, RePORTER application 10646357, Impact of ocular microbiome, immune response and Chlamydiae on trachoma following MDA (5R01AI158527-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10646357. Licensed CC0.

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