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Fungal eye infections leave over half a million people blinded each year

October 21 2020

Between 1 and 1.4 million fungal eye infections occur in the developing world per year, leaving over 600,000 blind say researchers from Manchester, London and Nairobi.

Lead researcher Lottie Brown from the University of Manchester today published the first estimation of global fungal keratitis figures in Lancet Infectious Diseases, showing high rates in a number of African countries as well as Nepal, Pakistan and India. Lower rates were identified in Europe.

Infection of the transparent cornea of the eye can be devastating, especially if it is caused by a fungus. Most cases are diagnosed too late to save vision, and overall about 100,000 eyes have to be removed as a result. In contrast early diagnosis usually saves both vision and the eye, although a high level of expertise, antifungal therapy and often surgery is required.

“Fungal keratitis is so neglected among neglected tropical diseases, even the WHO and G-Finder don’t list it. Poor agricultural workers are most affected, yet high quality care can takes days to access in most high incidence areas.” - Professor David Denning

The authors examined all 241 papers published listing the causes of microbial keratitis to derive country and regional estimates of annual incidence. In Kenya, Dr Michael Gichangi from the Ministry of Health had collected cases from each district over several years, enabling an estimate for Africa. The authors also checked for the ratio between fungal and bacterial keratitis which varied from 1% in Spain to 60% in Vietnam, typically ~45% in tropical and subtropical areas.

 

Continent

Estimated annual incidence*

Annual incidence per 100,000 population

Africa

75,200

13.5

Asia

940,000

33.9

Europe

100

0.02

North America

15,700

6.8

Latin America and Caribbean

19,200

5

Oceania

1,770

14.5

World

1,052,000

23.6

* rates are ~40% higher if culture and microscopy negative cases are assumed to be fungal

“Among all the major causes of eye infection in adults, fungal keratitis is too often devastating. My own experiences in Tanzania, Uganda, Nepal and India taught me what a challenge this problem can be – but enabled my team to develop pathways for major improvements in care.” - Professor Matthew Burton (ICEH, LSHTM)