Trachoma-causing bacteria could be transmitted through everyday surfaces

Chlamydia bacteria. Photograph: Aalbertus Versteeg

Chlamydia Trachomatis (Ct), the bacterium that causes trachoma, can survive on surfaces such as plastic, skin and cloth long enough to be transmitted, a first-of-its-kind study from ICEH has found.

Trachoma is the leading infectious cause of blindness worldwide. The disease, which is caused by repeated infection with Ct, affects around seven million people a year, primarily in low-income countries. The condition can be very painful before eventually leading to blindness.

Trachoma elimination efforts are hampered by a lack of understanding about the transmission of Ct between people. Previous studies have shown that Ct DNA can be found on surfaces within households of infected individuals. Although this DNA showed the presence of the bacterium, it did not however assess whether the bacteria were alive and viable to infect others.

This study, published in PLOS Neglected Tropical Diseases, used a new technique, known as ‘viability PCR’, to detect whether bacteria placed on common surfaces in a laboratory were alive at later time intervals. The materials tested were plastic, woven mat, cotton cloth and pig skin (chosen for its biological similarity to human skin).

After assessing the levels of viable bacteria at certain time points, the study found that viable Ct DNA remained detectable up to 24 hours on plastic, pig skin and cotton cloth.

For the first time within trachoma control, these results suggest that these surfaces may contribute to the transmission of the Ct strains that cause trachoma, by acting as reservoirs of bacteria that are later transferred into uninfected people.

Although so far only seen in laboratory conditions, these results provide good evidence for future efforts to combat the development of trachoma and improve eye health for endemic communities.

Publication

Versteeg B, Vasileva H, Houghton J, et al. Viability PCR shows that non-ocular surfaces could contribute to transmission of Chlamydia trachomatis infection in trachoma. PLoS Negl Trop Dis. 2020;14(7)

Contact

If you have any questions about this publication or for further details please get in touch at iceh@lshtm.ac.uk

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