Some time ago, we wrote about the devastating effects of the spread of chlamydia among the vulnerable koala bears of Australia. Since then, Australian scientists have been getting closer to the development of a vaccination for these beautiful marsupials against, what is for them, an extremely dangerous disease, sometimes rendering those infected, blind. Based on the results of a small but successful trial in Brisbane, things might be looking up for the koala bear and maybe even humans alike.

Chlamydia is still one of the most common sexually transmitted infections around today yet rates are generally consistent year after year. Apart from spreading awareness and launching STI health campaigns, there is little else we can do without a vaccine. Part of the problem is that in over 80% of cases, the infection is asymptomatic, and those who carry it spread the infection without even knowing. In koalas, the untreated infection can lead to blindness and infertility. Chlamydia also causes infertility in humans if left untreated. Other complications include pelvic inflammatory disease (PID), which causes infertility, ectopic pregnancy and miscarriage.

In this promising study, 30 out of 60 koalas were vaccinated and the trial group was then observed in its natural surroundings via radio collars thereafter. It was discovered that 7/8 koalas who were suffering from an eye infection at the time of vaccination, showed improvements. In stark contrast, of the koalas who were not vaccinated, 4/6 who were suffering from eye infections, only got worse. Symptoms of the infection in koalas manifest themselves in eye infections but also as infections of the reproductive tract.

Those who were infected with the strain of chlamydia, and who were simultaneously vaccinated, did not go on to experience the full-blown infection. This is a really positive outcome considering the loss of life among this species due, not only to the spread of the chlamydia infection which, in some areas, infection rates are up at 90%, but also down to habitat loss.

Koalas and humans both respond well to antibiotic treatment but in the case of koalas, it is not feasible to treat every koala infected and maintain control over the spread. The vaccine could act as a model for a human vaccine though, a development that has been researched for decades now, but so far, to no avail. If we could use the koala vaccine as a model for the human vaccine, we could prevent the infection across a large portion of the population. The result of this study is good news for the koalas, but it inspires hope for us too.

In the meantime, partner notification, diagnoses, and successful treatments (re-testing), are the key to beating chlamydia and stymieing the spread. Telling partners will directly affect rates of diagnosis, rates that must be consistently maintained in order to gain better control over the spread of infection.  You can find your local testing clinic here. If your are reluctant to attend a clinic then there are online options such as this website.

You can read more about Chlamydia and blindness here.