An STI caused by the bacteria Ureaplasma urealyticum

Illustration of polymorphic bacterial cells representing the STI Ureaplasma urealyticum infection

Another emerging disease that is even more poorly understood than Mycoplasma genitalium

What is Ureaplasma Urealyticum Infection?

Similar to Mycoplasma genitalium, a Ureaplasma urealyticum infection (UUI) is a bacterial STI that we don’t know enough about. What we do know is that it can be transmitted during intercourse or from mother to infant during childbirth, is often asymptomatic, and is difficult to diagnose [1]. 

How common is it?

Ureaplasma urealyticum is a pretty common bacteria, but the resulting infection is difficult to diagnose and a large percentage of cases are asymptomatic. As a result, we don’t really know how many people have a UUI.

What causes UUI and who is at risk?

UUI is caused by a complex yet commonly found bacteria called Ureaplasma urealyticum. It falls into the same category as Mycoplasma and is likewise characterized by a lack of cell walls which makes it notoriously difficult to diagnose and treat [2]. 

We don’t know why the bacteria becomes infectious, but we do know that sexually active men and women as well as pregnant women are at a higher risk of infection since the bacteria can be transferred during childbirth or intercourse [1]. Just like with other STIs, having unprotected sex, or having sex with new or multiple partners puts you at a higher risk of infection. Ureaplasma urealyticum is often found in cases of pelvic inflammatory disease (PID), urinary tract infections and neonatal infections [3].

What are the symptoms?

Symptomatic cases can result in vaginal bleeding as well as vaginal pain while urinating or during intercourse [4]. Even though most cases of UUI seem to not cause any symptoms at all, the potential complications of an untreated infection range from moderate to severe.

How is it diagnosed?

It is possible to diagnose a UUI using a culture test, but other methods like a PCR are more common. It can also be detected through Next Generation Sequencing (NGS). 

What are the treatment options?

Common antibiotics like penicillin which work by attacking the cell walls of a bacteria are not effective against Ureaplasma urealyticum since it doesn’t have any walls to attack [1]. As a result, only a small handful of antibiotics like Azithromycin can be used to treat a UUI. It is important to note that Azithromycin is also one of the most commonly used antibiotics. As a result of its widespread use, Azithromycin resistance seems to be on the rise. Therefore, it is important to consult your doctor before re-starting any treatment course [1].

Can UUI lead to other complications?

A UUI can lead to frequent UTIs and potentially pelvic inflammatory disease (PID). Research also suggests that UUIs are correlated with male infertility [4].

For pregnant women, UUI is linked to some dangerous pregnancy-related outcomes including stillbirths and chorioamnionitis, an inflammation of fetal membranes which can lead to preterm birth [1]. The infection can also be transferred to the newborn, potentially causing birth abnormalities. 

What can be done to prevent Ureaplasma Urealyticum Infection?

To reduce your chances of exposure to STIs including UUI, practice safe sex by always discussing sexual health with your partner, using barrier protection correctly (such as a condom or dental dam), and getting tested regularly. To protect yourself against infections, avoid disrupting the balance of protective bacteria in the vaginal microbiome by limiting the use of douches as well as the use of scented soaps, tampons or pads.

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1. Long S, Pickering L, Prober C.Principles and practice of pediatric infectious diseases. Edinburgh:Elsevier/Saunders; 2012.

2. Stillbirth - Causes [Internet].nhs.uk. 2020 [cited 17 September 2020]. Available from:https://www.nhs.uk/conditions/stillbirth/causes/

3. Vaginal bleeding Causes [Internet].Mayo Clinic. 2020 [cited 17 September 2020]. Available from:https://www.mayoclinic.org/symptoms/vaginal-bleeding/basics/causes/sym-20050756

4. OchsendorfF. Sexually transmitted infections: impact on male fertility. Andrologia.2008;40(2):72-75.

Written by Aisha Ommaya, science comms officer with Juno Bio

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