Abnormal Pap Smear: Is this STD-related? A Doctor Explains.

In this article, we’ll be exploring the implications of abnormal pap smear results and whether they warrant an STD test. Does an abnormal pap smear indicate the presence of an STD? Let’s find out.

Pap Smear Results

Pap smear is a simple and safe bedside procedure performed by your doctor for cervical cancer screening. The idea of the procedure is to use a small sterile brush to obtain cervical cells and incorporate them into a liquid medium which will then be sent to the laboratory for microscopy examination. This is to screen for any abnormal cells on the cervix.

Pap smear test reports tend to be jargon to most laymen unless your doctor explains them to you in detail. We attempt to simplify and facilitate your understanding of your pap smear test results here:

Normal or negative pap smear results for intraepithelial lesion or malignancy

The cervical cells obtained from the brush appear normal, and do not show pre-cancerous or cancerous findings.

Abnormal pap smear results

1. ASCUS (atypical squamous cells of undetermined significance)

The cervical cells on your pap smear are unusual but are not abnormal. This can be a mild change secondary to infection or hormonal changes. Your doctor will usually want you to follow up on the test or consider treating for any infection (if applicable).

2. LSIL (low grade squamous intraepithelial lesion)

The cervical cells obtained from the pap smear show low level or mild changes of cervical cells due to underlying HPV infection. Colposcopy is advised to investigate further and evaluate the extent of abnormalities of cervical cells.

3. CIN (cervical intraepithelial neoplasia)

The cervical cells obtained on your pap smear show pre-cancerous changes of the cervix. This is usually a finding secondary to underlying HPV infection and your doctor will advise you to evaluate further with colposcopy. You may require medical treatment to treat the condition and halt further progression of the HPV infection.

4. Cancer/ carcinoma

The cervical cells from the pap smear show cancer or severe pre-cancerous cells. You will be required to seek medical treatment from a gynaecologist without further delay.

Colposcopy — a detailed cervix examination

Colposcopy is a medical procedure to examine the cervix in detail. The cervix is examined under a colposcope which is a microscope used to magnify the cervix and identify pre-cancerous or cancerous changes. 

Acetic acid (vinegar) is applied to the cervix to highlight the HPV-affected area on the cervix to aid colposcopy examination. The cervical cells area that are of concern can be biopsied to obtain tissue samples for further confirmation of whether there are potential cancer/pre-cancerous cells. 

The procedure is usually done by the gynaecologist. It is painless, though light bleeding (similar to the start of a period), and some people may experience menstrual cramps after the procedure.

Abnormal Pap Smear and HPV infection

Human papillomavirus (HPV) remains the predominant reason a person develops cervical cancer. HPV contributes to 99.7% of cervical cancers worldwide. While most HPV infections are temporary and most people are able to abort the infection spontaneously by their own general immune system. Unfortunately, some may have a persistent HPV infection over the cervix. Over time, the cells over the cervix can transform into abnormal cells and tissues and eventually turn into invasive cancer cells.

To prevent cervical cancer, it is imperative to pick up early and manage abnormal findings found on pap smear screening. HPV vaccination is usually encouraged in age-eligible patients if this has yet to be done at the time of abnormal pap smear results.

To mitigate the risk of persistent HPV infection and subsequent risk of cervical cancer, concurrent infective vaginal or cervical infections that can promote persistent HPV infection should be screened and treated if required.

Abnormal pap smear result, HPV infection and their relationships with STDs

Co-infection of bacterial STDs is associated with higher incidence of abnormal pap smear results. Untreated bacterial STDs infections can disrupt the vaginal and cervical innate barrier/ protective lining, leading to susceptibility to HPV infections.

• Chlamydia trachomatis has been shown to be associated with high risk HPV infections, abnormal pap smear results involving cervical cell abnormalities and invasive cervical cancer.

• Herpes simplex virus infection increases the risk of persistent HPV infection and invasive cervical cancer.

• Untreated bacterial STDs such as trichomonas vaginalis, mycoplasma spp and ureaplasma spp are commonly associated with HPV infections and abnormal pap smear readings.

• Genital warts are commonly seen in the presence of abnormal pap smear test results.

A pap smear test is different from STD test

During pap smear procedure, the cervical cells (from the neck of the womb-cervix) are obtained to evaluate for precancerous or cancer cells. The confusion here is when an STD test involves vaginal testing. STD tests that involve vaginal swab are obtaining the cells and tissues from the vagina (which is the external mucosal tunnel that connects the outside world to the cervix/uterus). 

To evaluate vaginal infection from STD infections, the cells/tissues will be ‘cultured’ or processed through PCR testing. Pap smear sample, on the other hand, is reviewed under microscopy by the laboratory pathologist. It does not tell you specifically of any bacterial infection. 

Hence, a normal pap smear test does not rule out STD infection. An abnormal pap smear test that suggests HPV infection suggests increased correlation with other bacterial STDs, hence suggesting further screening and evaluation.

What are the abnormal symptoms that I should be looking for- in the case of abnormal pap smear results, HPV infection or STDs?

Unfortunately, most of the time, patients with abnormal pap smear results do not exhibit abnormal symptoms until late stages of invasive cervical cancer. Hence, pap smear should be offered routinely as part of cervical cancer screening.

Similarly, one can be well without symptoms or minimal discomfort when having STD infection. Overt STD infection symptoms include lower pelvic pain, abnormal discharge, vaginal itching, painful urination, bleeding between period and after sexual contact. 

If you are sexually active/ sexually active before, you should:

• Do a regular routine pap smear test.
• Consider STD testing if there is concern of exposure of infection.

What can I do if I have an abnormal pap smear test result? Do I need to do a STD test as well?

If you have an abnormal pap smear test result, it is important to discuss with your doctor on your results, and get your doctor to advise on follow up plans.

• Some abnormal (benign) pap smear test results may not require treatment or require a simple 6 months follow up.
• Some abnormal tests may require colposcopy to evaluate further.
• If you are within the age eligibility (9-45 years old) and has yet to do your HPV vaccination, you should get your immunization vaccine as soon as you can.

With an abnormal pap smear test results, it is worth to consider STD testing:

• If you are sexually active and/or have never been screened before for STD.
• If you are experiencing abnormal vaginal or urinary symptoms such as changes in vaginal color/volume/consistencies/ associated symptoms itch, odor, painful urination, lower pelvic pain, fever etc.
• If you have abnormal pap smear test results and visible genital warts seen.

Why is it important for me to treat any co-infection STD if I have an abnormal pap smear?

There are associations of untreated co-infected bacterial STDs and high risk of cervical abnormal cells/invasive cervical cancers.

Furthermore, bacterial STDs are treatable with the right antibiotics, right dose and duration. With eradication of the bacterial co-infection STDs, one can mitigate and lower the risk of persistent HPV infection and reduce the risk of cervical invasive cancers.

Take home messages

• Pap smear abnormalities such as precancerous or invasive cervical cancer are invariably related to HPV infection.
  
• There is a correlation of abnormal pap smear test/HPV persistent infection with simultaneous STD infections.
  
• Both cervical abnormalities and STDs can present with no symptoms or subtle symptoms that we are unaware of.
  
• Early screening of cervical cancer with pap smear can halt progression of cervical cancer and can be curative.
  
• Bacterial STD infections are mostly treatable with appropriate medical treatment.
  
• STD tests should be considered if there is abnormal pap smear and possible exposure risk involved.

References:

1. Fazlollahpour-Naghibi A. et al. Trichomonas vaginalis infection and risk of cervical neoplasia: A Systemic review and meta-analysis. PLoS One. 2023 Jul 12;18(7):e0288443.
2. Madaan N, Pandhi D, Sharma V, Bhattacharya SN, Guleria K, Mishra K, Bharadwaj M. Association of abnormal cervical cytology with coinfection of human papillomavirus and Chlamydia trachomatis. Indian J Sex Transm Dis AIDS. 2019 Jan-Jun;40(1):57-63.
3. Kim SI, Yoon JH, Park DC, Lee DS, Lee SJ, Choe HS, Kim JH, Park TC, Lee SJ. Co-infection Of Ureaplasma urealyticum And Human Papilloma Virus In Asymptomatic Sexually Active Individuals. Int J Med Sci. 2018 Jun 12;15(9):915-920.
4. Kim HS, Kim TJ, Lee IH, Hong SR. Associations between sexually transmitted infections, high-risk human papillomavirus infection, and abnormal cervical Pap smear results in OB/GYN outpatients. J Gynecol Oncol. 2016 Sep;27(5):e49. 
5. Biernat-Sudolska, M., Szostek, S., Rojek-Zakrzewska, D., Klimek, M., & Kosz-Vnenchak, M. (2011). Concomitant infections with human papillomavirus and various mycoplasma and ureaplasma species in women with abnormal cervical cytology. Advances in medical sciences, 56 2, 299-303 .
6. Verteramo R, Pierangeli A, Mancini E, Calzolari E, Bucci M, Osborn J, Nicosia R, Chiarini F, Antonelli G, Degener AM. Human Papillomaviruses and genital co-infections in gynaecological outpatients. BMC Infect Dis. 2009 Feb 12;9:16.