Syphilis treatment options: after exposure vs. after a positive test

Introduction

Syphilis is a highly contagious bacterial infection. There are more than 10.6 cases of it worldwide every year.¹

Though syphilis is potentially life-threatening, it is easily treated if diagnosed early. That’s why it’s essential to visit the STD clinic as soon as you realize you might have been exposed to this infection.

In this article, we summarize facts about syphilis that you might like to know.

You will learn how syphilis is distributed among males who have sex with men, heterosexual males, males who don’t specify their partner’s gender, and women.

And we’ll also tell you:

• How likely you are to get syphilis from one sexual act if you are heterosexual or homosexual
• When syphilis is contagious
• How urgent and effective treatment is
• When you can have sex again

And finally, we’ll describe the treatments available right after sex (before you’ve been tested) and after a positive test.

Syphilis’s prevalence

In the United States

In 2018, over 115,000 syphilis cases were reported in the United States. One-third (more than 38,000) were classified as primary or secondary syphilis.²

See the table below for more information about the prevalence of syphilis (2015 estimates).

In NYC

In New York City there were about 2,654 cases of syphilis in 2018. This is about 12.7% higher than in 2017. The increase is most noticeable among homosexual males (the number has almost doubled in recent years).³

The chance of getting syphilis from a single sexual act

The following table presents estimates of the risk of acquiring syphilis through one sexual act for heterosexuals and homosexuals.

When syphilis is contagious

The likelihood of syphilis transmission largely depends on the stage of the infection and the presence of a syphilis lesion (chancre). It is most infectious in the first stage of the disease (primary syphilis), when the syphilitic lesion appears (from 10 to 90 days after exposure). This lesion is painless and is located in the area of the body where the infectious agent (bacteria) entered it.

What to do if you’re exposed to syphilis

Anyone who may have had sexual intercourse with a syphilis-positive partner can get post-exposure prophylaxis for syphilis:³

• 1. Shot of penicillin (within 3 months of exposure)
• OR
• 2. Tablets of doxycycline (within 24 hours of exposure) in order to prevent the development of the disease ³

Treatment before or after testing

You can be treated for syphilis before or after you test positive for it, and people choose differently depending on their circumstances.

If you decide not to take the medication:

Some people prefer not to take medication unless they know they have a disease. This is the ideal way of dealing with any condition.

If you choose this option, you need to stop having sex (and be OK with that) for three months after exposure because a syphilis test is not reliable until then.

If you decide to take the medication:

There are a few things you should keep in mind if you make this decision:

• You might be taking the medication unnecessarily
• You might be exposing yourself to side effects (though the risk is extremely low with a one-time dose)

Post-exposure treatment is not urgent

It is ideal to be treated sooner rather than later but it is not an urgent matter (not an emergency). Post-exposure treatment is not extremely time-sensitive and can be given later.

Treatment will be effective if you had risky sex last night

Two doxycycline (100 mg) oral tablets taken within 24 hours of sexual intercourse may decrease the risk of syphilis acquisition by over 73%.^{3, 5}

The effectiveness of preventative treatment

The effectiveness of post-exposure prophylactic medication varies depending on the treatment option.

Sex can resume two weeks after treatment

You can have sex two weeks after finishing the treatment. Please note that to avoid giving syphilis to someone else, it is essential to avoid even skin-to-skin contact and protected sex during the treatment period and to stop having sex until two weeks after the end of treatment.

Testing after preventative treatment

You should have follow-up testing three months after finishing the prophylactic treatment. You can easily book an appointment online and have an examination and testing on any day you wish (weekends included).

What to do if you have a positive syphilis test

Penicillin dosage

The amount of penicillin you’ll need largely depends on how long it’s been since you were infected. Please see the table below.³

Treatment options for people allergic to penicillin

People who are allergic to penicillin have two treatment options:⁴

• Doxycycline (100mg) oral tablets
  
  Twice a day for two weeks
  
  OR
  
  
• Tetracycline (500mg)
  
  Four times a day for two weeks

Note: Pregnant women cannot get either of these treatments. They should be desensitized and then get a shot of penicillin.

Treatment is quite effective

Please see the table below for information about the effectiveness of treatment alternatives.

It’s best to start treatment immediately, but it’s not urgent

It’s not necessary to start treatment immediately. However, syphilis is a progressive disease, so the earlier you begin treatment , the easier and quicker the treatment will be. The more time the passes, the more time it will take to cure the infection.

How soon you should be tested

The CDC recommends that patients have follow-up syphilis testing six and twelve months after treatment ends. ⁴

Pregnant women and MSM should consider screening: ³

When you can have sex again

You can have sex 14 days after treatment is completed.

However, if your partner has not been treated for syphilis, he or she may infect you again. It is essential that sexual partners of infected persons be treated to prevent further reinfection.

References

1. Syphilis transmission: a review of the current evidence. NCBI

2. STD Facts - Syphilis (Detailed).CDC

3. The Great Imitator Revealed: Syphilis. NCBI

4. Syphilis - 2015 STD Treatment Guidelines. CDC

5. Impact of the Daily Doxycycline Pre-exposure Prophylaxis (PrEP) on the Incidence of Syphilis, Gonorrhoea and Chlamydia - Full Text View - ClinicalTrials