GITNUXREPORT 2025

Unprotected Sex Statistics

Unprotected sex causes most STIs, HIV, and teenage pregnancies worldwide.

Jannik Lindner

Jannik Linder

Co-Founder of Gitnux, specialized in content and tech since 2016.

First published: April 29, 2025

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Key Statistics

Statistic 1

Among teenagers aged 15-19, about 62% of sexually active females reported not using a condom during their last sexual encounter.

Statistic 2

Condoms are about 98% effective at preventing HIV transmission when used consistently and correctly.

Statistic 3

About 31% of women and 44% of men in the U.S. have reported unprotected sex at their last sexual encounter.

Statistic 4

Condom use at last sexual intercourse among adults in Europe varies widely but averages around 43%, indicating inconsistent protection.

Statistic 5

The global HIV transmission rate is reduced by approximately 90% when individuals use protection consistently.

Statistic 6

Consistent condom use can reduce the likelihood of pregnancy by about 98%, but inconsistent use significantly lowers effectiveness.

Statistic 7

The rate of condom usage at last sexual encounter among teenagers remains below 50%, contributing to STI spread.

Statistic 8

The effectiveness of condoms in preventing herpes transmission is estimated at around 70%, though unprotected sex increases risk.

Statistic 9

A significant portion of teenage pregnancies occurs due to unprotected sex, with rates varying by region.

Statistic 10

In the United States, African American women have the highest rate of new HIV diagnoses, largely due to unprotected sex.

Statistic 11

The cost of treating STIs globally exceeds $16 billion annually, much of which is linked to unprotected sex.

Statistic 12

The annual economic burden of STIs in the U.S. is estimated at over $16 billion, much of which is related to unprotected sex.

Statistic 13

About 40% of new HIV infections in the United States occur among individuals who are unaware of their infection, often due to unprotected sex.

Statistic 14

Globally, approximately 1.8 million people contracted HIV in 2020, many through unprotected sexual activities.

Statistic 15

The risk of transmission of HIV through unprotected receptive vaginal sex is approximately 1.38% per act.

Statistic 16

Unprotected sex accounts for roughly 85% of new sexually transmitted infections worldwide.

Statistic 17

In the U.S., around 19 million new STIs occur annually, with unprotected sex being a major contributing factor.

Statistic 18

The probability of acquiring chlamydia via unprotected vaginal sex is approximately 4-5% per act.

Statistic 19

The gonorrhea infection rate among sexually active young women aged 15-24 is approximately 700 per 100,000 persons in the U.S., often linked to unprotected sex.

Statistic 20

Unprotected oral sex can transmit HPV, which is linked to oral cancers, and its prevalence may be underestimated.

Statistic 21

The global prevalence of herpes simplex virus type 2 (HSV-2), often transmitted via unprotected sex, is approximately 13% among individuals aged 15-49.

Statistic 22

In sub-Saharan Africa, HIV prevalence remains high partly due to unprotected heterosexual encounters.

Statistic 23

About 30% of new HIV infections worldwide are transmitted through unprotected heterosexual intercourse.

Statistic 24

Teenagers engaging in unprotected sex are at a higher risk of contracting HPV, which can cause cervical cancer.

Statistic 25

Unprotected sex during multiple partners increases the risk of STI transmission substantially.

Statistic 26

Approximately 75% of new syphilis cases in the US are among gay, bisexual men, often linked to unprotected sex.

Statistic 27

Unprotected sex is responsible for nearly 70% of HPV infections worldwide.

Statistic 28

The average number of sexual partners for individuals engaging in unprotected sex is higher, increasing STI risk.

Statistic 29

About 10% of new HIV infections in the U.S. are transmitted through heterosexual unprotected sex.

Statistic 30

The prevalence of unprotected sex among college students is approximately 50%, contributing to STI spread.

Statistic 31

Unprotected sex increases the risk of HIV transmission by approximately 2-20 times depending on circumstances.

Statistic 32

In Asia-Pacific regions, unprotected sex is a major contributor to the high rates of HIV infection among key populations.

Statistic 33

In Latin America, unprotected sex remains the primary mode of HIV transmission among adults.

Statistic 34

Among men who have sex with men (MSM), unprotected anal sex carries a transmission risk of approximately 1.38% per encounter.

Statistic 35

Young women aged 15-24 are disproportionately affected by STIs due to unprotected sex practices.

Statistic 36

About 45% of new HIV infections among women are transmitted through unprotected heterosexual contact.

Statistic 37

In some countries, cultural taboos around condom use lead to unprotected sex and higher infection rates.

Statistic 38

Studies show that people engaging in unprotected sex are more likely to have multiple concurrent partners.

Statistic 39

The use of pre-exposure prophylaxis (PrEP) significantly reduces the risk of HIV acquisition in high-risk populations engaging in unprotected sex.

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Key Highlights

  • About 40% of new HIV infections in the United States occur among individuals who are unaware of their infection, often due to unprotected sex.
  • Globally, approximately 1.8 million people contracted HIV in 2020, many through unprotected sexual activities.
  • The risk of transmission of HIV through unprotected receptive vaginal sex is approximately 1.38% per act.
  • Unprotected sex accounts for roughly 85% of new sexually transmitted infections worldwide.
  • Among teenagers aged 15-19, about 62% of sexually active females reported not using a condom during their last sexual encounter.
  • Condoms are about 98% effective at preventing HIV transmission when used consistently and correctly.
  • In the U.S., around 19 million new STIs occur annually, with unprotected sex being a major contributing factor.
  • The probability of acquiring chlamydia via unprotected vaginal sex is approximately 4-5% per act.
  • The cost of treating STIs globally exceeds $16 billion annually, much of which is linked to unprotected sex.
  • The gonorrhea infection rate among sexually active young women aged 15-24 is approximately 700 per 100,000 persons in the U.S., often linked to unprotected sex.
  • A significant portion of teenage pregnancies occurs due to unprotected sex, with rates varying by region.
  • About 31% of women and 44% of men in the U.S. have reported unprotected sex at their last sexual encounter.
  • Unprotected oral sex can transmit HPV, which is linked to oral cancers, and its prevalence may be underestimated.

Unprotected sex continues to be a hidden epidemic worldwide, fueling nearly 85% of new sexually transmitted infections and accounting for a significant portion of HIV transmissions, with millions unaware of their infection and millions more risking their health every day.

Condom Efficacy and Usage Patterns

  • Among teenagers aged 15-19, about 62% of sexually active females reported not using a condom during their last sexual encounter.
  • Condoms are about 98% effective at preventing HIV transmission when used consistently and correctly.
  • About 31% of women and 44% of men in the U.S. have reported unprotected sex at their last sexual encounter.
  • Condom use at last sexual intercourse among adults in Europe varies widely but averages around 43%, indicating inconsistent protection.
  • The global HIV transmission rate is reduced by approximately 90% when individuals use protection consistently.
  • Consistent condom use can reduce the likelihood of pregnancy by about 98%, but inconsistent use significantly lowers effectiveness.
  • The rate of condom usage at last sexual encounter among teenagers remains below 50%, contributing to STI spread.
  • The effectiveness of condoms in preventing herpes transmission is estimated at around 70%, though unprotected sex increases risk.

Condom Efficacy and Usage Patterns Interpretation

Despite widespread awareness of their effectiveness—up to 98% in preventing HIV and pregnancies—over half of sexually active teenagers and sizable portions of adults worldwide still forgo condoms, risking a surge in STIs and unintended pregnancies that underscores the urgent need for improved education and access.

Demographic and Regional Variations

  • A significant portion of teenage pregnancies occurs due to unprotected sex, with rates varying by region.
  • In the United States, African American women have the highest rate of new HIV diagnoses, largely due to unprotected sex.

Demographic and Regional Variations Interpretation

While unprotected sex continues to fuel teenage pregnancies across regions, in the U.S., it’s also driving alarming disparities, with African American women facing the highest new HIV diagnosis rates—highlighting the urgent need for comprehensive safe sex education and access.

Economic and Healthcare Costs

  • The cost of treating STIs globally exceeds $16 billion annually, much of which is linked to unprotected sex.
  • The annual economic burden of STIs in the U.S. is estimated at over $16 billion, much of which is related to unprotected sex.

Economic and Healthcare Costs Interpretation

The staggering $16 billion annual price tag of treating STIs—largely attributed to unprotected sex—serves as a costly reminder that safety isn't just smart; it's economically essential.

HIV and STI Prevalence and Transmission Risks

  • About 40% of new HIV infections in the United States occur among individuals who are unaware of their infection, often due to unprotected sex.
  • Globally, approximately 1.8 million people contracted HIV in 2020, many through unprotected sexual activities.
  • The risk of transmission of HIV through unprotected receptive vaginal sex is approximately 1.38% per act.
  • Unprotected sex accounts for roughly 85% of new sexually transmitted infections worldwide.
  • In the U.S., around 19 million new STIs occur annually, with unprotected sex being a major contributing factor.
  • The probability of acquiring chlamydia via unprotected vaginal sex is approximately 4-5% per act.
  • The gonorrhea infection rate among sexually active young women aged 15-24 is approximately 700 per 100,000 persons in the U.S., often linked to unprotected sex.
  • Unprotected oral sex can transmit HPV, which is linked to oral cancers, and its prevalence may be underestimated.
  • The global prevalence of herpes simplex virus type 2 (HSV-2), often transmitted via unprotected sex, is approximately 13% among individuals aged 15-49.
  • In sub-Saharan Africa, HIV prevalence remains high partly due to unprotected heterosexual encounters.
  • About 30% of new HIV infections worldwide are transmitted through unprotected heterosexual intercourse.
  • Teenagers engaging in unprotected sex are at a higher risk of contracting HPV, which can cause cervical cancer.
  • Unprotected sex during multiple partners increases the risk of STI transmission substantially.
  • Approximately 75% of new syphilis cases in the US are among gay, bisexual men, often linked to unprotected sex.
  • Unprotected sex is responsible for nearly 70% of HPV infections worldwide.
  • The average number of sexual partners for individuals engaging in unprotected sex is higher, increasing STI risk.
  • About 10% of new HIV infections in the U.S. are transmitted through heterosexual unprotected sex.
  • The prevalence of unprotected sex among college students is approximately 50%, contributing to STI spread.
  • Unprotected sex increases the risk of HIV transmission by approximately 2-20 times depending on circumstances.
  • In Asia-Pacific regions, unprotected sex is a major contributor to the high rates of HIV infection among key populations.
  • In Latin America, unprotected sex remains the primary mode of HIV transmission among adults.
  • Among men who have sex with men (MSM), unprotected anal sex carries a transmission risk of approximately 1.38% per encounter.
  • Young women aged 15-24 are disproportionately affected by STIs due to unprotected sex practices.
  • About 45% of new HIV infections among women are transmitted through unprotected heterosexual contact.
  • In some countries, cultural taboos around condom use lead to unprotected sex and higher infection rates.
  • Studies show that people engaging in unprotected sex are more likely to have multiple concurrent partners.

HIV and STI Prevalence and Transmission Risks Interpretation

Unprotected sex, while often portrayed as a personal choice, remains the unwelcome catalyst behind nearly nine out of ten new STI transmissions worldwide, turning intimate moments into high-stakes gambles with public health.

Prevention Strategies and Behavioral Factors

  • The use of pre-exposure prophylaxis (PrEP) significantly reduces the risk of HIV acquisition in high-risk populations engaging in unprotected sex.

Prevention Strategies and Behavioral Factors Interpretation

While the statistics highlight PrEP as a powerful shield against HIV for high-risk groups, neglecting its use turns unprotected sex into a gamble where prevention is simply a pill away.