A new report suggests that just a fifth of all middle schools and less than 50% of all high schools in the United States teach every single sex education topic recommended by the US Centers for Disease Control & Prevention (CDC).

The findings, which have been released recently by the CDC, indicate that a large share of the students in the US is not receiving essential health and safety information on subjects such as pregnancy prevention, STDs ad HIV.

In one of his recent statements, Jonathon Mermin, the director of the National Center for HIV/AIDS, Viral Hepatitis, STD, and Tuberculosis Prevention at CDC, said that health officials need to perform better when it comes to providing young people in the US with the required knowledge and skills for protecting their health. He added that it’s extremely important to teach American students about ways of reducing sexual risk and maintaining healthy relationships before they start having sex.

The new report has been created based on CDC’s School Health Profiles for the year 2014. The data provided by the 2014 School Health Profiles were gathered by surveying schools all across the United States on whether they teach each of the 16 sexual health education topics recommended by the CDC along with other major health-related subjects.

CDC selected the sex education topics and adjusted them for age-appropriateness based on scientific evidence for the kind of subjects helping young individuals to avoid risk. The subjects picked by the federal agency range from fundamental information on how STDs including HIV get transmitted and ways of preventing infections to ways of getting condoms and tips for developing decision-making and communication skills that can help in reducing or eliminating risk.

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The report revealed that the percentage of middle and high schools meeting criteria set by the CDC for sexual health education varies significantly by state. For instance, the percentage of high schools teaching all 16 recommended topics vary from 21% in Arizona to 90% in New Jersey. What’s particularly alarming is that in the majority of the states, less than 50% of high schools teaches each of the 16 topics.

In the case of middle schools, the percentage of schools teaching all topics recommended by the CDC ranged from 4% in Arizona to 46% in North Carolina. Additionally, there’s not a single state where more than 50% of middle schools teach all 16 topics.