(AP photo.)

(CNSNews.com) -- The Centers for Disease Control and Prevention (CDC) says HIV infection rates are high among transgender women in the United States, and particularly high among black transgender women, compared to other groups.

On its website page “HIV Among Transgender People,” the CDC cites a systematic review of various studies which showed that 28% of all transgender women had HIV. (A transgender woman is a biological male who identifies as a female.)

Also, “56% of black/African American transgender women had positive HIV test results compared to 17% of white or 16% of Hispanic/Latina transgender women,” said the CDC. Black transgender women "are more likely to have HIV than transgender women of other races/ethnicities," said the health agency.

In addition, from the HIV testing events reported to the CDC in 2013, “the highest percentages of newly identified HIV-positive persons were among transgender persons,” reported the CDC.

HIV prevelance is very low (0-3%) among transgender men – women who identify as men – said the CDC, but a 2011 study “suggests that transgender men who have sex with men are at substantial risk for acquiring HIV.”

"Because data for transgender people are not uniformly collected, information is lacking on how many transgender people in the United States are infected with HIV," the CDC explains on its website, and adds, "However, data collected by local health departments and scientists studying these communities show high levels of HIV and racial/ethnic disparities."

The CDC also discusses the factors contributing to the higher HIV prevalence rate among transgender people, stating that, “Individual behaviors alone do not account for the disparate HIV diagnoses among transgender people,” and listing drug and alcohol abuse, incarceration, lack of familial support, and “negative health care encounters” as some of the factors that may contribute.

The Human Immunodeficiency Virus (HIV). (AP)

However, as shown by the systematic review, behaviors such as “receptive anal sex without a condom or medicines to prevent HIV… sex with multiple partners, and exchanging sex for drugs or money” may contribute to the higher risk of HIV infection, said the health agency.

The CDC website also states, “Some transgender people who experience poverty rely on sex work to meet their basic survival needs.”

The article further reports that, “Transgender men’s sexual health has been understudied,” and “additional research is needed,” noting that data specifically on transgender people are limited because “many federal, state, and local agencies inaccurately collect data about individual’s sex and gender.”

However, the CDC is funding efforts to prevent HIV among transgender people, including developing testimonial videos featuring transgender leaders and supporting National Transgender HIV Testing Day.

On its website, the CDC defines “transgender” as an “umbrella term for persons whose gender identity or expression (masculine, feminine, other) is different from their sex (male, female) at birth. Gender identity refers to one’s internal understanding of one’s own gender, or the gender with which a person identifies.”