Laurie Toich, Assistant Editor

Uptake in pre-exposure prophylaxis (PrEP) could significantly affect the rate of new HIV diagnoses, according to a recent study published in the

Journal of Acquired Immune Deficiency Syndromes.

The study suggests that if one-quarter of men who have sex with men (MSM) started PrEP with emtricitabine/tenofovir (Truvada), approximately 30% of new HIV cases would be mitigated.

In the study, the authors created a 10,000-person model of high-risk MSM to determine how varying levels of PrEP uptake would affect new diagnoses.

Significantly, if the model was implemented in the real-world, the United States would surpass the National HIV/AIDS Strategy—to reduce new infections 25% by 2020, according to the study.

The researchers investigated whether daily use of PrEP

would affect transmission. They found that PrEP uptake in any percentage of high-risk patients would result in an increased rate of HIV prevention, according to the study.

“We know that PrEP is highly effective at preventing HIV infection, what we don’t know is how much of an impact it will have at the population level considering the numerous behavioral strategies that men use to prevent infection,” said researcher Michael T. LeVasseur, PhD. “This study attempts to answer this question and future work with this model will attempt to identify specific strategies that will work best to stop the transmission of HIV.”

The authors also examined the efficacy of other HIV prevention methods on their own or in combination. Specifically, they analyzed condom use, seroadaptive behaviors, and treatment as prevention.

Included in the analysis were data modeled after a 10,000-person population including urban, non-monogamous MSM at a high risk of contracting HIV. Approximately 19% of the overall population were HIV-positive, with 44% unaware or their status. Another 36% of HIV-negative patients were not tested for HIV within the previous year.

When PrEP was the only preventive therapy used by 1% of HIV-negative patients, 1.6% of infections were mitigated. Notably, when 25% of the HIV-negative population used PrEP, 30.7% of infections were prevented, according to the study.

Condom use as the only prevention method averted 48.8% of new HIV infections, while seroadaptive behaviors averted 37.7% of infections. Treatment as prevention was also observed to reduce new infections by 27.1%, according to the study.

The authors found that when all 3 prevention methods were combined, 72.2% of new infections were inhibited.

“PrEP is just another ‘tool in the toolbox’ for HIV prevention, but it is an important one,” Dr LeVasseur said. “PrEP can empower individuals who are in relationships where one person has HIV and the other doesn’t. It can also ease anxieties around HIV testing, as well as enhance sexual intimacy.”

However, the researchers noted that PrEP use among high-risk individuals is low.

“It’s probably low because of a lack of knowledge among patients, as well as providers, coupled with high costs,” LeVasseur said.

Additionally, high costs may be a concern for patient adherence to PrEP, despite manufacturer discounts and insurer coverage, according to the authors.

These findings show that PrEP has the potential to decrease HIV cases and can increase testing for sexually transmitted infections, in addition to alleviating concerns among MSM, according to the study.

“Many men who have sex with men have felt significant anxiety around sexual intimacy due to fear of HIV infection, even with condom use, frequent HIV testing and seroadaptive techniques,” Dr LeVasseur said. “Highlighting how effective these prevention methods are would certainly lead to an increase in PrEP uptake and easing of the mind.”

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Uptake in pre-exposure prophylaxis (PrEP) could significantly affect the rate of new HIV diagnoses, according to a recent study published in the Journal of Acquired Immune Deficiency Syndromes.

Increased PrEP Uptake Could Lead to Significant Drop in New HIV Cases

Combatting viruses, such as HIV, may cause several enzymes in the immune system to malfunction and trigger cancer-related mutations, according a recently-published study in

“Our findings could change the way we treat cancer,” said researcher Linda Chelico, PhD.

The authors discovered that 3 enzymes in the APOBEC3 family trigger these mutations, despite their duties to protect the immune system. These findings may lead to novel inhibitors that suppress the enzymes or tests to determine their levels.

Previous research showed that the enzymes were linked to cancer mutations and may be present in patients with cancer who are not fighting viruses. However, the new study is the first that shows how the enzymes are able to mutate DNA.

“The enzymes we study are very important for building a defence [sic] against viruses, but some specifically activated to fight HIV

infection may end up being expressed in the wrong place at the wrong time, causing unintended mutations,” Dr Chelico said.

The authors said that enzymes bind to HIV DNA in order to mutate it and inhibit viral replication, but HIV is notoriously difficult to kill.

Since the enzymes are unable to combat HIV, it continues to scan DNA and may incorrectly cause mutations to healthy cells, according to the study. This process was observed to happen despite the presence of repair mechanisms that protect DNA.

“This is off-target behavior for the enzymes because they typically attack only single-stranded virus DNA,” said researcher Madison Adolph. “We have identified for the first time the biochemical features that allow these enzymes to bind to tiny regions of human DNA that are single-stranded.”

The authors previously attempted to isolate cells from the APOBEC3B enzyme since it was a critical factor in understanding the enzymes, according to the study.

“We were the first research team to study these enzymes outside cells, which is their natural environment,” Adolph said. “We were able to analyze how they cause mutations, instead of looking at already mutated cancer genomes as previous researchers did.”

Although these results are promising, the authors caution that the process that causes the cancer-related mutations is still unknown. The researchers also have yet to determine whether the enzyme mutations cause cancer directly or just increase risk, according to the study.

“We have started a new research phase where we mix healthy cells and these enzymes together in the lab to see what happens, but we are still at a very early stage,” Dr Chelico concluded.

Combatting viruses, such as HIV, may cause several enzymes in the immune system to malfunction and trigger cancer-related mutations, according a recently-published study in Nature Communications.

Can Fighting HIV Cause Cancer-Related Mutations?

Nearly half of cancer cases and related deaths are preventable, according to data recently published by

Based on current cancer rates, the authors estimated that 42% of cancer cases and 45% of cancer deaths are associated with modifiable risk factors.

In 2014 specifically, 659,640 out of 1.6 million cancer cases and 265,150 out of 587,521 cancer deaths were preventable, according to the study.

The authors calculated how much modifiable lifestyle behaviors contributed to the risk of 26 different cancers among adults 30 years of age and older. Risk factors included:

not eating enough fruits, vegetable, fiber, and calcium

hepatitis B virus, hepatitis C virus, human herpes virus type 8, HIV, and human papillomavirus (HPV).

The authors first examined the prevalence of the factors and their relative risk to determine the prevalence of associated cancers. The researchers then applied the estimates to actual cancer diagnosis and mortality data.

The authors said that their study improves upon previous research since they included additional risk factors and up-to-date national data.

Although cancer mortality rate has dropped 25% since 1991, the American Cancer Society projects that more than 1.6 million cancers and 600,000 deaths will occur in 2017. The authors note their findings may help guide prevention efforts, according to the study.

Cigarette smoking caused the highest number of cancers and cancer-related deaths, at 19% and 29%, respectively, according to the study.

The study found that excess body weight was also a major risk factor and accounted for 7.8% of cancers and 29% of related deaths in 2014.

Exposure to UV radiation was linked to 5% of cancer cases and 1.5% of deaths, while physical activity played a role in 2.9% of cancers and 2.2% of deaths, according to the study.

When excess body weight, alcohol consumption, poor diet, and physical activity were grouped, the authors discovered that the risks were linked to 18% of cancers and 16% of deaths.

Additionally, the authors found these risk factors contributed to 100% of cervical cancers and Kaposi sarcoma and more than 75% of melanoma, anal, lung, larynx, and oral cavity cancers.

For 15 of the 26 cancer types examined, the proportion of cancer cases connected to modifiable risk factors exceeded 50%, according to the study.

The authors suggest that increased awareness and availability of prevention strategies—including taxing cigarettes and increasing HPV vaccination&mdash;could reduce the burden of preventable cancers.

Nearly half of cancer cases and related deaths are preventable, according to data recently published by CA: A Cancer Journal of Clinicians.

Almost Half of Cancer Cases, Cancer-Related Deaths Are Preventable

Using multiple prevention strategies for HIV can significantly reduce new infections, according to a report published by

Previous studies show that voluntary medical male circumcision for HIV-negative men and starting antiretroviral therapy (ART) were effective at stopping sexual transmission of HIV

to uninfected partners, according to the authors of the current study. Other research also shows that changing sexual behavior can prevent HIV transmission.

“Before this study, we knew that these HIV prevention measures worked at an individual level, yet it was not clear that they would substantially reduce HIV incidence in a population — or even if it would be possible to get large numbers of people to adopt them,” said Anthony S. Fauci, MD, director of the National Institute of Allergy and Infectious Diseases (NIAID). “This new analysis demonstrates that scaling up combination HIV prevention is possible and can turn the tide of the epidemic.”

Included in the study were nearly 34,000 patients aged 15 to 49 years living in 30 communities participating in the Rakai Community Cohort Study (RCCS), which promoted HIV testing, ART, and voluntary medical male circumcision to patients.

Patients were tested for HIV and surveyed about their sexual behavior, use of ART, and male circumcision status every 1 or 2 years from April 1999 until September 2016, according to the study.

The investigators found that the number of HIV-positive patients taking ART increased from none in 2003 to 69% in 2016, according to the study.

The number of male study participants voluntarily undergoing circumcision increased from 15% in 1999 to 59% in 2016.

The authors noted that the frequency of condom use with casual partners and patients reporting multiple sexual partners was unchanged throughout the study; however, the number of participants aged 15 to 19 years who reported abstaining from sex increased from 30% in 1999 to 55% in 2016, according to the study.

The authors hypothesized that the uptick in ART use and circumcision resulted in the number of new infections dropping 42%, according to the study.

Additionally, the prevalence of viralogically suppressed patients with HIV increased from 42% in 2009 to 75% in 2016. The authors noted that this finding demonstrated the feasibility of the UNAIDS 90-90-90 initiative by achieving 73% viral suppression, according to the study.

“These findings are extremely encouraging and suggest that with sustained commitment to increase the number of people who use combination HIV prevention, it may be possible to achieve epidemic control and eventual elimination of HIV,” said David Serwadda, MBChB, MMed, MPH, co-founder of the Rakai Health Science Program and professor at Makerere University School of Public Health in Kampala, Uganda.

Overall, HIV cases dropped the most significantly among circumcised men. The authors said the 57% decrease was likely related to circumcision and HIV-positive female partners taking ART.

HIV prevalence was reduced 54% among all men during the study, but dropped only 32% among women. These gender disparities were likely due to more HIV-positive women taking ART than HIV-positive men and men had extra protection against HIV due to circumcision, according to the study.

The authors suggest these gaps can be addressed by having more HIV-positive men take ART and by giving HIV-negative women prevention tools, such as access to pre-exposure prophylaxis (PrEP). The authors said that it is likely RCCS will add PrEP as a prevention strategy in the future, according to the study.

“We expect that this multifaceted approach to HIV prevention will work as well in other populations as it has in rural Uganda,” Dr Grabowski concluded. “Our results make a strong case for further expanding ART and male circumcision for HIV prevention in Rakai District and beyond. Additional proven HIV prevention interventions, such as PrEP, should be added to the mix to reduce HIV infections in women and other high-risk groups.”

Using multiple prevention strategies for HIV can significantly reduce new infections.

Laurie Toich, Assistant Editor

Articles

Increased PrEP Uptake Could Lead to Significant Drop in New HIV Cases

Can Fighting HIV Cause Cancer-Related Mutations?

Almost Half of Cancer Cases, Cancer-Related Deaths Are Preventable

Combining HIV Prevention Services Can Reduce New Infections