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La circoncisione riduce i rischi di Hiv nelle donne e le protegge da trichomonas e vaginite batterica
Meglio preferire i maschi circoncisi per ridurre il rischio di contrarre malattie sessuali. Lo dicono gli esperti della Johns Hopkins University di Baltimora. Dopo aver effettuato le indagini su un campione di oltre 12.000 persone in Uganda, non hanno potuto fare a meno di notare, nelle donne che avevano un partner circonciso, un calo del 30% nell'infezione da HIV. Secondo gli esperti nei maschi non circoncisi il prepuzio è la parte del membro dove il virus si annida maggiormente ( nove volte di più che altrove). Rimuovere la pelle del prepuzio aiuta ad eliminare un covo molto pericoloso. I risultati, presentati ad un convegno dedicato alle malattie veneree, hanno confermato precedenti testimonianze riguardanti la minore incidenza e diffusione del virus HIV nelle regioni africane dove la circoncisione è praticata normalmente. La circoncisione protegge le donne anche dalla trichomonas e dalla vaginite batterica, ma non evita la trasmissione di papillomavirus, sifilide, gonorrea e clamidia.

La circoncisione maschile riduce il rischio di HIV: non sono necessarie ulteriori prove
Tre studi clinici recenti condotti in Africa supportano la pratica della circoncisione maschile per ridurre il rischio di HIV negli uomini eterosessuali. Dopo aver incluso i nuovi dati provenienti da questi studi nella revisione sistematica, i ricercatori della Cochrane Collaboration hanno modificato le loro prime conclusioni secondo le quali non c’erano sufficienti evidenze per raccomandare questa pratica per prevenire l’infezione da HIV negli uomini eterosessuali.

“La ricerca sull’efficacia della circoncisione maschile nella prevenzione dell’infezione da HIV negli uomini eterosessuali è definitiva. Non sono necessari ulteriori studi per stabilire che l’indice di infezione da HIV è ridotto dopo i primi due anni dalla circoncisione.” Ha detto il capo ricercatore Nandi Siegfried, vice direttore del Centro Cochrane del Sud Africa. “I decisori sanitari dovrebbero considerare questa pratica come una misura aggiuntiva nel programma di prevenzione dell’HIV”.  Il meccanismo attraverso il quale la circoncisione proteggerebbe contro il virus è legato alla rimozione delle cellule del prepuzio, nelle quali il virus si localizza. Queste cellule, dette del Langerhans, esprimono i recettori che consentono l’ingresso del virus sulla superficie delle cellule.

L’associazione tra la circoncisione e l’HIV era stata oggetto di precedenti studi non randomizzati , ma fino ad ora non sono state prodotte forti raccomandazioni per questo tipo di intervento a causa della mancanza di studi di alta qualità.
Nella revisione sono riportati studi clinici condotti in Sud Africa, Uganda e Kenya tra il 2002 e il 2006 che includono in totale 11054 uomini. I risultati mostrano che la circoncisione negli uomini eterosessuali riduce il rischio di contrarre l’HIV fino al 50% per un periodo di due anni, rispetto agli uomini non circoncisi. Questa riduzione di rischio è una stima dell’effetto medio del trattamento e corrisponde ad una “vera” riduzione compresa tra il 38% e il 66%. Sono comunque necessarie ulteriori ricerche per stabilire se la circoncisione maschile offra qualche beneficio anche a partner donne di uomini circoncisi e a uomini omosessuali.

I ricercatori suggeriscono ai decisori sanitari di valutare le circostanze culturali e le tradizioni delle popolazioni nelle quali la circoncisione maschile viene praticata. “In alcune zone, la circoncisione si inserisce in riti di iniziazione operati da guaritori e spesso non avviene attraverso procedure asettiche. Di conseguenza si possono verificare  complicazioni dello stato di salute degli uomini” ha detto Siegfried.

Riferimento bibliografico completo: Siegfried N, Muller M, Deeks JJ, Volmink J. Male circumcision for prevention of heterosexual acquisition of HIV in men. Cochrane Database of Systematic Reviews 2009, Issue 2. Art. No.: CD003362. DOI: 10.1002/14651858.CD003362.pub2.

Ricercatori statunitensi hanno scoperto che le persone circoncise avrebbero molte meno probabilità di contrarre infezioni.
Lo studio pubblicato sul “New England Journal of Medicine” afferma chiaramente che la circoncisione riduce il rischio di trasmissione sessuale di infezioni quali: herpes, papilloma virus e ridurrebbe drasticamente il rischio di contrarre il virus dell’HIV.

Per giungere a questi risultati gli studiosi hanno esaminato circa 3000 uomini di cui è stata esaminata l’attività sessuale per più di due anni. In numeri si parla del rischio di contrarre l’herpes ridotto del 25% e di circa un terzo quello di trasmissione del papilloma virus umano.

Il parere sulla circoncisione del comitato nazionale di bioetica

Male Circumcision Reduces Risk of Genital Herpes and HPV Infection, but Not Syphilis

Heterosexual men who undergo medical circumcision can significantly reduce their risk of acquiring two common sexually transmitted infections — herpes simplex virus type 2 (HSV-2), the cause of genital herpes, and human papillomavirus (HPV), which can cause cancer and genital warts, according to a report in the March 26 issue of the New England Journal of Medicine (NEJM). In the study, circumcision had no effect on their risk of becoming infected with the bacterium that causes syphilis, however.

The findings build upon earlier clinical research funded by the National Institute of Allergy and Infectious Disease (NIAID), part of the NIH, which found that circumcision decreases a man’s risk of acquiring HIV infection through heterosexual intercourse by more than 50 percent (http://www3.niaid.nih.gov/news/newsreleases/2006/AMC12_06.htm).

"Medically supervised adult male circumcision is a scientifically proven method for reducing a man’s risk of acquiring HIV infection through heterosexual intercourse," says NIAID Director Anthony S. Fauci, M.D. "This new research provides compelling evidence that circumcision can provide some protection against genital herpes and human papillomavirus infections as well."

The study was conducted by scientists at the Rakai Health Sciences Program in Uganda in collaboration with researchers at the Johns Hopkins University Bloomberg School of Public Health in Baltimore, Makerere University in Kampala, Uganda, and NIAID’s Division of Intramural Research. The collaborators examined samples from two parallel clinical trials in Rakai that successfully proved male circumcision as an HIV prevention method and also assessed the surgical procedure’s ability to prevent other sexually transmitted infections, including syphilis and HSV-2. These infections cause genital ulcers and are associated with an increased risk of HIV acquisition. The research team also assessed circumcision’s effect on HPV infections, which can cause anal, cervical and penile cancers and genital warts.

The two trials, one funded by NIAID and the other by the Bill & Melinda Gates Foundation, enrolled 3,393 uncircumcised men between the ages of 15 and 49 who initially tested negative for both HIV and HSV-2. The men were assigned at random to one of two study groups: 1,684 received immediate circumcision performed by trained medical professionals in an outpatient setting (intervention group); and 1,709 received medical circumcision after a delay of 24 months (control group). The researchers evaluated the volunteers at six, 12 and 24 months for HSV-2 and syphilis infection. Additionally, a subgroup of 697 volunteers (352 participants in the intervention group; 345 in the control group) was evaluated for HPV infection at enrollment and at 24 months.

In analyzing the effect of circumcision on HSV-2 acquisition across both studies, the researchers found that the cumulative probability of HSV-2 infection was significantly lower among those volunteers who received immediate circumcision (7.8 percent) than among those in the control group who were circumcised at 24 months (10.3 percent). Overall, the researchers found that medically supervised circumcision reduced the men’s risk of HSV-2 infection by 28 percent.

The combined results from both trials also demonstrated a 35 percent reduction in HPV prevalence among men in the intervention group. In evaluating a subgroup of volunteers at 24 months, high-risk HPV strains associated with certain cancers were detected in 42 of 233 men in the intervention group and in 80 of 287 men in the control group.

Circumcision did not, however, affect the incidence of syphilis. At 24 months, syphilis was detected in 50 men in the intervention group and 45 members of the control group.

"The cumulative scientific evidence supporting the public health value of medically supervised male circumcision is now overwhelming," says Thomas C. Quinn, M.D., study co-investigator, chief of the International HIV/STD Section in NIAID’s Laboratory of Immunoregulation and co-author of the study. "This new research confirms the substantial health benefits of male circumcision, including reduced acquisition of HIV, genital herpes, HPV and genital ulcer disease."

Dr. David Serwadda, co-principal investigator and dean of Makerere University’s School of Public Health, adds that "these findings have significant public health implications for the control of HIV, genital herpes and HPV in areas of high prevalence, such as Africa, and further suggest that efforts to scale-up male circumcision could have tremendous benefit."

"The next focus of our research will be to analyze additional data collected in the Rakai trials to assess the degree to which male circumcision may reduce transmission of HPV to female sexual partners," says Johns Hopkins professor Ronald H. Gray, M.D., co-principal investigator. "This would be of substantial significance because HPV causes cervical cancer."

The biological reasons why circumcision may reduce the risk of HSV-2 and HPV infection, but not syphilis, are not entirely known. HSV-2 and HPV multiply in epithelial cells found in the surface skin of the penis, and the foreskin may facilitate virus entry into those cells. Once circumcision has been performed, the risk of epithelial infection may be reduced, the authors note. Additionally, the analysis used to determine the effects of circumcision on syphilis had limited statistical power, and therefore, it is difficult to draw a firm conclusion as to whether or not circumcision may reduce syphilis incidence, the researchers add.

During each clinic visit, volunteers were given physical examinations, counseled on safe sex practices and offered condoms, voluntary HIV counseling and testing. Study staff also interviewed each volunteer to record sociodemographic characteristics and rates of specific sexual risk behaviors. Volunteers who acquired HIV infection during the two clinical trials were referred to Rakai Health Science Program clinics for HIV care funded by the U.S. President’s Emergency Plan for AIDS Relief. Volunteers who acquired genital ulcers or syphilis were also provided with appropriate medical care and treatment.

As with most strategies to prevent sexually transmitted infections, including HIV, adult male circumcision is not completely effective. Therefore, the authors note, safe sex practices, including consistent condom use, are still necessary to provide the best protection against such infections.

NIAID conducts and supports research — at NIH, throughout the United States, and worldwide — to study the causes of infectious and immune-mediated diseases, and to develop better means of preventing, diagnosing and treating these illnesses. News releases, fact sheets and other NIAID-related materials are available on the NIAID Web site at http://www.niaid.nih.gov.

The National Institutes of Health (NIH) — The Nation's Medical Research Agency — includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. It is the primary federal agency for conducting and supporting basic, clinical and translational medical research, and it investigates the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.

Reference: A.A.R Tobian et al. Male circumcision for the prevention of HSV-2 and HPV infections and syphilis. New England Journal of Medicine. DOI: 10.1056/NEJMoa0802556 (2009).

Male Circumcision Cuts Herpes And HPV Risk
Article Date: 26 Mar 2009 - 3:00 PDT

A new study by researchers in the US found that male circumcision cut the risk of genital herpes and human papillomavirus (HPV) infection, but not syphilis. The study, which is published in the 26 March issue of the New England Journal of Medicine, NEJM, was the work of scientists at the Rakai Health Sciences Program in Uganda and researchers at the Johns Hopkins University Bloomberg School of Public Health in Baltimore, Makerere University in Kampala, Uganda, and the Division of Intramural Research at the National Institute of Allergy and Infectious Disease (NIAID).

The researchers studied data from two clinical trials in Rakai that showed male circumcision reduced the incidence of HIV infection. One trial was funded by NIAID and the other by the Bill & Melinda Gates Foundation.

NIAID Director Dr Anthony S Fauci told the press that: "Medically supervised adult male circumcision is a scientifically proven method for reducing a man's risk of acquiring HIV infection through heterosexual intercourse."

"This new research provides compelling evidence that circumcision can provide some protection against genital herpes and human papillomavirus infections as well."

For this study, the researchers assessed the effectiveness of male circumcision in preventing infection by the herpes simplex virus type 2 (HSV-2) and human papillomavirus (HPV) and syphilis in HIV-negative adolescent boys and men (aged from 15 to 49). HSV-2 causes of genital herpes, and HPV can cause cancer and genital warts. 3,393 (61.3 per cent) of the 5,534 participants enrolled in the two trials tested negative for HSV-2, and of these 1,684 had been randomly assigned to undergo immediate circumcision performed by trained medical professionals, and 1,709 to have it 24 months later (the controls). At the start of the study (baseline), at 6, 12 and 24 months, all participants were tested for HSV-2, HIV and syphilis and underwent physical exams and interviews. A subgroup of 697 participants was also tested for HPV at baseline and 24 months (352 in the circumcision group and 345 in the control group).

The results showed that:

At 24 months, the cumulative probability of infection by HSV-2 was 7.8 per cent in the circumcision group and 10.3 per cent in the control group.

Overall, medically supervised circumcision reduced the men's risk of HSV-2 infection by 28 per cent (adjusted hazard ratio in the circumcision group, 0.72; with 95 per cent confidence interval [CI] ranging from 0.56 to 0.92; P=0.008).

The prevalence of high-risk HPV genotypes was 18.0 per cent in the circumcision group and 27.9 per cent in the control group, with a risk reduction of 35 per cent in the circumcision group (adjusted risk ratio, 0.65; 95 per cent CI, 0.46 to 0.90; P=0.009).

However, there was no significant difference between the two study groups in the incidence of syphilis (adjusted hazard ratio, 1.10; 95 per cent CI, 0.75 to 1.65; P=0.44).

The researchers concluded that:

"In addition to decreasing the incidence of HIV infection, male circumcision significantly reduced the incidence of HSV-2 infection and the prevalence of HPV infection, findings that underscore the potential public health benefits of the procedure."

Co-author Dr Thomas C. Quinn, who heads the the International HIV/STD Section in NIAID's Laboratory of Immunoregulation, said: "The cumulative scientific evidence supporting the public health value of medically supervised male circumcision is now overwhelming."

"This new research confirms the substantial health benefits of male circumcision, including reduced acquisition of HIV, genital herpes, HPV and genital ulcer disease."

Co-principal investigator Dr David Serwadda, who is dean of Makerere University's School of Public Health, added: "These findings have significant public health implications for the control of HIV, genital herpes and HPV in areas of high prevalence, such as Africa, and further suggest that efforts to scale-up male circumcision could have tremendous benefit."

Johns Hopkins Professor Ronald H Gray, co-principal investigator of the study said: "The next focus of our research will be to analyze additional data collected in the Rakai trials to assess the degree to which male circumcision may reduce transmission of HPV to female sexual partners."

"This would be of substantial significance because HPV causes cervical cancer," he added.

The researchers said they don't know why circumcision may reduce the risk of HSV-2 and HPV infection but not syphilis. The foreskin helps the HSV-2 and HPV viruses to get into the epithelial cells in the surface skin of the penis where they multiply. Circumcision removes the foreskin and perhaps reduces risk of epithelial infection.

Another reason for the odd result with syphilis could be the low statistical power of the analysis (presumably because of low numbers of syphilis cases) said the researchers, making it difficult to draw a firm conclusion about syphilis and circumcision.

"Male Circumcision for the Prevention of HSV-2 and HPV Infections and Syphilis."

Tobian, Aaron A.R., Serwadda, David, Quinn, Thomas C., Kigozi, Godfrey, Gravitt, Patti E., Laeyendecker, Oliver, Charvat, Blake, Ssempijja, Victor, Riedesel, Melissa, Oliver, Amy E., Nowak, Rebecca G., Moulton, Lawrence H., Chen, Michael Z., Reynolds, Steven J., Wawer, Maria J., Gray, Ronald H.

N Engl J Med March 26, 2009, Volume 360:1298-1309, Number 13.

Sources: NIH/National Institute of Allergy and Infectious Diseases, NEJM.

La circoncisione per evitare HIV e HPV
Sanihelp.it - La circoncisione abbassa il rischio di contrarre herpes genitale, un’infezione virale che causa le verruche genitali ed è spesso preludio di cancro, mentre non abbassa il rischio sifilide: è quanto sostiene uno studio condotto in collaborazione fra la Johns Hopkins degli Stati Uniti e l’università dell’Uganda, pubblicato sulla rivista New England Journal of Medicine.

Questo studio si inserisce fra tutti gli altri studi che stanno cercando di appurare se la circoncisione può migliorare la salute dell’uomo e se può salvaguardare anche la salute delle sue future partners.

Gli studi a disposizione, infatti, indicano come gli uomini circoncisi corrono meno rischi di contrarre il virus dell’HIV attraverso rapporti eterosessuali.

Questo studio condotto attraverso trial in parallelo in America e in Uganda, ha dimostrato come la circoncisione abbassi il rischio di infettarsi con il papilloma virus HPV, il virus più comunemente trasmesso nel mondo per via sessuale e come abbassi il rischio di infettarsi anche con l’herpes virus.

La circoncisione potrebbe essere una pratica molto utile soprattutto in Africa fra le persone a rischio HPV e HIV; non a caso dal 2007 la World Health Organization propone la circoncisione come mezzo per ridurre il rischio di infezione da HIV nelle aree dove il rischio di trasmissione eterossessuale è alto.

pagina aggiornata a martedì 11 marzo 2014
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.: eiaculazione precoce
.: circoncisione
.: impotenza
.: infertilità
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