Bactéria ataca comunidade gay nos EUA

Estudo sobre nova linhagem de micróbio resistente a antibióticos aponta núcleo de surto em bairro de San Francisco

Patógeno, comum em infecção hospitalar, cresce no ambiente exterior; risco para homossexual aumenta 13 vezes, diz pesquisador

DA REPORTAGEM LOCAL

Uma linhagem de bactéria potencialmente letal -e resistente a antibióticos- atravessou as fronteiras de hospitais nos EUA e está sendo transmitida entre homens gays pelo sexo, afirma estudo publicado anteontem. Os autores da pesquisa dizem que o patógeno conhecido como Sarm (Staphylococcus aureus resistente à meticilina), em geral restrito a casos de infecção hospitalar, está começando a aparecer fora dos ambientes clínicos em San Francisco e Boston.
"Uma vez que ela atingir a população geral, será mesmo irrefreável", diz Binh Diep, pesquisador da Universidade da Califórnia em San Francisco que liderou o estudo. "Tentamos divulgar a mensagem de prevenção." O trabalho de Diep, publicado na revista "Annals of Internal Medicine", diz que o risco de infecção para homens gays cresce 13 vezes em relação ao risco para heterossexuais. O estudo foi baseado no rastreamento de uma linhagem de S. aureus surgida por volta de 2000, identificada pela sigla USA300. A bactéria se espalha de forma rápida nas comunidades gays de San Francisco e Boston. "Achamos que ela se dissemina por meio de atividade sexual", afirma Diep.
Ao colher dados para o estudo, cientistas registraram os CEPs dos pacientes infectados, e o trabalho aponta que muitos habitam o bairro de Castro, em San Francisco, que tem uma grande comunidade gay.
Esse supermicróbio pode causar infecções mortais ou deixar cicatrizes profundas. Com freqüência, só um tratamento com antibióticos intravenosos caros é eficaz.
O Sarm matou cerca de 19 mil norte-americanos em 2005, a maioria deles em hospitais, segundo uma estimativa publicada em outubro na revista médica "Jama". O Brasil também tem infecções registradas da bactéria, mas não da linhagem USA300.
Cerca de 30% das pessoas em geral são portadoras de linhagens mais comuns de S. aureus. Elas podem ser transmitidas pelo toque direto ou por meio de objetos. A bactéria pode causar infecções mais grave se penetrar o corpo por feridas.
A maioria das pessoas portadoras de S. aureus leva a bactéria dentro do nariz, mas variedades do patógeno associadas a comunidades de pessoas infectadas podem viver também na região do ânus e serem passadas entre parceiros sexuais.
A incidência de Sarm nos EUA está aumentando ao lado de um ressurgimento de sífilis, gonorréia e novas infecções de HIV, parcialmente por causa de uma descrença sobre a gravidade do HIV e de um aumento dos comportamentos de risco, como o uso de drogas ilícitas e a prática de sexo abrasivo para a pele, escreve Diep.
"A probabilidade de alguém contrair cada uma dessas doenças aumenta com o número de parceiro sexuais", diz o cientista. "Provavelmente, o mesmo pode ser dito para a Sarm." O risco de infecção pela bactéria, porém, "parece ser independente de infecção por HIV", escreveram os cientistas.
Infecções por S. aureus costumam deixar pontos vermelhos nas áreas da pele atingidas. Se não forem tratadas, podem inchar. A melhor maneira de evitar a infeção é lavar mãos e genitália com sabão e água.
Segundo os pesquisadores, apesar de a Sarm encontrada em hospitais ser resistente a várias drogas, no caso da linhagem USA300 alguns antibióticos genéricos de tipos mais antigos ainda são capazes de controlar infecções menos complicadas de pele e mucosas. "Contudo, o crescente uso desses antimicrobianos pode levar ao surgimento de novos subclones [variantes] de Sarm associados a comunidades que são resistentes a muitas drogas", escrevem os cientistas.

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Com Reuters

Bacteria responsible for more deaths in the United States each year than AIDS.

Schools in Several States Report Staph Infections, and Deaths Raise the Alarm

Bill Crandall for The New York Times

The nurse, Jenny Jones, and the principal, William Gregory, at a Maryland high school where there were staph infections.

By IAN URBINA

The New York Times

SANDY SPRING, Md., Oct. 18 — When the football players here at Sherwood High School were not getting the message about washing their uniforms and using only their own jerseys, the school nurse paid a surprise visit to the locker room. She brought along a baseball bat.

“Don’t make me use this,” the nurse, Jenny Jones, said, pointing out that seven players on the team had already contracted a deadly drug-resistant strain of bacteria this year. “Start washing your hands,” she said. “I mean it.”

School officials around the country have been scrambling this week to scrub locker rooms, reassure parents and impress upon students the importance of good hygiene. The heightened alarm comes in response to a federal report indicating that the bacteria, methicillin-resistant Staphylococcus aureus, or MRSA, are responsible for more deaths in the United States each year than AIDS.

MRSA (pronounced MEER-suh) is a strain of staph bacteria that does not respond to penicillin or related antibiotics, though it can be treated with other drugs. The infection can be spread by sharing items, like a towel or a piece of sports equipment that has been used by an infected person, or through skin-to-skin contact with an open wound.

On Wednesday and Thursday, scores of schools were closed and events were canceled in Connecticut, Maryland, North Carolina, Ohio and Virginia as cleaning crews disinfected buses, lockers and classrooms. More closings are planned on Friday.

School officials in Mississippi, New Hampshire and Virginia reported student deaths within the past two weeks from the bacteria, while officials in at least four other states reported cases of students being infected.

The federal report, written by doctors at the Centers for Disease Control and Prevention, found that nearly 19,000 people had died in the United States in 2005 after an invasive MRSA infection. The study also suggested that such infections might be twice as common as previously thought.

This week, health officials began reporting a growing number of cases in schools, gyms and day care centers, and not just in nursing homes and hospitals, as has often been the case in the past.

Nicole Coffin, a spokeswoman at the centers, said that while the results of the study are striking, it is important to realize that about 85 percent of the infections reported from the bacteria were in health care settings.

“MRSA in the community is typically a mild skin infection that rarely becomes life-threatening,” she said, adding that even when it does become more severe, the death rates for this type of infection are low.

Here in Sandy Spring, students seem to be getting the message that they need to take extra care.

“I think they’re taking it seriously now,” William Gregory, the principal at Sherwood High School, said of members of the football team. “She is pretty emphatic,” he said, pointing to Ms. Jones. “But the students are also seeing the reports of deaths, and that has reminded them.”

He added that as he visits locker rooms now, the tell-tale stench is gone from athletes’ uniforms, and students are calling him and the nurse diligently when cuts do not seem to be healing.

Elsewhere in the state, more than two dozen staph infections have been reported by four Anne Arundel County high schools over the past three weeks. County officials sent letters to parents explaining that crews have been scrubbing schools with hospital-grade disinfectant.

Ashton Bonds was one of the rare cases of a death from MRSA contracted outside a health care facility. Mr. Bonds, a 17-year-old football player from Staunton River High School in Moneta, Va., died Monday from the bacteria.

“He put up a fight,” said Veronica Bonds, Ashton’s mother. “He was strong. I just think he was just tired, too.”

In response to the death, students throughout the county protested what they called unsanitary conditions in their school buildings.

Although school officials have observed that the bacteria mostly affect student athletes, cases have been reported in children of elementary school age as well.

“I worry about her getting sick anyway, but I don’t want her to catch something that will make her very, very ill,” said Kelli Stammen about her 2-year-old daughter, who attends city-sponsored recreation and library classes in Grove City, Ohio, where a 17-year-old high school student was put in intensive care unit in September with a staph infection.

The C.D.C. study found that 27 percent of all invasive MRSA infections originated in hospitals, while 58 percent began outside of a hospital but in patients with some recent exposure to the health care system.

The remaining 15 percent of invasive MRSA cases originated in the community without any apparent health care risk factor.

Bob Driehaus contributed reporting from Cincinnati.

Deadly Bacteria Found to Be More Common

By KEVIN SACK

Published: October 17, 2007

ATLANTA, Oct. 16 — Nearly 19,000 people died in the United States in 2005 after being infected with virulent drug-resistant bacteria that have spread rampantly through hospitals and nursing homes, according to the most thorough study of the disease’s prevalence ever conducted.

Ann Johansson for The New York Times
Dr. Elizabeth Bancroft called the findings “astounding.”

The government study, which is being published Wednesday in The Journal of the American Medical Association, suggests that such infections may be twice as common as previously thought, according to its lead author, Dr. R. Monina Klevens.

If the mortality estimates are correct, the number of deaths associated with the germ, methicillin-resistant Staphylococcus aureus, or MRSA, would exceed those attributed to H.I.V.-AIDS, Parkinson’s disease, emphysema or homicide each year.

By extrapolating data collected in nine places, the researchers estimated that 94,360 patients developed an invasive infection from the pathogen in 2005 and that nearly one of every five, or 18,650 of them, died. The study points out that it is not always possible to determine whether a death is caused by MRSA or merely accelerated by it.

The authors, who work for the Centers for Disease Control and Prevention, cautioned that their methodology differed significantly from previous studies and that direct comparisons were therefore risky. But they said they were surprised by the prevalence of serious infections, which they calculated as 32 cases per 100,000 people.

In an accompanying editorial in the medical journal, Dr. Elizabeth A. Bancroft, an epidemiologist with the Los Angeles County Department of Public Health, characterized that finding as “astounding.”

The prevalence of invasive MRSA — when the bacteria has not merely colonized on the skin, but has attacked a normally sterile part of the body, like the organs — is greater, Dr. Bancroft wrote, than the combined rates for other conditions caused by invasive bacteria, including bloodstream infections, meningitis and flesh-eating disease.

The study also concluded that 85 percent of invasive MRSA infections are associated with health care treatment. Previous research had indicated that many hospitals and long-term care centers had become breeding grounds for MRSA because bacteria could be transported from patient to patient by doctors, nurses and unsterilized equipment.

“This confirms in a very rigorous way that this is a huge health problem,” said Dr. John A. Jernigan, the deputy chief of prevention and response in the division of healthcare quality promotion at the disease control agency. “And it drives home that what we do in health care will have a lot to do with how we control it.”

The findings are likely to stimulate further an already active debate about whether hospitals and other medical centers should test all patients for MRSA upon admission. Some hospitals have had notable success in reducing their infection rates by isolating infected patients and then taking extra precautions, like requiring workers to wear gloves and gowns for every contact.

But other research has suggested that such techniques may be excessive, and may have the unintended consequence of diminishing medical care for quarantined patients. The disease control agency, in guidelines released last year, recommended that hospitals try to reduce infection rates by first improving hygiene and resort to screening high-risk patients only if other methods fail.

Dr. Lance R. Peterson, an epidemiologist with Evanston Northwestern Healthcare, said his hospital system in the Chicago area reduced its rate of invasive MRSA infections by 60 percent after it began screening all patients in 2005.

“This study puts more onus on organizations that don’t do active surveillance to demonstrate that they’re reducing their MRSA infections,” Dr. Peterson said. “Other things can work, but nothing else has been demonstrated to have this kind of impact. MRSA is theoretically a totally preventable disease.”

Numerous studies have shown that busy hospital workers disregard basic standards of hand-washing more than half the time. This week, Consumers Union, the nonprofit publisher of Consumer Reports, called for hospitals to begin publishing their compliance rates for hand-washing.

Lisa A. McGiffert, manager of the “Stop Hospital Infections” campaign at Consumers Union, said, “This study just accentuates that the hospital is ground zero, that this is where dangerous infections are occurring that are killing people every day.”

MRSA, which was first isolated in the United States in 1968, causes 10 percent to 20 percent of all infections acquired in health care settings, according to the disease control agency. Resistant to a number of front-line antibiotics, it can cause infections of surgical sites, the urinary tract, the bloodstream and lungs. Treatment often involves the intravenous delivery of other drugs, causing health officials to worry that overuse will breed further resistance.

The bacteria can be brought unknowingly into hospitals and nursing homes by patients who show no symptoms, and can be transmitted by contact as casual as the brush of a doctor’s lab coat. Highly opportunistic, they can enter the bloodstream through incisions and wounds and then quickly overwhelm a weakened immune system.

On Monday, a Virginia teenager died after a weeklong hospitalization for an MRSA infection that spread quickly to his kidneys, liver, lungs and the muscle around his heart. Local officials promptly closed 21 schools for a thorough cleaning.

A major difference between the new study and its predecessors is that it compiled confirmed cases of MRSA infection, rather than relying on coded patient records that sometimes lack precision. The study found higher prevalence rates and death rates for the elderly, African-Americans and men. The figures also varied by geography, with Baltimore’s incidence rates far exceeding those of the eight other locations: Connecticut; Atlanta; San Francisco; Denver; Portland, Ore.; Monroe County, N.Y.; Davidson County, Tenn.; and Ramsey County, Minn.

Dr. Klevens said further research would be needed to understand the racial and geographic disparities.