Healthcare systems urged to vaccinate workers

Medical Tribune August 2008 P7
David Brill

Widespread vaccination programs should be introduced for all healthcare workers and backed by the WHO, according to an infectious diseases expert from Mexico City.

Describing healthcare as “a very risky activity,” Dr. Samuel Ponce de Leon told the ICID that death and disease among personnel can have serious consequences for systems that are already short of important resources.

“Healthcare workers are an endangered species and a very reluctant one to be protected. A total of 57 countries, mostly in sub-Saharan Africa but also some Asian countries, face crippling healthcare worker shortages.

“Every health system, hospital, institute and outpatient clinic, private or public, should establish a program to vaccinate all healthcare workers as part of a comprehensive healthcare program,” he said, adding that “the WHO should establish obligatory regulation to protect healthcare workers.”

Hepatitis B, influenza, measles, rubella, tetanus and diphtheria – just some of the diseases faced by healthcare workers – should form the very minimum components of vaccination programs, according to Ponce de Leon.

Workers risk catching a wide range of infectious diseases from their patients if they are not vaccinated, and can be responsible for passing these on to other patients, medics and the community at large.

Compliance to healthcare worker vaccination schemes is typically poor, he said, suggesting that poor communication and lack of knowledge are typically responsible. Workers may also be reluctant to give up their time, have a fear of needles, or perceive vaccination as dangerous or unnecessary.

“Healthcare workers should be clear that compliance to be vaccinated is an ethical duty,” he said.

Despite the obstacles, vaccine uptake can be successfully promoted said Ponce de Leon, citing the example of a hospital campaign in Korea which boosted influenza vaccination rates among workers from 27 to 52 percent. [Infect Control Hosp Epidemiol 2006 Jun;27(6):612-7]

Beyond the basic schedule, vaccination programs could be extended to include hepatitis A, varicella and pneumoccocus, he said.

He added that avian influenza is also an area to consider but several issues remain unresolved as to what the best vaccine is and when best to use it.

Hygiene and education key to reducing catheter-related infections

Medical Tribune August 2008 P7
David Brill

Some 250,000 catheter-related bloodstream infections (BSIs) occur each year in the US, with mortality as high as 35 percent and avoidable costs totaling around US$6.25 billion.
Pic: hospital patient with a catheter line

However the number of infections can be dramatically reduced by following a range of simple steps, according to Trish Perl who is Professor of medicine, pathology and epidemiology at Johns Hopkins Hospital (JHH) in Baltimore.

Since introducing measures to reduce the rates of catheter-related BSIs, JHH has seen a 75 percent decrease across all of their adult intensive care units in the past 6 years, she said. The hospital published a report in 2004 in which they estimate that 43 BSIs, 8 deaths and nearly US$2 million dollars in costs have been prevented each year by the intervention strategy. [Crit Care Med 2004 Oct;32(10):2014-20]

Perl outlined three major contamination sites that can cause BSIs: the skin and insertion site, the catheter hub and the infusate. Each of these points provides a focal target for prevention strategies, she said, noting that the former two are of the greatest concern in developed countries whereas the latter is more of a problem in the developing world.

“It remains important to cleanse your hands … that recommendation actually has the strongest evidence,” said Perl, adding that employing maximal barrier precautions and educating health care workers who place catheters can also help to avoid skin-derived infections.

“These three recommendations are highly, highly supported by the evidence and should be in place in all settings. Knowledge and adherence to guidelines for all persons placing lines has also been shown to decrease your BSI rates,” she said.

Suggested maximal barrier precautions include wearing sterile gloves and gowns and tight-fitting non-sterile masks and hats, and covering the patient’s body with a sterile drape. Consideration should also be given to the site of catheter insertion, as the subclavian vein is associated with lower infection rates than the internal jugular and femoral veins she said.

Beyond the insertion site, catheter hubs and infusates are also an important source of infections said Perl, citing a study of four pediatric hospitals in Mexico City which found that 70 percent of injection ports and 7 percent of infusates were contaminated. [Infect Control Hosp Epidemiol 2004 Mar;25(3):226-30]

“Coated catheters have been shown to decrease BSI rates but given the cost we need to determine the high-risk patients and ensure that other prevention strategies are in place,” she said, adding that the use of antiseptic ports and caps and new stopcock models seem to cut infection rates.

BSI rates also seem to increase when nursing staff levels are low, and ensuring adequate levels of care at all times may also be an important prevention strategy.

Perl noted, however, that certain newer models of needleless connectors have actually led to increased infection rates.

“I think we have to really start considering whether or not the technology can actually contribute to BSIs,” she said.

Perl concluded by adding that future infection control programs should use standard definitions, so that feedback can be easily provided to the healthcare workers who are responsible for the placement of catheters.

Community-acquired MRSA: The new breed of nosocomial pathogen

Medical Tribune August 2008 P9
David Brill

The emergence of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) as a nosocomial pathogen presents a range of new challenges for both prevention and management, according to a leading infectious disease specialist.

Professor Richard Wenzel, president of the International Society for Infectious Diseases, told the audience at the ICID that CA-MRSA appears to be more virulent than other nosocomial strains and has an unknown epidemiology.

He described the case that first “gave him respect for CA-MRSA:” a 22-year old male who deteriorated rapidly and died within 36 hours.

The patient had normal heart sounds on admission, yet developed a systolic murmur and symptoms of endocarditis after 16 hours. CT at presentation was also normal, yet MRI performed shortly before death showed around 100 brain abscesses which were later confirmed by biopsy.

It is unclear exactly what makes CA-MRSA so virulent, said Wenzel. The Panton-Valentine leucocidin (PVL) gene and alpha hemolysin have both been implicated in animal models, but their precise roles remain unclearly defined.

Screening also appears to be a complicated issue: a prospective cohort study of 51 CA-MRSA patients found that only 41 percent were nasal carriers, while a report of five patients who received the infection via heterosexual transmission revealed that only one was a nasal carrier.

Screening would therefore underestimate the prevalence of the USA-300 and USA-400 strains, Wenzel said, whereas in cases of nosocomial MRSA the majority of patients test positive for USA-100.

“This is important because people in the US are saying we just have to screen people so we know who’s out there. But it’s not that simple,” he said.

The antiobiogram for CA-MRSA also seems to differ from other types of infection, and the optimal treatment strategy remains unclear.

“The problem is what drugs do you use? I want to tell you this is getting complicated,” said Wenzel, who is chairman of the department of internal medicine at Virginia Commonwealth University, US.

“For life-threatening infections, antibiotics that inhibit protein synthesis and intravenous immunoglobulin may be useful,” he said, but noted that side effects are an issue with many of the available drug treatments.

“Linezolid we think is a relatively good drug but neuropathy, lactic acidosis and serotonin syndrome have all been described.

“Daptomycin looks good in comparative trials for skin and soft tissue. However, it’s not recommended for pneumonia because surfactant inhibits the antibacterial activity.”

He added that vancomycin can lead to renal failure when given with amino glycosides, while trimethoprim causes hyperkalemia in the majority of patients.

Definitive answers are still lacking on what treatments to use either for preventative prophylaxis of CA-MRSA or for treating ventilator-associated pneumonia, Wenzel said, noting that there are currently no clinical trials which can inform these decisions.

Improving our knowledge of resistant pathogens, drug interactions and the adverse events of antibiotics may help in future, he said.

“The plans for changing the prophylactic and empirical therapy for nosocomial infections need to begin right now,” he concluded.