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Infection Control Articles


Extensively Drug Resistant Tuberculosis (XDR-TB)

July 2007

The news story seemed reminiscent of a Keystone Kops cinema: police and health officials chasing a handsome, healthy-looking 31-year-old globe-trotting attorney Andrew Speaker, and his beautiful bride, through city after city in at least 5 countries, being eluded at hotels, airports, and border checkpoints, only to have the gentleman turn himself in at a New York City hospital, and finally having agents of the Centers of Disease Control and Prevention (CDC) put him into strict isolation for being infected with a deadly and dangerous contagion - tuberculosis (TB)! Wait - is TB dangerous? Isn't TB easily treatable and curable?

What is Extensively Drug Resistant-TB (XDR-TB)? TB is caused by the micro-organism Mycobacterium tuberculosis (MTb). XDR-TB is a strain of MTb resistant not only to the first-line anti-TB drugs (rifampicin and isoniazid), but also to the best second-line drugs, fluoroquinolones, and at least one of the injectable drugs (i.e., amikacin, kanamycin, or capreomycin). This leaves very few treatment options for the patient diagnosed with XDR-TB. According to the aid agency, Doctors Without Borders, treatment for XDR-TB is non-existent in many countries. Health officials think Andrew Speaker may have been infected when he visited Asia as a hospital fundraiser.

Each year, around the world, an estimated 450,000 patients are diagnosed with multiple drug resistant TB, and only two-thirds of them are cured. The World Health Organization (WHO) has confirmed 269 cases of XDR-TB in 35 countries, including the United States. About 85% of these patients are expected to die as a result of this disease. The worst health ramifications come to those who are infected with HIV/AIDS - approximately 90% die within months of contracting TB. According to the CDC, there have been 49 XDR-TB cases in the US since 1993. In March 2007 Italy reported the first case of a patient with TB resistant to "all known drugs." Generally speaking, resistant TB resulted when people self-prescribed or otherwise did not take their antibiotics as directed.

What are the symptoms of XDR-TB? Symptoms of TB disease can vary depending on what part of the body is affected. However, the disease is only contagious when it is located in the lungs or throat. General symptoms include feelings of sickness or weakness, weight loss, fever, and night sweats. Active pulmonary TB disease symptoms may also include coughing, chest pain, and hemoptysis (coughing up blood).

How do I protect myself when I travel? Singing, coughing, sneezing, or speaking can aerosolize MTb into the air where it can "float" for several hours, depending on the environment. Persons who breathe in the air containing MTb can become infected. Airline travel carries a relatively low risk of infection to TB, as TB transmission requires prolonged close contact with someone who is highly infected. However, travelers should avoid high-risk settings where few or no infection control measures are in place, such as crowded hospitals, prisons, homeless shelters, and other settings where susceptible persons come in contact with persons with active TB disease. A TB skin test or the QuantiFERON®-TB Gold blood test can help determine if a person has been exposed to MTb. Final diagnosis for TB, and especially for XDR TB, may take from 6 to 16 weeks.

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Hepatitis B (March 2004)


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Infections caused by C. trachomatis (CT) and N. gonorrhoeae (NG)

Infections caused by C. trachomatis (CT) and N. gonorrhoeae (NG)are two of the most common sexually transmitted diseases (STD) in the United States and worldwide. Each may cause asymptomatic infections, compounding the problem of diagnosis and contributing to the spread of disease. The application of sensitive and specific screening methods for the diagnosis of CT and GC infection is an important tool for controlling the spread of these organisms and reducing the serious complications of untreated disease.

There has been a revolution in diagnostic methodology in recent years with the introduction of nucleic acid testing. Estimates of prevalence of infection determined in the past by tissue culture or antigen detection methods were gross underestimates. NAAT offers the highest sensitivity: 96-99% for CT and NG, and highest specificity: 96-99% for CT and NG. Nucleic acid amplification tests (NAAT) have consistently exceeded the sensitivities and specificities of non-NAAT methods (culture and indirect fluorescent antibody testing) in the detection of these organisms. The CDC, therefore, recommends use of a NAAT to screen for genitourinary infection with CT and GC. At JMMC, the Roche Cobas Amplicor is employed for the detection of CT and NG by PCR. Acceptable specimens include female endocervical swabs, urine or ThinPrep Pap Test specimens and male urethral swabs or urine specimen.

Genital infection with Chlamydia is the most common bacterial STD in the U.S. and is responsible for about 40% of nongonococcal urethritis in men. In women, genital chlamydial infections are a major cause of pelvic inflammatory disease (PID), which is an important cause of chronic pelvic pain, ectopic pregnancy, and infertility. Perinatal transmission of C.trachomatis to infants can cause neonatal conjunctivitis and pneumonia. Since infections in women and men are asymptomatic, rapid and accurate laboratory diagnosis is important for optimal management of infection in patients and for the interruption of transmission to contacts.

Gonorrhea is an important cause of urethritis in men and cervicitis in women. Approximately 20% to 40% of pelvic inflammatory disease and 14% of tubal infertility can be attributed to gonococcal infections. Additionally, 30-50% of men and women with gonococcal disease are co-infected with C.trachomatis. Therefore, laboratory tests designed to simultaneously detect C.trachomatis and N. gonorrhoeae from a single amplification reaction offer a distinct advantage.

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Influenza (December 2003)


Here are some facts published in Hospital Employee Health - March 2003:

The article recommendations include:

Become proactive. Now is the time to implement a strategy for vaccination!

The most common reason employees are not vaccinated stems from the common misconception that influenza can be acquired as a result. This of course is not possible! So, order your vaccine soon, and develop a strategy to encourage all employees and your elderly patients to get vaccinated!

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Influenza Pandemic (March 2006)

An influenza pandemic is a worldwide outbreak of infection. This occurs when a new influenza A virus subtype emerges that has never circulated among people or has not circulated among people for a long time. No one will have immunity to this virus. To cause a pandemic the new subtype must be able to spread easily from person to person. This is different from seasonal outbreaks that are caused by influenza subtypes that are already in circulation.

There were three pandemics during the 20th century. The 1918-19 Spanish Flu, the 1957-58 Asian Flu, and the 1968-69 Hong Kong Flu . During the Spanish Flu pandemic more than 500,000 people died in the US and more than 50 million people died worldwide. Many people died within a few days after infection and nearly half of those were young healthy adults. The Asian and Hong Kong flu pandemics were caused by viruses containing a combination of genes from human and avian influenza viruses. The Spanish flu virus seemed to have an avian origin.

Scientists believe that there will be another influenza pandemic and that it is only a question of when this will occur. No one knows how severe it will be but even a moderate pandemic could cause 200,000 deaths in the US, and millions more to become sick. Such a pandemic could overwhelm our nation's health care system and cause a severe economic impact. A vaccine would probably not be available in the early stages of a pandemic due to production time. The four different antiviral medications currently available to treat or prevent influenza may not be effective because influenza virus strains can become resistant to them.

The Centers for Disease Control and Prevention and the World Health Organization are monitoring influenza around the world, searching for possible pandemic strains. There is currently a concern about the H5N1 avian influenza causing human infection in Asia. The current mortality rate for human H5N1 infection in Asia is about 50%. Federal, state and local public health organizations are working together to be able to respond effectively to an influenza pandemic.

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List Of Reportable Diseases

April 2008

Facilities have a special responsibility to their patients, especially those susceptible to adverse reactions to infection, to practice constant and systematic surveillance for early detection of nosocomial infections and to respond rapidly to contain outbreaks. Outbreaks can be caused by any number of organisms (bacteria, viruses, fungi, parasites) or their toxins. Early recognition of such adverse events followed by an immediate response to reduce their spread is vital. The California Department of Public Health (CDPH) can be of major assist to facilities in the recognition and control of outbreaks of infectious diseases.

While certain diseases are defined by law or public health decree to be reportable (the list for California can be found at http://www.cdph.ca.gov/HealthInfo/Pages/ReportableDiseases.aspx) any "OCCURRENCE of ANY UNUSUAL DISEASE" and "OUTBREAKS OF ANY DISEASE (including diseases not listed in Section 2500)" are reportable to the local public health officer. This means that even if not listed, the disease or event may be reportable if it is rare or the number of cases is beyond what is generally expected (definition of an "outbreak").

Reporting these events to the local Public Health Officer is the mandated duty of "every health care provider" or health facility administrator: all who "may know of a case, a suspected case or an outbreak of diseases within the facility." Certainly, if there is a question as to whether an event should be reported to either public health or one's licensing body, it is always better to ask the agency or Health Officer if they want to know about it, than not report the event at all.

The reportable diseases list was first published in 1945 and has been amended nine times to reflect the changing needs and priorities for Statewide surveillance. In 2004 legislation was signed into law to allow the list to be changed by CDPH in consultation with the California Conference of Local Health Offices (CCLHO), without going through the formal regulatory process.

In 2006 shiga toxin became reportable by both providers and laboratories. The Centers for Disease Control and Prevention (CDC) also recommended that all stool specimens be tested for the toxin. This necessitated a change in the collection of stool specimens: all stool specimens brought to the lab now had to be refrigerated and tested for shiga toxin, even if this test is not specifically requested by the physician.

In 2007 four disease additions were made to Section 2500 (list of diseases): avian influenza, chickenpox hospitalizations and deaths, Cruetzfeldt-Jakob Disease and other transmissible spongiform encephalopathies (TSE), and influenza deaths in persons less than 18 years of age.

More recently, in February 2008, Staphylcoccus aureus was added: "Staphylococcus aureus infection (only a case resulting in death or admission to an intensive care unit of a person who has not been hospitalized or had surgery, dialysis, or residency in a long-term care facility in the past year, and did not have an indwelling catheter or percutaneous medical device at the time of culture.)" See http://www.cdph.ca.gov/HealthInfo/news/Pages/Update%2003-08.aspx. This includes both the methicillin sensitive (MSSA) and methicillin resistant (MRSA) strains. The date as to when this regulation goes into effect has, as of February 2008, not been published.

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Norwalk-Like Viruses (April 2004)


Norwalk-Like Viruses are responsible for causing gastroenteritis outbreaks in many long-term care facilities. The transmission route is fecal-oral. The virus can be spread by food or water but is most frequently spread by the contaminated hands of healthcare workers. Environmental surfaces can also become contaminated, especially in areas where vomiting has suspended viral particles in the air.

The virus is from a family called Caliciviridae. This small virus is extremely infectious requiring only a small number of viral particles to produce symptoms. This virus can survive freezing, and heating to 60C, making it difficult to eliminate from food and water.

The incubation period is 12-48 hours and produces symptoms for 12-60 hours. The symptoms may include nausea, vomiting, abdominal cramps, diarrhea, headache, fever, chills and mylagia. The virus is present in vomitus and stool. Viral shedding begins a few hours before symptoms and may last a week or more even if symptoms are minimal. Immunity does occur after the infection but it will probably only last for six months.

There is no specific therapy available for treatment. The illness is self-limited requiring supportive care occasionally including fluid and electrolyte replacement. Facility outbreaks must be reported to DHS and public health. Control measures must be taken to interrupt the person to person transmission. Outbreaks should be detected early based on symptoms not lab test results.

DHS and some public health departments can provide PCR testing of stools free of charge in outbreak situations. MuirLab can provide stool testing through our reference lab. Specimens need to be obtained during early symptoms and sent fresh. Be sure to follow the lab directions for correct container and refrigeration requirements.

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Pets & Vector Control

In the US West Nile Virus has been identified in over 200 species of birds. Avian influenza tends to favor wild water fowl, dogs, cats, skunks, raccoons, bats, and some other animals can transmit rabies. Though rats are the most frequent carrier, domestic cats are also highly susceptible to plague (Yersinia pestis). In 2005, four pet cats in California were found to have plague. As such, we are reminded that disease vectors are not limited to feral animals.

This year (2006) a healthy 4-year old toy poodle was found to be the carrier of a new epidemic strain of CDAD (Clostridium difficile associated disease). This strain has been implicated in outbreaks of CDAD in hospitals in North America and Europe. It is spreading internationally at an alarming rate, and infecting people who are without the usual risk factors for C difficile. The strain, found in the dog, is classified as ribotype 027, toxinotype III, and possesses genes encoding toxins A, B, and CDT (binary toxin) as well as a deletion in the tcdC gene, which is believed to increase virulence. Infection control investigators became suspicious when outbreaks at several hospitals and nursing homes coincided with the pet's visit.

Such situations highlight the importance of protecting one's clothing (Clostridium difficile can cling to clothes) when handling visiting animals. Careful hand-washing after handling animals is important. Consideration should be given to visiting animals and pets when investigating sources of facility outbreaks.

There are no specific rules or regulations regarding surveillance of infection in facility pets or animal visitors. It is, however, prudent that all pet owners be able to name their animal's veterinarian, attest to the health and immunization status of their animals, and if asked, have the ability to produce documents attesting to this.

Pets, like their human owners, should be protected from common vectors, such as mosquitoes and fleas, and discouraged from approaching sick feral animals. Notify your local public health or animal health agency to remove sick or dead birds and other animals.

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Reducing MRSA (Methicillin-resistant Staphylococcus aureus) Transmission

January 2008

According to an October 2007 report from CDC researchers1, more people in the United States now die from an MRSA infection than from AIDS. About 85% of MRSA infections in 2005 were acquired in the healthcare setting. Those at highest risk for an MRSA infection in the healthcare setting are patients who undergo invasive medical procedures, patients with weakened immune systems and are being treated in hospitals, and patients in nursing homes and dialysis centers. Approximately 15% of invasive MRSA infections were in people with no known health care risk or exposure. Those over age 65 were four times more likely and Blacks twice as likely to get an MRSA infection than the general population. Males were more likely to become infected than females. Those at lowest risk were children over the age of 4 and teenagers.

Transmission of MRSA tend occur in 5 general situations referred to as the 5 C's: Crowding, frequent skin-to-skin Contact, Compromised skin (i.e., cuts or abrasions), Contaminated items and surfaces, and lack of Cleanliness. Healthcare workers' hands are most often cited as the primary means of person to person MRSA transmission. Therefore, basic patient care dictates all healthcare workers wash all surfaces of their hands frequently; when personal protective equipment (PPE), such as gloves, are removed; when the hands become visibly soiled; and after contact with the patient or patient's environment. Gloves, PPE, contaminated bandages and other materials should be discarded in a covered container or a sealed plastic bag. If infectious material is also contaminated with blood, then disposal is according to blood borne pathogen regulations.

Preventing MRSA transmission in the healthcare setting requires a multi-pronged approach.
  1. Good Hand Hygiene: prior to performing a procedure on a patient ask - Am I going to come into contact with any body fluids, blood, open skin, or mucous membranes? If yes, then appropriate PPE should be donned. Use lotion to maintain healthy hands.
  2. Good skin hygiene: patients should be assisted in maintaining clean and intact skin - by bathing or showering several times a week and washing hands frequently. Skin tends to dry and crack in the wintertime. The skin of geriatric and immuno-compromised patients tend to tear and bruise easily.
  3. Dedicated Medical Equipment: if dedicating equipment is not possible, disinfect reusable equipment prior to use on another patient. The necessity of urinary catheters and other devices should be well-considered before placement and removed as soon as possible.
  4. Good Housekeeping should ensure regular and routine cleaning of patient's room; and deep cleaning and disinfection when a patient is discharged or returned to Standard Precautions; and after an outbreak.
  5. Laundry should ensure availability of fresh, clean clothes or gowns for patients' daily wear.
  6. Reservoirs, patients who are colonized or actively infected, should be closely monitored and any potential drainage controlled and covered.
  7. Antibiotic use should be targeted and prudent.

1 See Journal of the American Medical Association 2007;298(15):1763-1771

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Urinary Tract Infections

Urinary tract infections (UTIs) are the most common type of healthcare-associated infection in both the acute and long term care setting. UTIs are the most difficult nosocomial infection to control and eradicate, and contribute substantially to patient morbidity, mortality, healthcare costs, annual doctor visits, and antibiotic use. With advancing age and debilitation the risk for a UTI increases. However, infections in the elderly pose special problems since they are difficult to diagnose due to their atypical presentation or the older person's inability to mount a typical reaction to infection. Rather than presenting the usual symptoms of frequency and dysuria, they may instead demonstrate decreased functional capacity, increased incontinence or number of falls, or worsening mental status.

Women, in particular, are susceptible to UTIs and are also noted to present with atypical symptoms, such as feeling irritable, hot, tired, weak, restless, or, generally unwell. Older women may have additional risks: increased vaginal pH, vaginal atrophy, incomplete bladder emptying or urinary retention, weak pelvic floor muscles, and general debility.

In dealing with UTIs, consider the following: A complete and careful assessment at the start is vital. Treatment of bacteriuria without the accompanying symptoms is NOT recommended. For the elderly treatment of asymptomatic UTIs does not reduce morbidity or mortality.

Discriminate use of antibiotics. Antibiotics are generally NOT recommended for the asymptomatic person despite pyuria or a urine culture suggestive of a UTI.

Diligent hand washing, hygienic practice, and use of aseptic technique are recommended. This may mean more frequent perineal cleansing, showers, or changes of urinary pads or underwear; antibacterial soaps for pericare; softer pads, toilet tissues, or underwear; instruction in or assistance with personal hygiene, e.g. gentle wiping from front to back after toileting; reduction of urinary retention or residual urine by complete and frequent bladder emptying. Urologic consult and treatment may be needed for frequent or recurrent UTIs.

While cloudy or foul-smelling urine does not always necessitate a UTI workup, a workup should be considered if the person has a previous history of UTI. Consider prophylactic cranberry supplements such as juice, capsules, tablets, or dried cranberries.

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West Nile Virus (July 2004)


This virus was first identified in 1937 in the West Nile District in Uganda. It arrived in the US during the summer of 2000. California had two imported human cases in 2002 and several cases in the Los Angeles area in 2003. Dead birds, infected with West Nile Virus, were found in the Los Angeles area in 2004.

This viral infection is spread by mosquitoes primarily to birds, but horses and humans can also be infected. Mosquitoes become infected carriers when they feed on infected birds. A very small number of people have been infected through blood transfusions, organ transplants and breast milk.

Most people who are bitten by a mosquito with West Nile Virus will not get sick. Approximately 20% will get a mild illness including fever, muscle aches, headache, nausea, and vomiting. Approximately 1 in 150 infections will result in severe neurological disease. Encephalitis is more commonly reported than meningitis.

The incubation period for this virus is thought to range from 2 to 14 days, but most typically from 2 to 6 days. Mild cases usually produce symptoms for 3 to 6 days. The most significant risk for developing severe neurological disease is advanced age.

Although West Nile Virus can be transmitted year round in warmer climates, it is most commonly seen in the summer and autumn. Prevention includes using DEET mosquito repellent, the wearing of long sleeve clothing, and avoiding outdoor activity at dusk and dawn. Make sure window screens are in good repair, and drain sources of standing water where mosquitoes may breed and lay their eggs.

Diagnostic testing for West Nile virus can be obtained through local or state health departments for patients with encephalitis or meningitis. The most efficient diagnostic method is detection of IgM antibody to WNV in serum or cerebral spinal fluid collected within 8 days of illness onset using the IgM antibody capture enzyme-linked immunosorbent assay (MAC-ELISA).

Treatment is supportive often involving hospitalization, IV fluids, respiratory support and prevention of secondary infections.

West Nile virus infection is reportable to both local and state health departments. WNV encephalitis is on the list of designated nationally notifiable arboviral encephalitides.

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