SCREENING FOR ABDOMINAL AORTIC ANEURYSM:U.S PREVENTIVE SERVICES TASK FORCE RECOMMENDATION STATEMENT

 

 

 

 

 

 

Recommendation:

Ø The USPSTF recommends 1-time screening for Abdominal Aortic Aneurysm (AAA) with ultrasonography in men aged 65 to 75 years who have ever smoked (B recommendation)

Ø The USPSTF recommends that clinicians selectively offers screening for AAA in men aged 65 to 75 years who have never smoked (C recommendation)

Ø The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for AAA in women aged 65 to 75 years who have ever smoked (I statement)

Ø The USPSTF recommends against routine screening for AAA in women who have never smoked (D recommendation)

Risk factor for AAA include older age, a positive smoking history, having a first-degree relative with an AAA; and having history of other vascular aneurysms, coronary artery disease, cerebrovascular disease, atherosclerosis, hypercholesterolemia, obesity, or hypertension.

Factor associated with a reduced risk for AAA include African American race, Hispanic ethnicity, and diabetes.

Abdominal duplex ultrasonography is the standard approach for AAA screening. Screening with ultrasonography is noninvasive and easy to perform and has high sensitivity (94 % t0 100%) and specificity (98 % to 100 %) for detection.

Patient with large AAA (> or = 5.5 cm) are referred for open surgical repair or endovascular aneurysm repair. Patient with smaller aneurysm (3.0 to 5.4 cm) are generally managed conservatively via surveillance (repeated ultrasonography every 3 to 12 mo).

Early open surgery for the treatment of smaller AAAs does not reduce AAA-specific or all-cause mortality. Surgical referral of smaller AAAs is typically reserved for rapid growth (>1.0 cm per year) or once the threshold of > 5.5 cm on repeated ultrasonography is reached.

Short-term treatment with antibiotics or B-blockers does not seem to reduce AAA growth.

Bibliography

LeFevre, M. L. (2014, Aug 18). Screening for Abdominal Aortic Aneurism: U.S. Preventive Services Task Force Recommendation Statement. Ann of Int Med, ;161(4):281-291. Retrieved from Annals of Internal Medicine: http://annals.org

 

 

 

 

FLESH-EATING BACTERIA: VIBRIO VULNIFICUS & NECROTIZING FASCIITIS

Recently we have been hearing news about the “flesh eating bacteria”, creating a panic in our community. While the existence of this bacterium is real, it would be important to know more details about the bacteria that are affecting the Florida coastal area of the Gulf of Mexico and the bacteria commonly known as "flesh-eating bacteria" which produce what is medically known as "necrotizing fasciitis".

VIBRIO VULNIFICUS:

The first documented case of a disease caused by the Vibrio Vulnificus was in 1979, it is a gram-negative bacillus that only affects humans and other primates, and is usually found in warm, shallow, coastal salt water in temperate climates throughout most of the world (Schwartz, 2012).

Vibrio Vulnificus is a bacterium in the same family as those that cause cholera, the Vibrionaceae family that includes the genera Vibrio, Plesiomonas, and Aeromonas. As we mentioned before, they are natural inhabitants of sea water but they can also be found in fresh water, and they are part of the group of vibrios that known as halophilic because they require salt for growth (Ho, 2011).

These bacteria can cause disease in those who eat contaminated seafood or have an open wound that is exposed to seawater. Among healthy people, ingestion of Vibrio Vulnificus can cause vomiting, diarrhea, and abdominal pain. In immuno-compromised persons, particularly those with chronic liver disease, it can infect the bloodstream, causing a severe and life-threatening illness characterized by fever and chills, decreased blood pressure, and blistering skin lesions. 50 % of the time the bloodstream infection of Vibrio Vulnificus can be fatal (CDC, 2013).

Vibrio Vulnificus, according to Centers for Disease Control and Prevention (2013), can cause an infection of the skin when open wounds are exposed to warm seawater; these infections may lead to skin breakdown and ulceration. Persons who are immuno-compromised are at higher risk for invasion of the organism into the bloodstream and potentially fatal complications.

Antibiotics are necessary to eradicate the infection because it improves survival. In case of wound infection, aggressive debridement is useful to remove necrotic tissue, amputation of the infected limb is sometimes necessary. Also in patients with shock, resuscitate interventions should be performed (Schwartz, 2012).

The CDC recommends:

ü Culture of wound or hemorrhagic bullae, all V. Vulnificus isolates should be forwarded to a public health laboratory.

ü Blood cultures are recommended if the patient is febrile, has hemorrhagic bullae, or has any signs of sepsis.

ü Antibiotic therapy:

·        Doxycycline (100 mg PO/IV twice a day for 7-14 days) and a third-generation cephalosporin (e.g. ceftazidime 1-2 g IV/IM every eight hours) are generally recommended.

·        A single agent regimen with a fluoroquinolone such as Levofloxacin, Ciprofloxacin or Gatifloxacin, has been reported to be at least as effective in animal model as combination drug regimens with Doxycycline and a Cephalosporin.

·        Children, in whom Doxycycline and Fluoroquinolones are contraindicated, can be treated with Trimethoprim-Sulfamethoxazole plus an Aminoglycoside.

·        Necrotic tissue should be debrided; severe cases may require fasciotomy or limb amputation.

 

V. Vulnificus septicemia is the most common cause of death from seafood consumption in the United Stated (Haq & Dayal, 2005).

Choi, et al., reported in 2005 that the first evidence of V. Vulnificus septicemia was in the skin as purpura fulminans, which can take a catastrophic course without inmediate and intensive empirical antibiotic treatment. Furthermore V. Vulnificus infection may be a rare cause of necrotizing fasciitis, but it can be fatal (Tajiri, et al., 2008).

NECROTIZING FASCIITIS:

Necrotizing Fasciitis, first discribed by Joseph Jones, a Conferate Army surgeon, during the US Civil War, is a serious bacterial infection that spreads rapidly and destroys the body’s soft tissue (Quirk & Sternbach, 1996). It is considered a life-threatening disease that is often difficult but crucial to diagnose as soon as possible in order to save a life (Swain, Hatcher, Azadian, Soni, & De Souza, 2013).

Commonly called a “flesh-eating infection”, Necrotizing Fasciitis is a rare disease with a rapidly progressive inflammatory infection of the facia and a secondary necrosis of the subcutaneous tissue.

The causative bacteria, as mentioned by Richard E Edlich (2013), may be aerobic, anaerobic, or mixed flora (Kihiczak, Schwartz, & Kapila, 2006). There are a few recognized distinct syndromes of this entity where the most important are:

·        Type I, or polymicrobial

·        Type II, or group A streptococcal

·        Type III gas gangrene, or Clostridial Myonecrosis

There are a variety of organisms capable to causing Necrotizing Fasciitis; these include group A Streptococcus, Klebsiella, Clostridium, E. Coli, Staphylococcus aureus, and Aeromonas hydrophila, among others (CDC, 2013). A variant of Necrotizing Fasciitis type I is a saltwater necrotizing fasciitis, in which an apparently minor skin wound is contaminated with saltwater containing a Vibrio species (Edlich, 2013).

In many cases of Necrotizing Fasciitis, antecedent trauma or surgery can be identified; the initial lesion is often trivial, such as an insect bite, minor abrasion, boil, or injection site. The hallmark symptom is intense pain and tenderness over the involved skin and underlying muscle (Olafsson, Zeni, & Wilkes, 2005). But also the symptoms may begin at a site distant from the initial traumatic insult.

Most people who get Necrotizing Fasciitis have other health problems that may lower their body’s ability to fight infection such as diabetes, kidney disease, cancer, or other chronic health conditions that weaken the immune system.

Beginning an immediate treatment is essential in Necrotizing Fasciitis once the diagnose is confirmed. Antibiotic therapy is a key consideration, including a combination of penicillin G and an Aminoglycoside, as well as Clindamycin. Keep in mind that Necrotizing fasciitis is a surgical emergency and the patient should be admitted immediately to a surgical intensive care unit, where the surgical staff is skilled in performing extensive debridement and reconstructive surgery (Edlich, 2013).

If you are healthy, have a strong immune system, and practice good hygiene and proper wound care, your chances of getting Necrotizing Fasciitis are extremely low, explains m the CDC.

 

Bibliography

 

CDC. (2013, Jun 28). cdc.gov. Retrieved from Necrotizing Fasciitis: A rare disease, especially for the healthy: http://www.cdc.gov/features/NecrotizingFasciitis/

CDC. (2013, Oct 21). Centers for Disease Control and Prevention. Retrieved from Vibrio Illness: http://www.cdc.gov/vibrio/vibriov.html

Choi, H., Lee, D., Lee, M., Choi, M., Moon, K., & Koh, J. (2005). Vibrio Vulnificus septicemia presenting as purpura fulminans. J Dermatol, ;32(1):48-51.

Edlich, R. F. (2013, Apr 29). medscape.com. Retrieved from Necrotizing Fasciitis: http://emedicine.medscape.com/article/2051157-overview#a0101

Haq, S., & Dayal, H. (2005). Chronic Liver diseaseand consumtion of raw oysters: a potentially lethal combination--a review of Vibrio vulnificus septicemia. Am J Gastroenterol, ;100(5):1195-9.

Ho, H. (2011, Aug 15). medscape.com. Retrieved from Vibrio Infection: http://emedicine.medscape.com/article/232038-overview#a0104

Kihiczak, G., Schwartz, R., & Kapila, R. (2006). Necrotizing Fasciitis: a deadly infection. J Eur Acad Dermatol Venereol, ;20(4):365-9.

Olafsson, E., Zeni, T., & Wilkes, D. (2005). A 46 year old man with excruciating shoulder pain. Chest, ;127(3):1039-44.

Quirk, W., & Sternbach, G. (1996). Joseph Jones: infection with flesh eating bacteria. J Emerg Med, ;14(6):747-53.

Schwartz, R. A. (2012, Sep 17). medscape.com. Retrieved from Vibrio Vulnificus Infection: http://emedicine.medscape.com/article/1055523-overview

Swain, R., Hatcher, J., Azadian, B., Soni, N., & De Souza, B. (2013). A five-year review of necrotizing fasciitis in a tertiary referral unit. Ann R Coll Surg Engl, ;95(1):57-60.

Tajiri, T., Tate, G., Akita, H., Ohike, N., Masunaga, A., Kunimura, T., . . . Morohoshi, T. (2008). Autopsy cases of fulminant-type bacterial infection with necrotizing fasciitis: group A (beta) hemolytic Streptococcus pyogenes versus Vibrio vulnificus infection. Pathol Int, ;58(3):196-202.

 

 

EBOLA VIRUS INFECTION: BRIEF REVIEW

 

The Centers for Disease Control and Prevention on Wednesday ramped up its response to the expanding Ebola outbreak, a move that frees up hundreds of employees and signals the agency sees the health emergency as a potentially long and serious one (NBCNews.com, 2014). 

The CDC’s “level 1 activation” is reserved for the most serious public health emergencies, and the agency said, according to NBCNEWS, the move was appropriate considering the outbreak’s “potential to affect many lives.” The CDC took a similar move in 2005 in the aftermath of Hurricane Katrina, and again in 2009 during the bird-flu threat.

The Ebola outbreak is believed to have killed 932 people in the African nations of Liberia, Sierra Leone, Nigeria and Guinea. Two American aid workers sickened by the disease were flown back to the U.S. for treatment at a medical facility in Atlanta.

The CDC is deploying additional staff to the four affected countries, and said 50 more disease-control experts should arrive there in the next 30 days. It also issued instructions to airlines that may come into contact with passengers from the affected countries designed to minimize the chance of infection (NBCNews.com, 2014).

Ebola Virus Infection:

Ebola virus is one of at least 30 known viruses capable of causing viral hemorrhagic fever syndrome. Although agents that cause viral hemorrhagic fever syndrome constitute a geographically diverse group of viruses, all those identified to date are RNA viruses with a lipid envelope, all are considered zoonoses, all damage the microvasculature resulting in increased vascular permeability, and all are member of one of the following families: Arenaviridae, Bunyaviridae, Flaviviridae or Filoviridae (King, 2013).

The genus Ebolavirus is one of three members of the Filoviridae family (WHO, 2014) currently classified into 5 separate species such as Sudan Ebolavirus, Zaire Ebolavirus, Tai Forest (Ivory Coast) Ebolavirus, Reston Ebolavirus, and Bundibugyo Ebolavirus (King, 2013).

According to John W King, there are recognized two type of exposure: Primary (involves travel to or work in an Ebola endemic area) and Secondary (refers to human to human exposure, primate to human exposure, or personal who collect or prepare bush meat for human consumption.

The natural reservoir host of ebolaviruses remains unknown (Centers for Disease Control and Prevention , 2014). However, on the basis of available evidence and the nature of similar viruses, researchers believe that the virus is zoonotic (animal-borne) with bats being the most likely reservoir.

Ebola Hemorrhagic Fever is one of numerous Viral Hemorrhagic Fevers; it is severe, often fatal disease in humans and nonhuman primates such as monkeys, gorillas, and chimpanzees. The physical finding depends on the stage of disease at the time of presentation. With African-derived Ebolavirus infection, there is an incubation period typically 3 to 8 days in primary cases and slightly longer in secondary cases (King, 2013), symptoms occur 4-16 days after infection with fever, chills, headache, myalgia, and anorexia (Dambro, 2001). Later findings may include expressionless facies, bleeding from intravenous puncture sites and mucous membranes, myocarditis and pulmonary edema, in terminally ill patients, tachypnea, hypotension, anuria and coma.

Diagnosis:

Ø  Basic blood test: CBC with differential, bilirubin, liver enzymes, BUN, Creatinine, ph.

            The early phase of infection is characterized by thrombocytopenia, leukopenia, and a pronounced lymphopenia. Neutrophilia develops after several days, as do elevations in aspartate aminotransferase and alanine aminotransferase. Bilirubin may be normal or slightly elevated.

           With the onset of anuria, blood urea nitrogen and serum creatinine increase. Terminally ill patients may develop a metabolic acidosis that may contribute to the observation that these patients often have tachypnea, which may be an attempt at compensatory hyperventilation.

Ø  Studies for isolating the virus: tissue culture, reverse-transcription polymerase chain reaction assay.

Ø  Serologic testing: ELISA for antigens or for immunoglobulin M and immunoglobulin G antibodies.

Ø  Other studies: immunochemical testing of postmortem skin, Electron microscopy has been used to identify filoviruses in tissue but has obvious limitations as a diagnostic modality in the areas where human outbreaks have occurred (Geisbert & Jahrling, 1995).

Management (King, 2013).

General medical support is critical and should include replacement of coagulation factors and heparin if disseminated intravascular coagulation develops. Such care must be administered with strict attention to barrier isolation. All body fluids (blood, saliva, urine, and stool) contain infectious virions and should be handled with great care.

Maintaining  oxygen status and blood pressure and treating them for any complicating infection are the standard on the management of supportive Ebola therapy (Centers for Disease Control and Prevention , 2014). Because early symptoms such as headache and fever are nonspecific to ebolaviruses, cases of Ebola may be initially misdiagnosed.

Currently, no specific therapy is available that has demonstrated efficacy in the treatment of Ebola hemorrhagic fever. Surgical intervention generally follows a mistaken diagnosis in which Ebola-associated abdominal signs are mistaken for a surgical abdominal emergency. Such a mistake may be fatal for the patient and for any surgical team members who become contaminated with the patient’s blood.

There are no commercially available Ebola vaccines. However, a recombinant human monoclonal antibody directed against the envelope GP of Ebola has been demonstrated to possess neutralizing activity. This Ebola neutralizing antibody may be useful in vaccine development or as a passive prophylactic agent. Work on a vaccine continues.

Summary of General principles of care:

Supportive therapy with attention to intravascular volume, electrolytes, nutrition, and comfort care is of benefit to patient.

Such therapy must be administered with strict attention to barrier isolation; all body fluids contain infectious virions and should handled with great care

No specific therapy is available that has demonstrated efficacy in the treatment of Ebola hemorrhagic fever

There are no commercially available Ebola vaccines; however, neutralizing antibodies have been studied that may be useful in vaccine development or as passive prophylactic agents.

Prevention:

The CDC states that the Ebola’s prevention presents many challenges because it is unknown how exactly people are infected with the virus. As pointed out by the CDC when cases appear, there is increased risk of transmission within health care setting. Therefore, health care workers must be able to recognize a case of Ebola and be ready to employ practical viral hemorrhagic fever isolation precautions or barrier nursing techniques, and also have the capability to request diagnostic test or prepare samples for shipping and testing elsewhere. (Centers for Disease Control and Prevention , 2014).

As we know, Ebola is transmissible from person to person via direct contact with an infected patient’s blood or other fluids. Moreover, Dr King (2013) explains that the airborne transmission of Reston ebolavirus is known to have ocurred among primates; thus, although most cases in humans occur after contact with a patient or their blood or body fluids, transmission of Ebola virus via the airbone route connot be dismissed.

Infection control inside and outside of medical facilities relies on the following barrier nursing or protection techniques: (Centers for Disease Control and Prevention , 2014) (King, 2013).

Ø  Wearing of protective clothing: mask, gloves, gowns, goggles

Ø  The use of infection control measures: complete equiment sterilization and routine use of desinfectant

Ø  Isolation of Ebola patients from contact with unprotected persons

The CDC emphasizes on the aim of all of thouse techniques is to avoid contact with the blood or secretion of an infected patient, also they points out if a patient with Ebola dies, it is equally important that direct contact with the body of the deceased patient be prevented.

Bibliography

Centers for Disease Control and Prevention . (2014, Aug 5). cdc.gov. Retrieved from Ebola Hemorrhagic Fever: http://www.cdc.gov/vhf/ebola/about.html

Dambro, M. R. (2001). Griffith's 5 minute clinical consult. Philadelphia: Lippincott Williams & Wilkins.

Geisbert, T., & Jahrling, P. (1995). Differentiation of filoviruses by electron microscopy. Virus Res, ;39(2-3):129-50. Retrieved from Differentiation of filoviruses by electron microscopy.

King, J. W. (2013, Aug 19). emedicine.medscape.com. Retrieved from Ebola Virus Infection: http://emedicine.medscape.com/article/216288-overview#a0101

NBCNews.com. (2014, Aug 7). NBCNEWS. Retrieved from http://www.nbcnews.com/storyline/ebola-virus-outbreak/paramedics-take-us-inside-ambulance-ride-ebola-victims-n174456

WHO. (2014, April). who.int. Retrieved from World Health Organization: www.who.int/mediacenter/factsheets/fs 103/en/

Other:

Infection Control for Viral Haemorrhagic Fever in African Health Care Setting by World Health Organization and U.S Department of Health & Human Services (online source http://www.cdc.gov/vhf/abroad/pdf/african-healthcare-setting-vhf.pdf)