Prosthetic valve endocarditis

Prosthetic valve infective endocarditis represents a defined pathological entity which follows an epidemiological and nosological pattern in accordance to an arbitrary classification. Chronologically it is divided into the entities of early and late prosthetic valve endocarditis, each with its own unique characteristics. The clinical features, complications and diagnosis do not vary much from native valve endocarditis. There are clear and precise indications to aid in the diagnosis and treatment of this entity which differ from native valve endocarditis

Phenotypic confirmation of extended-spectrum B-lactamases (ESBL) in clinical isolates of Escherichia coli and Klebsiella pneumoniae at the San Juan Veterans Affairs Medical Center

Extended-spectrum Beta (beta)-lactamases (ESBLs) have emerged as an important mechanism of resistance to B-lactam antibiotics in gram-negative bacteria (GNB). They are enzymes that hydrolyze older B-lactam antibiotics as well as broad-spectrum cephalosporins and monobactams. ESBL producers have been reported in many bacteria but special attention has been paid to the ones in E.coli and Klebsiella spp. Detection of the ESBLs by the clinical laboratory is a special challenge. Surveillance to monitor resistance is important to decide when detection of ESBLs must be started. This study determined the prevalence of ESBL producers in the strains E.coli and K.pneumoniae at the San Juan VA Medical Center, and characterized their phenotypes to evaluate the importance to identify these bacteria as a standard routine procedure in the institution. All E.coli and K.pneumoniae isolated from Jan 1 to Mar 31, 2003 were evaluated according to National Committee for Clinical Laboratory Standards (NCCLS) screening criteria for suspected ESBL producers. Phenotypic confirmation of the ESBL production was performed using the Etest method. A total of 112/253 (44%) E.coli and 72/137 (53%) K.pneumoniae were identified as suspected ESBL producers. Etest was performed in 60% of the E.coli and 57% of the K.pneumoniae suspected to be ESBL producers. The overall ESBL prevalence for E.coli was 25% and in K.pneumoniae was 26%. Most E.coli ESBL-producers were from urine while the K.pneumoniae were from sputum. ESBL-producers were isolated from different sources including pleural and synovial fluids, blood, and skin besides urine and sputum. According to susceptibility results, the most reliable antibiotic in predicting a negative ESBL was cefpodoxime (CPD), and in the strains studied, the ESBL producers were consistently resistant to aztreonam (ATM). A large proportion (95%) of ESBL producing K.pneumoniae were susceptible to cefepime (CEP). Of the ESBL producing E.coli, 24% were susceptible. In the case of E.coli ESBLproducers, Cefepime can be considered as a therapeutic option if susceptibilities are available. Automated identification and sensitivity systems are valid alternatives for routine evaluation of B-lactam resistance but when increased resistance is documented in GNB and/or ESBL prevalence is high, ESBL detection should be performed. All confirmed ESBL producers should be reported resistant to all penicillins, cephalosporins, and aztreonam in spite of having susceptible ra

Antibiotics in older adults

Antibiotics are frequently prescribed in the older person, the dosification needs special care, since the pharmacokinetic parameters changes with aging and the side effects can be different in the older person. The creatinine clearance changes and we must modify the way we prescribe such antibiotics to the elderly, calculating. The variety of antibiotics now available led us to consider this paper in which we have presented the antimicrobial agents that can be considered in the treatment of the older person. We present several groups: the penicillins, cephalosporins, monobactams, carbapenems and betalactamase inhibitors or the great betalactam group. Other trimetroprin-sulfame-thoxazole, the newer macrolides (azithromycin and clarithromycin) as well as the aminoglycosides, vancomycin, clindamycin, metroridazole. The indications and contraindications are presented and reviewed.

Potentially serious infections in the aging person: diagnosis, treatment and prevention

Infections in the elderly patient are a challenge, since the classical signs of infection are absent or ill defined. The present paper describes the presentation, diagnosis, clinical manifestations and treatment for a selected group of potential serious infections including influenza, bacterial pneumonia, urinary tract infections as well as infections caused by multiresistant bacteria, like vacomycin-resistant enterococcus and methicillin resistant S. aureus. We conclude with the need for prevention in the older person with the use of vaccines, specifically the influenza and pneumococcal vaccine as well as the prevention of urinary infections. Influenza is a significant cause of morbidity, whose ill effects can be prevented in many older persons with the use of a vaccine. The use in prophylaxis and treatment of antiviral agents like amantadine, rimatadine, and oseltamivir is presented. Bacterial pneumonia is one of the leading causes of death in the USA among the older persons. The emergence of drug resistant Streptococcus pneumoniae leads to the consideration as empiric therapy the newer fluoroquinolones or the use of third or fourth generation cephalosporis. Of importance is the use of pneumococcal vaccine among people age 60 or above. The frequency of urinary tract infections among the elderly is of primary although in many instances important do not require treatment. When infection of the urinary tract is diagnosed, most authors use a fluoroquinolone as empiric theraphy. The emergence of multiresistant bacteria like methicillin resistant S. aureus and or vancomycin resistant enterococci leads to the need to consider new agents like quinipristin-dalfopristin, linezolid and deptomycin in the management of such patients.

Management of urinary tract infections, decubitus ulcer and pneumonia in the aging person

Infections in the older person are common and a significant cause of morbidity and mortality. Infections of the urinary tract, skin and soft tissue infections including decubitus ulcers, antibiotics associated diarrhea and lower respiratory tract infections are particularly important in the elderly because of their frequency. While most initial antibiotic therapy is empiric, its important before treatment to try to document the etiology for better use of antibiotics. Infections of the urinary tract are frequently and potentially serious in the elderly, they must be separated from asymptomatic bacteriuria that requires no therapy. Upper and lower urinary tract infections are frequently caused by aerobic gram negative bacilli and or enterococci. Most authors prefer the use of fluoroquinolones to manage such infections. The elderly with decubitus ulcer presents a problem in management, since these are frequent polymicrobic infections in which anaerobes play an important role. The initial therapy usually involves the combination of a fluoroquinolone plus an antianaerobic agent like clindamycin. C. difficile diarrhea as frequent in nursing home residents as well as the older person with prior antibiotics. The treatment should be with metronidazole and avoid the use of vancomycin. Pneumonias in the elderly can be acquired in the community, the nursing home or during a hospitalization. The etiologic agents that predominate change from S. pneumoniae and atypicals in those from the community to an increase in gram negative pneumonia. The initial treatment as started by most authors as well as guidelines include the use of a new fluoroquinolone like gatifloxacin alone or in combination with a beta-lactamic agent like ceftriaxone. For those infections acquired in the hospital therapy with third or fourth generation cephalosporins, carbapenems, beta-lactams with betalactamase inhibitors alone or in combination with an aminoglucoside and or vancomycin if MRSA is suspected is accepted therapy

Ebola: síndrome letal / Ebola: a fatal syndrome

No other clinical entity has attached more attention now-a-day than those precipitated by the infection with a Hemorrhagic Fever Virus. Potentially caused by Arena, Bunya, Flavi, and Filoviradae, only the latter has had such a major impact throughout the world. Two major genuses have been recognized since they become evident for the first time in 1967, the single-species Marburg, and the 3-species-Ebola (E. zaire, sudan and reston). With the exception of the 2 outbreaks of E. reston (Washington, USA 1989-1993), all of them have taken place in Africa, where the virus is still hiding among the wild-life of the Tropical Rain Forest. Currently (in April 1995) the reemergence of Ebola virus has once more proven its fatality, leaving around 170 deaths in Zaire, 250 miles from its capital, Kinshasa. There is worldwide alert, sponsored by the CDC in Atlanta, the World Health Organization and the authorities in Zaire regarding its potential spreading to naive regions, in and out of Africa. The characteristic clinical picture of a viral hemorrhagic fever has no match. After a 2-21 days incubation period a viral-like illness develops. As days go by, symptoms worsen, and by the 7th day, a severe and diffuse bleeding tendency ensues. The individual's death is the most likely outcome in the great majority of cases. As a lethal virus, without an available treatment and a possible airborne-route of transmission, Ebola virus will always be considered a persistent threat to the global health

Bacillary angiomatosis: microbiology, histopathology, clinical presentation, diagnosis and management

Bacillary angiomatosis is known to be caused by a rickettsial organism; Rochalimaea henselae. This causative agent has been compared with different microorganisms and clinical conditions that appear in similar settings but that have been clearly differentiated from them; e.i. Cat-scratch disease (Afipia felis), Bartonella bacilliformis, other Rochalimaea sp., Kaposi;s sarcoma, Lobular capillary hemangioma, Angiosarcoma, and Epithelioid hemangioma. Clinically the bacillary angiomatosis (BA) skin lesions vary from a single lesion to thousands. The cutaneous lesion appears as a bright-red round papule, subcutaneous nodule, or as a cellulitic plaque. When the lesion is biopsied it tends to blanch-out, bleed, and cause pain. The patient might present with signs and symptoms of chills, headaches, fever, malaise, and anorexia with or without weight loss. The extracutaneous lesions found in BA tend to be from multiple organs affecting from the oral lesions to anal mucosal lesions to widespread visceral lesions. The sites of preferences for BA lesion manifestation tend to be the liver, spleen, lymph nodes, and bone. To diagnose bacillary angiomatosis the physician should prepare a differential diagnosis based primarily on its histopathological and clinical characteristics. To confirm the results from the stain, electron microscopy can identify the bacillus and pin-point the diagnosis of bacillary angiomatosis. The lesions presented by BA respond well to therapy with erythromycin 500mg four times daily for a duration of 2 weeks to 2 months. In case of intolerance to erythromycin the second line of drug that successfully treats the BA bacillus is doxycycline. If relapses of the BA lesion recur, then a prolonged antibiotic therapy is necessary and in AIDS patients the duration may be extended as life-long suppressive therapy

Infections caused by parvovirus B19

Parvovirus B19 was discovered in 1974 by Cossart et al; is a single stranded unenveloped DNA virus, which virion is isometric, uniform and has icosagedral symmetry. B19 infection has been found in all countries, it is almost certainly world-wide in distribution. Infections occurs most frequently in late winter, spring and early summer months and are transmitted by respiratory route. Erythema infectiosum is the most common manifestation of human parvovirus B19 infection, is most commonly acquired between 4 and 10 years of age and at least 60 of adults are seropositive. Erythema Infectiosum is characterized by three stages of rash that involves the face and may also involves trunk and extremities. In adult patients, particularly women, arthralgia or arthritis have been associated with up to 80 of Erythema Infectiosum casually starts in the small joints of the hand. Maternal parvovirus B19 infection with or without rash, can affect fetus. Transient aplastic crisis can be caused by HPV B19 in patient who have increased rate of RBC destruction or loss. Others diseases or symptoms complexes may be associated with B19 infection in the coming years as this virus and its infections continues being an interesting field of investigation

Hantavirus infection: a rare disease which you should be aware

Hantavirus infection is caused by viruses classified in the Hantavirus genus, of the Bunyaviridae family. Recently a new hantavirus has been recognized. Specific endemic areas has been identified, however a new outbreak was identified in the southwestern of the United States. The principal vectors are rodents. Human infection occur by aerosol from rodent urine, saliva, feces and rodent bites. The infection classically is manifested clinically by fever, hemorrhage and renal failure. The recent outbreak was associated with acute respiratory illness without renal involvement. The treatment is with intravenous Ribavirin. Specific recommendations for prevention and control are presented here in

Infecciones en prótesis de pene: tratamiento y prevención / Infections of penile prosthesis: treatment and prevention

To date, there are 10,000,000 men with impotence in the United States and it is estimated that at least 17,000 penile prosthesis are implanted annually. The most fearsome complication is the infection of the prosthesis which is usually caused by Staphylococcus epidermidis (in 40-80 of the cases). In general, the incidence of infection is actually 0.8-8.3, but it can increase to 37 in patients with tertiary implants. The initial empiric treatment is usually with vancomycin and aminoglycosides and prophylaxis is recommended with a penicillinase-resistant synthetic penicillins, first generation cephalosporins, or vancomycin in case of penicillin allergy

Absceso pancreático y pseudoquiste infectado / Pancreatic abscess and infected pseudocyst

Acute pancreatitis is a sterile inflammatory process caused by a chemical auto digestion of the pancreas. The pancreatic abscess and infected pseudocyst are complications of acute pancreatitis of a high mortality rate that require a prompt diagnosis. The pseudocyst is defined as a localized collection of pancreatic juices confine to a retroperitoneal area by a fibrous membrane without epithelium; an abscess is a collection of pus and necrotic tissue. This illnesses should be suspected when patients with acute pancreatitis develop fever, tachycardia, abdominal distention or mass after 14-22 days after the initial attack. These entities require different treatment. The definite treatment is surgical intervention

Cytomegalovirus retinitis in AIDS patients: a clinical review

Cytomegalovirus (CMV) retinitis is an ocular condition previously seen in organ transplant recipients, patient on chemotherapy for malignancy, and in infants with congenital infections. As it present in immunocompromised, the AIDS patient has integrated this group of patients that can present with CMV retinitis. Moreover, it is the leading cause of opportunistic ocular infection in the AIDS patient, and the second most common ocular manifestation. As new drugs and modes of administration are studied that can effectively halt this progressively blinding condition, the awareness and recognition of CMV retinitis on AIDS patients has become increasingly important. This author will review the epidemiology, clinical presentation, and differential diagnosis of this condition. The current treatments being used and complications will also be discussed

Catheter related infections in Damas Hospital

The purpose of this study is to investigate the extent of catheter-related infections in our Institution. We examined retrospectively 89 medical records of patients in whom an intravascular catheter tip culture were obtained during January through December 1991. Forty-seven catheter related infections were identified in 43 patients. There were 33 multiple lumen infected catheters and 14 single lumen. Catheters for hemodialysis were infected in 38.3 of the patients. Twenty catheters were inserted into the subclavian vein. Fifty percent of the reinserted catheters were placed in the same site, of which 28.6 became infected. Staphylococcus epidermis was isolated in 28.1 of the patients, while in 50 of the patients with Staphylococcus aureus, bacteremia was identified. Staphylococci and Enterococci were more sensitive to Vancomycin than to any other antibiotic