Fungal Infections in the Elderly

Fungi are increasingly recognised as major pathogens in critically ill patients. Several reasons have been proposed for the increase in invasive fungal infections, including the use of antineoplastic and immunosuppressive agents, broad-spectrum antibiotics, and prosthetic devices and grafts, and more aggressive surgery. Patients with burns, neutropenia, HIV infection and pancreatitis are also predisposed to fungal infection Candidiasis is caused by infection with species of the genus Candida, predominantly with Candida albicans. Candida species are ubiquitous fungi that represent the most common fungal pathogens that affect humans. The growing problem of mucosal and systemic candidiasis reflects the enormous increase in the number of patients at risk and the increased opportunity that exists for Candida species to invade tissues normally resistant to invasion.

Fungi are increasingly recognised as major pathogens in critically ill patients.Several reasons have been proposed for the increase in invasive fungal infections, including the use of antineoplastic and immunosuppressive agents, broadspectrum antibiotics, and prosthetic devices and grafts, and more aggressive surgery.Patients with burns, neutropenia, HIV infection and pancreatitis are also predisposed to fungal infection Candidiasis is caused by infection with species of the genus Candida, predominantly with Candida albicans.
Candida species are ubiquitous fungi that represent the most common fungal pathogens that affect humans.The growing problem of mucosal and systemic candidiasis reflects the enormous increase in the number of patients at risk and the increased opportunity that exists for Candida species to invade tissues normally resistant to invasion.

INTRODUCTION
Candida species are true opportunistic pathogens that exploit recent technological advances to gain access to the circulation and deep tissues.The increased prevalence of local and systemic disease caused by Candida species has resulted in numerous new clinical syndromes, the expression of which depends primarily on the immune status of the host.Candida species produce a wide spectrum of diseases, ranging from superficial mucocutaneous disease to invasive illnesses, such as hepatosplenic candidiasis, Candida peritonitis, and systemic candidiasis.

Candida
Over 200 species of Candida exist in nature; thus far, only a few species have been associated with disease in humans.
The medically significant Candida species include the following [2]: C albicans, the most common species identified (50-60%) Candida glabrata (previously known as Torulopsis glabrata) (15-20%) Candida dubliniensis, primarily recovered from patients infected with infected with HIV C glabrata and C albicans account for approximately 70-80% of Candida species recovered from patients with candidemia or invasive candidiasis.C glabrata has recently become very important because of its increasing incidence worldwide, its association with fluconazole resistance in up to 20% of clinical specimens, and its overall decreased susceptibility to other azoles and polyenes.
C krusei is important because of its intrinsic resistance to ketoconazole and fluconazole (Diflucan); it is also less susceptible to all other antifungals, including itraconazole (Sporanox) and amphotericin B.
Another important Candida species is C lusitaniae; although not as common as other Candida species, C lusitaniae is of clinical significance because it may be intrinsically resistant to amphotericin B, although it remains susceptible to azoles and echinocandins.
C parapsilosis is also an important species to consider in hospitalized patients.It is especially common in infections associated with vascular catheters prosthetic devices.Additionally, in vitro analyses have shown that echinocandins have a higher minimum inhibitory concentration (MIC) against C parapsilosis than other Candida species.The clinical relevance of this in vitro finding has yet to be determined [3].
C tropicalis has frequently been considered an important cause of candidemia in patients with cancer (leukemia) and in those who have undergone bone marrow transplantation.

Oral candidiasis.
White plaques that are present on the buccal, palatal, or oropharyngeal mucosa and can easily be removed are the typical lesions seen in patients with oral candidiasis.Some patients develop painful cracks at the corns of the mouth [angular cheilitis].Factors that predispose patients to the development of thrush include xerostomia,the use of broad-spectrum antibiotics, inhaled corticosteroids, and diminished cellmediated immunity.Age alone is not sufficient for the development of oral candidiasis .In an older adult ,oral thrush-in the absence of an obvious cause or extension to involve the esophagus-may herald underlying immunosuppression in the form of cancer or AIDS.The presence of xerostomia has been shown to correlate with both increased colonization of the oropharynx and increase oral mucosal lesions due to yeast [4].In older adults ,the presence of systemic diseases and a multiplicity of medications can frequently cause xerostomia, which may than place patients at risk of developing oral thrush.

Denture stomatitis.
Denture stomatitis, a variant of oral candidiasis, presents as chronic mucosal erythema beneath a denture.This may affect up to 65% of all patients who wear dentures, occurring particularly in those with full sets [5].Patients who do not remove the dentures at night and who have poor oral hygiene are the most likely to be affected.

Skin and nail infections.
Candidal infection of the skin under the breasts, a pannus,or the perineum occurs when these areas become macerated.Lesions are almost always pruritic, erythematous, and have a distinct border.Small, flat, erythematous satellite lesions provide an additional clue to the diagnosis of candidiasis.

Paronychia and onychomycosis.
Candida uncommonly causes infection in the periungual area and underneath the nailbed.Inflammation leads to thickening and even loss of the nail.The disease occurs most often in persons who frequently immerse their hands in water and has not been a major problem in older patients.However, one group of older adults in whom onychomycosis can have serious consequences in those with diabetes mellitus.In comparison with nondiabetic patients, patients with diabetes have both increase susceptibility to and worse outcome from bacterial infection of the feet.Onychomycosis can contribute to difficulty cutting the toenails, predisposing these patient to trauma and thus bacterial foot infection.Onychomycosis is found more frequently in the elderly and more often in males than females.There are four types of onychomycosis; distal subungual onychomycosis, proximal subungual onychomycosis, white superficial onychomycosis, and candidal onychomycosis.

Vulvovaginal candidiasis (VVC)
This is the second most common cause of vaginitis.The patient's history includes vulvar pruritus, vaginal discharge, dysuria, and dyspareunia.Approximately 10% of women experience repeated attacks of VVC without precipitating risk factors.Physical examination findings include a vagina and labia that are usually erythematous, a thick curdlike discharge, and a normal cervix upon speculum examination [6].
Candiduria often presents a dilemma to the clinician as it may represent contamination, colonization,or infection.Contamination may be detected by repeating collection and culture of the urine.However, straight catheterization of the urethra may be needed to obtain an uncontaminated urinary specimen in older women.the asymptomatic patient,some clinicians consider the presence of any yeast in the urine to represent infection ,whereas some authors suggest that <10,000 cfu/mL may represent only colonization [7].The presence of a urinary catheter limits the usefulness of colony quantitation.Most authors would agree that the presence of symptoms such as suprapubic discomfort, dysuria, or frequency usually comprise infection, rather than colonization.Asymptomatic candiduria: Most catheterized patients with persistent candiduria are asymptomatic, similar to noncatheterized patients.Most patients with candiduria have easily identifiable risk factors for Candida colonization.Thus, invasive disease is difficult to differentiate from colonization based solely on culture results because approximately 5-10% of all urine cultures are positive for Candida [8].

Candidemia
Candida species are currently the fourth most commonly isolated organism in blood cultures, and Candida infection is generally considered a nosocomial infection [9].The patient's history commonly reveals the following: Several days of fever that is unresponsive to broad-spectrum antimicrobials; frequently the only marker of infection -Fever.

CONCLUSION
Infections in the elderly are more common than in younger individuals.They are more complicated by the multiple medications used to control the diseases that accompany normal ageing.Understanding the diseases an elderly patient might suffer enhances their health and well being.
Prolonged intravenous catheterization A history of several key risk factorsPossibly associated with multiorgan infectionPhysical examination results may include the following: