Clostridium difficile as a nosocomial pathogen

Role of the environment in the transmission of Clostridium difficile in health care facilities

Recent data demonstrate that the contaminated hospital surface environment plays a key role in the transmission of Clostridium difficile. Enhanced environmental cleaning of rooms housing Clostridium difficile-infected patients is warranted, and, if additional studies demonstrate a benefit of "no-touch" methods (eg, ultraviolet irradiation, hydrogen peroxide systems), their routine use should be considered.

The role of environmental cleaning in health care-associated infections

Multidrug-resistant organisms such as methicillin-resistant Staphylococcus aureus (MRSA) and toxin-producing organisms such as Clostridium difficile have been a concern for over 30 years. An increasing focus is being placed on the role that an unclean environment can play in transmission. This article describes the pathogens of concern and the use of a robust environmental cleaning program to help reduce the chances for hospital-acquired infections.

Reassessment of Clostridium difficile susceptibility to metronidazole and vancomycin

Clostridium difficile is the most frequently identified enteric pathogen in patients with nosocomially acquired, antibiotic-associated diarrhea. The drugs most commonly used to treat diseases associated with C. difficile are metronidazole and vancomycin. Most clinical laboratories assume that all C. difficile isolates are susceptible to metronidazole and vancomycin. We report on the antimicrobial susceptibilities of 415 C. difficile isolates to metronidazole and vancomycin over an 8-year period (1993 to 2000). The overall rate of resistance to metronidazole at the critical breakpoint (16 microg/ml) was 6.3%. Although full resistance to vancomycin was not observed, the overall rate of intermediate resistance was 3.1%. One isolate had a combination of resistance to metronidazole and intermediate resistance to vancomycin. Rates of resistance to metronidazole and vancomycin were higher among isolates from human immunodeficiency virus-infected patients. Molecular typing methods proved the absence of clonality among the isolates with decreased susceptibilities to the antimicrobials tested.

Clostridium difficile toxin and faecal lactoferrin assays in adult patients

Clostridium difficile is the primary aetiological agent of antibiotic-associated diarrhoea. The faecal lactoferrin (FL) assay is a simple in vitro test which is highly sensitive to the presence of a marker of polymorphonuclear cells. We evaluated the use of the FL assay in conjunction with the C. difficile toxin assay in faecal samples obtained from 231 adult patients. The relationship between C. difficile toxin and FL in both negative and positive status was highly significant statistically (P < 0.001). Therefore, the FL assay performed simultaneously with the C. difficile toxin assay can help rule out asymptomatic carriage of C. difficile.

Clostridium difficile-associated diarrhea and colitis: clinical manifestations, diagnosis, and treatment

PURPOSE

This review examines the pathogenesis, clinical manifestations, diagnosis, and current medical and operative strategies in the treatment of Clostridium difficile diarrhea and colitis. Prevention and future avenues of research are also investigated.

METHODS

A review of the literature was conducted with the use of MEDLINE.

RESULTS

C. difficile is a gram-positive, spore-forming bacterium capable of causing toxigenic colitis in susceptible patients, usually those receiving antibiotics. Overgrowth of toxigenic strains may result in a spectrum of disease, including becoming an asymptomatic carrier, diarrhea, self-limited colitis, fulminant colitis, and toxic megacolon. Diagnosis requires a high index of suspicion and depends on clinical data, laboratory stool studies (enzyme-linked immunoabsorbent assay and cytotoxin test), and endoscopy in selected cases. Protocols for treatment of primary and relapsing infections are provided in algorithm format. Discontinuation of antibiotics may be enough to resolve symptoms. Medical management with oral metronidazole or vancomycin is the first-line therapy for those with symptomatic colitis. Teicoplanin, Saccharomyces spp. and Lactobacillus spp., and intravenous IgG antitoxin are reserved for more recalcitrant cases. Refractory or relapsing infections may require vancomycin given orally or other newer modalities. Fulminant colitis and toxic megacolon warrant subtotal colectomy. Cost, in terms of extended hospital stay, medical and surgical management, and, in some cases, ward closure, is thought to be formidable. Review of perioperative antibiotic policies and analysis of hospital formularies may contribute to prevention and decreased costs.

CONCLUSION

C. difficile diarrhea and colitis is a nosocomial infection that may result in significant morbidity, mortality, and medical costs. Standard laboratory studies and endoscopic evaluation assist in the diagnosis of clinically suspicious cases. Appropriate perioperative antibiotic dosing, narrowing the antibiotic spectrum when treating infections, and discontinuing antibiotics at appropriate intervals prevent toxic sequelae.

Surgical aspects of Clostridium difficile colitis

BACKGROUND

There has been a marked increase in the number of surgical patients developing Clostridium difficile colitis. The epidemiology, pathogenesis, diagnosis and management of C. difficile infection were reviewed from a surgical perspective.

METHODS

A literature review was carried out based primarily on a Medline search of all English language publications containing the term C. difficile.

RESULTS

The recent dramatic increase in diagnosis of C. difficile infection amongst surgical patients results from heightened awareness of the condition, better methods of diagnosis, more widespread use of antibiotics for treatment and prophylaxis, and the increasing numbers of elderly and immunocompromised patients with malignancy, sepsis, and (multiple) organ failure being cared for within intensive therapy and high-dependency units. In addition to morbidity and mortality, the economic burden of C. difficile infection in terms of delayed discharge and other hospital costs is considerable.

CONCLUSION

Appropriate use of antibiotics, isolation of affected patients and meticulous hygiene measures on the part of staff are vital if the morbidity, mortality and economic consequences of this nosocomial infection are to be minimized.

Management and control of a large outbreak of diarrhoea due to Clostridium difficile

In the six-month period 1 November 1991 to 1 May 1992 175 patients developed diarrhoea due to Clostridium difficile in three hospitals in Manchester, UK. Most patients (90%) were over 60 years old and had been admitted to acute geriatric or medical wards with other illnesses. Infection is thought to have contributed to 17 deaths. Twenty-two patients relapsed clinically after antibiotic treatment. The outbreak began in one ward and affected 15 patients and two nurses. During the following months cases occurred on 34 wards. The pattern of spread suggested that a ward index case was followed by several secondary cases. Pyrolysis mass spectrometry showed that 79% of isolates of C. difficile belong to a single cluster and this putative outbreak strain also extensively colonizes the hospital environment. It was also responsible for a smaller outbreak in 1991 and many 'sporadic' cases in our hospitals before then. An outbreak control team was convened at an early stage and expert opinion co-opted. Infection control measures included: intensive education of staff; increased vigilance; strict enteric precautions; cohort nursing in a designated ward; rigorous cleaning procedures including emptying and 'deep' cleaning of wards where several cases had occurred; restriction of staff and patient movement; and restriction of antibiotic use. Subsequent to these measures there has been a substantial and sustained decrease in the number of new cases.

Effects of Clostridium difficile toxin B on human monocytes and macrophages: possible relationship with cytoskeletal rearrangement

Toxin B from Clostridium difficile is cytopathic in vitro for various types of cells, including polymorphonuclear cells, lymphocytes, and monocytes. Since intestine lamina propria is rich in macrophages, we studied the effect of toxin B on human monocytes and on human macrophages generated in vitro by long-term culture of purified circulating blood monocytes. Upon addition of toxin B, human monocytes exhibited few modifications whereas macrophages adopted a stellate morphology, with rounding up of the perikaryon. Toxin B made microfilaments of actin disappear and induced an important reorganization of vimentin and a redistribution of tubulin. Membrane area increased by approximately 16%. Toxin B did not affect the viability of human mononuclear phagocytes and did not exert any significant lytic effect. It profoundly altered the phagocytic function of macrophages. When activated by gamma interferon in the presence of toxin B, monocytes were more cytotoxic for U-937 target cells than control monocytes activated in absence of toxin. Finally, the combined treatment of monocytes with gamma interferon and toxin B increased significantly the secretion of tumor necrosis factor alpha, whereas toxin B alone was unable to induce tumor necrosis factor production. These results suggest that morphological and functional alterations induced in human mononuclear phagocytes by toxin B from C. difficile are due to the disorganization of the cytoskeleton and the resulting impairment of the membrane traffic equilibrium.

Lack of care giver hand contamination with endemic bacterial pathogens in a nursing home

Prevalences of Clostridium difficile and multiply resistant Staphylococcus aureus (MRSA) were determined in nursing staff and residents of a 233-bed long-term care facility. Twenty of 38 (52.6%) patients in the long-term care ward and three of 69 (4.3%) in the skilled-nursing ward were colonized with MRSA; 16 of 48 (33%) patients in the long-term care ward and seven of 52 (13%) in the nursing home ward were colonized with C. difficile. None of the 79 staff members whose hands were cultured had chronic C. difficile hand carriage and MRSA was present on only three of 79 (3.9%). Over a 6-month period, 128,000 pairs of gloves were worn. Since C. difficile and MRSA are rarely present on washed hands of care providers, appropriate handwashing and gloving should make a significant contribution to reducing the spread of these agents in long-term care facilities.