Viral hepatitis. A staff hazard in dialysis units

Development of an investigation form for hemodialysis infection outbreak: Identifying sources in the early stage

BACKGROUND

There are many infectious factors causing the outbreak of hemodialysis infection, which may easily lead to the delay of investigation and treatment. This study aimed to develop an investigation form for hemodialysis infection outbreak (HIO), and to identify sources of outbreak in early stage.

METHODS

After an exhaustive literature review, we used the Delphi method to determine the indicators and relative risk scores of the assessment tools through 2 rounds of specialist consultation and overall consideration of the opinions and suggestions of 18 specialists.

RESULTS

A total of 87 studies of HIOs were eligible for inclusion. The mean authority coefficient (Cr) was 0.89. Kendall's W coefficient of the specialist consultation was 0.359 after 2 rounds of consultation (P < .005), suggesting that the specialists had similar opinions. Based on 4 primary items and 13 secondary items of the source of HIO, and tripartite distribution characteristics of infected patients, we constructed the investigation form.

CONCLUSIONS

The investigation form may be implemented during the initial phase of an outbreak investigation, it is a prerequisite for taking effective control measures, avoiding HIO occurrence. However, the efficacy of the investigation form needs to be further evaluated.

Chronic viral hepatitis in hemodialysis patients

Ever since the first outbreaks of hepatitis in hemodialysis units in the late 1960s, a number of hepatotropic viruses transmitted by blood and other body fluids have been identified. This review summarizes the current state of knowledge regarding these blood-borne agents from an epidemiologic and preventive perspective. Data source and study selection were obtained from research and review articles related to the epidemiology of viral hepatitis in hemodialysis and indexed on Medline and Embase from 1965 to 2004. Hepatitis B virus (HBV) was the first significant hepatotropic virus to be identified in hemodialysis centers. HBV infection has been effectively controlled by active vaccination, screening of blood donors, the use of erythropoietin, and segregation of HBV carriers. To date, HBV remains an important cause of morbidity in endemic areas. Hepatitis delta virus is a defective virus that can only infect HBV-positive individuals. Hepatitis C virus is the most significant cause of non-A, non-B hepatitis and is mainly transmitted by blood transfusion. The introduction in 1990 of routine screening of blood donors for HCV contributed significantly to the control of HCV transmission. An effective HCV vaccine remains an unsolved challenge, however. Pegylation of interferon-alpha has made it possible to treat HCV-positive dialysis patients. Unexplained sporadic outbreaks of hepatitis by the mid-1990s prompted the discovery of hepatitis G virus and hepatitis GB virus C in 1995 and the TT virus in 1997. Although epidemiologic analyses revealed high prevalence rates of both viruses in the hemodialysis population, their exact role in liver disease has yet to be determined. The vigilant observation of guidelines on universal precaution and regular virologic testing are the cornerstones of the effective control of chronic hepatitis in the setting of hemodialysis.

Blood-borne virus infections in dialysis units--a review

Hepatitis outbreaks in haemodialysis unit patients and staff were reported in the late 1960s. In 1972, the Rosenheim report in the UK established guidelines which included routine tests for hepatitis B surface antigen and isolation facilities for dialysing patients with hepatitis B virus which resulted in a dramatic fall in cases of hepatitis. However, since these guidelines were introduced, other blood-borne viruses, notably HCV and HIV have been discovered, and failures of infection control practices still lead to outbreaks of HBV in haemodialysis units. The prevalence of HCV in dialysis patients varies considerably throughout the world, with reported prevalence ranging from 3.9% to 71%. The number of blood transfusions and the length of time on dialysis have consistently been associated with HCV prevalence. Several reports provide evidence of patient-to-patient HCV transmission with environmental blood contamination the most significant factor in intra-unit transmission. There is no evidence that HCV has been transmitted by re-use of dialysis machines but being dialysed next to an HCV positive patient is associated with a significant risk of HCV acquisition. Several studies have shown that dialysing HCV positive patients in a separate unit or in a defined sector of a dialysis unit significantly reduces nosocomial HCV infection. HGV is prevalent in dialysis units where there is evidence of transmission to patients but no evidence of associated symptoms. HIV is infrequently transmitted in dialysis units and several units treating many HIV-positive patients have shown no evidence of transmission. Careful attention needs to be paid to infection control procedures and regular virological testing.

Emergencies in continuous dialysis patients: diagnosis and management

The number of patients undergoing long-term hemodialysis and peritoneal dialysis is growing in the United States. To provide adequate emergent care to these patients emergency physicians must understand the alterations in normal physiologies present in these patients and how this may affect care. Cardiovascular disease and infection (especially Staphylococcus aureus sepsis) are the leading causes of death among dialysis patients. These patients are also subject to a significantly higher incidence of life-threatening electrolyte disturbances, particularly hyperkalemia and hypercalcemia, than the general population. Suicide, cardiac tamponade, intracranial hemorrhage, bleeding disorders, and bowel infarction are also much more frequent. The inability of dialysis patients to excrete drugs, metabolites, toxins, and fluids significantly alters their responses to common emergencies and should directly influence their care. Failure to recognize these differences in physiology may result in the use of standard forms of emergency therapy that may compound, rather than treat, the underlying disorder. Although most dialysis patients who come into an emergency department have conditions that can, and should, be managed by their nephrologist, the presence of a life threatening emergency requires prompt, appropriate therapy by the emergency physician.

Non-A, non-B hepatitis: a prospective study of a hemodialysis outbreak with evaluation of a serologic marker in patients and staff

An outbreak of non-A, non-B hepatitis (NANBH) in a hemodialysis unit was prospectively studied and the clinical, biochemical, and serologic events were correlated with an experimental immunodiffusion assay for serum antigen and antibody. One hundred sixteen subjects (76 dialysis patients and 40 staff members) were studied over an 8-month period. Hepatitis was defined as two consecutive SGPT levels greater than two times the upper limit of normal occurring in two separate samples drawn greater than 7 days apart in the absence of other likely causes of liver disease. Weekly serum specimens were obtained and tested for SGPT, SGOT, alkaline phosphatase, bilirubin HBsAg, anti-HBc, anti-HBs, total anti-HAV, and anti-HAV IgM by commercial reagents, and for antigen and antibody by agar gel diffusion using reference reagents previously obtained from well-documented posttransfusion NANBH patients. Clinical evaluations were performed three times per week. Thirty patients and none of the staff developed NANBH. The NANBH patients were asymptomatic, except for two patients with jaundice. Fifteen of the 30 patients were positive for antigen which was detectable in at least one serum collected during the acute phase. Six patients and 10 staff without clinical NANBH or abnormal serology had antigen. Antigenemia was also observed in three patients with acute hepatitis B, with chronic hepatitis B in one patient and with alcoholic hepatitis in one patient. Thus, an antigen was detected in a high proportion of patients during the acute phase of NANBH, and it was also found in exposed patients who had other liver diseases.(ABSTRACT TRUNCATED AT 250 WORDS)

A ten-year follow-up of a hepatitis B epidemic in a dialysis unit

A hepatitis B epidemic at the hemodialysis unit of the University Hospital of Lund, Sweden, occurred in 1968-71. Since then all patients on regular hemodialysis have been tested with regard to hepatitis B. 196 patients were followed for more than 6 months (5 for more than 10 yr). 50 patients (26 males/24 females) became HBsAg-positive. The majority, 40 (25/15), never lost their HBsAg during the observation period. 35 of these chronic HBsAg; carriers were also chronic HBeAg carriers. 10/50 HBsAg-positive patients lost their HbsAg; females in much higher frequency than men. Six HBsAg-negative patients developed anti-HBs and anti-HBc. The highly infectious carriers constituted a continuous source of infection. Nevertheless, it was possible to keep the spread of infection under control in the unit. The most effective precaution from spread to the staff is probably protective gloves during all handling of patients. As regards the patients the most important measure was the introduction of separate units for HBsAG-positive and HBsAg-negative patients.

Hepatitis B virus infection in medical and health care personnel

Analysis of 51 cases of hepatitis B virus infection in health care workers admitted as patients to the liver unit over seven years showed three healthy carriers of hepatitis B virus, seven cases of fulminant hepatic persistent hepatitis, 17 cases of chronic active hepatitis (of whom 11 had cirrhosis), and five cases of hepatocellular carcinoma. To date 11 of these patients have died. Only 15 of the 51 patients had a history of direct occupational exposure and only three patients could recall specific inoculation injuries. In contrast, the source of infection was apparent in 32 of 50 consecutive cases of fulminant hepatic failure or acute hepatitis B in nonmedical staff. Since specific inoculation injuries are not the usual mode of infection ion medical staff and since only a few of the patients who are hepatitis B virus carriers will be detected by selective screening of "high-risk" patients, the overall risk of infection can be reduced only by stricter precautions in the handling of any patient's blood and by the use of hepatitis B virus vaccines for medical staff at high risk.

Maintenance dialysis of patients infected with hepatitis B virus

Haemodialysis of patients who were acutely or chronically infected with hepatitis B virus has been undertaken at Fairfield Hospital for Communicable Diseases for the past 10 years. Over this period, only one staff member has shown serological evidence of infection. The procedures taken to prevent the spread of infection, and the results of an ongoing serological survey of all persons associated with the haemodialysis unit are presented.

Viral hepatitis A and B in hemodialysed patients

In 113 hemodialysed patients, 167 hospitalized patients, and 143 outpatients the frequency of HAV and HBV markers were studied by testing HBsAg, anti-HBs, anti-HBc, HBeAg, anti-HBe, and anti-HAV. The hemodialysis patients in a dialysis-center had significantly more often HBV markers (85.7%) than those maintained on home-dialysis (46.5%). 29.9% of the hospitalized patients and 32.1% of the outpatients had HBV markers. By the anti-HBc test up to 41% of additional HBV infections could be detected.--The prevalence of anti-HAV was very high in all groups. Significant differences between the hemodialysis patients and the control groups existed only in the age groups up to 39 years.--The frequencies of HAV and HBV markers were related to age, duration of dialysis treatment, transfusional frequency, and transaminases. The HBV appeared as the clinically important hepatitis agent in dialysis.

Hepatitis B surface antigen (HBSAg) in peritoneal fluid of HBSAg carriers undergoing peritoneal dialysis

Samples of ascitic fluid and outflow dialysate were collected from HBSAg carriers undergoing peritoneal dialysis and tested for HBSAg by solid-phase radioimmunoassay. The surface antigen was detected in every sample from HBSAg carriers. This finding was not dependent upon the presence of occult blood in the sample. Surface antigen particles and possibly Dane particles were also observed in HBSAg-positive samples by immunoelectron microscopy. These results identify the outflow dialysate of HBSAg carriers undergoing peritoneal dialysis as a potential source of hepatitis B virus transmission.

Host resistance in liver disease--its evaluation and therapeutic modification

We have attempted to review some of the factors involved in host resistance and the variations in the individual responses to the infectious and noxious agents to which we are increasingly exposed. Few treatment modalities are available to favorably influence host resistance, but clearly, this approach to the treatment of liver disease represents an opportunity for the future.

Liver disease in renal transplant recipients

Liver disease is a common complication in renal transplant recipients. Several types of liver disease can occur. The most common are acute and chronic hepatitis. The variety of acute hepatitis include hepatitis A, hepatitis B, cytomegalovirus hepatitis, herpes simplex hepatitis and azathioprine hepatitis. The incidence of azathioprine hepatitis may not be as high as initially suggested. Chronic hepatitis is a serious problem because the disease seems to be progressive despite prednisone therapy. The causes of this chronic hepatitis are not fully known, although hepatitis B, cytomegalovirus and herpes simplex virus have been implicated. Discontinuation of azathioprine therapy has no appreciable effect on the course of chronic hepatitis.

HBs-Ag-negative hepatitis in a hemodialysis unit: relation to Epstein-Barr virus

Eleven of 40 patients in a hemodialysis unit had clinical or biochemical evidence of hepatitis during a five-week period. The clinical disease was mild, being limited solely to dialysis patients. Epidemiologic investigation indicated that the incubation period was between 17 and 35 days and that 10 of 11 patients had been exposed to a single venous-pressure monitor before onset. Dried blood and evidence of blood reflux up the venous-pressure gauge suggested that cross-contamination of the blood of successive patients probably resulted in transmission of disease. No association with the hepatitis B surface antigen or anti-hepatitis B antibody was demonstrated, but 10 of the 11 patients with elevated transaminase levels had evidence of recent exposure, to Epstein-Barr virus as manifested either by Ox-cell hemolysin titers or rises in titers to viral capsid antigen.

Hepatitis B in a pediatric hemodialysis unit

Serial HB Ag determinations were obtained on 62 children undergoing hemodialysis during a 31/2-year period. Thirty six (58%) of the patients had atleast one positive HB Ag determination (titer larger than 1:8) either during the period of dialysis or within 2 months after transplantation. Of the children who became HB Ag positive during the period of dialysis, 89% demonstrated hepatitis B antigenemia during the initial 6 months of dialysis. Becuase of the temporal relationship between the development of HB Ag positivity and the duration of dialysis, contamination of equipment was proposed as a contributing source for transmission of HB Ag. Although 67% of the patients who were HB Ag positive during dialysis developed biochemical evidence of hepatic dysfunction, only two patients had clinical manifestations. The incidence of hepatic involvement appeared to be related to age; only one of nine children less than 12 years of age had evidence of hepatic disease. Intermittent persistence of HB Ag for periods larger than 3 years was observed. Both the incidence and persistence of HB Ag indicate the need to prevent its acquisition by pediatric patients undergoing hemodialysis.

Liver impairment during chronic hemodialysis and after renal transplantation

Liver impairment has been evaluated in a consecutive series of 79 patients with chronic renal failure of whom 23 were treated with hemodialysis alone and 37 with hemodialysis and renal transplantation alone. In half of the chronic hemodialysis patients and half of the patients receiving a renal allograft elevation of serum alanine aminotransferases was observed for a shorter or longer period during the study. In half of these cases from both groups the clinical course, laboratory data and liver histology were consistent with virus hepatitis and four patients died from fulminant hepatic failure. In the other half of the patients with elevated transaminases, this was either asymptomatic and unexplained or due to other causes such as septicaemia or urinary leakage. Liver biopsy showed unspecific changes. Renal transplantation was not performed in patients suffering from virus hepatitis, but 12 of the 37 patients who received a renal allograft had elevated aminotransferases at the time of transplantation. In seven of them a marked increase in aminotransferase was observed postoperatively, but none developed clinical sign of liver disease. It is concluded that elevated aminotransferase activity per se is no contraindication to surgical procedures, including renal transplatation, in these patients. However, a liver biopsy should be performed to detect a possible liver disease.

Subtypes of hepatitis B antigen among patients and symptomless carriers

A study of the distribution of subtypes ad and ay among sera from hepatitis B antigen-positive subjects in North West England and North Wales revealed a marked contrast between symptomless carriers among whom ad predominated and patients with acute hepatitis the majority of whom were ay. Those with hepatitis associated with drug addiction or other forms of "needle transmission" were almost all of subtype ay. On the other hand in cases of "sporadic" hepatitis without evidence of parenteral exposure subtypes ad and ay are about equally distributed. These findings are similar to those reported from other countries in Northern Europe and North America. Although geographical and social factors clearly affect the distribution of the two subtypes it is suggested that the virus of subtype ay may be more readily transmitted than subtype ad by parenteral routes involving small amounts of blood.

Hepatitis in dialysis units in the United Kingdom

A prospective study of hepatitis in 20 dialysis units in the United Kingdom showed that the number of units with outbreaks increased from one in 1968 to three in 1969 and the overall attack rate rose from 1.7 to 5.3% in patients and from 0.5 to 1.3% in staff.In July 1969 a pilot study of patients' sera showed that all of the outbreaks were associated with Australia (Au) antigen. Au antigen was not detected in the unaffected units or in one unit in which there were several patients with abnormal liver function.In January 1970 systematic prospective testing for Au antigen was begun. Au antigen was detected in single patients in five more of the 20 units. The transfer of the affected patients to isolation for dialysis seemed to prevent the spread of infection in the units. The incidence of hepatitis in 1970 was 5.6% in patients and 0.4% in staff.

Neuropathy associated with hepatitis in patients maintained on haemodialysis

During a study of peripheral nerve function in chronic renal failure, 11 patients who were being treated by chronic intermittent haemodialysis developed serum hepatitis. Before the infection there was a trend towards improvement in nerve conduction velocities. A pronounced deterioration in the conduction velocities in motor fibres of peripheral nerves occurred in association with hepatitis. In the months after recovery from the infection there was again a trend towards improvement in conduction velocities. We suggest that this reflects the occurrence of a peripheral neuropathy which is at least in part demyelinating. The neuropathy is related to the serum hepatitis, but its pathogenesis is indeterminate.

Australia antigen and heaptitis: a review

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The prevention of hepatitis in haemodialysis units

The efforts that have been made to prevent outbreaks of hepatitis in haemodialysis units are briefly reviewed.

Human immunoglobulin is of doubtful value in prophylaxis.

The preliminary results of screening for Australia antigen and the prompt isolation of carriers are encouraging.

Hepatitis-associated antigen and antibody in haemodialysis patients and staff

The screening of a dialysis population for the presence of hepatitis-associated antigen (H.A. antigen) has proved to be of value in locating a probable source of infection and in terminating an outbreak of hepatitis by early detection of H.A. antigen positive patients and staff.

ABO blood group distribution in serum hepatitis

A disproportionate excess of blood group O was found in a circumscribed outbreak of serum hepatitis among patients and staff of a haemodialysis unit. The more severe cases were also mostly of group O. This suggests that host factors may be important in the genesis of this disease.