Saudi Journal of Kidney Diseases and Transplantation

BRIEF COMMUNICATION
Year
: 2010  |  Volume : 21  |  Issue : 5  |  Page : 909--913

Methods used to reduce the prevalence of hepatitis C in a dialysis unit


Magdi M Hussein, Jaap M Mooij 
 Departments of Nephrology and Dialysis, Al Hada Armed Forces Hospital, Taif, Saudi Arabia

Correspondence Address:
Magdi M Hussein
Department of Nephrology and Dialysis, Al Hada Armed Forces Hospital, P.O. Box 1347, Taif
Saudi Arabia

Abstract

In the present study, we report on the follow-up of the epidemiology of hepatitis C viremia in our dialysis unit after our previous report, over the period from July 1, 2003 to December 31, 2005. The methods to reduce the prevalence of hepatitis C viremia in our center included: strict adherence to universal infection control precautions, separation of hepatitis C virus (HCV) positive patients from the negative patients and using specially designated machines for them, and from July 2003, periodic testing of all patients for HCV-RNA. Following the application of the above men­tioned methods, we have not had, since 31 December 2005, any case of sero-conversion from HCV­negative to HCV-positive in our dialysis unit and the only HCV-positive patients present were those who were already positive at entry. The overall prevalence of HCV-RNA positive patients in our unit has presently come down to 6.5%. Although isolation and use of designated machines for HCV-RNA positive patients is not recommended following the latest guidelines of «DQ»Kidney Disease: Improving Global Outcomes«DQ» (KDIGO, 2008), the present study supports previous reports that these measures might be beneficial, when there is a high prevalence of HCV-RNA positive patients, and in units where due to understaffing or other causes, break in infection control pro­cedures is likely to occur.



How to cite this article:
Hussein MM, Mooij JM. Methods used to reduce the prevalence of hepatitis C in a dialysis unit.Saudi J Kidney Dis Transpl 2010;21:909-913


How to cite this URL:
Hussein MM, Mooij JM. Methods used to reduce the prevalence of hepatitis C in a dialysis unit. Saudi J Kidney Dis Transpl [serial online] 2010 [cited 2021 Apr 15 ];21:909-913
Available from: https://www.sjkdt.org/text.asp?2010/21/5/909/68890


Full Text

 Introduction



Hepatitis C virus (HCV) is a serious, poten­tially lethal infection that can affect patients on dialysis and after transplantation, frequently ac­quired while on dialysis, and can itself cause kidney disease. Prevention of infection is there­fore of great importance.

Previously, we reported on the introduction of routine HCV-RNA screening of all patients in our dialysis unit in an attempt to reduce the number of HCV-positive patients, in addition to other measures such as isolation of HCV-posi­tive patients and assignment of dedicated dia­lysis machines to them, combined with strict adherence to universal infectious control pre­cautions. [1]

The rationale for performing routine HCV­RNA screening in all patients, in addition to tes­ting for HCV-antibody (HCV-Ab), is based on the presence of a certain percentage of false HCV-Ab negative results. These HCV-Ab nega­tive, but hepatitis C-RNA-positive patients are, as all hepatitis C-RNA-positive patients, a po­tential source of infection in the dialysis units. When the overall prevalence and incidence of HCV is high, the absolute number of HCV-Ab­negative, but HCV-RNA-positive patients will also be high, and consequently, the number of potential infectious sources. [2]

Contrary to the guidelines of the Centre for Diseases Control (CDC) of 2001, [3] the guide­lines of the "Kidney Disease: Improving Global Outcomes" (KDIGO) in 2008 state that in hemo­dialysis units with a high prevalence of hepatitis C viremia, initial testing with NAT (nuclear acid testing) should be considered. [2] However, isola­tion of HCV-RNA-positive patients is not reco­mmended in these guidelines. [2]

In the present study, we report on the epi­demiology of HCV-RNA-positive patients in our dialysis unit, and analyze some factors which might be responsible for the decrease of its pre­valence, which is currently about 6.5%.

 Patients and Methods



Since the early nineties, when testing for HCV­Ab became available, patients who tested posi­tive were separated from the HCV-Ab-negative patients in our unit and, dialyzed using special designated machines. This was in addition to strict adherence to universal infection control precautions, which were implemented since the start of the center in 1980.

Since July 2003, all patients were also tested for HCV-RNA using a qualitative hepatitis­RNA assay (COBAS Amplicor; PCR), version 2 (Roche Diagnostics, Branchburg, NJ, USA). The patients who tested positive with the HCV qualitative assay underwent further quantitative testing with the COBAS Amplicor HCV Moni­tor™ test, version 2 (Roche Diagnostics, Bran­chburg, NJ, USA). All HCV-PCR tests were ca­rried out at the Molecular Pathology Laboratory of our hospital and the methods have been pub­lished previously. [1] The frequency of testing was initially every six months, and was later in­creased to every three months.

The results of the HCV-RNA screening in our center over the period July 2003 to December 2005 have been reported. [1] In the present study, we follow-up on the epidemiology of positive HCV-RNA viremia in our center, using flow diagrams to assess factors which might have contributed to decrease of its prevalence.

[Figure 1] presents the follow-up of patients from the period July 2003 to December 2005 until March 2009. It includes the outcome parame­ters such as conversion from HCV-RNA-po­sitive to negative, transplantation, still on dia­lysis, death and lost to follow-up. During the follow-up period of the outcome parameters, analysis of conversion from HCV-RNA-nega­tive to positive started on January 1, 2006, since patients who converted to HCV-RNA-positive before this date (n = 3), were included in the total group of 29 HCV-RNA-positive patients in the period July 1, 2003 until December 31, 2005. [Figure 2] shows the HCV status of the pa­tient-group presently on dialysis numbering 124 (March 2009).{Figure 1}{Figure 2}

 Results



[Figure 1] shows the follow-up data of the 180 patients who were reported in our previous study over the period July 1, 2003 to December 31, 2005. [1] Out of the group of 180 patients reported earlier, 50 were still on dialysis in March 2009. The remaining 130 patients have been trans­planted, died, or lost to follow-up (transferred to other centers).

Of the 180 patients, 29 were HCV-RNA-posi­tive (16.1%). Of these 29 HCV-RNA-positive patients, three became HCV-RNA-negative (one after interferon treatment and 2 spontaneously); one of whom underwent a successful renal trans­plantation. Four of the remaining 26 HCV­RNA-positive patients are still on dialysis, and 22 were lost to follow-up or expired.

[Figure 2] presents the patients on dialysis in our unit in March 2009. There are eight HCV­RNA-positive patients (6.5%). As mentioned above, four of them were already on dialysis in the period from July 2003 to December 2005. The remaining four (new) patients were HCV­positive at entry to the dialysis program. None of the 46 HCV-RNA-negative patients who con­tinued on dialysis in our center from January 1, 2005 until March 2009, had converted to hepa­titis C-RNA-positive.

 Discussion



The results of our study suggest that the pro­cedures being presently followed in our unit to limit the transmission of HCV have been effec­tive. Isolation of HCV-positive patients and dedication of special machines to them is not re­commended following the latest guidelines of KDIGO, [2] and is supported by some observa­tional studies. [4],[5]

However, there are also reports indicating that these measures may be considered beneficial in situations when there is a high prevalence of HCV-positive patients, and in cases of a break, in infection control procedures, due to under­staffing of dialysis units or other causes. [6],[7],[8],[9],[10]

In our unit, from an early phase, soon after HCV-Ab testing became available, HCV-Ab­positive patients were isolated, and dedicated dialysis machines were used for them. Isolation will result in clustering of infectious foci, there­fore possibly reducing the risk of transmission to HCV-negative patients. In addition, it might increase the awareness of the nursing staff about the presence of HCV activity in the cen­ter. [2] Although a causal relationship cannot be proven, these factors might have played a role in the observation that during the period from July 2003 until December 2005, when the scree­ning for HCV-RNA had just started, the num­ber of HCV-Ab positive patients (18.9%) was already well below that of the 47.8% reported for dialysis patients in the Kingdom of Saudi Arabia as a whole in 2002. [11]

Isolation based on screening for HCV-Ab only, and not for HCV-RNA, is, as expected, far from effective and is one of the reasons behind questioning the usefulness of isolation. [2] In our previous study, we found that 3.24% of patients who were negative for HCV-Ab, tested positive for HCV-RNA. [1] These patients form a hidden source of potential infectious foci, and in fact, three out of the group of 180 patients pre­viously reported by us, [1] had converted from HCV-RNA negative to positive during the pe­riod from July 2003 to December 2005.

The observation that since January 2006, no patients converted from HCV-RNA negative to positive, might be because, in our center, since July 1, 2003 all HCV-RNA positive patients were identified and isolated from the other patients, in addition to strict implementation of universal infection control procedures. The only "new" HCV-RNA patients were discovered at entry to the dialysis program; this together with discon­tinuation of dialysis treatment of several pre­valent HCV-RNA positive patients in our unit due to transplantation, loss of follow-up or death [Figure 1], resulted in a large decrease of the number of HCV-RNA positive patients.

Based on our study results, we suggest that in areas with a high prevalence of HCV, espe­cially in units with understaffing, regular testing of all patients for HCV-RNA, isolation of posi­tive patients and using designated machines for their dialysis, in addition to strict adherence to infection control policies, might be helpful mea­sures in reduction of the spread of HCV within dialysis units.

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