Hepatitis C seroprevalence in accepted versus deferred blood-donor candidates evaluated by medical history and self-exclusion form

Successful exclusion of blood-borne viral disease in blood donors

BACKGROUND

All blood transfusion services have various rules to insure that blood products are kept safe for transfusion. Donor selection is crucial in providing safe blood. We propose in our study to determine the influence of donor selection on blood safety.

METHODS

In this case-control study, donors who were referred to the Qazvin Blood Transfusion Organization during 2007-2009 were selected. Based on a special questionnaire, all blood donors were examined by physicians and every donor was categorized as one of two types of rejected donors (high risk and low risk) or as accepted donors. Data were analyzed by SPSS version 13.0, using chi-square and Fisher's exact tests, where P<0.05 was considered significant.

RESULTS

Single donors, the self-employed, the unemployed and students were banned from donation due to high-risk criteria (P<0.0001, 0.003). Female donors were banned from donation due to low-risk criteria. Hepatitis B was more prevalent among cases rejected for donation due to high-risk criteria than among healthy controls (P=0.014); but not so for hepatitis C (P=0.058). Hepatitis B was not significantly more prevalent among those cases rejected for donation due to low-risk criteria, than among healthy cases.

CONCLUSION

Those having a history of unsafe sexual conduct and intravenous drug abusers and their spouses are at risk for hepatitis C. Cases rejected for donation due to low-risk criteria were banned from donation to maintain the donors' health, while other cases with low-risk criteria were banned to guarantee the blood recipients' health.

Hepatitis C virus infection in blood donors from the state of Puebla, Mexico

Background

Worldwide, 130 million persons are estimated to be infected with HCV. Puebla is the Mexican state with the highest mortality due to hepatic cirrhosis. Therefore, it is imperative to obtain epidemiological data on HCV infection in asymptomatic people of this region. The objective of present study was to analyze the prevalence of antibodies and genotypes of hepatitis C virus (HCV) in blood donors from Puebla, Mexico.

Results

The overall prevalence was 0.84% (515/61553). Distribution by region was: North, 0.86% (54/6270); Southeast, 1.04% (75/7197); Southwest, 0.93% (36/3852); and Central, 0.79% (350/44234). Ninety-six donors were enrolled for detection and genotyping of virus, from which 37 (38.5%) were HCV-RNA positive. Detected subtypes were: 1a (40.5%), 1b (27.0%), mixed 1a/1b (18.9%), undetermined genotype 1 (5.4%), 2a (2.7%), 2b (2.7%), and mixed 1a/2a (2.7%). All recovered donors with S/CO > 39 were HCV-RNA positive (11/11) and presented elevated ALT; in donors with S/CO < 39 HCV-RNA, positivity was of 30.4%; and 70% had normal values of ALT. The main risk factors associated with HCV infection were blood transfusion and surgery.

Conclusions

HCV prevalence of donors in Puebla is similar to other Mexican states. The most prevalent genotype is 1, of which subtype 1a is the most frequent.

Reduction of hepatitis B seroprevalence in blood banking units by combined utilization of self-exclusion forms and clinical evaluation of blood donation candidates in Turkey

SUMMARY

In this retrospectively designed study, we evaluate the influence of the permanence and qualifications of health-care professionals on blood disposal rates due to hepatitis seropositivity. We observed a decrease of 44.2% in the number of blood units being rejected due to the donor's hepatitis B seropositivity in the second study period in which self-exclusion forms and where blood donation candidates were evaluated by a family physician. However, a similar decrease of the disposal rate due to hepatitis C seropositivity was not observed. This is especially important in countries which cannot afford many of the expensive modern laboratory tests. A comprehensive evaluation of self-exclusion forms and a brief examination prior to donation will greatly increase transfusion safety. Unfortunately, there are blood banks in Turkey which employ no physicians at all.

Prevalence of hepatitis C virus in the Mexican population: a systematic review

BACKGROUND

Although hepatitis C virus (HCV) infection is considered a relevant public health problem in Mexico, the prevalence is still under discussion. The objective of this study was to conduct a systematic review to explore the prevalence of HCV infection in the Mexican population.

METHODS

A systematic review of studies reporting prevalence in Mexican population was performed using several free-access databases.

RESULTS

Sixty-eight works fulfilled the search criteria. From these, 44 studies involved asymptomatic subjects and 28 involved patients or high-risk subjects. Prevalence of blood donors (6,955,558 persons) ranged from 0.0% to 2.05%, with 7/32 studies reporting values >1%, whereas prevalence of non-donor asymptomatic subjects (28,528 persons) from 0.0% to 2.7%, with 7/11 studies reporting values >1%, and medical personnel from 0.0% to 2.08% (1,227 persons), with 4/11 studies reporting values >1%. Prevalence of patients with chronic hepatic disease ranged from 6.7% to 77%. The most prevalent genotype was 1 (30.0-87.5%), of which subtype 1b is the most frequent (11.9-61.9%). The main risk factors were blood transfusion and unprotected sex or having multiple sex partners.

CONCLUSIONS

The prevalence in the Mexican population seems to be in accordance with that previously estimated by the World Health Organization (1-2.5%).

Aggressive Use of Diagnostic Services is Counterproductive

BACKGROUND

Medical fraternity requisitions diagnostic tests for multiple reasons. More often than not, the tests lead to more tests either to exclude or to confirm doubts raised by the test results. These tests have an inherent morbidity, discomfort and cost. Growing expenditure on diagnostic tests without matching improvement in the health status warrants an internal audit of the laboratory utilization.

METHODS

A retrospective utility audit was done for certain routinely advised laboratory tests at a hospital. Blood urea estimation in annual / periodic medical examination (AME/ PME), bleeding and clotting time in pre-anaesthetic check-up and aspartate aminotransferase (AST) and antibodies to hepatitis C virus (anti-HCV) in diagnostic work-up of acute onset jaundice were included in the audit.

RESULTS

During the study period, 793 individuals underwent AME / PME and urea estimation did not provide any additional information in these cases which was not inferred by serum creatinine. Similarly, in diagnostic workup of acute onset jaundice, 6049 aspartate aminotransferase (AST) estimations in 1024 patients did not contribute anything more than what was inferred by alanine aminotransferase (ALT). Prevalence of anti HCV antibodies in acute onset jaundice in serving soldiers (11 out of 1225; 0.89%) though more than that in the blood donors from the same population (17 out of 4105; 0.41%) was less than anticipated false positives (18 out of 1225; 1.5%) as per the claimed specificity (98.5%) of the test kit. None of the 2766 bleeding and clotting time tests detected a bleeding or coagulation disorder.

CONCLUSION

The study reveals significant overuse of the laboratory that may not be good for the patient and the organization in terms of direct and indirect costs due to false positive results. This laboratory overload adversely affects the quality and availability of laboratory results. Therefore, a test should only be advised, if positive or negative result would dictate a change in patient management.

Low prevalence of anti-hepatitis C virus antibodies in Mexico: A systematic review

BACKGROUND

The prevalence of reactive tests to anti-hepatitis C virus (HCV) antibodies in Mexico is unknown, though estimated to be 1%. There is no single nation-wide study or comprehensive literature review addressing the epidemiology of HCV infection in Mexico.

METHODS

We did a systematic review of English- and Spanish-language literature reporting on the frequency of anti-HCV antibodies in asymptomatic persons at low risk, of studies performed in Mexico. An exhaustive search in MEDLINE, IMBIOMED, MedicLatina, ARTEMISA and MEDIGRAPHIC databases was undertaken. Weighted mean prevalence (WMP) was calculated after combining the results of each study.

RESULTS

22 studies involving 825,377 persons at low risk, mainly blood donors, were identified. Crude seroprevalence reported in each study ranged from 0.1 to 2%, with 16 (73%) studies reporting below 1%. Overall, WMP of anti-HCV antibodies (tested by enzyme immunoassay) was 0.37% (95% CI, 0.36-0.38%), differing by country region and immunoassay generation (p < 0.01). The most frequent risk factor reported was blood transfusion. Confirmation of specific anti-HCV antibodies by recombinant immunoblot assay ranged from 30 to 100%, whereas confirmation of viremia by PCR ranged from 16 to 80%. In 3 studies on HCV genotype frequency, genotype 1 had crude prevalence ranging from 63 to 70%, subtype 1b being the most prevalent (21-47%).

CONCLUSIONS

The prevalence of anti-HCV antibodies in Mexico might be lower than previously estimated. Transfusion of blood products is the main risk factor. HCV subtype 1b is the most prevalent among persons with confirmed viremia. Information of a nation-wide survey is mandatory.

Detection of West Nile virus in the Mexican blood supply

BACKGROUND

West Nile virus (WNV) is the etiologic agent of an emerging disease in the Western Hemisphere that can be transmitted to humans by blood transfusion. WNV first appeared in the United States in 1999, in Canada in 2001, and in Mexico in 2002. The aim of this nationwide study was to determine the prevalence of WNV in blood donors in Mexico as a first step in preventing its transfusion-associated transmission.

STUDY DESIGN AND METHODS

In July and August 2004, a total of 3856 fresh plasma specimens collected from each state's center for blood transfusion in 29 of 31 Mexican states were screened with an investigational WNV assay (Procleix,(R) Gen-Probe Inc. and Chiron Corp.), a nucleic acid test based on transcription-mediated amplification (TMA). Reactive specimens were confirmed with a second TMA-based test, the alternative WNV assay (Gen-Probe), and with WNV capture enzyme-linked immunosorbent assays (ELISAs) for detection of immunoglobulin M (IgM) and IgG antibodies. In addition, 3714 frozen plasma samples collected in 2002 and 2003 were similarly tested.

RESULTS

One of 3856 fresh samples from an asymptomatic donor from Chihuahua was reactive by both TMA-based tests and IgM ELISA, suggesting a recently acquired infection. The observed percentage of viremic donors blood donors was 0.03 percent. Results from frozen samples were not included in the prevalence calculation and none were TMA-reactive for WNV.

CONCLUSIONS

WNV is present in the Mexican blood supply and measures should be taken to reduce the risk of transfusion transmission.

Prevalence of selected viral infections among temporarily deferred donors who returned to donate blood: American Red Cross blood donor study

BACKGROUND

Health history questions are introduced into the predonation interview to identify blood donors believed to pose a higher risk of infectious diseases to recipients. This study assesses the current impact of some of those questions.

STUDY DESIGN AND METHODS

Donor deferral and donation data were extracted from a research database of the American Red Cross. The prevalence of hepatitis B surface antigen or antibodies to human immunodeficiency virus, hepatitis C virus, or human T-lymphotropic virus was obtained for different groups of donors who were temporarily deferred in 2000 through 2001 and later returned to donate blood in 2000 through 2003. The results were compared with either first-time or repeat donors in 2000 through 2003, while controlling for differences in sex, age, and year of donation.

RESULTS

Of donors temporarily deferred in 2000 through 2001 who had had no donation or deferral during the previous 2 years, only 22.08 percent subsequently returned to donate blood in 2000 through 2003. Donations from returning donors who had been deferred for potential infectious disease risk did not show a higher prevalence for any of the viral markers when those with no donation or deferral during the previous two years were compared with first-time donations, and those with prior donation were compared with repeat donations.

CONCLUSION

Blood donors temporarily deferred in 2000 through 2001 for potential risk of viral infection who later returned to donate blood did not appear to pose a higher risk compared to first-time or repeat donors. The effectiveness of some of the currently used deferral questions in reducing viral risks warrants further study.