Seroprevalence of HIV and HCV infections in Alexandria, Egypt

Characterizing the historical role of parenteral antischistosomal therapy in hepatitis C virus transmission in Egypt

Background

Egypt is the nation most affected by hepatitis C virus (HCV) infection, following an epidemic of historic proportions. We aimed to characterize the epidemic’s historical evolution and to delineate the role of parenteral antischistosomal therapy (PAT) campaigns in transmission.

Methods

A mathematical model was constructed and analysed in order to understand HCV-transmission dynamics. The model was fitted to Egypt’s Demographic and Health Survey data and to a systematic database of HCV-prevalence data.

Results

The incidence rate peaked in 1966 at 15.7 infections per 1000 person-years—a period of time that coincides with the PAT campaigns—and rapidly declined thereafter, beginning the mid-1990s. The annual number of new infections peaked in 1993 at 581 200 (with rapid demographic growth), leading to a high-incidence-cohort effect, and declined to 67 800 by 2018. The number of individuals ever infected (1950–2018) was 16.4 million, with HCV prevalence peaking in 1979. The number of individuals ever exposed to PAT was 8.3 million; however, of these individuals, 7.3 million were alive in 1980 and only 3.5 million alive in 2018. The number of individuals ever infected due to PAT exposure was 963 900, with 850 200 individuals alive in 1980 and only 389 800 alive in 2018. The proportion of PAT-attributed prevalent infections peaked at 19.9% in 1972, declining to 5.5% by 2018.

Conclusions

PAT campaigns played an important role in HCV transmission, yet explain only 6% of infections—they appear to be a manifestation, rather than a cause, of the epidemic. A possible driver of the epidemic could be the mass expansion of inadequate-quality healthcare during PAT campaigns and subsequent decades. Despite a historic toll, the epidemic has been rapidly diminishing since the mid-1990s.

Individual-level key associations and modes of exposure for hepatitis C virus infection in the Middle East and North Africa: a systematic synthesis

PURPOSE

To identify, map, and synthesize the individual-level key associations and modes of exposure for hepatitis C virus (HCV) infection in the Middle East and North Africa (MENA), the most affected region by HCV.

METHODS

Source of data was the MENA HCV Epidemiology Synthesis Project database, populated through systematic literature searches. Risk factors determined to be statistically significant after adjustment for confounders were extracted and categorized into key associations or modes of exposure.

RESULTS

In total, 329 risk factors were identified from 109 articles in 14 of 24 MENA countries. Among key associations, age was most frequently reported (n = 39; 34.2%), followed by other infections/diseases (n = 20; 17.5%), and incarceration (n = 17; 14.9%). Among modes of exposure, health care-related exposures were most frequently reported (n = 127; 59.5%), followed by injecting drug use exposures (n = 45; 20.9%), community-related exposures (n = 34; 15.8%), and sexual-related exposures (n = 8; 3.7%). Blood transfusion, hemodialysis, surgical and other medical procedures, dental work, and medical injections were identified as key health care-related exposures.

CONCLUSIONS

Health care appears to be the primary driver of prevalent (and possibly incident) infections in MENA, followed by injecting drug use. HCV screening should target the identified modes of exposure. Commitment to prevention should be an integral component of HCV response to achieve HCV elimination by 2030, with focus on strengthening infection control in health care facilities, improving injection safety and blood screening, and expanding harm reduction services for people who inject drugs.

Characterizing hepatitis C virus epidemiology in Egypt: systematic reviews, meta-analyses, and meta-regressions

Egypt is the most affected nation by hepatitis C virus (HCV) and needs a comprehensive characterization of HCV epidemiology to inform the scale-up of treatment and prevention programs. Systematic reviews, meta-analyses, and meta-regressions were conducted. A total of 25 incidence, 259 prevalence, and 47 genotype studies were identified. Incidence and prevalence levels were high across all populations. Genotype 4 accounted for 94.1% of infections with a relative Shannon Diversity Index of only 14.4%. Pooled mean HCV prevalence was estimated at 11.9% (95% CI = 11.1–12.6%) among the general population, 55.6% (95% CI = 49.4–61.7%) among populations at high risk, 14.3% (95% CI = 10.3–18.8%) among populations at intermediate risk, 56.0% (95% CI = 50.4–61.6%) among populations with liver-related conditions, and 35.0% (95% CI = 27.3–43.1%) among special clinical populations. Mean HCV viremic rate was estimated at 66.7% (95% CI = 61.7–71.5%). Meta-regression indicated 6% lower odds for HCV prevalence for each one-year increment in publication year (AOR = 0.94; 95% CI = 0.92–0.96). HCV prevalence is high with evidence for ongoing transmission mainly through healthcare. Genotype diversity is low with genotype 4 dominance. Two-thirds of antibody-positive Egyptians are chronically infected and need treatment. Clinical populations should be prioritized for screening. Despite the large-scale epidemic, prevalence appears to be declining rapidly consistent with a contracting epidemic.

Status of HIV and hepatitis C virus infections among prisoners in the Middle East and North Africa: review and synthesis

INTRODUCTION

The status of HIV and hepatitis C virus (HCV) infections among incarcerated populations in the Middle East and North Africa (MENA) and the links between prisons and the HIV epidemic are poorly understood. This review synthesized available HIV and HCV data in prisons in MENA and highlighted opportunities for action.

METHODS

The review was based on data generated through the systematic searches of the MENA HIV/AIDS Epidemiology Synthesis Project (2003 to December 15, 2015) and the MENA HCV Epidemiology Synthesis Project (2011 to December 15, 2015). Sources of data included peer-reviewed publications and country-level reports and databases.

RESULTS AND DISCUSSION

We estimated a population of 496,000 prisoners in MENA, with drug-related offences being a major cause for incarceration. Twenty countries had data on HIV among incarcerated populations with a median prevalence of 0.6% in Afghanistan, 6.1% in Djibouti, 0.01% in Egypt, 2.5% in Iran, 0% in Iraq, 0.1% in Jordan, 0.05% in Kuwait, 0.7% in Lebanon, 18.0% in Libya, 0.7% in Morocco, 0.3% in Oman, 1.1% in Pakistan, 0% in Palestine, 1.2% in Saudi Arabia, 0% in Somalia, 5.3% in Sudan and South Sudan, 0.04% in Syria, 0.05% in Tunisia, and 3.5% in Yemen. Seven countries had data on HCV, with a median prevalence of 1.7% in Afghanistan, 23.6% in Egypt, 28.1% in Lebanon, 15.6% in Pakistan, and 37.8% in Iran. Syria and Libya had only one HCV prevalence measure each at 1.5% and 23.7%, respectively. There was strong evidence for injecting drug use and the use of non-sterile injecting-equipment in prisons. Incarceration and injecting drugs, use of non-sterile injecting-equipment, and tattooing in prisons were found to be independent risk factors for HIV or HCV infections. High levels of sexual risk behaviour, tattooing and use of non-sterile razors among prisoners were documented.

CONCLUSIONS

Prisons play an important role in HIV and HCV dynamics in MENA and have facilitated the emergence of large HIV epidemics in at least two countries, Iran and Pakistan. There is evidence for substantial but variable HIV and HCV prevalence, as well as risk behaviour including injecting drug use and unprotected sex among prisoners across countries. These findings highlight the need for comprehensive harm-reduction strategies in prisons.

Epidemiology of hepatitis C virus exposure in Egypt: Opportunities for prevention and evaluation

AIM: To critically evaluate the current epidemiology data on exposures, rather than infection, to hepatitis C virus (HCV) transmission and recommend epidemiologic strategies to fill gaps.

METHODS: Standard methods for identifying and evaluating relevant epidemiologic literature and available data were used.

RESULTS: There is a large body of literature on the epidemiology of HCV transmission in Egypt that collectively identifies ongoing iatrogenic exposures as the major driver for HCV transmission due to short comings in infection control and standard procedures. Additional epidemiologic studies on HCV transmission that requires the participation of human subject is unwarranted. Alternatively, very little literature was found on the epidemiology of exposure to HCV, infection control, and safe injection practices. The information that is available on patterns of HCV exposure shows high frequencies of inadequate infection control, problems in sterilization in health care facilities, low rates of hand washing, untrained personnel, lack of stated policies in facilities, HCV contamination of instruments and very large injection frequencies with low but very significant syringe and needle reuse. There is an important need to increase the number, size, and diversity of epidemiologic studies on HCV exposures, patterns of risk factors for infection, infection control, and safe injection practices. In addition to health care facilities evaluation, relevant knowledge attitude and practice studies are recommended.

CONCLUSION: Epidemiologic methods on HCV exposure can be used to characterize the magnitude of exposures to HCV infection, target interventions to reduce exposures, and provide the best method for evaluating interventions by demonstrating the reduction of exposure to HCV infection.

Potential for human immunodeficiency virus parenteral transmission in the Middle East and North Africa: An analysis using hepatitis C virus as a proxy biomarker

The Middle East and North Africa (MENA) region has endured several major events of infection parenteral transmission. Recent work has established the utility of using hepatitis C virus (HCV) as a proxy biomarker for assessing the epidemic potential for human immunodeficiency virus (HIV) parenteral transmission. In this review, we use data on the prevalence of HCV infection antibody (seroprevalence) among general population and high risk population groups to assess the potential for HIV parenteral transmission in MENA. Relatively low prevalence of HCV infection in the general population groups was reported in most MENA countries indicating that parenteral HIV transmission at endemic levels does not appear to be a cause for concern. Nonetheless, there could be opportunities for localized HIV outbreaks and transmission of other blood-borne infections in some settings such as healthcare facilities. Though there have been steady improvements in safety measures related to parenteral modes of transmission in the region, these improvements have not been uniform across all countries. More precautions, including infection control training programs, surveillance systems for nosocomial infections and wider coverage and evaluation of hepatitis B virus immunization programs need to be implemented to avoid the unnecessary spread of HIV, HCV, and other blood-borne pathogens along the parenteral modes of transmission.

The state of hepatitis B and C in the Mediterranean and Balkan countries: report from a summit conference

The burden of disease due to chronic viral hepatitis constitutes a global threat. In many Balkan and Mediterranean countries, the disease burden due to viral hepatitis remains largely unrecognized, including in high-risk groups and migrants, because of a lack of reliable epidemiological data, suggesting the need for better and targeted surveillance for public health gains. In many countries, the burden of chronic liver disease due to hepatitis B and C is increasing due to ageing of unvaccinated populations and migration, and a probable increase in drug injecting. Targeted vaccination strategies for hepatitis B virus (HBV) among risk groups and harm reduction interventions at adequate scale and coverage for injecting drug users are needed. Transmission of HBV and hepatitis C virus (HCV) in healthcare settings and a higher prevalence of HBV and HCV among recipients of blood and blood products in the Balkan and North African countries highlight the need to implement and monitor universal precautions in these settings and use voluntary, nonremunerated, repeat donors. Progress in drug discovery has improved outcomes of treatment for both HBV and HCV, although access is limited by the high costs of these drugs and resources available for health care. Egypt, with the highest burden of hepatitis C in the world, provides treatment through its National Control Strategy. Addressing the burden of viral hepatitis in the Balkan and Mediterranean regions will require national commitments in the form of strategic plans, financial and human resources, normative guidance and technical support from regional agencies and research.

The epidemiology of hepatitis C virus in Egypt: a systematic review and data synthesis

BACKGROUND

Egypt has the highest prevalence of hepatitis C virus (HCV) in the world, estimated nationally at 14.7%. Our study's objective was to delineate the evidence on the epidemiology of HCV infection among the different population groups in Egypt, and to draw analytical inferences about the nature of HCV transmission in this country.

METHODS

We conducted a systematic review of all data on HCV prevalence and incidence in Egypt following PRISMA guidelines. The main sources of data included PubMed and Embase databases. We also used a multivariate regression model to infer the temporal trend of HCV prevalence among the general population and high risk population in Egypt.

RESULTS

We identified 150 relevant records, four of which were incidence studies. HCV incidence ranged from 0.8 to 6.8 per 1,000 person-years. Overall, HCV prevalence among pregnant women ranged between 5-15%, among blood donors between 5-25%, and among other general population groups between 0-40%. HCV prevalence among multi-transfused patients ranged between 10-55%, among dialysis patients between 50-90%, and among other high risk populations between 10% and 85%. HCV prevalence varied widely among other clinical populations and populations at intermediate risk. Risk factors appear to be parenteral anti-schistosomal therapy, injections, transfusions, and surgical procedures, among others. Results of our time trend analysis suggest that there is no evidence of a statistically significant decline in HCV prevalence over time in both the general population (p-value: 0.215) and high risk population (p-value: 0.426).

CONCLUSIONS

Egypt is confronted with an HCV disease burden of historical proportions that distinguishes this nation from others. A massive HCV epidemic at the national level must have occurred with substantial transmission still ongoing today. HCV prevention in Egypt must become a national priority. Policymakers, and public health and medical care stakeholders need to introduce and implement further prevention measures targeting the routes of HCV transmission.

A systematic review of hepatitis C virus epidemiology in Asia, Australia and Egypt

BACKGROUND

The hepatitis C pandemic has been systematically studied and characterized in North America and Europe, but this important public health problem has not received equivalent attention in other regions.

AIM

The objective of this systematic review was to characterize hepatitis C virus (HCV) epidemiology in selected countries of Asia, Australia and Egypt, i.e. in a geographical area inhabited by over 40% of the global population.

METHODOLOGY

Data references were identified through indexed journals and non-indexed sources. In this work, 7770 articles were reviewed and 690 were selected based on their relevance.

RESULTS

We estimated that 49.3-64.0 million adults in Asia, Australia and Egypt are anti-HCV positive. China alone has more HCV infections than all of Europe or the Americas. While most countries had prevalence rates from 1 to 2% we documented several with relatively high prevalence rates, including Egypt (15%), Pakistan (4.7%) and Taiwan (4.4%). Nosocomial infection, blood transfusion (before screening) and injection drug use were identified as common risk factors in the region. Genotype 1 was common in Australia, China, Taiwan and other countries in North Asia, while genotype 6 was found in Vietnam and other Southeast Asian countries. In India and Pakistan genotype 3 was predominant, while genotype 4 was found in Middle Eastern countries such as Egypt, Saudi Arabia and Syria.

CONCLUSION

We recommend implementation of surveillance systems to guide effective public health policy that may lead to the eventual curtailment of the spread of this pandemic infection.

Epidemiology of HIV infection in the Middle East and North Africa

OBJECTIVE

The Middle East and North Africa (MENA) region continues to be perceived as a region with very limited HIV epidemiological data, raising many controversies about the status of the epidemic in this part of the world. The objective of this review and synthesis was to address the dearth of strategic interpretable data on HIV in MENA by delineating a data-driven overview of HIV epidemiology in this region.

METHODS

A comprehensive systematic review of HIV, sexually transmitted infections (STIs) and risk behavior studies in MENA, irrespective of design, was undertaken. Sources of data included Medline for peer-reviewed publications, Google Scholar for other scientific literature published in nonindexed local and regional journals, international organizations reports and databases, country-level reports and database including governmental and nongovernmental organizations publications, as well as various other institutional documents.

RESULTS

Over 5000 sources of data related to HIV and STIs were identified and reviewed. The quality of data and nature of study designs varied substantially. There was no evidence for a sustainable HIV epidemic in the general population in any of the MENA countries, except possibly for southern Sudan. The general pattern in different countries in MENA points towards emerging epidemics in high-risk populations including injecting drug users, men who have sex with men (MSM) and to a lesser extent female sex workers, with heterogeneity between countries on the relative role of each of these high-risk groups. Exogenous HIV exposures among nationals linked to travel abroad appeared to be the dominant HIV transmission pattern in a few MENA countries with no evidence for much epidemic or endemic transmission. The role of bridging populations in bridging the HIV infection to the general population was found to be very limited.

CONCLUSION

Although they do not provide complete protection against HIV spread, near universal male circumcision and possibly the prevailing sexually conservative cultural norms seemed to have played so far a protective role in slowing and limiting HIV transmission in MENA relative to other regions. If the existing social and epidemiological context remains largely the same, HIV epidemic transmission is likely to remain confined to high-risk populations and their sexual partners, in addition to exogenous exposures. HIV prevention efforts in this region, which continue to be stymied by stigma associated with HIV/AIDS and related risk behaviors, need to be aggressively expanded with a focus on controlling HIV spread along the contours of risk and vulnerability. There is still a window of opportunity to control further HIV transmission among high-risk groups in MENA that, if missed, may entail a health and socioeconomic burden that the region, in large part, is unprepared for.

Survey of Hepatitis Markers Among Donors in the State of Qatar

A total of 78,428 blood units collected by the Blood Donor Unit, Hamad Medical Corporation, Doha, from the multinational donors of Qatar (28,622 Qatari nationals donors and 49,806 Non-Qatari donors) in the period January 1994 to Dececember 2001 were screened for hepatitis markers. About 10,382 units (13.2%) were discarded because of positivity for one or more hepatitis markers; 769 units (0.9%) were positive for hepatitis-B surface antigen (HBsAg), 8516 units (10.9%) were positive for hepatitis-B core antibodies (HBcAb) and 1097 units (1.39%) were positive for hepatitis C (HCV) antibodies. There was no significant difference between the rate of positivity for HBcAb and HBsAg in indigenous Qataris and Non-Qataris despite a slightly higher rate ofpositivity for HCV antibodies in the Non-Qatari group. An outstanding finding was the significantly high rate of positivity for HCV antibodies in Egyptian donations (11.2%), which accounted for 31.2% of all discards for the Non-Qatari group. As the Blood Donor Unit at HMC is the only blood collection center in Qatar it is assumed that the results could be representative of the country as a whole.

HIV in prison in low-income and middle-income countries

High prevalence of HIV infection and the over-representation of injecting drug users (IDUs) in prisons combined with HIV risk behaviour create a crucial public-health issue for correctional institutions and, at a broader level, the communities in which they are situated. However, data relevant to this problem are limited and difficult to access. We reviewed imprisonment, HIV prevalence, and the proportion of prisoners who are IDUs in 152 low-income and middle-income countries. Information on imprisonment was obtained for 142 countries. Imprisonment rates ranged from 23 per 100,000 population in Burkina Faso to 532 per 100,000 in Belarus and Russia. Information on HIV prevalence in prisons was found for 75 countries. Prevalence was greater than 10% in prisons in 20 countries. Eight countries reported prevalence of IDUs in prison of greater than 10%. HIV prevalence among IDU prisoners was reported in eight countries and was greater than 10% in seven of those. Evidence of HIV transmission in prison was found for seven low-income and middle-income countries. HIV is a serious problem for many countries, especially where injection drug use occurs. Because of the paucity of data available, the contribution of HIV within prison settings is difficult to determine in many low-income and middle-income countries. Systematic collection of data to inform HIV prevention strategies in prison is urgently needed. The introduction and evaluation of HIV prevention strategies in prisons are warranted.

Ageing, care dependency, and care for older people in Egypt: a review of the literature

AIMS

The purpose of this study was to gain an overview of the current situation of ageing and elderly care in Egypt and to consider the ensuing socio-economical problems, which provide the framework for the provision of care.

BACKGROUND

Recent discussions about demographic transition in developing countries suggest a change in their age group composition. Possible implications of this development for nursing care require closer examination.

METHOD

Literature about ageing and elderly care in Egypt of the period from 1980-2004 was researched and reviewed.

RESULTS

Despite the scarcity of literature and the lack of precision in many cases, it is possible to outline an overall development. Ageing is a slowly emerging phenomenon in Egypt contributing to a change in the country's age group composition. The ensuing care dependency appears to become a problem especially for lower and middle class members due to economical restrictions and life-style changes. In relation to the need, there is a shortage of care-providing institutions. Furthermore, geriatric homes seem to differ in their quality according to the residents' social status.

CONCLUSION

The existing types of geriatric homes will serve as prototypes for future development. There is however, a need for additional homecare services to reduce care givers' strain in the families.

Monophyletic HIV type 1 CRF02-AG in a nosocomial outbreak in Benghazi, Libya

A cluster of HIV-1 infection has been identified in Libya in 1999, involving 402 children admitted to "El-Fath" Children's Hospital in Benghazi (BCH) during 1998 and 19 of their mothers. Nosocomial transmission has been indicated as responsible for the spread of infection. Out of this group, 104 children and 19 adult women have been followed at the National Institute for Infectious Diseases L. Spallanzani in Rome during 1 year. At BCH, all children had received intravenous infusions but not blood or blood products. A single child receiving a blood transfusion in 1997 and the 17 infected mothers were never hospitalized in Benghazi. In addition, two nurses were diagnosed as HIV-1 infected. In 40 subjects out of this group HIV-1 gag, env, and pol fragments were amplified and sequenced. The phylogenetic analyses showed that a monophyletic recombinant HIV-1 form CRF02-AG was infecting all of the HIV-1-seropositive patients admitted at BCH with no close similarities to the other CRF02-AG reported to GenBank. A different strain was found in the child infected by blood transfusion. The data thus suggest a highly contagious nosocomial spread of HIV-1 infection and possibly transmission of the virus from child to mother during breastfeeding in connection with primary HIV-1 infection.

Hepatic dysfunction in children with acute lymphoblastic leukemia in remission: relation to hepatitis infection

BACKGROUND

Viral hepatitis is a cause of hepatic dysfunction in children with ALL in remission during maintenance therapy is debated. The aims of the current study were (1) to explore the incidence of hepatic dysfunction in a group of children (Egyptian and Saudi) with ALL under maintenance therapy, (2) to study the prevalence of hepatitis B (HBV) and/or C (HCV) infection and their contributions to chronic liver disease that might be induced by maintenance therapy.

PROCEDURE

The current study included 105 children with ALL (54 Egyptian and 51 Saudi). All eligible patients had been on maintenance therapy for at least 12 months and all had serial assessments of liver function. These included determination of total bilirubin, AST, ALT, and alkaline phosphatase. Markers for HBV and HCV including HBsAg, anti-HBC, and anti-HCV and for some patients HCV RNA by PCR were studied. Percutaneous liver biopsy was performed for a group of children.

RESULTS

The prevalence of hepatitis infection (HBV and/or HCV) among Egyptian children was found to be high (43/54-80%). Only five Saudi children had evidence of exposure to HBV (5/51-9.8%), P<0.0001. During the period of study, 22 Egyptian patients vs. four Saudi patients (41 vs. 7.8%, P<0.0001) experienced at least one episode of elevation of liver enzymes, three times the upper limit of normal or more. Twenty-six of the 48 patients (54%) with HBV and/or HCV infection had episodes of elevated liver enzymes, while there was no occurrence among the patients negative for HBV and HCV. In patients with HBV infection, the presence of HBsAg was strongly associated (100%) with elevated liver enzymes. Histopathologic examination of liver biopsies obtained from 35 patients revealed that all five patients negative for HBV and HCV had normal liver biopsies in spite of being under maintenance therapy.

CONCLUSION

In children undergoing treatment for ALL, elevations in liver enzymes may be primarily due to hepatitis viruses. However, maintenance therapy using known hepatotoxic drugs, may have additive deleterious effects. Liver enzymes are normalized in affected patients when maintenance therapy is temporarily suspended.

The role of parenteral antischistosomal therapy in the spread of hepatitis C virus in Egypt

BACKGROUND

The population of Egypt has a heavy burden of liver disease, mostly due to chronic infection with hepatitis C virus (HCV). Overall prevalence of antibody to HCV in the general population is around 15-20%. The risk factor for HCV transmission that specifically sets Egypt apart from other countries is a personal history of parenteral antischistosomal therapy (PAT). A review of the Egyptian PAT mass-treatment campaigns, discontinued only in the 1980s, show a very high potential for transmission of blood-borne pathogens. We examine the relative importance of PAT in the spread of HCV in Egypt.

METHODS

The degree of exposure to PAT by cohort was estimated from 1961-86 Ministry of Health data. A cohort-specific exposure index for PAT was calculated and compared with cohort-specific HCV prevalence rates in four regions.

FINDINGS

HCV prevalence was calculated for 8499 Egyptians aged 10-50 years. A significant association between seroprevalence of antibodies to HCV and the exposure index (1.31 [95% CI 1.08-1.59]; p=0.007) was identified across four different regions. In all regions cohort-specific HCV prevalence was lowest in children and young adults than in older cohorts. These lower prevalence rates coincided with the gradual and final replacement of PAT with oral antischistosomal drugs at different points in time in the four regions.

INTERPRETATION

The data suggest that PAT had a major role in the spread of HCV throughout Egypt. This intensive transmission established a large reservoir of chronic HCV infection, responsible for the high prevalence of HCV infection and current high rates of transmission. Egypt's mass campaigns of PAT may represent the world's largest iatrogenic transmission of blood-borne pathogens.

Hepatitis C: public health strategies

Hepatitis C virus (HCV) is a major global public health problem. As with many recently discovered diseases, there is still considerable controversy within the scientific community regarding the prevalence, incidence and socio-economic burden of acute and chronic hepatitis C. New infections continue to occur. Given the substantial morbidity and mortality attributable to HCV-related chronic liver disease, each country, irrespective of its economic status, should develop an HCV-related public health plan for the prevention of new HCV infections. The source of HCV infection includes transfusion of blood or blood products from unscreened donors, transfusion of blood products that have not undergone viral inactivation, parenteral exposure to blood through the use of contaminated and inadequately sterilized instruments and needles used in medical, dental and "traditional" medicine, individuals undergoing procedures such as haemodialysis, persons who participate in high risk sexual practices, household or sexual contacts with HCV-infected persons and infants of HCV-infected mothers. In many countries, the relative contribution of the various sources of infection has not been defined with population-based epidemiological studies. Wherever possible, such studies should be performed to enable countries to prioritise their preventive measures and to make the most appropriate use of available resources.