Estimated risk of HIV transmission by blood transfusion in Kenya

Red blood cell alloantibodies in paediatric transfusion in sub-Saharan Africa: A new cohort and literature review

Blood transfusion support predisposes transfused children to the risk of erythrocyte alloimmunization in Sub-Saharan Africa. A cohort of 100 children receiving one to five blood transfusions were recruited for screening and identification of irregular antibodies using gel filtration technique. The mean age was 8 years and the sex-ratio at 1.2. The retrieved pathologies were: major sickle cell anaemia (46%), severe malaria (20%), haemolytic anaemia (4%), severe acute malnutrition (6%), acute gastroenteritis (5%), chronic infectious syndrome (12%) and congenital heart disease (7%). The children presented with haemoglobin levels ≤6 g/dl, and 16% of them presented positive irregular antibodies directed against the Rhesus (30.76%) and Kell (69.24%) blood group systems. A literature review shows that irregular antibody screenings vary from 17% to 30% of transfused paediatric patients in Sub-Saharan Africa. These alloantibodies are in particular directed against the Rhesus, Kell, Duffy, Kidd and MNS blood group and generally found in sickle cell disease and malaria. This study highlights the urgent need of extended red blood cell phenotyping including typing for C/c, E/e, K/k, and Fya/Fyb, and if possible Jka/Jkb, M/N, and S/s for children before transfusion in Sub-Saharan Africa.

Assessing the global burden of hemorrhage: The global blood supply, deficits, and potential solutions

There is a critical shortage of blood available for transfusion in many low- and middle-income countries. The consequences of this scarcity are dire, resulting in uncounted morbidity and mortality from trauma, obstetric hemorrhage, and pediatric anemias, among numerous other conditions. The process of collecting blood from a donor to administering it to a patient involves many facets from donor availability to blood processing to blood delivery. Each step faces particular challenges in low- and middle-income countries. Optimizing existing strategies and introducing new approaches will be imperative to ensure a safe and sufficient blood supply worldwide.

Symptoms of acute transfusion reactions at a general referral hospital in Kinshasa, Democratic Republic of Congo: a cross-sectional study

OBJECTIVES

Blood transfusion is a life-saving procedure and is also associated with a range of risks including the occurrence of symptoms of acute transfusion reactions (ATRs). Very few studies in sub-Saharan Africa have reported on ATRs. The present study addresses this gap in the literature by documenting the prevalence of and factors associated with ATRs in the Democratic Republic of Congo (DRC).

DESIGN

This is a cross-sectional descriptive and analytical study using blood bank data from a general referral hospital.

SETTING

Centre Hospitalier Mère-Enfant (CHME) Monkole, a general referral hospital in Kinshasa, DRC.

PARTICIPANTS

General population who have received blood transfusion in CHME Monkole between 2014 and 2019.

RESULTS

The data set included a total of 7166 patients; 3153 (44%) men and 4013 (56%) women. The overall prevalence of symptoms of ATRs was 2.6%; the lowest prevalence was in 2017 (2.34%) and highest in 2018 (2.95%) and 2019 (2.94%). The documented symptoms included 74 (39.6%) cases of dyspnoea/respiratory distress, 60 (32.1%) cases of fever, 36 (19.2%) cases of pruritus/urticaria and 17 (9.1%) cases of vomiting. None of the studied factors was associated with symptoms of ATRs.

CONCLUSION

Symptoms of ATRs were not uncommon in the studied population. Dyspnoea and respiratory distress, fever and pruritus/urticaria were the most common symptoms of ATRs. This study highlights the need for a clinical and biological surveillance to detect, prevent and manage ATRs in the context of the DRC.

Transmission routes of human immunodeficiency virus and affecting factors

Acquired immunodeficiency syndrome (AIDS) was first reported more than 30 years ago among homosexuals in the United States. The epidemiology of this disease indicates that there are three modes of transmission: Blood, mother-to-child, and sexual contact transmission. The pathogen of AIDS is human immunodeficiency virus (HIV), primarily HIV-1. HIV-1 could not break through the structurally and functionally integral skin, and primarily invades the human body through the mucosa irrespective of their integrity. Therefore, the mucosae are the natural transmission routes for HIV-1. The mucosae involved in HIV-1 transmission include the mucosae of the gastrointestinal tract and the urogenital tract. The risks of HIV-1 transmission vary significantly between mucosal sites and individuals, and are associated with mucosal integrity, abundance of target cells, immune status of the host, commensal microbes, and host genetic background. Many factors are closely related to the barrier function of the mucosa, and studies on their roles in HIV-1 invasion could promote the prevention and control of mucosal transmission of HIV-1.

The Law and Economics of Grindr: A Response to Carson

In the Winter 2017 edition of JLME, Dr. Carson outlined an economic approach to the epidemiology of HIV transmission within the gay community, with a special emphasis on mobile apps. His conclusion is that HIV transmission amongst the gay community constitutes a collective action problem, which is resolved by the social norm of using a condom. This article critiques Dr. Carson's approach from an economic perspective. By utilizing classic law and economic theory, this article will argue that HIV transmission may not, in fact, constitute a collective action problem in economic terms, and that instead condom use as a method of disease protection in theory can arise from purely rational, market driven actions. To do so, it borrows from transactional theory of information asymmetry to show the potential to alert counterparts as to serostatus. This conclusion provides an important supplement to Carson: rather than social norms being the core driver in condom usage to prevent HIV, instead condom use may arise solely as a result of rational, private decision making arising from market signaling. The article then critiques its own findings to demonstrate that it is unclear whether Carson's argument or the argument in this paper is, indeed, correct - which may represent a limitation in the analytical techniques advanced.

Seroprevalence and determinants of transfusion transmissible infections among voluntary blood donors in Homabay, Kisumu and Siaya counties in western Kenya

Objective

Since the implementation of a series of blood donation safety improvements in Kenya, information about seroprevalence and determinants of transfusion transmissible infections among voluntary blood donors especially in high HIV burden regions of Homabay, Kisumu and Siaya counties remain scanty. A cross-sectional study examining HIV, syphilis, hepatitis B and C virus sero-markers and associated determinants was conducted among voluntary blood donors. Their demographic characteristics and previous risk exposure were recorded in a pre-donation questionnaire, while blood samples collected were screened for hepatitis B, hepatitis C, human immunodeficiency viruses by ELISA and RPR (syphilis), then confirmed using CMIA.

Results

Overall TTIs seroprevalence was 114 (9.4%), distributed among HIV, HBV, HCV and syphilis at 14 (1.15%), 42 (3.46%), 39 (3.21%) and 19 (1.56%), respectively, with co-infections of 3 (0.25%). There were no significant differences in proportions distributions among demographic variables. However, high risk sex was significantly associated with higher odds of HBV infections [> 1 partner vs. 0–1 partner; odd ratio (OR) 2.60; 95% confidence interval (CI) 1.098–6.86; p = 0.046]. In conclusion, a substantial percentage of blood donors still harbor transfusion transmissible infections despite recent safety improvements with greater majority cases caused by HBV infections arising from previous exposure to high risk sex.

Electronic supplementary material

The online version of this article (10.1186/s13104-018-3276-y) contains supplementary material, which is available to authorized users.

External quality control program in screening for infectious diseases at blood banks in Mexico

INTRODUCTION

Quality control for the detection of infectious markers in blood banks is a necessary activity to ensure the accuracy of donor screening results. Considering that in Mexico blood safety is one of the goals of the National Action Programs, it is essential to evaluate banks through an External Quality Control Program.

OBJECTIVE

To analyze one of the evaluations that showed the greatest participation (2014-2/lot46) of banks in the Mexican Republic in the detection of transfusion-transmitted diseases.

MATERIALS AND METHODS

A randomized panel of infectious markers of HIV, HCV, HBV, Treponema pallidum and Trypanosoma cruzi was manufactured under high quality standards. The evaluation criteria for each infectious marker were the identification of false positives and false negative results. Additionally, technologies used to detect infectious markers were requested for each bank.

RESULTS

Of the 503 banks, only 374 participated in the evaluation. Technologies based on chemiluminescence, immunofluorescence and immunocolorimetry were used to detect viral markers. Even rapid tests for T. pallidum continue to be the methods of choice with 42%. Trypanosoma cruzi was 20% with fast techniques versus 80% with automated tests. Highest incidence of false positives was identified for T. pallidum and HBV, followed by T. cruzi, HIV and HCV. Fourteen (3.74%) false negatives results were identified for T. cruzi, followed by T. pallidum (n = 5/1.33%), HCV (n = 4/1.06) and HVB/HIV (n = 2/0.53%).

CONCLUSION

False positive results identified for each infectious marker was considered high. This evidence will allow us to focus on areas of opportunity during serologic screening with greater emphasis on good laboratory practices.

High prevalence of HIV p24 antigen among HIV antibody negative prospective blood donors in Ile-Ife, Nigeria

Blood transfusion service centers in Nigeria screen donated blood for markers of HIV infection using antibody- (Ab) based rapid test and in some centers, positives are re-tested using Ab-based ELISA. Paucity of data exists on p24 antigen prevalence among HIV Ab-negative donors in Nigeria. This study aims at detecting HIV p24 antigen among prospective blood donors in Osun State, Nigeria. Prospective blood donors negative for HIV antibodies using Determine test kit were re-tested using BIORAD GENSCREEN Ultra Ag-Ab ELISA kit, a fourth-generation ELISA kit that detects HIV antibodies/p24 antigen. Of the 169 HIV Ab-negative prospective donors, 10 (5.9%) were positive for HIV p24 antigen and 70% (7/10) of them were in the age range 18-30 years. Results of this study show that blood transfusion is still one of the major routes of HIV transmission in Nigeria and a higher proportion is among youth. Inclusion of p24 antigen testing into the blood donor screening will help reduce transfusion associated HIV in Nigeria if Nucleic Acid Testing (NAT) of all blood donor samples is not affordable; also, HIV enlightenment programs tailored toward youth may help reduce this rate among donors since more young people donate blood in low/middle-income countries than in high-income countries.

The contribution of unsafe blood transfusion to human immunodeficiency virus incidence in sub-Saharan Africa: reexamination of the 5% to 10% convention

BACKGROUND

Historical estimates have attributed 5% to 10% of new human immunodeficiency virus (HIV) infections in sub-Saharan Africa (SSA) to unsafe blood transfusions. Although frequently cited, the validity of this statistic is uncertain or outdated. Recent estimates suggest blood transfusion's contribution to new HIV infections in the region may be much lower.

STUDY DESIGN AND METHODS

We searched the peer-reviewed and gray literature for quantitative estimates of the specific contribution of unsafe blood transfusion to the proportion of new HIV infections occurring in SSA. The sources and methods used to generate attribution estimates were evaluated against published country-specific HIV prevalence data.

RESULTS

Despite multiple secondary citations, a primary published source attributing 5% to 10% of new HIV infections to blood transfusions in SSA could not be established for the current era. The United Nations Programme on HIV and AIDS (UNAIDS) modes of transmission (MOT) reports representing 15 countries suggest that between 0 and 1.1% of new HIV infections per year (median, 0.2% or approx. two out of 1000 new infections each year) may be attributable to blood transfusions.

CONCLUSION

Recent modeled estimates suggest that blood transfusions account for a very low proportion of new HIV infections in SSA, likely an order of magnitude lower than 5% to 10%. Direct quantification of risk is challenging given the paucity of data on the variables that impact transfusion-associated HIV. Specifically, data on HIV incidence in blood donors, blood bank laboratory test performance, and posttransfusion surveillance are lacking. Findings suggest an urgent need for improved surveillance and modeling of transfusion-associated HIV transmission in the region.

Transfusion-Associated HIV Infection in Mexico Related to Paid Blood Donors; HIV Epidemic

The objective of the study was to describe the clinical, epidemiological profile and conditional incubation period in a group of transfusion-associated HIV-infected (TAHI) patients seen in five national tertiary care centres in Mexico from 1983 to April 1998. Date of transfusions, AIDS diagnoses, opportunistic infections and malignancies were collected. The incubation period was estimated through a non-parametric conditional analysis.

One hundred and fifty-seven TAHI cases were analysed. The frequency of TAHI by year of transfusion was: 0.6% in 1980 and 1981, 4.5% in 1984, 22.4% in 1985, 54.5% in 1986, 10.3% in 1987, 0.6% in 1988, 1.9% in 1989 and 1990, 1.3% in 1993 and 0.6% in 1994 and 1996. The median incubation period was 4.3 years.

A well-defined epidemic period of HIV-infection among blood-recipients was identified that coincided with the HIV-epidemic among paid donors. TAHI patients in Mexico developed AIDS in a shorter time than that described for other populations.

Investments in blood safety improve the availability of blood to underserved areas in a sub-Saharan African country

BACKGROUND AND OBJECTIVES

Since 2004, several African countries, including Namibia, have received assistance from the U.S. President's Emergency Plan for AIDS Relief (PEPFAR). Gains have been documented in the safety and number of collected units in these countries, but the distribution of blood has not been described.

MATERIALS AND METHODS

Nine years of data on blood requests and issues from Namibia were stratified by region to describe temporal and spatial changes in the number and type of blood components issued to Namibian healthcare facilities nationally.

RESULTS

Between 2004 and 2007 (early years of PEPFAR support) and 2008-2011 (peak years of PEPFAR support), the average number of red cell units issued annually increased by 23.5% in seven densely populated but less-developed regions in northern Namibia; by 30% in two regions with urban centres; and by 35.1% in four sparsely populated rural regions.

CONCLUSION

Investments in blood safety and a policy decision to emphasize distribution of blood to underserved regions improved blood availability in remote rural areas and increased the proportion of units distributed as components. However, disparities persist in the distribution of blood between Namibia's urban and rural regions.

Estimating per-act HIV transmission risk: a systematic review

BACKGROUND

Effective HIV prevention programs rely on accurate estimates of the per-act risk of HIV acquisition from sexual and parenteral exposures. We updated the previous risk estimates of HIV acquisition from parenteral, vertical, and sexual exposures, and assessed the modifying effects of factors including condom use, male circumcision, and antiretroviral therapy.

METHODS

We conducted literature searches to identify new studies reporting data regarding per-act HIV transmission risk and modifying factors. Of the 7339 abstracts potentially related to per-act HIV transmission risk, three meta-analyses provided pooled per-act transmission risk probabilities and two studies provided data on modifying factors. Of the 8119 abstracts related to modifying factors, 15 relevant articles, including three meta-analyses, were included. We used fixed-effects inverse-variance models on the logarithmic scale to obtain updated estimates of certain transmission risks using data from primary studies, and employed Poisson regression to calculate relative risks with exact 95% confidence intervals for certain modifying factors.

RESULTS

Risk of HIV transmission was greatest for blood transfusion, followed by vertical exposure, sexual exposures, and other parenteral exposures. Sexual exposure risks ranged from low for oral sex to 138 infections per 10,000 exposures for receptive anal intercourse. Estimated risks of HIV acquisition from sexual exposure were attenuated by 99.2% with the dual use of condoms and antiretroviral treatment of the HIV-infected partner.

CONCLUSION

The risk of HIV acquisition varied widely, and the estimates for receptive anal intercourse increased compared with previous estimates. The risk associated with sexual intercourse was reduced most substantially by the combined use of condoms and antiretroviral treatment of HIV-infected partners.

Rapid tests for detection of viral markers in blood transfusion

Since the early 1990s, rapid tests have been available for detection of HIV infection. They were intended for field diagnosis, emergency and home testing. In addition, rapid tests for anti-HIV, hepatitis B surface antigen and antihepatitis C virus have been used for blood screening in many resource-poor areas to save resources and overcome lack of funding, equipment and electrical supply. The performance of rapid tests varies widely but some have sensitivity and specificity levels that meet standards established by enzyme immunoassays for anti-HIV. Compared with genomic detection of hepatitis B virus, hepatitis B surface antigen rapid tests and enzyme immunoassays have insufficient sensitivity. The clinical consequences of this performance deficit remain to be clarified. Anti-hepatitis C virus rapid tests detect chronically infected individuals who are viremic, however, further studies are required to fully assess their performance. In settings where few blood donations are collected and equipment is unavailable, rapid tests provide a flexible, technically undemanding and relatively inexpensive approach to ensuring a safer blood supply. When utilized for predonation screening in areas of high endemicity of viral markers, rapid tests provide the means to limit blood bag wasting, store only clinically usable blood and inform and counsel deferred donors. As with any laboratory assay, adequate training and sustained quality assurance programs are critical to maintain a safe supply of blood. As a means of achieving a safe blood supply, rapid tests for viral markers and nucleic acid testing have a place next to classic enzyme immunoassays in the definition of strategies that are adapted to a setting's epidemiology, the size and type of donor base, equipment, staff training and resources.

Estimation of the prevalence and rate of acute transfusion reactions occurring in Windhoek, Namibia

BACKGROUND

Acute transfusion reactions are probably common in sub-Saharan Africa, but transfusion reaction surveillance systems have not been widely established. In 2008, the Blood Transfusion Service of Namibia implemented a national acute transfusion reaction surveillance system, but substantial under-reporting was suspected. We estimated the actual prevalence and rate of acute transfusion reactions occurring in Windhoek, Namibia.

METHODS

The percentage of transfusion events resulting in a reported acute transfusion reaction was calculated. Actual percentage and rates of acute transfusion reactions per 1,000 transfused units were estimated by reviewing patients' records from six hospitals, which transfuse >99% of all blood in Windhoek. Patients' records for 1,162 transfusion events occurring between 1(st) January - 31(st) December 2011 were randomly selected. Clinical and demographic information were abstracted and Centers for Disease Control and Prevention National Healthcare Safety Network criteria were applied to categorize acute transfusion reactions.

RESULTS

From January 1 - December 31, 2011, there were 3,697 transfusion events (involving 10,338 blood units) in the selected hospitals. Eight (0.2%) acute transfusion reactions were reported to the surveillance system. Of the 1,162 transfusion events selected, medical records for 785 transfusion events were analysed, and 28 acute transfusion reactions were detected, of which only one had also been reported to the surveillance system. An estimated 3.4% (95% confidence interval [CI]: 2.3-4.4) of transfusion events in Windhoek resulted in an acute transfusion reaction, with an estimated rate of 11.5 (95% CI: 7.6-14.5) acute transfusion reactions per 1,000 transfused units.

CONCLUSION

The estimated actual rate of acute transfusion reactions is higher than the rate reported to the national haemovigilance system. Improved surveillance and interventions to reduce transfusion-related morbidity and mortality are required in Namibia.

Blood supply safety in Afghanistan: a national assessment of high-volume facilities

BACKGROUND

Little information is available regarding blood supply safety in Afghanistan. The purpose of this study was to assess blood safety through serologic and observational measures in Afghanistan.

STUDY DESIGN AND METHODS

This cross-sectional assessment included the 40 highest-volume facilities collecting and transfusing blood nationally identified in a previous survey. At each facility, study representatives completed a standardized instrument assessing staff performance of transfusion-related activities and performed rapid testing for human immunodeficiency virus, syphilis, and hepatitis B and C with rapid diagnostic tests on clinically discarded specimens. Reactive samples received confirmatory testing. Descriptive statistics were generated, with differences analyzed using chi-square or Fisher's exact tests.

RESULTS

Between November 2010 and May 2011, a total of 332 blood donor collection procedures were observed. Only 52.4% of observed encounters correctly screened and deferred donors by international criteria. Public and private facilities demonstrated glove use, proper sharps disposal, and patient counseling and relayed screening test results in less than 75% of observed events, significantly less likely than military facilities (p < 0.01). Of 1612 specimens assessed, confirmed cases of hepatitis B (n = 6), hepatitis C (n = 1), and syphilis (n = 3) were detected among units already prescreened and accepted for transfusion.

CONCLUSION

Lapses in proper donor screening contributed to the presence of confirmed-positive units available for transfusion, as detected in this study. Steps must be taken to ensure standardization of testing kits requirements, documentation, and mandatory training and continuing education for blood bank staff with regard to counseling, drawing, processing, and transfusion of blood products.

Prevalence and risk factors for hepatitis C virus, hepatitis B virus, and human immunodeficiency virus in transfused children in Kinshasa

OBJECTIVE

To determine seroprevalence of hepatitis C virus (HCV), human immunodeficiency virus (HIV), and hepatitis B virus (HBV) and associated factors among transfused children.

METHODS

A multicenter cross-sectional study of transfused children aged between 18 mo and 13 y old was conducted in 4 hospitals in Kinshasa. Blood samples were collected for the detection of Hepatitis B surface antigen (HBsAg) and antibodies to HCV, HIV 1 and 2.

RESULTS

A total of 177 (47.7 %) boys and 194 (52.3 %) girls participated in the study. The median age was 59.5 mo (Interquartile range IQR = 60.6). The prevalence rates of HCV, HBV, and HIV infection were 13.5 %, 1.6 %, and 1.3 %, respectively. Frequency of transfusion events were significantly associated with HCV (p < 0.001) and HIV (p < 0.05) infections.

CONCLUSIONS

HCV infection was by far more frequently identified than HBV and HIV infections among Congolese transfused children. Frequency of transfusion events was the only significant risk factor associated with HCV and HIV infections but not for HBV.

The evolving epidemiology of HIV/AIDS

Following its recognition in 1981, the HIV/AIDS epidemic has evolved to become the greatest challenge in global health, with some 34 million persons living with HIV worldwide. Early epidemiologic studies identified the major transmission routes of the virus before it was discovered, and enabled the implementation of prevention strategies. Although the first identified cases were in MSM in the United States and western Europe, the greatest impact of the epidemic has been in sub-Saharan Africa, where most of the transmission occurs between heterosexuals. Nine countries in southern Africa account for less than 2% of the world's population but now they represent about one third of global HIV infections. Where broadly implemented, HIV screening of donated blood and antiretroviral treatment (ART) of pregnant women have been highly effective in preventing transfusion-associated and perinatally acquired HIV, respectively. Access to sterile equipment has also been a successful intervention for injection drug users. Prevention of sexual transmission has been more difficult. Perhaps the greatest challenge in terms of prevention has been in the global community of MSM in which HIV remains endemic at high prevalence. The most promising interventions are male circumcision for prevention of female-to-male transmission and use of ART to reduce infectiousness, but the extent to which these interventions can be brought to scale will determine their population-level impact.

Contribution of population factors to estimation of human immunodeficiency virus prevalence trends: a cohort study in rural Uganda, 1989-2007

Because the incidence of human immunodeficiency virus (HIV) infection is difficult to measure directly, prevalence trends often serve to track epidemiologic changes. Adult HIV prevalence in open population cohort studies, however, reflects changes in incidence, population factors (migration, deaths, and aging), and survey coverage. Data from an open cohort in rural Uganda enabled estimation of the contribution of these factors to prevalence trends from 1989 to 2007. New infections within this cohort represented on average 44% of new prevalent cases per year. Other factors affecting changes in prevalence included migration and death. Migrants and mobile people (those who leave and return to the study area) are in a higher-risk group and thus can affect prevalence trends. Incidence of HIV infection among mobile people was 2-4 times greater than among stable residents. The importance of mortality is shown by the rise in prevalence from 6.8% in 2005 to 7.4% in 2007, which was accompanied by a fall in mortality among HIV-infected participants (8.7% of HIV-infected in 2005, 5.2% in 2006, and 4.3% in 2007). Assessing HIV epidemic trends through prevalence requires consideration of population factors. Measuring HIV incidence directly remains the most accurate measure of trends with which to monitor the effect of intervention activities and should complement strategies such as national prevalence surveys.

Seroprevalence and incidence of transfusion-transmitted infectious diseases among blood donors from regional blood transfusion centres in Burkina Faso, West Africa

BACKGROUND AND OBJECTIVE

The high prevalence of numerous transfusion-transmitted infectious diseases such as HIV, HBV, HCV and syphilis in sub-Saharan Africa affects blood safety for transfusion recipients. The aim of this study was to evaluate the prevalence and incidence of transfusion-transmissible infectious diseases among blood donors in Burkina Faso.

METHODS

A retrospective study of blood donors' records from January to December 2009 was conducted. Prevalence and incidence of viral infections were calculated among repeat and first-time blood donors.

RESULTS

Of the total of 31405 first-time volunteer blood donors in 2009, 24.0% were infected with at least one pathogen and 1.8% had serological evidence of multiple infections. The seroprevalence of HIV, HBV, HCV and syphilis in first-time volunteer donors was 1.8%, 13.4%, 6.3% and 2.1%, respectively. In 3981 repeat donors, the incidence rate was 3270.2, 5874.1 and 6784.6 per 100000 donations for anti-HIV-1, HBsAg and anti-HCV, respectively. These numbers varied significantly according to populations where blood is collected and blood centres in Burkina Faso.

CONCLUSION

The relatively high prevalence of viral markers in first-time volunteers and remarkably high incidence of infections in repeat donors raise concerns regarding the safety of these donors and suggest that implementation of NAT might significantly improve the situation.

Quality of medical devices and in vitro diagnostics in resource-limited settings

The phenomenon of poor-quality medicines in resource-limited settings is well documented, and field observations reveal similar problems with medical devices (MDs) and in vitro diagnostics (IVDs). In scientific literature, however, there are only scarce reports and documents providing evidence of quality problems of MDs or IVDs in resource-limited settings. This discrepancy may be ascribed to (i) the poor regulatory oversight of MDs/IVDs in resource-limited settings, (ii) a general lack of awareness of the problem of poor-quality MDs/IVDs amongst the scientific community and decision-makers, and (iii) poor quality assurance in diagnostic laboratories in resource-poor settings, precluding tracing quality problems of IVDs from the other potential causes of diagnostic inaccuracy. The problem of poor-quality MDs/IVDs in resource-limited settings is a complex one to address. Firstly, operational definitions for substandard and counterfeit MDs/IVDs are required, as well as ad hoc field surveys, to ensure proper appraisal of the real extent of the problem. Investments are needed to reinforce the national regulatory oversights on MDs/IVDs in resource-limited settings, and to encourage a proactive and transparent exchange of information between Northern and Southern regulatory authorities. Industrialized countries can play a role by expanding and strengthening their regulatory oversight and quality labels to those MDs/IVDs that are frequently used in resource-poor settings. Hopefully, the combination of these measures will result in better protection of patients in resource-poor countries from the effects of being exposed to poor-quality MDs and IVDs.

Transfusion transmitted infections - a retrospective analysis from the National Blood Transfusion Service in Eritrea

BACKGROUND

The emergence of transfusion transmitted infection (TTI) especially HIV/AIDS has created a huge obstacle in ensuring blood safety. To assess the situation in Eritrea, we carried out a retrospective study of 29,501 blood donors for the prevalence of TTI's i.e. HIV, HBV, HCV and Syphilis.

METHODS

The study population included all donors who donated blood from January 2006 to November 2009. The data was collected from the National Blood Transfusion Services (NTBS) of Eritrea and includes category of donor and result for TTI markers.

RESULTS

A total of 29,501 units of blood were collected from 23,385(79%) voluntary blood donors and the rest 6,116(21%) units were collected from family replacement donors. The over all prevalence of TTI's were 3.8% with 3.5% in voluntary blood donors and 5.1% in family replacement donors. The sero-prevalence for TTI markers were 0.18% HIV, 2.58% HBV, 0.57% HCV and 0.49% Syphilis.

CONCLUSION

In conclusion, even if the TTI prevalence rate among Eritrean blood donors is low, ensuring blood safety has a long way to go.

High Prevalence of Hepatitis C virus Among Injection Drug Users in Zhenjiang, Jiangsu, China

The constant increase in the number of drug users and rapidly spread of Hepatitis C virus (HCV) and Human immunodeficiency virus (HIV) among drug users result in a serious public health problem in China. To investigate HCV prevalence among drug users in Zhenjiang city, Jiangsu, China, 207 drug users from Zhenjiang were enrolled in this study during 2009 and the prevalence of HCV, HIV and syphilis infection were detected. HCV prevalence among injection drug users (IDUs) was 81.6%, significantly higher than that (22.9%) among oral drug users (P < 0.001), suggesting a strong association of HCV infection with injection drug use (IDU). Most drug users were more than 25 years old (89.2%), single (60.5%, including single and divorced/widowed), and had a history of drug abuse over 6 years (92.9%). HCV prevalence among drug users with middle (72.6%) or high (83.8%) school diplomas was significantly higher than that among those with lower (46.9%) education level (P = 0.007). HCV prevalence among IDUs did not obviously change along with the increase in duration of drug use and in frequency of injection per day, suggesting less association of HCV infection with both variables. These results suggest that most Chinese addicts might start drug use after their middle/high school education. To reduce drug use and to prevent HIV and HCV transmission via IDU, large-scale drug prevention educations should be urgently conducted in all China's middle and high schools.

Moving on from voluntary non-remunerated donors: who is the best blood donor?

Blood transfusion safety in sub-Saharan Africa (SSA) is marred by the high prevalence of infectious agents, chronic blood shortage and lack of resources. However, considerable pressure is applied by richer countries and international transfusion bodies to establish voluntary, non-remunerated blood donors (VNRD) as the only source of blood, excluding the traditional family/replacement donors on the grounds of a higher level of safety. Such a policy increases the cost of a unit of blood by two to fivefold and exacerbates the pre-existing blood shortage. This review provides compelling evidence that first-time VNRD are no safer than family/replacement donors and that only repeat donation provides improved blood safety. In order to limit blood shortage and maintain affordability of the blood supply in SSA, both types of donors should be accepted and both should be encouraged to donate regularly.

Keeping health facilities safe: one way of strengthening the interaction between disease-specific programmes and health systems

The debate on the interaction between disease-specific programmes and health system strengthening in the last few years has intensified as experts seek to tease out common ground and find solutions and synergies to bridge the divide. Unfortunately, the debate continues to be largely academic and devoid of specificity, resulting in the issues being irrelevant to health care workers on the ground. Taking the theme 'What would entice HIV- and tuberculosis (TB)-programme managers to sit around the table on a Monday morning with health system experts', this viewpoint focuses on infection control and health facility safety as an important and highly relevant practical topic for both disease-specific programmes and health system strengthening. Our attentions, and the examples and lessons we draw on, are largely aimed at sub-Saharan Africa where the great burden of TB and HIV ⁄ AIDS resides, although the principles we outline would apply to other parts of the world as well. Health care infections, caused for example by poor hand hygiene, inadequate testing of donated blood, unsafe disposal of needles and syringes, poorly sterilized medical and surgical equipment and lack of adequate airborne infection control procedures, are responsible for a considerable burden of illness amongst patients and health care personnel, especially in resource-poor countries. Effective infection control in a district hospital requires that all the components of a health system function well: governance and stewardship, financing,infrastructure, procurement and supply chain management, human resources, health information systems, service delivery and finally supervision. We argue in this article that proper attention to infection control and an emphasis on safe health facilities is a concrete first step towards strengthening the interaction between disease-specific programmes and health systems where it really matters – for patients who are sick and for the health care workforce who provide the care and treatment.

Reduced risk of transfusion-transmitted HIV in Kenya through centrally co-ordinated blood centres, stringent donor selection and effective p24 antigen-HIV antibody screening

BACKGROUND

Following a 1994 study showing a high rate of transfusion-associated HIV, Kenya implemented WHO blood safety recommendations including: organizing the Kenya National Blood Transfusion Service (NBTS), stringent blood donor selection, and universal screening with fourth-generation p24 antigen and HIV antibody assays. Here, we estimate the risk of transfusion-associated HIV transmission in Kenya resulting from NBTS laboratory error and consider the potential safety benefit of instituting pooled nucleic acid testing (NAT) to reduce window period transmission.

METHODS

From November to December 2008 in one NBTS regional centre, and from March to June 2009 in all six NBTS regional centres, every third unit of blood screened negative for HIV by the national algorithm was selected. Dried blood spots were prepared and sent to a reference laboratory for further testing, including NAT. Test results from the reference laboratory and NBTS were compared. Risk of transfusion-associated HIV transmission owing to laboratory error and the estimated yield of implementing NAT were calculated.

FINDINGS

No cases of laboratory error were detected in 12,435 units tested. We estimate that during the study period, the percentage of units reactive for HIV by NAT but non-reactive by the national algorithm was 0·0% (95% exact binomial confidence interval, 0·00-0·024%).

INTERPRETATION

By adopting WHO blood safety strategies for resource-limited settings, Kenya has substantially reduced the risk of transfusion-associated HIV infection. As the national testing and donor selection algorithm is effective, implementing NAT is unlikely to add a significant safety benefit. These findings should encourage other countries in the region to fully adopt the WHO strategies.

Blood donors in Kenya: a comparison of voluntary and family replacement donors based on a population-based survey

BACKGROUND AND OBJECTIVES

Blood safety and sufficiency are major challenges in Kenya and other sub-Saharan African countries forcing many countries to rely on family replacement donors (FRD). We analysed data from a national AIDS indicator survey to describe blood donors in Kenya and potential risks of transfusion transmissible infections (TTI) comparing voluntary donors and FRD.

MATERIALS AND METHODS

A population-based, cross-sectional survey was conducted in 2007 among 15- to 64-year-olds. Consenting participants were interviewed about blood donation history and were tested for HIV, HSV-2 and syphilis.

RESULTS

Of the 17,940 people surveyed, 445 (2·3%) reported donating blood in the prior 12 months. Sixty-four per cent were voluntary donors, and the rest were FRD. Compared to FRD, the majority of voluntary donors were <25 years old (59% versus 18%), from the highest wealth quintile (57% versus 42%) and single (64% versus 23%). In addition, voluntary donors were less likely to have been sexually active than replacement donors (43% versus 13%). HIV prevalence was lower among voluntary donors than among FRD (2·6% versus 7·4%, P-value=0·07).

CONCLUSIONS

The majority of blood donors in Kenya are voluntary with lower potential risk of TTI.

Hemolysis is associated with low reticulocyte production index and predicts blood transfusion in severe malarial anemia

BACKGROUND

Falciparum Malaria, an infectious disease caused by the apicomplexan parasite Plasmodium falciparum, is among the leading causes of death and morbidity attributable to infectious diseases worldwide. In Gabon, Central Africa, one out of four inpatients have severe malarial anemia (SMA), a life-threatening complication if left untreated. Emerging drug resistant parasites might aggravate the situation. This case control study investigates biomarkers of enhanced hemolysis in hospitalized children with either SMA or mild malaria (MM).

METHODS AND FINDINGS

Ninety-one children were included, thereof 39 SMA patients. Strict inclusion criteria were chosen to exclude other causes of anemia. At diagnosis, erythrophagocytosis (a direct marker for extravascular hemolysis, EVH) was enhanced in SMA compared to MM patients (5.0 arbitrary units (AU) (interquartile range (IR): 2.2-9.6) vs. 2.1 AU (IR: 1.3-3.9), p<0.01). Furthermore, indirect markers for EVH, (i.e. serum neopterin levels, spleen size enlargement and monocyte pigment) were significantly increased in SMA patients. Markers for erythrocyte ageing, such as CD35 (complement receptor 1), CD55 (decay acceleration factor) and phosphatidylserine exposure (annexin-V-binding) were investigated by flow cytometry. In SMA patients, levels of CD35 and CD55 on the red blood cell surface were decreased and erythrocyte removal markers were increased when compared to MM or reconvalescent patients. Additionally, intravascular hemolysis (IVH) was quantified using several indirect markers (LDH, alpha-HBDH, haptoglobin and hemopexin), which all showed elevated IVH in SMA. The presence of both IVH and EVH predicted the need for blood transfusion during antimalarial treatment (odds ratio 61.5, 95% confidence interval (CI): 8.9-427). Interestingly, this subpopulation is characterized by a significantly lowered reticulocyte production index (RPI, p<0.05).

CONCLUSIONS

Our results show the multifactorial pathophysiology of SMA, whereby EVH and IVH play a particularly important role. We propose a model where removal of infected and non-infected erythrocytes of all ages (including reticulocytes) by EVH and IVH is a main mechanism of SMA. Further studies are underway to investigate the mechanism and extent of reticulocyte removal to identify possible interventions to reduce the risk of SMA development.

Health economics of blood transfusion safety--focus on sub-Saharan Africa

BACKGROUND AND OBJECTIVES

Health economics provides a standardised methodology for valid comparisons of interventions in different fields of health care. This review discusses the health economic evaluations of strategies to enhance blood product safety in sub-Saharan Africa.

METHODS

We reviewed health economic methodology with special reference to cost-effectiveness analysis. We searched the literature for cost-effectiveness in blood product safety in sub-Saharan Africa.

RESULT

HIV-antibody screening in different settings in sub-Saharan Africa showed health gains and saved costs. Except for adding HIV-p24 screening, adding other tests such as nucleic acid amplification testing (NAT) to HIV-antibody screening displayed incremental cost-effectiveness ratios greater than the WHO/World Bank specified threshold for cost-effectiveness. The addition of HIV-p24 in combination with HCV antibody/antigen screening and multiplex (HBV, HCV and HIV) NAT in pools of 24 may also be cost-effective options for Ghana.

CONCLUSIONS

From a health economic viewpoint, HIV-antibody screening should always be implemented in sub-Saharan Africa. The addition of HIV-p24 antigen screening, in combination with HCV antibody/antigen screening and multiplex (HBV, HCV and HIV) NAT in pools of 24 may be feasible options for Ghana. Suggestions for future health economic evaluations of blood transfusion safety interventions in sub-Saharan Africa are: mis-transfusion, laboratory quality and donor management.

Web interface-supported transmission risk assessment and cost-effectiveness analysis of postdonation screening: a global model applied to Ghana, Thailand, and the Netherlands

BACKGROUND

The goal of our research was to actively involve decision makers in the economic assessment of screening strategies in their region. This study attempted to accomplish this by providing an easy-to-use Web interface at http://www.bloodsafety.info that allows decision makers to adapt this model to local conditions.

STUDY DESIGN AND METHODS

The cost-effectiveness was compared of 1) adding antigen screening to antibody screening for hepatitis C virus (HCV) and human immunodeficiency virus (HIV); 2) adding nucleic acid amplification testing (NAT) on hepatitis B virus (HBV), HCV, and HIV in minipool (pool of 6 [MP6] and 24 [MP24]) to antibody screening and hepatitis B surface antigen (HBsAg) screening; and 3) individual-donation NAT on HBV, HCV, and HIV to antibody screening and HBsAg screening for Ghana, Thailand, and the Netherlands.

RESULTS

The combination of HCV antibody-antigen combination (combo) and HIV combo added to antibody screening in Ghana and Thailand was cost-effective according to the WHO criteria. MP24-NAT screening in Ghana was also cost-effective. MP24-NAT on HBV, HCV, and HIV was not cost-effective compared to the other screening strategies evaluated for the Netherlands. Large regional differences in cost-effectiveness were found for Thailand.

CONCLUSION

The young transfusion recipient population of Ghana in combination with a high risk of viral transmission yields better cost-effectiveness for additional tests. The advanced age of the transfused population of the Netherlands and a small risk of viral transmission gives poor cost-effectiveness for more sensitive screening techniques. It was demonstrated that a global health economic model combined with a Web interface can provide easy access to risk assessment and cost-effectiveness analysis.

[Impact of malaria on HIV infection]

Malaria and HIV are two major public health issues, especially in sub-Saharan Africa. HIV infection increases the incidence of clinical malaria, inversely correlated with the degree of immunodepression. The effect of malaria on HIV infection is not as well established. Malaria, when fever and parasitemia are high, may be associated with transient increases in HIV viral load. The effect of subclinical malaria on HIV viral load is uncertain. During pregnancy, placental malaria is associated with higher plasma and placental HIV viral loads, independently of the severity of immunodeficiency. However, the clinical impact of these transient increases of HIV viral load remains unknown. Although some data suggests that malaria might enhance sexual and mother-to-child transmissions, no clinical study has confirmed this. Nevertheless pregnant women and children with malaria-induced anemia are also exposed to HIV through blood transfusions. Integrated HIV and malaria control programs in the regions where both infections overlap are necessary.

The risk of transfusion-transmitted infections in sub-Saharan Africa

BACKGROUND

Blood transfusions carry the risk of transmitting infections. This risk has been studied in detail in high-income countries but not in sub-Saharan Africa. This study estimates the risks of acquiring human immunodeficiency virus (HIV), hepatitis B virus (HBV), or hepatitis C virus (HCV) from a single unit of blood in sub-Saharan Africa.

STUDY DESIGN AND METHODS

A mathematical model was constructed to quantify transfusion risks across 45 sub-Saharan African countries using three components: the risk of a contaminated unit entering the blood supply, the risk that the unit will be given to a susceptible patient, and the risk that receipt of the unit will lead to infection in the recipient. Variables included prevalence of infection in donors, extent of blood testing, test sensitivity, and susceptibility of recipients. Data from the World Health Organization (WHO) African Region and a systematic review of the literature were used to parameterize the model. Uncertainty in the risk estimates was quantified using probabilistic sensitivity analysis.

RESULTS

The median overall risks of becoming infected with HIV, HBV, and HCV from a blood transfusion in sub-Saharan Africa were 1, 4.3, and 2.5 infections per 1000 units, respectively. If annual transfusion requirements projected by the WHO were met, transfusions alone would be responsible for 28,595 HBV infections, 16,625 HCV infections, and 6650 HIV infections every year. Sensitivity analysis suggests that the true risks may be even higher.

CONCLUSIONS

This study is the first to systematically quantify the risks of transfusion-transmitted infections across sub-Saharan Africa. Although the results are limited by the quality and quantity of available data, these may be the most reliable estimates at this time.

Retrospective surveillance of HIV prevalence in blood donors can help in the selection of the best social group for blood donation in Mali

The National Centre for Blood Transfusion, Bamako, Mali has collected data that characterizes trend in HIV prevalence over 10 years by gender, age, occupation, marital status and donor category. These data help to describe national HIV prevalence and assist in formulating blood donation policies. Donations from 1993 to 2002 were categorized by donor age (decade), occupation (student, military and other), marital status (single, married and other), gender and donor status (volunteer, occasional and family). Comparisons were made using conservative estimates of donation frequency/donor category. Donations increased by more than 400%. By 1999, increased HIV prevalence in donations from women was consistently present. Donations from the age group of 30-39 years showed an increased prevalence beginning in 2000, which by 2002 was almost 10 times greater than in the low-prevalence (<20 years) group (5.9 vs. 0.6%). By 2000, both categories - students and military were less likely to be HIV positive than those from other occupational categories, and donations from married persons were less likely to be HIV positive by 1997. The highest prevalence was observed in the 'occasional' donor category, which increased to >14% by 2001; volunteer donation HIV positive peaked at 2.3% in 1999. HIV prevalence in blood donations in Bamako, Mali, demonstrates important trends from 1993 to 2002. The prevalence of > 14% in donations from occasional donors and significant trends by decade, gender, marital status and occupation argue for increased analysis of the blood donor population to improve blood safety and to understand the demographics of HIV infection in Mali.

Quality of paediatric blood transfusions in two district hospitals in Tanzania: a cross-sectional hospital based study

Background

Blood transfusion (BT) can be lifesaving for children; however, monitoring the quality of BT is important. The current study describes the quality of paediatric BT delivered in two district hospitals in north-east Tanzania in order to identify areas for quality assurance and improvement in the administration of BT.

Methods

All 166 children admitted in the paediatric wards and receiving BT through April to June 2007 were prospectively observed. Medical records, request forms and registers in the laboratories were reviewed to identify blood source, blood screening and indications for BT. BT was observation before, during and after transfusion process.

Results

Malaria related anaemia accounted for 98% of the BTs. Ninety-two percent of the children were assessed for paleness. Clinical signs such as difficult breathing and symptoms of cardiac failure were only assessed in 67% and 15% of the children respectively, prior to the BT decision. Pre-transfusion haemoglobin and body temperature were recorded in 2/3 of the patients, but respiratory rate and pulse rate were not routinely recorded. In 40% of BTs, the transfusion time exceeded the recommended 4 hours.

The zonal blood bank (ZBB) and local donors accounted for 10% and 90% of the blood, respectively. ABO and RhD typing and screening for HIV and syphilis were undertaken in all transfused blood. Evidence for hepatitis B or C infection was not checked except in the ZBB.

Conclusion

Criteria for BT are not always fulfilled; time to initiate and complete the transfusion is often unacceptable long and monitoring of vital signs during BT is poor. Blood from the ZBB was often not available and BT often depended on local donors which implied lack of screening for hepatitis B and C. It is recommended that an external supervision system be established to monitor and evaluate the quality of BT performance in the laboratories as well as in wards.

Acute hepatitis C: prevention and treatment

HCV can cause acute or chronic hepatitis and is a health problem all over the world. It is one of the leading causes of cirrhosis and hepatocellular carcinoma, and is a common indication for liver transplantation. Unrecognized patients with HCV infection may transmit the virus to uninfected people. The acute form of the disease leads to chronic hepatitis in the majority of cases. Since the success rate of treatment given in the chronic phase is much lower than that given in the acute phase, recognizing acute hepatitis is critical. Although HCV is less prevalent since 1990s in the Western world after improved blood-donor screening programs, needle-exchange facilities and education among intravenous drug users, it is still endemic in some regions, including African countries, Egypt, Taiwan, China and Japan. Acute HCV infection may be a challenge for the clinician; since it is often asymptomatic, detection and diagnosis are usually difficult. After an incubation period of 7 weeks (2-12 weeks), only a minority of patients (10-15%) report symptoms. The spontaneous clearance of the virus is more frequent primarily during the first 3 months of clinical onset of the disease, but may occur anytime during the 6 months of acute infection. This spontaneous resolution seems to be more frequent in symptomatic cases. Viremia persisting more than 6 months is accepted as chronic infection. The virus is transmitted more frequently through infected blood or body fluids. Detection of antibodies against HCV is not a reliable method of diagnosing acute HCV infection since the appearance of antibodies against HCV can be delayed in up to 30% of patients at the onset of symptoms. Thus, the diagnosis of acute hepatitis C relies on the qualitative detection of HCV RNA, which may appear as early as 1-2 weeks after exposure quickly followed by highly elevated alanine aminotransferase. After a follow-up period of 8-12 weeks for allowing spontaneous resolution, treatment should be initiated. Pegylated interferon monotherapy for 24 weeks seems effective, and the therapy can be individualized according to the characteristics of the patient.

Blood safety in Sub-Saharan Africa: a multi-factorial problem

Although the World Health Organization (WHO) has set targets for safe blood by 2012, Sub-Saharan Africa remains confronted with multi-factorial issues that compromise blood safety in most countries of the region. Some of these include the development and implementation of national policies for transfusion, the recruitment of voluntary and unpaid donors, proper screening of collected blood as well as a strategy for its rational use in a setting already plagued by a high prevalence of blood-borne agents, poverty, and sometimes organizational deficits. Furthermore, the organization of hemovigilance, as well as quality systems that could monitor transfusion practices is lacking in these settings. There is no funding and global improvement of blood safety has to be cheap to be feasible. Specific solutions for the African continent need to be developed and implemented. This paper examines the current status and difficulties of blood safety in Africa and reviews available data on transfusion medicine in the region.

Cost-effectiveness of HIV screening of blood donations in Accra (Ghana)

OBJECTIVES

Areas with high HIV-incidence rates compared to the developed world may benefit from additional testing in blood banks and may show more favorable cost-effectiveness ratios. We evaluated the cost-effectiveness of adding p24 antigen, mini pool nucleic acid amplification testing (MP-NAT), or individual donation NAT (ID-NAT) to the HIV-antibody screening at the Korle Bu Teaching Hospital (Accra, Ghana), where currently only HIV-antibody screening is undertaken.

METHODS

The residual risk of HIV transmission was derived from blood donations to the blood bank of the Korle Bu Teaching Hospital in 2004. Remaining life expectancies of patients receiving blood transfusion were estimated using the World Health Organization life expectancies. Cost-effectiveness ratios for adding the tests to HIV-antibody screening only were determined using a decision tree model and a Markov model for HIV.

RESULTS

The prevalence of HIV was estimated at 1.51% in 18,714 donations during 2004. The incremental cost per disability-adjusted life-year (DALY) averted was US$1237 for p24 antigen, US$3142 for MP-NAT and US$7695 compared to the next least expensive strategy. HIV-antibody screening itself was cost-saving compared to no screening at all, gaining US$73.85 and averting 0.86 DALY per transfused patient. Up to a willingness-to-pay of US$2736 per DALY averted, HIV-antibody screening without additional testing was the most cost-effective strategy. Over a willingness-to-pay of US$11,828 per DALY averted, ID-NAT was significantly more cost-effective than the other strategies.

CONCLUSIONS

Adding p24 antigen, MP-NAT, or ID-NAT to the current antibody screening cannot be regarded as a cost-effective health-care intervention for Ghana.

Acute hepatitis C

Symptomatic acute hepatitis C occurs in only about 15% of patients who are infected with hepatitis C virus (HCV). Acute hepatitis C is most often diagnosed in the setting of post-exposure surveillance, or seroconversion in high-risk individuals (eg, health-care professionals or injecting drug users) previously known to be seronegative. Although transmission via transfusion and injecting drug use has declined in developed countries, unsafe blood products and medical practices continue to increase transmission of HCV in many developing countries. Clinically, acute hepatitis C can increase concentrations of alanine aminotransferase to ten times the upper limit of normal but almost never causes fulminant hepatic failure. Diagnosis of HCV infection in the acute phase is difficult since production of antibodies against HCV can be delayed by up to 12 weeks, and about a third of infected individuals might not have detectable antibody at the onset of symptoms. Therefore, testing for HCV RNA by PCR is the only reliable test for the diagnosis of acute infection. Symptomatic patients with jaundice have a higher likelihood of spontaneous viral clearance than do asymptomatic patients, and thus should be monitored for at least 12 weeks before initiating antiviral therapy. By contrast, asymptomatic patients have a much lower chance of spontaneous clearance, and might benefit from early antiviral therapy. Antiviral therapy for 12 weeks is generally effective in treating patients who are HCV RNA negative after 4 weeks of treatment; lengthier courses could be needed for those who relapse or fail to show early virological clearance.

Reducing replacement donors in Sub-Saharan Africa: challenges and affordability

In 1975, the World Health Assembly recommended that blood for transfusion should come from voluntary, non-remunerated donors; yet, in Africa, 75-80% of blood for transfusion still comes from hospital-based replacement donors. Although comprehensive economic data are scarce, evidence indicates that blood from voluntary donors recruited and screened at centralized transfusion centres, costs four to eight times as much as blood from a hospital-based, replacement donor system. Donor recruitment, quality assurance systems and distribution mechanisms in the centralized system are major reasons for the cost difference. There are concerns about the sustainability of centralized voluntary donor systems and their compatibility with the levels of health care that exist in many poor countries yet burdening patients' families with the responsibility of finding replacement blood donors will exacerbate poverty and reduce the safety of the blood supply. There are measures that can be introduced into hospital-based systems to improve safe blood supply in Africa but their effectiveness in different contexts needs to be evaluated.

Deactivation of human immunodeficiency virus type 1 in medium by copper oxide-containing filters

Human immunodeficiency virus type 1 (HIV-1) can be transmitted through breast-feeding and through contaminated blood donations. Copper has potent biocidal properties and has been found to inactivate HIV-1 infectivity. The objective of this study was to determine the capacity of copper-based filters to inactivate HIV-1 in culture media. Medium spiked with high titers of HIV-1 was exposed to copper oxide powder or copper oxide-impregnated fibers or passed through copper-based filters, and the infectious viral titers before and after treatment were determined. Cell-free and cell-associated HIV-1 infectivity was inhibited when exposed to copper oxide in a dose-dependent manner, without cytotoxicity at the active antiviral copper concentrations. Similar dose-dependent inhibition occurred when HIV-1 was exposed to copper-impregnated fibers. Filtration of HIV-1 through filters containing the copper powder or copper-impregnated fibers resulted in viral deactivation of all 12 wild-type or drug-resistant laboratory or clinical, macrophage-tropic and T-cell-tropic, clade A, B, or C, HIV-1 isolates tested. Viral inactivation was not strain specific. Thus, a novel means to inactivate HIV-1 in medium has been developed. This inexpensive methodology may significantly reduce HIV-1 transmission from "mother to child" and/or through blood donations if proven to be effective in breast milk or plasma and safe for use. The successful application of this technology may impact HIV-1 transmission, especially in developing countries where HIV-1 is rampant.