Three-Dimensional Imaging and Quantitative Analysis of Blood Vessel Distribution in The Meniscus of Transgenic Mouse after Tissue Clearing

OBJECTIVE

Blood supply to the meniscus determines its recovery and is a reference for treatment planning. This study aimed to apply tissue clearing and three-dimensional (3D) imaging in exploring the quantitative distribution of blood vessels in the mouse meniscus.

MATERIALS AND METHODS

In this experimental study, tissue clearing was performed to treat the bilateral knee joints of transgenic mice with fluorescent vascular endothelial cells. Images were acquired using a light sheet microscope and the vascular endothelial cells in the meniscus was analysed using 3D imaging. Quantitative methods were employed to further analyse the blood vessel distribution in the mouse meniscus.

RESULTS

The traditional three-equal-width division of the meniscus is as follows: the outer one-third is the red-red zone (RR), the inner one-third is the white-white zone (WW), and the transition area is the red-white zone (RW). The division revealed significant signal differences between the RW and WW (P<0.05) zones, but no significant differences between the RR and RW zones, which indicated that the division might not accurately reflect the blood supply of the meniscus. According to the modified division (4:2:1) in which significant differences were ensured between the adjacent zones, we observed that the width ratio of each zone was 38 ± 1% (RR), 24 ± 1% (RW), and 38 ± 2% (WW). Furthermore, the blood supply to each region was verified. The anterior region had the most abundant blood supply. The fluorescence count in the anterior region was significantly higher than in the central and posterior regions (P<0.05). The blood supply of the medial meniscus was superior to the lateral meniscus (P<0.05).

CONCLUSION

Analysis of the blood supply to the mouse meniscus under tissue clearing and 3D imaging reflect quantitative blood vessel distribution, which would facilitate future evaluations of the human meniscus and provide more anatomical references for clinicians.

The blood supply in Sub-Saharan Africa: needs, challenges, and solutions

Sub-Saharan Africa (SSA) is burdened with a growing population and poor health care resources. Transfusion medicine is uniquely affected for SSA as a result of a combination of factors which put tremendous pressure on the blood supply. In this review, we consider these factors including: malaria, sickle cell anemia, transfusion medicine infrastructure, and past transfusion medicine policies including those which are tied to foreign aid, such as a VNRD-only practice. We also consider how SSA can overcome some of these hurdles to achieve a safe and adequate blood supply for its people through the advent of new vaccines, medications, infrastructure development, policy changes, and education.

The arterial blood supply of the temporomandibular joint: an anatomical study and clinical implications

PURPOSE

The aim of this study was to analyze three-dimensional images of the arterial supply to the temporomandibular joint.

MATERIALS AND METHODS

Ten patients (five men and five women, mean age 36 years) without signs or symptoms of temporomandibular disorders, who underwent contrast-enhanced computed tomographic (CT) scanning with intravenous contrast, were studied. The direct volume rendering technique of CT images was used, and a data set of images to visualize the vasculature of the human temporomandibular joint in three dimensions was created. After elaboration of the data through post-processing, the arterial supply of the temporomandibular joint was studied.

RESULTS

The analysis revealed the superficial temporal artery, the anterior tympanic artery, the deep temporal artery, the auricular posterior artery, the transverse facial artery, the middle meningeal artery, and the maxillary artery with their branches as the main arterial sources for the lateral and medial temporomandibular joint.

CONCLUSION

The direct volume rendering technique was found to be successful in the assessment of the arterial supply to the temporomandibular joint. The superficial temporal artery and maxillary artery ran along the lateral and medial sides of the condylar neck, suggesting that these arteries are at increased risk during soft-tissue procedures such as an elective arthroplasty of the temporomandibular joint.

Financing blood transfusion services in sub-Saharan Africa: a role for user fees?

The provision of a secure and safe blood supply has taken on new importance in sub-Saharan Africa with the onset of the AIDS epidemic. Blood transfusion services capable of providing safe blood are not cheap, however, and there has been some debate on the desirability and sustainability of different financing mechanisms for blood transfusion services. This paper examines patterns of financing blood transfusion in three countries--Côte d'Ivoire, Zimbabwe and Mozambique. It goes on to consider the conceptual options for financing safe blood, and to examine in detail the possible role of user fees for blood transfusion in Africa, developing a simple model of their likely burden to patients based on data from Côte d'Ivoire. The model indicates that, at best, there can only be a limited role for user fees in the financing of safe blood transfusion services, due mainly to the relatively high cost of producing a unit of safe blood. Charging individuals for the blood they receive is likely to be administratively complex and costly, could realistically recover only a fraction of the production costs involved, and is further complicated by the fact that the main recipients of blood transfusion in sub-Saharan Africa are children and pregnant women. If cost-recovery for safe blood is to be attempted, the most viable option appears to be that of charging a collective fee, levied upon all inpatients, not just on those who receive blood. Such a mechanism is not without problems, not least in its failure to offer incentives for more appropriate blood use, and it is still likely to recover only a portion of the costs of producing safe blood. Whether or not cost-recovery is instituted, there will remain an important role for public funding of blood transfusion services, and, by implication, an important role for foreign donor support.

Evaluation of blood bank practices in Karachi, Pakistan, and the government's response

BACKGROUND

National legislation in Pakistan regulating blood banks has been introduced several times, but has never been passed. To support provincial-level efforts to develop legislation we conducted a study to evaluate blood-banking practices in Karachi, Pakistan, to identify areas that could be improved.

METHODS

Thirty-seven blood banks were randomly selected from a list of 87 Karachi blood banks. The research team interviewed blood bank personnel, inspected available facilities and equipment, and observed blood collection using structured questionnaires and observation forms.

RESULTS

Of the 37 selected facilities, 25 were operational and 24 agreed to participate. Twelve (50%) of the facilities reported regularly utilizing paid blood donors, while only six (25%) activity recruited volunteer donors. During observation only 8% of facilities asked donors about injecting drug use, and none asked donors any questions about high-risk sexual behaviour. While 95% of blood banks had appropriate equipment and reagents to screen for hepatitis B, only 55% could screen for HIV and 23% for hepatitis C. Twenty-nine percent of the facilities were storing blood products outside the WHO recommended temperature limits.

IMPLICATIONS

Practices at most Karachi blood banks fell well below WHO standards. Findings from this study were instrumental in developing and passing legislation to regulate blood transfusion throughout Sindh Province, and suggest a method for improving blood transfusion practices in other developing countries.

Feasibility of hospital-based blood banking: a Tanzanian case study

The demand for blood transfusion is high in sub-Saharan Africa because of the high prevalence of anaemia and pregnancy related complications, but the practice is estimated to account for 10% of HIV infections in some regions. The main response to this problem by the international donor community is to establish vertically implemented blood transfusion services producing suitable (safe) blood at a cost of US$25-40 per unit. However, the economic sustainability of such interventions is questionable and it is argued here that hospital-based blood transfusion services operating at a basic adequate level are sufficient for low-income African countries. The results of a project aimed at improving such services in Tanzania are presented. The main findings are: (1) the cost per suitable blood unit produced was US$12.4; (2) at an HIV test sensitivity of 93.5% during the study period, discounted financial benefits of the interventions exceeded costs by a factor of between 17.2 and 37.1; (3) the cost per undiscounted year of life saved by use of these interventions was US$2.7-2.8; and (4) safe blood transfusion practices can be assured at an annual cost of US$0.07 per capita. Recommendations are made to ensure safe blood transfusion practices at hospital-based blood banks in Tanzania.

KEMRI Hep-cell II hepatitis B surface antigen screening kit

BACKGROUND

Kenya is a high hepatitis B virus (HBV) endemic zone. Prevention of HBV transmission by transfusing safe blood is necessary. Kits for screening hepatitis B surface antigen (HBsAg) are usually imported and are expensive. Hence it has been difficult to screen donated and patient blood samples all over Kenya.

OBJECTIVE

To produce a HBsAg screening kit locally in order to be able to screen donated and patient blood samples all over Kenya.

DESIGN

A laboratory based study.

SETTING

Centre for Virus Research (CVR), Kenya Medical Research Institute (KEMRI), Nairobi.

METHOD

Purified HBsAg from plasma of carriers obtained from National Public Health Laboratories Services (NPHLS) was used to minimise guinea pigs to produce antihepatitis B (anti HBs) antibody. The anti HBs was then used to sensitise sheep red blood cells (SRBC). The final product was freeze dried (lyophilised) and its sensitivity and specificity was compared with other commercial kits.

RESULTS

The sensitivity and specificity of KEMRI Hep-cell II was found to be 98% and 99%, respectively. The kit was found to be stable and potent for one year whether kept 4 degrees C, 37 degrees C or room temperature.

CONCLUSION

KEMRI Hep-cell II was successfully produced locally. The sensitivity and specificity were comparable to other commercial kits. The kit was stable and potent for one year between temperature of 4 degrees C and 37 degrees C. The kit required only simple apparatus to carry out the test hence it can be used anywhere in Kenya. It was also cheap and affordable.

Prevalence of hepatitis C virus antibodies and genotypes in asymptomatic, first-time blood donors in Namibia

Reported is the prevalence of hepatitis C virus (HCV) in Namibia as determined using a third-generation enzyme-linked immunosorbent assay (ELISA) on samples of blood collected from all asymptomatic, first-time blood donors between 1 February and 31 July 1997 (n = 1941). The HCV seroprevalence was 0.9% (95% confidence interval (CI): 0.5-1.5%) and no associations were detected between a positive HCV serostatus and the person's sex, region of residence, or previous hepatitis B exposure or hepatitis B carrier status, as determined by hepatitis B surface antigen (HBsAg). The only significant association in a logistic regression model was an increase in HCV positivity with increasing age (P = 0.04). Viral RNA was amplified from 2 out of 18 (11.1%) specimens that were ELISA positive. Genotyping of these specimens, by restriction fragment length polymorphism (RFLP), showed the presence of genotypes 5 and 1a. The positive predictive value of using HBsAg positivity as a surrogate screening marker for HCV in Namibian blood donors was poor (1.6%), with low sensitivity (16.7%) and specificity (89.3%), and detecting only 3 out of 18 serologically HCV-positive specimens. The results of this first study of the prevalence and epidemiology of HCV infection in Namibia suggest that donor blood should be screened for HCV by ELISA in order to prevent the transmission of hepatitis C virus.

HIV-1 subtypes among blood donors from Rio de Janeiro, Brazil

The prevalence of HIV infection in Brazil is one of the highest in the world. In addition, transfusion-transmitted HIV accounts for 2.3% of all AIDS cases in Brazil. The objective of this study was to evaluate genetic diversity and distribution of HIV-1 strains circulating in the blood-donor population. We characterized 43 seropositive blood units collected from volunteer blood donors residing throughout Rio de Janeiro, Brazil. Viral RNA was extracted from plasma, reverse transcribed, and amplified by nested polymerase chain reaction (PCR) using HIV group M degenerate primers. Genetic heterogeneity was evaluated by direct automated cycle sequencing of the following gene fragments: gag p24 (399 bp), env C2V3 (345 bp), and env gp41 (369 bp). Phylogenetic analysis reflected the complexity of the Brazilian HIV epidemic: the majority of specimens, 33 of 43 (76.7%) were subtype B, and 6 of 43 (14%) were subtype F. The remaining 4 samples (9.3%) involved potential mosaic viruses of subtypes B and F or B and D. This survey is the first to document HIV-1 genetic variation in the Brazilian blood-donor population.

Gynaecological conditions associated with HIV infection in women who are partners of HIV-positive Thai blood donors

Women who were partners of HIV-positive blood donors were enrolled in a study of heterosexual HIV transmission between March 1992 and December 1996 and were interviewed and examined. Gynaecological conditions, including cervical dysplasia, human papillomavirus (HPV) infection, gonorrhoea, chlamydial infection, trichomoniasis, bacterial vaginosis, vaginal candidiasis and syphilis were assessed in addition to HIV status and CD4 level. Of 481 women enrolled, 224 (46.6%) were HIV seropositive. HIV-infected women were more likely to have abnormal vaginal discharge on physical examination (OR=2.6, P <0.01), HPV infection with a high-risk type (OR=6.9, P <0.01), and cervical dysplasia (OR=5.3, P <0.01). The prevalence of other gynaecological conditions detected at the enrolment visit did not differ by HIV status. History of prior STD (OR=2.0, P <0.01) was more common among HIV-infected women. The median CD4 count was 400 cells/microl among HIV-infected women. The prevalence of abnormal vaginal discharge and bacterial vaginosis increased significantly with decreasing CD4 count. The prevalence of ectopy, vaginal candidiasis, and cervical dysplasia increased with decreasing CD4 count, but these trends were not significant. We conclude that HIV-infected Thai women appear to have increased prevalences of abnormal vaginal discharge, squamous intraepithelial lesions and self-reported history of STD.

Prevention of HIV transmission by blood transfusion in the developing world: achievements and continuing challenges

In industrialized countries, the use of sensitive HIV screening tests, donor deferral, and more conservative use of blood have resulted in a dramatic decrease in the transmission of HIV infection by blood transfusion. The risk of HIV transmission in the USA by blood screened negative for HIV antibody was recently estimated at one in 440,000-660,000 donations. Despite this low risk, continued public concern has compelled blood collection agencies and policy makers to continue to search for more sensitive HIV screening tests. Genome amplification techniques are receiving increased attention and are being piloted in Germany. HIV-1 p24 antigen testing was implemented in the USA in March 1996. In the first 18 months of p24 antigen testing, an estimated 18 million blood donations were tested at a cost of US$90 million to detect three antigen-positive, antibody-negative donations. However, in many developing countries where severe anemia is widespread and the prevalence of HIV infection among blood donors is orders of magnitude greater than in industrialized countries, the blood supply is either incompletely screened or not screened at all for HIV antibody. Although the contribution of transfusion-transmitted infection to the HIV epidemic has not been accurately assessed, an estimated 5-10% of HIV infections in developing countries are due to blood transfusion. In a study conducted 1 year after implementation of HIV blood screening in the largest hospital in the capital city of the Democratic Republic of the Congo, an estimated 25% of pediatric HIV infections, and 40% of infections among children over 1 years of age, were due to transfusion. Lack of commitment by national governments and international aid organizations to this fundamental element of HIV prevention has resulted in a shortage of basic equipment, supplies, and trained personnel for blood screening. Moreover, provision of test kits alone cannot prevent HIV transmission by transfusion in resource-poor areas. More comprehensive programs are needed to improve the recruitment and retention of safe donors, essential laboratory services for blood banking and screening, technical training and supervision, appropriate use of transfusions, and the prevention of severe anemia. This article summarizes the steps being taken by developing countries to prevent HIV transmission by blood transfusion, lessons learned, and the work that still lies ahead.

Risk factors for HIV seropositivity among first-time blood donors in Zimbabwe

BACKGROUND

Factors associated with an increased likelihood of HIV infection among newly recruited blood donors in Zimbabwe are identified. Their feasibility as criteria for exclusion from donation is assessed.

STUDY DESIGN AND METHODS

A self-administered survey including demographic and behavioral questions was completed by 1199 first-time, volunteer blood donors in Harare, Zimbabwe. Methods for subject recruitment and laboratory screening followed usual blood bank protocols.

RESULTS

Fifteen percent of subjects were HIV positive. Factors significantly associated with HIV seropositivity at the p<0.05 level included recruitment venue, age, marital status, donor residence, residence of primary partner, occupation, history of sexually transmitted disease, and condom use. An exclusion strategy based on donor age, condom use, recruitment venue, sexually transmitted disease history, and residence of primary partner would exclude a large proportion of HIV-infected donors without substantial loss of uninfected donors.

CONCLUSIONS

Exclusion of donors who are likely to be infected with HIV is a sound policy for improving blood safety and reducing operating costs worldwide. Identification of efficient donor selection criteria requires knowledge of the local epidemiology of HIV infection and the asking of questions that are likely to be answered accurately.

High prevalence of hepatitis G virus infection in multiply transfused children with thalassaemia

We investigated the prevalence of hepatitis G virus (HGV) RNA in relation to the frequency of blood transfusions in thalassaemic children and in volunteer blood donors in Thailand. Furthermore, we studied the frequency of coinfection with hepatitis B virus (HBV) and/or hepatitis C virus (HCV) as well as a possible relationship to the alanine aminotransferase (ALT) status of the blood samples, taken at random from thalassaemic children who have received multiple blood transfusions and from volunteer blood donors. The results show detectable HGV-RNA in 32.6% of transfusion patients and in 5% of blood donors. The prevalence of HGV-RNA peaked between the 11th and 50th transfusion. The relationship between HGV infection and ALT status was not statistically relevant.

The AIDS epidemic and commercial plasmapheresis

In 1986 an epidemic of HIV infection among paid plasma donors was identified in Mexico; paid donors were iatrogenically infected in a plasmapheresis center. These paid donors sold both plasma and blood: they provided one-third of blood consumed in 1986. This led to infection of blood recipients, mainly women of childbearing age. Blood transfusion is the leading cause of AIDS in women in Mexico. The male:female ratio decreased from 30:1 in 1986 to 5:1 1990; that coincided with the increase of transfusion-associated AIDS cases. Mexico prohibited the blood trade in 1987, ending the epidemic in paid donors and recipients. latrogenic infection of paid donors in plasmapheresis facilities could help to explain the explosive AIDS epidemic in central Africa and Haiti in the 1980s. There is a temporal and geographical coincidence in the early eighties between that AIDS epidemic, high numbers of hepatitis B asymptomatic carriers and an increased production of serum inactivated hepatitis B vaccine. Plasmapheresis facilities in these developing countries may have taken advantage of the high prevalence of hepatitis B asymptomatic carriers in their populations to obtain plasma for exportation through brokers to developed countries where the vaccine and other plasma products were manufactured. This hypothesis is relevant to establishing preventive policies and warrants further investigation.

Risk factors for HIV-1 transmission from HIV-seropositive male blood donors to their regular female partners in northern Thailand

OBJECTIVE

To describe risks for HIV transmission from male blood donors to their regular female sex partners in Chiang Mai, Thailand.

DESIGN

Cross-sectional study.

METHODS

From March 1992 through September 1995, 405 HIV-seropositive male blood donors (index cases) and their regular female partners were enrolled in the study. Women with risk factors for HIV infection other than sexual contact with the index male were excluded. Couples were interviewed and examined; specimens were collected for laboratory analysis.

RESULTS

Overall, 46% of the 405 women enrolled were HIV-positive. Ninety-eight per cent of male index cases had a history of sex with a female prostitute; 1.5% reported always using condoms with their regular partner. History of sexually transmitted disease (STD) and swollen inguinal lymph nodes in the female partner were associated with an increased risk of HIV infection in the female. History in the female of genital herpes [odds ratio (OR), 3.46; 95% confidence interval (CI), 1.50-8.78], gonorrhea or chlamydia infection (OR, 2.71; 95% CI, 1.39-5.53), and stable relationship of longer than 24 months (OR, 2.28; 95% CI, 1.02-5.09) were associated with an increased risk of HIV infection in the female. Consistent condom use in the past 2 years (OR, 0.10; 95% CI, 0.01-0.79) was associated with a decreased risk of HIV infection in the female.

CONCLUSIONS

Married women in northern Thailand who appear otherwise to be at low risk for HIV infection may be exposed to this virus by their husbands. High rates of sex with commercial sex workers among men and low use of condoms within stable relationships may be important factors promoting the transmission of HIV in married couples. Programs to increase the regular use of condoms among married couples could be an important public health intervention to prevent transmission of HIV and other types of STD in northern Thailand.

Seroprevalence of HIV-1, HIV-2, and HIV-1 group O in Nigeria: evidence for a growing increase of HIV infection

To determine current data on HIV infection and to further confirm the presence of HIV-1 group O infection in Nigeria, 2300 samples from five states were tested for the presence of HIV antibody. A convenience sampling was obtained from pregnant women, tuberculosis (TB) patients, commercial sex workers (CSWs), blood donors, patients with sexually transmitted diseases (STDs), patients with skin diseases, male clients of CSWs, outpatients suspected to have AIDS, truck drivers, and community dwellers. With the exception of pregnant women, the HIV prevalences in all these groups were high: 60.6% in CSWs, 16.2% in TB patients, 7.7% in blood donors in some states, and 16% in the rural area of Kano State. Male clients of CSWs, truck drivers, and STD patients had prevalences of 7.8%, 8.6%, and 21.2%, respectively. Regional differences in relation to HIV prevalences were observed; HIV-2 and most of the HIV-1/2 infections were found in the southern states of Nigeria. Higher HIV prevalences were observed in the north-northeast in pregnant women, TB patients, and CSWs, but for blood donors, higher rates were seen in the southeast-southwest. One asymptomatic 50-year-old woman, a community dweller in Kano, was identified to be HIV-1 group O-positive. Compared with data from national surveillance studies in 1991/1992 and 1993/1994, a substantial increase in HIV infection was observed. Our results show a growing incidence of HIV infection in Nigeria and suggest the presence of a rural HIV epidemic. The identification of HIV-1 group O in Kano shows that this virus strain is geographically widespread in Nigeria.

Risk factors for prevalent and incident HIV infection in a cohort of volunteer blood donors in Harare, Zimbabwe: implications for blood safety

OBJECTIVES

To compare risk factors for HIV seropositivity with risk factors for HIV seroconversion in a population of volunteer blood donors in Harare, Zimbabwe, and to assess the impact of risk factor exclusion strategies on the safety of the blood supply.

DESIGN

A secondary analysis of a longitudinal cohort study was performed.

SUBJECTS AND METHODS

The subjects were volunteer blood donors who were also taking part in a prospective cohort study in Harare, Zimbabwe. They were tested for HIV antibodies upon enrollment and at 6-month intervals. Their donation history, age, marital status and the presence or absence of multiple sex partners and paying for sex were assessed as predictors of HIV seropositivity and HIV seroconversion. The impact of exclusion strategies on blood safety was modeled by estimating the number of HIV-infected units that would escape detection by antibody screening if blood donors with these risk factors were excluded.

RESULTS

The HIV seroprevalence among persons accepted for blood donation was 8.8%; the HIV seroincidence was 2.1 per 100 person-years. Significant risk factors for HIV seropositivity were being a new donor (odds ratio 7.3, 95% confidence interval 4.4-1 2.1), age over 25 years (odds ratio 1.6, confidence interval 1.1-2.4), being married (odds ratio 1.7, confidence interval 1.2-2.6), paying for sex (odds ratio 2.6, confidence interval 1.7-3.9) and multiple sex partners (odds ratio 2.1, confidence interval 1.4-2.9). Significant risk factors for HIV seroconversion were age under 25 years (hazard ratio 2.5, confidence interval 1.4-5.0) and being unmarried (hazard ratio 2.5, confidence interval 1.4-5.0). Of note, age and marital status reversed their direction of association with respect to HIV seropositivity and HIV seroconversion. Exclusion strategies based on strong predictors of HIV seroconversion were the most effective in improving the safety of the blood supply.

CONCLUSIONS

A distinction between risk factors for HIV seropositivity and HIV seroconversion is necessary in order to develop strategies to reduce the residual risk of transfusion-associated HIV transmission. Because window-period donations are the most important source of residual HIV contamination and arise from incident infections, research to develop risk factor exclusion strategies must focus on predictors of HIV seroconversion.

Risk of iatrogenic human immunodeficiency virus infection through transfusion of blood tested by inappropriately stored or expired rapid antibody assays in a Zambian hospital

BACKGROUND

The purpose of this study was to estimate the risk of human immunodeficiency virus (HIV) infection via the transfusion of blood tested by inappropriately stored or expired rapid antibody assays in Zambia.

STUDY DESIGN AND METHODS

Surgical patients (n = 370) were tested with antibody assays (HIV-spot and HIV 1+2) that had expired 3 to 6 months previously. Blood donors (n = 211) were tested by inappropriately stored but non-expired HIV-spot assay. Serum samples from both groups were retested with enzyme immunoassays, and the seropositivity of samples was confirmed by immunoblotting.

RESULTS

Seroprevalence in surgical patients and blood donors was 19.8 and 11.6 percent, respectively. Sensitivity and specificity of HIV-spot (expired) were 88.2 and 98.1 percent; those of HIV 1+2 (expired) were 82.1 and 94.7 percent; and those of HIV-spot (non-expired) were 91.7 and 98.8 percent, respectively. The risk of HIV infection via the transfusion of blood tested by HIV-spot (expired), HIV-spot (nonexpired), or HIV 1+2 (expired) was calculated to be 1.4, 1.0, and 3.2 percent, respectively.

CONCLUSION

Manufacturers of the HIV-spot and HIV 1+2 assays claim sensitivity and specificity of 98.8 and 100 percent and 100 and 99.5 percent, respectively. In this study, sensitivity and specificity were 11 to 18 percent lower. Moreover, in-date reagents also performed less well than the manufacturers claimed, but the worst results were with expired or improperly stored reagents. According to the manufacturers of HIV-spot and HIV 1+2, the risk of HIV infection would be 0.2 and 0 percent, respectively. However, the risk of contracting HIV through transfusion is at least six times higher than expected.

Association of HCV and Treponema pallidum infection in HIV infected northeastern Thai male blood donors

The study was performed to determine the association of seroprevalence of hepatitis C virus (HCV) and Treponema pallidum (T. pallidum) infection among HIV infected first time male blood donors (HIV group) in comparison with the HIV seronegative blood donors (control group) in the Northeast of Thailand (NET). Serum samples were collected from 10,321 first blood donation voluntary male donors. All samples were screened for anti-HIV and anti-HCV by particle agglutination test, and syphilis antibody by RPR. The anti-HIV positive sera were repeated by EIA and confirmed by western blot. The reactive anti-HCV samples were confirmed by EIA whereas reactive syphilis antibody samples were confirmed by TPPA. Fisher's exact test was used for statistical analysis. The prevalence of anti-HIV in first time male donors was 0.70 per cent (72/10,321). The age of HIV group and 10,018 male control group ranged from 17-50 years old. The prevalence of HIV among 21-40 years old age group was significantly higher than the 17-20 years old (p = 0.00003). The 17-20 years old HIV group showed significantly higher sero-prevalence of TPPA (p = 0.003). The 21-30 years old HIV group gave significantly higher sero-prevalence of anti-HCV (p = 0.0008) and TPPA (p = 0.045), but the seroprevalence of anti-HCV and TPPA among the 31-50 year old group were nonsignificantly different (p > 0.05). The concurrence of anti-HCV and TPPA in HIV groups was not found. This result indicated that HIV infection among NET voluntary male blood donors was significantly associated with T. pallidum infection in young adults and the HCV infection in mature adults.

Laboratory characterization of human T cell lymphotropic virus types 1 (HTLV-1) and 2 (HTLV-2) infections in blood donors from Sao Paulo, Brazil

Serologic screening for human T cell lymphotropic virus types 1/2 (HTLV-1/2) infection in blood donors has been recently introduced in Brazil. Analysis of 351,639 blood donations in Sao Paulo from January 1992 to October 1993 identified 1,063 positive (0.30%) and 2,238 indeterminate (0.63%) samples based on serologic confirmation using a 21e Western blot. A detailed analysis (serologic, molecular, and virologic), based on a laboratory diagnostic algorithm for characterization of HTLV-1 and HTLV-2 infections was undertaken in 50 seropositive or seroindeterminate blood donors. Modified serologic assays (2.3 Western blot that incorporate type-specific recombinant peptides) performed in 29 HTLV-1/2 positive and 21 HTLV-1/2 indeterminate donors with the 21e Western blot identified 25 as infected with HTLV-1, four with HTLV-2, five with untypable HTLV-1/2, 15 as HTLV-1/2 indeterminate, and one as seronegative. Polymerase chain reaction (PCR) analysis using DNA amplification of proviral pol and tax sequences from peripheral blood mononuclear cells confirmed HTLV-1 and HTLV-2 infections in all 2.3 Western blot seropositive donors; of the five serologically untypable donors, three were confirmed to be HTLV-1 positive, one HTLV-2 positive, and one negative by PCR. All of the seroindeterminate donors were also negative by PCR. Furthermore, HTLV-1 could be isolated in cocultures from 10 of 18 infected donors. Cell lines developed from two HTLV-1-infected donors were of T cell phenotype (CD2+, CD3+), exhibiting surface markers of activated CD4 cells (CD4+ CD25+ HLA-DR+). Thus, we provide evidence for the high seroprevalence of HTLV infection in blood donor population in Sao Paulo, Brazil compared with North American donors and propose a comprehensive serologic and genotypic diagnostic algorithm for HTLV-infected donors that has strong implications for counseling of these individuals.

HIV and blood transfusion in sub-Saharan Africa

Blood transfusion services were poorly developed until the mid 1980s in most of sub-Saharan Africa, and were unable to provide adequate supplies of blood with acceptable safety. The pandemic of HIV was recognized seroepidemiologically from 1985 onwards. Blood transfusion was contributing from 10 to 15% to transmission in Africa. Groups at highest risk are children with malaria and anaemia, women with pregnancy-related haemorrhage or anaemia, victims of trauma and subjects with sickle-cell disease. Haemophiliacs are not a major risk group in comparison. Blood transfusion services have undoubtedly benefitted from the international, national and regional responses to the AIDS epidemic. Organizational structures have been established. There have been concerted moves to recruit voluntary unremunerated blood donors, selected from population groups with low seroprevalence. Serological screening for HIV, hepatitis viruses and syphilis has been introduced or strengthened. Standards for blood group serology, blood storage and handling have been improved. Guidelines for the appropriate use of blood have been formulated and adopted. There have been many training and retraining programmes. Much remains to be completed, however, using national and international resources, before the blood supply reaches acceptable standards of safety and is adequate in remote as well as in central areas of Africa.

[Current status of HIV infection in Yunnan Province of China]

In cooperation with the Chinese Academy of Preventive Medicine and Yunnan Province Provincial Office for AIDS Control and Prevention, we studied the current status of HIV infection intravenous drug users (IVDUs) and other high risk groups in Yunnan province of China. As of the end of 1995, 1,807 HIV cases were officially reported (Positive rate was 0.6%), of which 1,278 (77.9%) were IVDUs, and 24 were their spouses. The majority of cases were found among the Dai minority male farmers near Ruili which borders on Myammar, but HIV also appears to be spreading among the Han people. HIV antibody positive rates among commercial sex workers, pregnant women and blood donors were 0.2%, 0.07% and 0.04%, respectively. A system for surveillance of HIV has been developed, but preventive strategies to cope with HIV epidemic are not sufficient. As HIV/AIDS is now a global issue, (1) the integration and coordination of such preventive strategies in cooperation with community health workers, (2) general health education for condom use promotion and (3) care of psychological vulnerable person such as IVDUs, should be developed.

HIV-related risk factors of blood donors in northern Thailand before and after knowing HIV test results

BACKGROUND

The epidemic of Human Immunodeficiency Virus (HIV) infection led blood banks to initiate donation deferral criteria based on self-reported risk factors. However little information is available on the differences in reporting risk factors before and after HIV status is known.

METHODS

Between April and July 1994, blood donors in a provincial hospital in northern. Thailand were interviewed at the time of donation, about their demographic characteristics and risk factors. All donors had agreed to learn their test results and were called back for post-test counselling and reinterview.

RESULTS

HIV-positive blood donors were more likely to change from 'denying' to 'acknowledging' risk factors while HIV-negatives were more likely to change from 'acknowledging' to 'denying'. The differences between risk factors obtained before and after test results were known resulted in stronger, weaker or even opposite risk measures.

CONCLUSION

The study results raise questions about the impact of the differences in reporting HIV-related risk factors by the donors on how effective donation deferral criteria can be developed.

Infection with HIV, syphilis and hepatitis B in Ethiopia: a survey in blood donors

Sera of all male donors appearing at the blood bank of a regional hospital in Northwest Ethiopia in 1994 (n = 1022) and 1995 (n = 1164), were screened for the presence of human immunodeficiency virus (HIV-1) and treponemal antibodies. Additionally, screening for hepatitis B surface antigen (HBsAg) was carried out on 549 consecutive sera. In 1995, the crude seroprevalence of HIV-1 infection and syphilis was 16.7% and 12.8%. Seroprevalence of HBsAg was 14.4%. HIV and syphilis seroprevalence was highest in soldiers (30.6% and 20.9%) and daily workers (18.8% and 13.5%), and lowest in farmers (8% and 6.7%). However, farmers had the highest rate of HBsAg (18.8%). HIV-positive donors had an increased risk for being positive for syphilis antibodies (OR = 3.69, 95% CI = 2.69-4.96), but not for HBsAg (OR = 0.79, 95% CI = 0.36-1.67). The data indicate that (i) the HIV epidemic has not yet reached a plateau phase in Ethiopia, and (ii) the transmission and epidemiology of HBsAg in Ethiopia is different from that of HIV and syphilis.

Sexual transmission of hepatitis B in Mwanza, Tanzania

BACKGROUND

Hepatitis B virus (HBV) is endemic and poses a grave public health problem in Africa where it is mainly transmitted from mother to baby or during childhood. Sexual transmission has also been suggested to play a role in East Africa, but this has never been properly demonstrated. Additional preventive strategies may be proposed if sexual transmission of HBV occurred in this region where HIV and other STDs are highly prevalent.

GOALS

To determine the prevalence of markers for hepatitis B virus (HBV)and other sexually transmitted diseases (STD) in routine blood samples taken from three populations in Mwanza, Tanzania, and to use the data collected to look at the association between hepatitis B and other STDs, including human immunodeficiency virus (HIV).

STUDY DESIGN

Routine blood samples were collected from 1,025 patients attending a clinic for STDs, 253 voluntary blood donors from secondary schools, and 952 blood donors who gave blood in a hospital specifically for a relative who needed a blood transfusion. All samples were tested for HIV by double enzyme-linked immunosorbent assay (ELISA), and for syphilis using the Treponema pallidum hemagglutination (TPHA) and rapid plasma reagin (RPR) tests. Two markers for HBV were examined by the double ELISA method, the presence of the anti-hepatitis B core antigen (anti-HBc) and the hepatitis B surface antigen (HBsAg).

RESULTS

There were high prevalences of HBV, syphilis, and HIV in relative donors and STD patients. Although HBV markers were more prevalent in men of increasing ages, syphilis and HIV markers were more prevalent in young women. Evidence of past infection with HBV (presence of anti-HBc) was associated with serologic markers of recent treponemal infection (both TPHA and RPR positive) in both sexes (men odds ratio [OR] = 1.91, P < 0.011; women OR = 2.34, P < 0.02) and with HIV in men (OR = 1.93, P < 0.003). Current infection with HBV (presence of HBsAg) was associated with recent syphilis in men (OR = 2.13, P < 0.006). In STD patients, current infection with HBV was associated with Trichomonas vaginalis in women (OR = 3.57, P < 0.002) and recent syphilis in men (OR = 3.46, P < 0.001). There was no further association between HBV markers and any other STD pathogen or any particular STD syndrome, nor was there any association between current HBV infection and HIV in both sexes. The population attributable fraction for sexual acquisition of hepatitis B is estimated at 7.2% in men and 3.0% in women, based on the association between hepatitis B and syphilis.

CONCLUSIONS

These findings suggest that sexual acquisition of hepatitis B occurs at low levels in Mwanza, and that HBV can be prevented through enhancement of the current HIV/STD control activities, in addition to improved vaccination strategies.

Prevalence of HIV1 in leprosy patients in Rio de Janeiro, Brazil

The purpose of this study was to learn if HIV1 infection was associated with leprosy in Rio de Janeiro, Brazil by comparing the prevalence rates of 1.016 leprosy patients tested on a voluntary basis and 78.482 blood donors. A cross-sectional survey of anti-HIV1 antibodies was conducted in Rio de Janeiro, from 1990 to 1992 for this purpose. HIV1 prevalence found among leprosy patients was (3 cases) 2.9 per 1000, and among blood donors was (282 cases) 3.8 per 1000. Such difference was not significant (OR = 0.79; p = 0.69). Since HIV1 cases were only found among male leprosy patients, further analysis excluded females. Male leprosy patients showed a slightly higher prevalence of HIV1 than blood donors before and after age adjustment. However, this result was not statistically significant (adjusted odds ratio = 1.38, 95% CI 0.35-4.5; p = 0.83). These data do not provide evidence that leprosy and HIV1 infection are associated in the State of Rio de Janeiro. This is consistent with similar investigations conducted elsewhere.

[Detection of hepatitis c in blood donors in Niamey]

We searched for HCV antibodies in a random sample of 410 blood donors negative for HIV infection, hepatitis B and syphilis. 16 peoples were positive by ELISA and 13 by RIBA. So 3.2% of these donors negative for the three actual compulsory tests, are able to transmit HCV.

Using existing health care systems to respond to the AIDS epidemic: research and recommendations for Chile

Chile is a country with a relatively low prevalence of HIV infection, where successful prevention has the potential to change the future course of the epidemic. A controversial national prevention strategy based upon public education has emerged in response to characterizations of the epidemic as well-dispersed with a growing involvement of heterosexuals. This characterization is not consistent with the observed facts. There is a comparatively well-organized health care system in Santiago that is doing a good job of detecting HIV infection and already has in place the elements of a targeted intervention scheme. Chile should place priority on the use of the existing health care infrastructure for implementing both the traditional public health interventions for sexually transmitted diseases (contact tracing and partner notification) and the AIDS-necessitated strategy of focused counseling and education.

Analysis of quality assurance programmes for HIV screening in blood transfusion centres in Delhi

The safety of blood transfusion has attained tremendous importance because of the problems posed by acquired immunodeficiency syndrome (AIDS) and other transfusion-transmissible diseases. While performing screening tests for human immunodeficiency virus (HIV) antibodies in donated blood is indispensable, it is also essential to introduce an effective quality assurance programme covering inspection of specimens, review of record-keeping, maintenance of equipment, and verification of results. We carried out an analysis of such quality assurance programmes during routine annual inspection of 11 blood transfusion centres in Delhi, India. The following parameters were studied: standardization of sample collection and handling; adherence to the recommended technical procedure; use of standard operating procedure; proper use of test reagents; laboratory record-keeping; proper handling of HIV-positive blood units; recording and communication of results; observation of safety guidelines; equipment quality control; and training of staff. A pretested closed-type questionnaire with a weighted scoring system was used for evaluation. Performance for each parameter was graded as follows: 76-100%, excellent; 51-75%, good; 26-50%, fair; and < 25%, poor. Centres were categorized according to the total score obtained for all parameters. Overall performance > 50% was considered satisfactory. Of the 11 centres, none was excellent overall, five were considered satisfactory, and six were unsatisfactory.

Herpes simplex virus type 2 in Brazil: seroepidemiologic survey

BACKGROUND

The incidence of genital herpes is increasing worldwide. Herpes simplex virus type 2 (HSV-2) is the most common cause of genital ulcerations among the sexually transmitted diseases (STDS). In order to investigate the sexual transmission of genital herpes infection in Brazil, the prevalence of specific antibodies to HSV-2, in populations of high and low risk for STDS was evaluated.

METHODS

The population at low risk for STDS was composed of 155 voluntary blood donors at the University Hospitals between February and August, 1994. The population at high risk for STDS was composed of 85 HIV-seropositive persons, consisting of homosexual and promiscuous heterosexual men. A group of 20 highly active prostitutes was also studied between May and July, 1994. All blood samples were screened using an enzyme-linked immunosorbent assay (ELISA) that detects type-specific antibodies to HSV-2 glycoprotein G. Before donating blood, all persons in the study group were given a questionnaire concerning risk factors for acquisition of STDS and suitable to show the socioepidemiologic characteristics of the subjects.

RESULTS

The prevalence of ELISA showing HSV-2 infections among HIV-seroposite persons, was 73% (P < 0.01). In the whole group at high risk for STDS, the prevalence was 72% (P < 0.05). Infection with HSV-2, as determined by seroprevalence, was significantly and independently associated with years of sexual activity, history of previous STDS, number of sexual partners in the previous month, number of pregnancies, and previous induced abortions, as well as the percentage of sexual acts involving receptive anal intercourse.

CONCLUSIONS

The current strategy for diagnosing genital HSV-2 infection misses many cases. Newly developed type-specific serologic methods can identify cases of unrecognized or subclinical infection. With the high seroprevalence rates detected, routine screening for HSV-2-specific antibodies should be considered in populations at high risk for STDS.

Blood safety: improvements needed in Thailand

There is still a "... relatively high rate of HIV window-period blood donation in Thailand," according to a multicenter team. The results of their recent survey "... underscore the need to improve blood safety, especially in northern Thailand were HIV rates are substantially higher than in Bangkok" (AIDS 1996; 10: 1157-1162). The Thailand-based team, which included Dr. Timothy D. Mastro of the US Centers for Disease Control and Prevention (CDC), conducted a retrospective analysis using blood samples collected from nearly 60,500 blood donors over a 3-year period. For all repeat donors, Mastro calculated the incidence of HIV infection to be 307/100,000 person-years in 1990. Mastro found that the "... probability of a window-period donation was 38/100,000 donations or 1/2644 donations." However, improvements over time occurred, and this probability decreased by 50% between 1991 and 1993. Mastro also found the risk of HIV seropositivity among one-time donors to be twice as high as the risk calculated for repeat donors. This is of concern because approximately two-thirds of all blood donations in Thailand are from first-time donors. "Although HIV incidence among repeat blood donors in Bangkok has decreased over the last 3 years, it remains at an unacceptably high level," Mastro concluded. Among his recommendations to improve the situation included refinements to donor deferral procedures, improvements in HIV antibody testing procedures, with the addition of more accurate tests, and the development of a Thai national policy to include p24 antigen testing.

Estimated rate of HIV-1-infectious but seronegative blood donations in Bangkok, Thailand

OBJECTIVES

To determine HIV seroprevalence and incidence among various blood donor types, and to estimate the rate of window-period blood donations.

DESIGN

Retrospective cohort from computerized donor records.

METHODS

Records were analysed from all 60,483 donors (contributing 97,464 donor units) at a public university teaching hospital blood bank in Bangkok, Thailand, from 1 January 1990 to 30 June 1993. Annual HIV incidence among 14,482 repeat donors who were HIV-seronegative on their first donation was calculated assuming equal probability of seroconversion between last seronegative and first seropositive donations. To estimate the probability of window-period donations, we assumed that the time from HIV infectivity to onset of detectable antibody was 45 days.

RESULTS

In 1990, HIV incidence calculated for all repeat donors was 307 per 100,000 person-years; the probability of a window-period donation was 38 in 100,000 donations or one in 2644 donations. During 1991-1993, this probability decreased by one-half. However, one-time donors were more than twice as likely as repeat donors to be HIV-1-seropositive.

CONCLUSIONS

The rate of HIV window-period blood donations among Thai repeat donors was relatively high compared with that in developed countries and was probably even higher among one-time donors. Improved donor deferral criteria are needed in Thailand.

Sentinel surveillance and cross sectional survey on HIV infection prevalence: a comparative study

Despite widespread use of sentinel surveillance systems in monitoring the magnitude of HIV-1 infection in populations, little is known of how the trends they produce compare with those of the larger populations which they support to represent. The objective of this study, therefore, was to assess how useful sentinel surveillance data on HIV-1 infection might be in estimating the magnitude of HIV-1 infection in the general population. To achieve this, results from a population based study on HIV-1 infection in Bukoba town were compared with those from antenatal mothers and blood donors, all from the same town. The studies were done during the period of 1987-90. The overall HIV-1 prevalence was highest in the general population sample at 24.2% (95% CI 20.6-27.8) followed by that in antenatal mothers at 22.4% (95% CI 20.6-25.2) and lowest in blood donors at 11.9% (95% CI 9.1-15.3). Seroprevalence among antenatal clinic attenders was significantly lower than that of females from the general population sample (p = 0.016). Prevalence among female blood donors did not differ significantly from that of females from the general population sample (p = 0.06). Blood donor males had a lower HIV-1 seroprevalence when compared to that from the general population males (p = 0.038). The age group 25-34 years had the highest prevalence of HIV-1 infection in all the three populations indicating that this group is at the highest risk of HIV infection and that the three populations show a similar trend of age specific prevalence. From these findings, it is noted that female blood donors as a sentinel population represents more closely estimates of HIV-1 seroprevalence of females in the general population than antenatal clinic attenders or male blood donors. Further studies are proposed in different settings in order to come up with guidelines on the methodology of using sentinel surveillance populations in monitoring HIV-1 infection.

HIV heterosexual transmission to stable sexual partners of HIV-infected Brazilian hemophiliacs

Nineteen Brazilian HIV-infected hemophiliacs and their stable heterosexual sexual partners were studied with the aim of assessing the rate of HIV transmission in this at risk group. The mean length of relationship between couples was 7.4 years. The hemophiliac men were Class II (n = 6), III (n = 11) and IVa (n = 2) of the CDC classification. They had decreased CD4+ and elevated CD8+ cell numbers; five had p24 antigenemia. We found 3 HIV-infected women (15.8 percent) by routine and confirmatory tests, a prevalence similar to that seen in other countries. They were asymptomatic and had no detectable p24 antigenemia. The 3 seropositive women's partners were Class II and III-CDC, and had normal CD4+ and CD8+ values and no p24 antigenemia. All seronegative women also had normal CD4+ and CD8+ numbers, except for elevated CD8+ cells in three of them, but immune abnormalities had already been seen in some seronegative partners at high risk for HIV infection. Our results reinforce previous suggestions that heterosexual transmission to stable female partners occurs preferentially early after initiation of sexual exposure, and possibly when the transmitter had high levels of viremia and regular sexual activity.