A Systematic Review of Transfusion-Transmissible Infections Among Blood Donors and Associated Safety Challenges in Pakistan

Prevalence of HIV, syphilis, hepatitis B, and hepatitis C in patients attending STI/RTI clinic of a tertiary care teaching hospital

BACKGROUND

Patients attending Sexually transmitted infection/ Reproductive tract infection (STI/RTI) clinics are investigated for HIV and syphilis under the National AIDS Control Program (NACP). Although sexual contact is one of the modes of transmission of hepatitis B and C, they are not investigated under NACP. This study was planned to find the prevalence of HIV, syphilis, hepatitis B, and C in patients attending STI/RTI clinics and to identify the predictive risk factors.

METHODS

A prospective cross-sectional study was carried out over 5 years on 500 consenting adults. 10 ml blood was collected and tests were performed as per standard protocol for HIV, syphilis, hepatitis B, and C. Risk factors for the sexually transmitted diseases were queried.

RESULTS

500 samples were tested, 117(23.4%) men and 383 (76.6%) women. 26(22.2%), 20(17.1%), 11(9.4%) and 01(0.9%) men and 8(2.1%), 36(9.4%), 01(0.3%) and 0(0%) women were positive for HIV, RPR, hepatitis B and C respectively. Dual infection for HIV and syphilis was detected in four (0.8%) men and HIV and hepatitis B in three (0.6%) men.

CONCLUSION

To investigate all patients attending STI/RTI clinics for Hepatitis B and to integrate Hepatitis B testing into the National AIDS Control Program.

Degree of blood safety of voluntary non-remunerated versus replacement blood donations: A multi-centre study of the large cohort of blood donors from two provinces of Pakistan

BACKGROUND AND OBJECTIVES

Voluntary non-remunerated blood donors (VNRBDs) are recognized as being crucial for the safety and sustainability of national blood supplies. Systems based on replacement donors (RDs) pose high risks of transfusion transmissible infections (TTIs). Currently, only 10%-13% of blood donations are voluntary in Pakistan. No large-scale studies have been conducted to objectively evaluate the impact of the mode of donation on the frequency of TTIs, a gap this study aimed to fill.

MATERIALS AND METHODS

The study was conducted at the Indus Hospital, Karachi. Data from a total of 591,820 blood donations were included from 1 October 2017 to 30 May 2021 and evaluated for type of donations and results of TTI testing, primarily performed on Architect i2000SR (Abbott). The TTIs tested include hepatitis B virus, hepatitis C virus, human immunodeficiency virus, syphilis and malaria.

RESULTS

A total of 477,938 (80.7%) RDs and 113,882 (19.3%) VNRBDs were screened. Among these, 53,590 (9.06%) were positive for TTIs. There were 10.2% positive RDs (10.08-10.25 95% confidence interval [CI]) while 4.4% in VNRBDs (4.29-4.53 95% CI). Co-infections were observed in 2367 (0.4%) RDs, while 159 (0.02%) in VNRBDs. Geographically, the highest frequency of TTIs was observed in semi-urban areas of Sindh (11.2%) and Punjab (9.6%). A site-wise comparison of TTIs in RD versus VNRBD showed significant differences (p-value 0.00).

CONCLUSION

RDs are associated with higher frequencies of TTIs, compared with VNRBD. However, the study was unable to assess whether the significant difference was related to individual risk or repeat/first time status of the donors. Other important variables affecting frequency are the catchment area of the blood donors in Pakistan. Urban areas have less prevalence than semi-urban areas.

Prevalence and risk factors for hepatitis C virus infection in an informal settlement in Karachi, Pakistan

The burden of hepatitis C virus (HCV) infection in Pakistan is amongst the highest in the world. People living in slums are likely to be at high risk of infection. Here, we describe the results of a cross-sectional survey conducted in March 2022 that aimed to quantify the prevalence of HCV infection in Machar Colony, one of the largest and oldest slum settlements in Karachi. Risk factors for HCV seropositivity were identified using multi-level logistic regression. We recruited 1,303 individuals in a random selection of 441 households from Machar Colony. The survey-adjusted HCV-seroprevalence was 13.5% (95% Confidence Interval (CI) 11.1-15.8) and survey-adjusted viraemic prevalence was 4.1% (95% CI 3.1-5.4) with a viraemic ratio of 32% (95% CI 24.3-40.5). Of 162 seropositive people, 71 (44%) reported receiving previous treatment for chronic hepatitis C. The odds of HCV seropositivity were found to increase with each additional reported therapeutic injection in the past 12 months (OR = 1.07 (95% Credible Interval (CrI) 1.00-1.13)). We found weaker evidence for a positive association between HCV seropositivity and a reported history of receiving a blood transfusion (OR = 1.72 (95% CrI 0.90-3.21)). The seroprevalence was more than double the previously reported seroprevalence in Sindh Province. The overall proportion of seropositive people that were viraemic was lower than expected. This may reflect the long-term impacts of a non-governmental clinic providing free of cost and easily accessible hepatitis C diagnosis and treatment to the population since 2015. Reuse of needles and syringes is likely to be an important driver of HCV transmission in this setting. Future public health interventions should address the expected risks associated with iatrogenic HCV transmission in this community.

Prevalence of Transfusion-Transmitted Infections (HCV, HIV, Syphilis and Malaria) in Blood Donors: A Large-Scale Cross-Sectional Study

Blood plays a major role in transmitting infectious diseases such as hepatitis C virus (HCV), human immunodeficiency virus (HIV), hepatitis B virus (HBV), syphilis, malaria, and many others. Thus, this study sought to evaluate the distribution of HCV, HIV, syphilis, and malaria among blood donors in Yemen. This is a cross-sectional study, conducted on blood donors at the national center in Yemen. Blood donors’ specimens were serologically tested for the presence of anti-HCV and anti-HIV antibodies, as well as anti-Treponema pallidum, anti-Plasmodium falciparum, and anti-Plasmodium vivax. A total of 16,367 donors were included in this study. Based on the donor’s occupation, the study showed that the relative seroprevalence of anti-HCV Ab among the donors was statistically significant, and relatively high prevalence was found among military donors (2.8%). Positive HIV antibody tests were only reported in 33 male donors (0.2%), who were mostly manual workers. A remarkably high prevalence of anti-Treponema pallidum was observed among manual workers (3.1%). There was a statistically significant difference in the distribution of anti-malaria Ab based on residency and age groups. This study revealed that the prevalence of HCV, HIV, syphilis, and malaria among donors was 2.0%, 0.2%, 2.4%, and 0.7%, respectively. Further genotyping studies are necessary to provide a complete picture of the prevalence of transfusion-transmitted infections (TTIs).

Transfusion Transmitted Infections: A Present-Day Danger for Pakistan

Over 1.5 million units of blood are collected in Pakistan each year, with around 65% of this donation coming from replacement donors-relatives or close friends of the affected who willingly donate blood to support the patient. Although blood transfusion is a life-saving therapy, it also involves the danger of spreading blood-borne illnesses if not appropriately screened. It has been extensively discussed that the precise number of transfusion transmitted infections (TTIs) in the Pakistani population is still unclear, and the estimates reported by the Sindh Blood Transfusion Authority may be a major underestimation because of the country's lack of inexpensive and effective screening tests. Regular blood transfusions are the mainstay of treatment of patients with blood diseases such as thalassemia and anemia. They are also commonly used to handle acute injuries, surgery, bleeding, and birthing difficulties. However, the risk of getting a TTI results in an increased hesitancy among blood transfusion recipients. Hence, to reduce the occurrence of TTIs, effective and vigorous measures must be implemented.

The utility of grey zone testing in improving blood safety

OBJECT

Transfusion-transmitted infections threaten blood safety. The management of samples with weak reactivity is confusing. Our study aimed to investigate the utility of grey zone (GZ) testing in the screening of the hepatitis B virus (HBV), the hepatitis C virus (HCV), and the human immunodeficiency virus (HIV).

METHODS

Chemiluminescence assays (CLA) were used for the blood screening. For each infectious marker, two CLA kits were used, but for each sample, only one kit was used for each infectious marker. An S/CO ≥ 8.0 was considered reactive, and an S/CO < 0.8 was considered non-reactive. A 0.8 ≤ S/CO < 1.0 was set as GZ1, a 1.0, ≤ S/CO < 4.0 was set as GZ2, and a 4.0 ≤ S/CO < 8.0 was set as GZ3. The samples located at different GZs were separately verified using nucleic acid testing (NAT).

RESULTS

22,081 patients requiring blood transfusions were included in this study. The cohort had an average age of 32.6 ± 10.6 years old. HBV test kit B (0.41% reactivity and 0.58% GZ rate) was more sensitive than kit A (0.28% reactivity and 0.43% GZ rate). HCV test kit A (0.29% reactivity and 0.57% GZ rate) was more sensitive than kit B (0.27% reactivity and 0.31% GZ rate). HIV test kit A (0.10% reactivity and 0.20% GZ rate) was more sensitive than kit B (0.08% reactivity and 0.11% GZ rate). All the samples in GZ1 were negative for NAT. HBV test kit A has negativities of 20.00% and 4.35% in GZ2 and GZ3, respectively, while HBV test kit B has negativities of 36.84% and 35.48% in GZ2 and GZ3, respectively. HCV test kit A has negativities of 100.00% and 66.67% in GZ2 and GZ3, respectively, while HCV test kit B has negativities of 72.73% and 27.78% in GZ2 and GZ3, respectively. HIV test kit A has negativities of 100.00% and 88.24% in GZ2 and GZ3, respectively, while HCV test kit B has negativities of 100.00% and 50.00% in GZ2 and GZ3, respectively.

CONCLUSION

The GZ is useful in blood screening for HBV, HCV, and HIV. A test kit with a high sensitivity has a low specificity. Different test kits should be set with different GZs based on their sensitivity and specificity.

Plasmodium in the bone marrow: case series from a hospital in Pakistan, 2007-2015

Background

Malaria is a life-threatening, multisystem disease caused by the plasmodial parasite with a global incidence of approximately 229 million annually. The parasites are known to have unique and crucial interactions with various body tissues during its life cycle, notably the liver, spleen, and recent work has shown the bone marrow to be a reservoir of infection.

Methods

This study is a case series of patients in whom examination of bone marrow revealed malarial parasites. A retrospective record review of 35 parasite-positive bone marrow specimens examined at Aga Khan University Hospital (AKUH), Karachi, Pakistan, over the years 2007 to 2015 was conducted. Bone marrow aspirates were collected as per International Council for Standardization in Haematology (ICSH) guidelines.

Results

The median age of patients was 22 years (range 1–75), and 60 % (n = 21) were male. 22 patients had evidence of Plasmodium falciparum, 12 had evidence of Plasmodium vivax and 1 patient had a mixed infection. Gametocytes and trophozoites were the most common stages identified on both peripheral blood and bone marrow examinations. Indications for bone marrow examination included fever of unknown origin and the workup of cytopenias and malignancies.

Conclusions

The incidental finding of Plasmodium in samples of bone marrow suggests the reticuloendothelial system may be regularly harbour these parasites, be the infection acute or chronic in character.