Abstract
Background
Transmissible Infections (TTI's) are a cause of significant burden on health care facilities by imposing a threat of infection transmission through disease reservoirs in asymptomatic donors. This eventually leads to a serious challenge in acquiring blood bags in a country like Pakistan where transfusion dependent disease are of high prevalence. The objective of this study is to determine the seroprevalence of TTI's in blood donors in Rawalpindi District through a multi-center approach.
Materials and Methods
This is an observational descriptive retrospective study based on 6 transfusion centers in the Rawalpindi District. The time frame of the study was from January 2015 to December 2018. A total of 223,242 donors were consecutively included and data on donor type, the purpose of transfusion, and seroprevalence (HBV, HCV, HIV, Syphilis, and Malaria) were collected through a structured questionnaire and laboratory investigation results. The collected data were entered in SPSS version 21.0 for analysis.
Results
The seroprevalence of blood borne infections was 7,897 (3.537%) of which HBV, HCV, HIV, Syphilis and Malaria accounted for 2410 (1.080%), 3105(1.391%), 0(0.000%), 2017 (0.933%) and 365 (0.171%), respectively. Reactive samples reduced from 4.850% to 3.537% over 4 years, while there was a rise of 37.478% of blood donors from 2015 to 2018. The total number of voluntary donors and replacement donors was 22079 (9.890%) and 201156 (90.107%), with a rising incidence in voluntary donors from 2015 to 2018. A considerable number of donor bags were transfused to Thalassemia, Anemia, Leukemia and Hemophilia patients, 28156 (12.612%). This number also showed increasing rates from 11.654% to 14.017%.
Conclusion
In conclusion, our study suggests that the risk of transmission through transfusion is still considerable. Targeting donors with a low-risk profile, a screening questionnaire, an ample supply of quality screening tests, and awareness campaigns for the diseases in question must be carried to further decrease the risk of transmission of TTIs in Pakistan.
Keywords: Transfusion, Hepatitis, HIV, Syphilis, Malaria, Pakistan
Introduction
Blood transfusions are an essential part of patient care in trauma and critical settings1. According to WHO, “Blood is a universal right”. It can save the lives of millions of people worldwide from acute as well as chronic illnesses. Today, the use of whole blood is a well-accepted and commonly employed measure, without which many modern surgical procedures could not be carried out2. But all these advantages come with the potential of transmitting a collection of debilitating diseases through these blood products if improperly screened. The diseases that can be transmitted through blood include Hepatitis B, Hepatitis C, Acquired Immunodeficiency Syndrome (AIDS), Syphilis, Malaria, and many more3.
More than 17.4 million units of blood are donated every year in the world4. In Pakistan, more than 1.5 million pints of blood are collected each year. Among them, replacement donors, voluntary donors, and professional donors account for 65%, 25%, and 10%, respectively5. A study regarding Transfusion Transmissible Infections was done in Pakistan in 2012. This study reported prevalence for Hepatitis B surface antigen (HBsAg), anti-HCV, anti-HIV, and Syphilis to be 2.68%, 2.46%, 0.06%, and 0.43% respectively, with an increasing trend in frequencies of transfusion-transmitted infections (TTIs).
However the study was based on a single center in Peshawar6. Very limited studies have been conducted within Pakistan as well as internationally which would report TTI's. Not only does this pose a threat to the patients who receive transfusion on need basis but also puts a burden on the economy of countries which is afflicted due to raised cost of provision of health care to these patients. Joint United Nations Programme on HIV and AIDS (UNAIDS) has estimated that only 50 % of the 1.5 million blood bags are screened in Pakistan7. Keeping this data into consideration, it seems crucial to screen the blood for TTIs to minimize further the risk of transmitting potentially fatal disease through the blood.
There is a dire need to increase the number of safe blood products available for emergency use. Furthermore, this increase should complement the proper screening of the donated blood to minimize the risk of spreading transfusion-transmissible infections. The trends are an ever-changing thing, and so is the literacy rate and the mindset of people. The basic premise of our study was to provide an epidemiological analysis of Transfusion Transmissible Infections (TTIs) amongst the blood donors of Rawalpindi District, Pakistan. Our study also aimed to determine the prevalence of HIV, Hepatitis B, Hepatitis C, Malaria, and Syphilis amongst healthy blood donors of Rawalpindi. Adding further, percentage of transfusions aimed to provide blood bags to patients with blood-related disorders was also aimed to be calculated as a part of this study.
Design and Methodology
Study Design
It is a retrospective observational study based on the data obtained from the blood banks of Holy Family Hospital, Benazir Bhutto Hospital, District Headquarter Hospital Rawalpindi, Tehsil Headquarter Hospital Murree, Samli TB Sanitorium, and Jamila Sultana Foundation. The duration of this study was from 2015–2018. Data were obtained by permission of the blood bank in-charge of the respective blood banks.
Study Population
The study included the screening results of 223,242 blood donors. They donated blood in any of the above-mentioned blood banks between 2015 and 2018. The donors included volunteer donors, who gave blood voluntarily to the blood banks, and replacement donors, who were called upon to donate blood to the patients. However, the data did not segregate the two categories. According to the blood donors' guidelines of WHO, males with Hb level less than 12.5 g/dl and females with Hb level less than 12 g/dl were not allowed to donate blood. Similarly, the donors who had a recent history of active TTI were not permitted to donate blood.
According to the blood donors' protocol of the government of Pakistan, all the blood donors were screened for TTI, including HBV, HCV, HIV, Syphilis, and Malaria.
Laboratory Procedures
Blood Collection: Venous blood of the donors was obtained with a 5mm syringe in an EDTA-containing vile to be screened for anti-HIV (1&2), anti-Syphilis, Hepatitis B surface antigen (HBsAg), anti-Hep C, and Malaria PF/PAN antigen.
Statistical Analysis
The collected data were entered and analysed in SPSS version 21.0. Frequencies and percentage, summary statistics were computed for all the variables and presented in the form of tables. The results were also represented in line diagrams to show trends in seroprevalence from 2015 to 2018. Chi-square/Fischer exact test was applied to check if any significant difference exist among prevalence of different pathogen over the years.
Results
From January 2015 to December 2018, 223,242 blood donors were analyzed among the general population, among which 201,156 (90.10%) were replacement donors, while 22,079 (9.9%) were voluntary donors. There was a rise of 37.478% donors from year 2015 to 2018, and a rise in percentage of voluntary donors. Table 2 shows the year-wise percentages of replacement and voluntary donors.
Table 2.
Distribution of Voluntary and Replacement Donors
Year | Total donors |
VD* | % | RD** | % |
2015 | 45854 | 4276 | 9.3252 | 41578 | 90.6748 |
2016 | 55558 | 5069 | 9.1238 | 50482 | 90.8636 |
2017 | 58791 | 5750 | 9.7804 | 53041 | 90.2196 |
2018 | 63039 | 6984 | 11.0789 | 56055 | 88.9211 |
P-value | 0.176*** | 0.231*** | 0.099*** | ||
Total | 223242 | 22079 | 9.89016 | 201156 | 90.1067 |
Voluntary Donors
Replacement Donors
Fischer Exact Test (Year vs total donor/donor type)
All the donors were screened for Hep B, Hep C, and HIV during these four years. Total number of samples that came out positive for Hep B, Hep C & HIV were 2410 (1.07%), 3105 (1.39%) and 0 (0%) respectively. The total number of samples screened for Syphilis, and Malarial parasite was 216190 & 213902, respectively. The total number of samples that came out positive was 2017 (0.93%) and 365 (0.17%). From 2015 to 2018, none of the donors tested positive from HIV. The year-wise prevalence of Hep B, Hep C, Syphilis and Malaria is given in Table 3
Table 3.
Screening Results
Hepatitis B | Hepatitis C | Syphilis | Malaria | |||||||
Year | Total donors |
Total Reactive (Percentage) |
Total screened |
HBV +ve, (Percentage) |
Total screened |
HCV +ve (Percentage) |
Total screened |
Syphilis +ve, (Percentage) |
Total screened |
MP +ve (Percentage) |
2015 | 45854 | 2224, (4.85%) | 45854 | 602, (1.31%) |
45854 | 935 (2.04%) | 39176 | 542, (1.38%) |
38534 | 145, (0.38%) |
2016 | 55558 | 2058, (3.70%) | 55558 | 621, (1.12%) |
55558 | 810 (1.46%) | 55355 | 524, (0.95%) |
53819 | 103, (0.19%) |
2017 | 58791 | 1856, (3.16%) | 58791 | 610, (1.04%) |
58791 | 683 (1.16%) | 58791 | 511, (0.87%) |
58791 | 52, (0.09%) |
2018 | 63039 | 1759, (2.79%) | 63039 | 577, (0.92%) |
63039 | 677 (1.07%) | 62868 | 440, (0.70%) |
62758 | 65, (0.10%) |
P-value | 0.472* | 0.341* | - | 0.134* | - | 0.176* | - | 0.289* | - | 0.341* |
223242 | 7897 (3.54%) | 223242 | 2410, (1.08%) |
223242 | 3105 (1.39%) | 216190 | 2017, (0.93% |
213902 | 365, (0.17%) |
Fischer Exact Test
The total number of positive samples for one or multiple TTIs during these four years was 7897 (3.537%) as summarized in Table 3. The seroprevalence reduced over the years for all the infections from 2224 reactive samples in 2015 to 1759 reactive samples in 2018, as shown by figure 1. This decrease in reactive samples was non-significant as shown in table 3. Among the individual diseases, trend analysis did not given any significant differences.
Figure 1.
Seroprevalence changes over 4 years of TTI's
Blood demand for certain blood-related disorders (Thalassemia, Hemophilia, Leukemia & anemia) is increasing day by day as the number of blood donations for these diseases increases every year (P-value=0.098) (Table 4).
Table 4.
Demand for Blood Donation for Blood-Related Disorders
Year | Total donors |
Transfusions going to thalassemia, Leukemia, anemia, hemophilia pts |
% |
2015 | 45854 | 5344 | 11.65 |
2016 | 55558 | 6201 | 11.16 |
2017 | 58791 | 7775 | 13.22 |
2018 | 63039 | 8836 | 14.02 |
223242 | 28156 | 12.61 | |
P-value | 0.098* |
Fischer exact test
Discussion
Pakistan is endemic for many TTI's while the demand for blood donation is increasing on an annual basis, which is evident from our results. Thus, the frequent transfusion of blood to these patients increases the chances of being affected by a TTI considerably. Therefore, strict screening procedures should be carried out all over the country before the blood is transfused.
In our study, 90.10% of donors were replacement donors, while 9.9% were voluntary donors. Similar studies in Pakistan have come up with comparable figures, such as the study conducted by Arshad and Saeed et al. in Karachi and Lahore, respectively8,9. In contrast, studies in other Asian countries show a more significant number of voluntary donors. A study conducted in India showed that 65.3% were voluntary donors, and 34.7% were replacement donors. The study also showed a sharp rise in the yearly rates of voluntary donors rising from 15.2% to 94 % over ten years (i.e., 2004–13). In contrast, the number of voluntary donors in our study remained relatively consistent. Sharma et.al attributed this sharp rise in voluntary donors to the effort of government institutions to raise public awareness10. A study by Stockx et al. in Mozambique also found a high percentage (50.5%) of voluntary donors11. However, a survey by Chaudhary et al. conducted in Uttar Pradesh India found only 39.47% of their donors to be voluntary. Although lower than Sharma's study, these numbers are still comparatively higher than those of Pakistan. The low prevalence of voluntary blood donors in Pakistan represents a general lack of awareness and health education. Furthermore, there could be fears and misconceptions in the public related to donating blood.
Our study focused on four main TTIs. The overall seroprevalence of HBV was 1.93 %. Similar results have been reported in studies conducted all over the country such as by Memon et al. (1.4%) in Hyderabad (2017)12, Awan et al. (1.09%) in Islamabad (2018) (13), Arshad et al. (1.7%) in Karachi (2016)8 and Saeed et al. (1.1%) in Lahore9. Hussain et al., however, reported a slightly higher figure of 2.32% in Multan (2015)14. Internationally, a study in Uttar Pradesh reported a comparable number of 1.93% (2014)15. Several studies showed a comparatively lower prevalence for HBV, such as the one done by Farshadpur et al. in Iran (2016)16. The survey conducted by Zou et al. in the U.S.A in 2009 showed an even lower number (1 for every 280,000)17. The reason for that is probably the high level of awareness among the population and generally low prevalence. A study in Namibia in 2014 also found a low figure of 0.6%, which could be due to the small sample size of the study18. This is because most of the results reported from all over Africa are considerably higher, ranging from 5%–14.96% in various countries of the continent11,19–22. In a study conducted in 2011, Nagalo et al. attributed their particularly high figure (14.96%) to the fact that the majority of their donors belonged to the rural population as well as the marked use of tattooing among the Mossi, Gourounsi, and Bobo, the major ethnic groups in the Koudougou region19. Tattooing has been further confirmed as a significant risk factor for HBV transmission by Jombo et al.20.
In this study, we found the prevalence of HCV to be 1.39%, which is similar to that of various local studies i.e., 1.3% (13) and 1.8%8. On the other hand, the other local studies all reported higher numbers of 3.52%11, 2.62%9, and 3.44%14. This is alarming as HCV is extremely dangerous, and the true extent of its prevalence in our society is still yet to be determined. Looking outwards, a study in Ethiopia and one in India found somewhat similar figures of 1.7% and 1.02, respectively14,22, while Nagalo et al. reported a towering figure of 8.69%19. On the other hand, most of the studies showed a reported lower value i.e., 0.1% in Iran and Namibia, 0.7% in Eritrea, and 0.36% in Gwalior10,16,18,22.
In this study, we did not find a single HIV+ patient during our 4-year study period. This was, regrettably, not the case for many other studies, as most of them reported HIV+ percentages ranging from 0.01–0.16%8,9,12–14. Waheed et al., however, conducted a study in 2012, where they reported an HIV prevalence of 0% in Islamabad24. This could be attributable to screening variations in different locations and the fact that screening tests lack complete sensitivity. Farshaadpour et al. reported a similarly low figure of 0.004% from Iran16. Others have reported higher numbers ranging from 0.13% in Gwalior, India, to 0.8 % in Eritrea10,15,18,21,22. Studies from other parts of Africa have reported even higher numbers, namely Burkina Faso (2.21%) and Mozambique (8.5%)11,19. This is not surprising, as it coincides with the fact that the general prevalence rates for Africa are highest in the world25.
Moving on, the prevalence rate for Syphillis was 0.93%. Awan and Waheed et al. found a comparable rate of 0.75% and 0.89% in separate studies in Islamabad13,24. Figures for Lahore, Karachi, and Hyderabad were all higher, i.e., 1.55%, 2.1%, and 3.01%, respectively8,9,12. This could reflect a difference in the level of awareness about the disease in a particular region. Hussain et al., however, reported a considerably low figure of 0.07%. Internationally, Stokx et al. reported a similar figure of 1.2%. Mavenyengwa et al. reported a lower figure of 0.3%, while India reported even lower prevalence rates of 0.16% and 0.17% form Uttar Pradesh and Gwalior, respectively10,15,18. On the other hand, figures from different parts of Africa were considerably higher, i.e., 3.96% in Burkina Faso and 7.2% in Eritrea19,22. The study by Nagalo et al. was primarily conducted in the rural setting, which could account for the higher prevalence rates. At the same time, Keleta et al. postulate their result could be suggestive of a high-density carrier state or active infection19,22.
Finally, our results showed a prevalence rate of 0.17% for Malaria. Most developed countries around the world do not screen for Malaria. However, in countries where the disease is endemic, it is still a notable transfusion transmissible reaction. Thus, strict screening is carried out for Malaria, as it poses a significant threat to the local population. Ali et al. reinforce this point by saying that blood donors in developing countries mostly comprise a low-income group and are commercial donors, which significantly increase transmission risk26. They also reported a considerably higher prevalence rate of Malaria (0.577%) in Peshawar's blood donors26.
On the other hand, Hussain, Awan, and Arshad et al. reported considerably lower figures of 0.07% (14), 0.02%13 and 0.07%8 respectively but data reported by Saeed et al. (0.1%) and Memon et al. (0.1%) were more comparable to our study9,12. Hussain et al. attribute this difference of results to the primary geographical and climatic variations that directly affect the reproduction of the parasite14. A study in Nigeria corroborated this fact as they found a considerable variation in their prevalence rates depending upon the season. It varied from an average of 26.92% in the dry season to an average of 55% during the rainy season27. The extremely high prevalence in Nigeria is also reported in a study by Achidi et al.28. According to Okocha et al., such a high prevalence rate reflects the high rate of asymptomatic malaria parasitemia in endemic malaria regions, which reinforces the need for strict screening practices in these regions27. Gelaw et al. reported a much closer number of 1% from Ethiopia, although it is still considerably higher than our results23. In contrast to this, studies from India and Sudan reported significantly lower prevalence rates of 0.03% and 0.056%, respectively10,29.
Although our study was conducted over a substantial period, it was a retrospective study. Thus, all of the limitations inherent to retrospective studies apply here as well. Furthermore, our focus was mainly the urban setting. The prevalence of the surrounding rural areas might well be comparatively different, and studies focusing on those areas are needed. Furthermore, only rapid screening tests were used, and no confirmatory testing by PCR was performed. The actual prevalence rates may be somewhat different from those found here. However, the current results are adequate to give us an approximate idea of the prevalence of TTI's in the study population.
Conclusion
our study suggests that the risk of transmission through transfusion is still considerable. However, the decreasing trends seen throughout the study are heartening as they show a growing awareness about the diseases. They also show the effectiveness and the necessity of the continuation of strict screening protocols, which is supported by other studies as well. Thus, the current efforts must be continued, while further awareness about the benefits of blood donation must be raised to increase the population of voluntary donors. Furthermore, targeting donors with a low-risk profile, a screening questionnaire, an ample supply of quality screening tests, and awareness campaigns for the diseases in question must also be carried to further decrease the risk of transmission of TTIs in Pakistan.
Table 1.
Blood testing Kits Used
Screening | Device & Method |
Detection in Serum/Plasma |
Sensitivity | Specificity |
HIV | Advanced Quality TM one step Test, Rapid Anti-HIV (1&2); Immunochromatography method |
Antibodies against HIV (1&2) |
99.80% | 100.00% |
Syphilis | ImuMed TM, One Step test; Immunochromatography method |
Anti-Treponema pallidum antibodies |
89.20% | 90.90% |
HBV | Quindao Hightop Biotech Co., Ltd. HBsAg Rapid Test Cassette (S/P); Immunochromatography method |
Hepatitis B surface antigen |
95.90% | 96.40% |
HCV | Healgen Scientific LLC, HCV Rapid Test Cassette; Immunochromatography method |
Anti- HCV antibodies |
98.10% | 98.90% |
Malaria | Accurate TM Malaria PF/PAN (ICT) Test Device (Whole Blood); Immunochromatography method |
Plasmodium falciparum and Plasmodium Vivax antigen |
92.50% | 98.30% |
References
- 1.Reasons for Blood Transfusions | Red Cross Blood Services. (no date). Available at: https://www.redcrossblood.org/donate-blood/blood-donation-process/what-happens-to-donated-blood/blood-transfusions/reasons-transfusions.html.
- 2.Zmijewski Chester M, Haesler Walter E. blood banking science. New York: Appleton Century Croft; 1982. p. 2. [Google Scholar]
- 3.WHO, author. Guidelines of Blood Transfusion Safety Appia, CH-1211 Geneva 27, Switzerland. Available from: https://www.who.int/health-topics/blood-transfusion-safety.
- 4.WHO fact sheet on Blood safety and donation. 2008. Available from: https://www.who.int/news-room/factsheets/detail/blood-safety-and-availability.
- 5.Asif N, Kokhar N, Ilahi F. Seroprevalence of HBV, HCV and HIV infection among voluntary non remunerated and replacement donors in Northern Pakistan. Pak J Med Sci. 2004;20(1):24–28. Available from: http://www.pjms.com.pk/issues/janmar04/pdf/article4.pdf] [Google Scholar]
- 6.Siraj N, et al. BMC Infectious Diseases. 1. Vol. 18. BioMed Central Ltd.; 2018. Seroprevalence of transfusion-transmissible infections among blood donors at National Blood Transfusion Service, Eritrea: a seven-year retrospective study; p. 264. Available from: [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.National AIDS control program, Ministry of health, Pakistan. Available from: https://www.nacp.gov.pk/
- 8.Arshad A, Borhany M, Anwar N, Naseer I, Ansari R, Boota S, et al. Prevalence of transfusion transmissible infections in blood donors of Pakistan. BMC Hematol. 2016;16(1):2–7. doi: 10.1186/s12878-016-0068-2. Available from: [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Saeed M, Hussain S, Rasheed F, Ahmad M, Arif M, Tariq M, et al. Silent killers: Transfusion Transmissible infections.-TTI, among asymptomatic population of Pakistan. JPakist Med Ass_2017. 2017;67(3):369–374. Available from: https://www.jpma.org.pk/PdfDownload/8112. [PubMed] [Google Scholar]
- 10.Chandra Sharma D, Rai S, Bharat S, Iyenger S, Gupta S, Jain B. A 10 Years Comparative Study to Assess Trends in Seroprevalence of Transfusion Transmitted Infections among Blood Donors at Gwalior, India. Open J Blood Dis. 2014;04(02):24–32. doi: 10.4236/ojbd.2014.42004. Available from: [DOI] [Google Scholar]
- 11.Stokx J, Gillet P, De Weggheleire A, Casas EC, Maendaenda R, Beulane AJ, et al. Seroprevalence of transfusion-transmissible infections and evaluation of the pre-donation screening performance at the Provincial Hospital of Tete, Mozambique. BMC Infect Dis. 2011;11:2–9. doi: 10.1186/1471-2334-11-141. Available from: [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Memon FA, Ujjan ID, Memon AI, Shaikh AR, Rao AR, Naz A. Seroprevalence of transfusion transmitted infections among different blood group donors at blood bank LUMHS, Hyderabad. Pakistan J Med Sci. 2017;33(2):443–446. doi: 10.12669/pjms.332.11691. Available from: [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Awan SA, Junaid A, Sheikh S. Transfusion Transmissible Infections: Maximizing Donor Surveillance. Cureus. 2018;10(12) doi: 10.7759/cureus.3787. Available from: [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Hussain A. Seroprevalence of Transfusion based Transmissible Infections among Clinically Healthy Donors in the Community of Multan, Pakistan. J Infect Mol Biol. 2015;3(2):47–51. doi: 10.14737/journal.jimb/2015/3.2.47.51. Available from: [DOI] [Google Scholar]
- 15.Chaudhary V, Agrawal V, Sexena S, Upadhyay D, Singh A, Singh S. Seroprevalence of common transfusion transmissible infections among blood donors in western Uttar Pradesh, India. Int J Med Sci Public Heal. 2014;3((11):1381. doi: 10.5455/ijmsph.2014.160820143. Available from: [DOI] [Google Scholar]
- 16.Farshadpour F, Taherkhani R, Tajbakhsh S, Tangestani MG, Hajiani G, Sharifi N, et al. Prevalence and trends of transfusion-Transmissible viral infections among blood donors in south of Iran: An Eleven-Year retrospective study. PLoS One. 2016;11(6):1–18. doi: 10.1371/journal.pone.0157615. Available from: [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Zou S, Stramer SL, Notari EP, Kuhns MC, Krysztof D, Musavi F, et al. Current incidence and residual risk of hepatitis B infection among blood donors in the United States. Transfusion. 2009;49(8):1609–1620. doi: 10.1111/j.1537-2995.2009.02195.x. Available from: [DOI] [PubMed] [Google Scholar]
- 18.Mavenyengwa RT, Mukesi M, Chipare I, Shoombe E. Prevalence of human immunodeficiency virus, Syphilis, hepatitis B and C in blood donations in Namibia. BMC Public Health. 2014;14(1):1–7. doi: 10.1186/1471-2458-14-424. Available from: [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19.Nagalo MB, Sanou M, Bisseye C, Kaboré MI, Nebie YK, Kienou K, et al. Seroprevalence of human immunodeficiency virus, hepatitis B and C viruses and Syphilis among blood donors in Koudougou (Burkina Faso) in 2009. Blood Transfus. 2011;9(4):419–424. doi: 10.2450/2011.0112-10. Available from: https://dx.doi.org/10.2450%2F2011.0112-10. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Jombo GT, Egah DZ, Banwat EB. Hepatitis B virus infection in a rural settlement of northern Nigeria. Niger J Med [Internet] 2005;14(4):425–428. Available from: http://europepmc.org/abstract/MED/16353707. [PubMed] [Google Scholar]
- 21.Siransy LK, Nanga ZY, Zaba FS, Tufa NY, Dasse SR. ABO/Rh Blood Groups and Risk of HIV Infection and Hepatitis B among Blood Donors of Abidjan, Côte D'Ivoire. Eur J Microbiol Immunol. 2015;5(3):205–209. doi: 10.1556/1886.2015.00029. Available from: [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22.Keleta YT, Achila OO, Haile AW, Gebrecherkos BH, Tesfaldet DT, Teklu KS, et al. Seroprevalence of transfusion transmitted infections among blood donors in Gash Barka Zonal Blood Transfusion Center, Barentu, Eritrea, 2014 through 2017. BMC Hematol. 2019;19(1):1–9. doi: 10.1186/s12878-019-0136-5. Available from: [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23.Gelaw B, Development YM-EJ of H The prevalence of HBV, HCV and malaria parasites among blood donor in Amhara and Tigray regional states. 2008. undefined. ajol.info [Internet]. [cited 2020 Jun 4]; Available from: https://www.ajol.info/index.php/ejhd/article/viewFile/10056/31330.
- 24.Pak A, Waheed U, Khan H, Shafique Satti H, Asim Ansari M, Arshad Malik M, et al. Prevalence of Transfusion Transmitted Infections among Blood Donors of a Teaching Hospital in Islamabad. Inst Med Sci. 2012;8(4):236–239. [Google Scholar]
- 25. AIDSinfo | UNAIDS [Internet]. [cited 2020 Jun 4]. Available from: http://aidsinfo.unaids.org/#.
- 26.Ali N, Ahmed J, Ali N, Jehan F, Saleem S. Transfusion transmitted Malaria in three major blood banks of Peshawar, Pakistan. African J Biotechnol. 2010;9(33):5445–544. Available from: https://www.ajol.info/index.php/ajb/article/view/92093. [Google Scholar]
- 27.Okocha EC, Ibeh CC, Ele PU, Ibeh NC. The prevalence of malaria parasitaemia in blood donors in a Nigerian teaching hospital. J Vector Borne Dis. 2005;42(1):21–24. Available from: https://shorturl.at/npx36. [PubMed] [Google Scholar]
- 28.Achidi EA, Perlmann, Berzins K. Asymptomatic malaria parasitaemia and seroreactivities to Plasmodium falciparum antigens in blood donors from Ibadan, south-western Nigeria. Ann Trop Med Parasitol. 1995;89(6):601–610. doi: 10.1080/00034983.1995.11812994. Available from: [DOI] [PubMed] [Google Scholar]
- 29.Ali MSM, Gader A, Kadaru MY, Mustafa MS. Screening blood donors for malaria parasite in Sudan. Ethiop J Heal Dev. 2005;18(2):2–6. doi: 10.4314/ejhd.v18i2.9940. Available from: [DOI] [Google Scholar]
- 30.Sultan F, Mehmood T, Mahmood MT. Infectious pathogens in volunteer and replacement blood donors in Pakistan: a ten-year experience. Int J Infect Dis. 2007 Sep;11(5):407–412. doi: 10.1016/j.ijid.2006.10.004. Available from: [DOI] [PubMed] [Google Scholar]