Malaria seroprevalence in blood bank donors from endemic and non-endemic areas of Venezuela (original) (raw)
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Malaria seroprevalence in blood bank donors from endemic & non-endemica areas Venezuela
In Venezuela, a total of 363,466 malaria cases were reported between [1999][2000][2001][2002][2003][2004][2005][2006][2007][2008][2009]. Several states are experiencing malaria epidemics, increasing the risk of vector and possibly transfusion transmission. We investigated the risk of transfusion transmission in blood banks from endemic and non-endemic areas of Venezuela by examining blood donations for evidence of malaria infection. For this, commercial kits were used to detect both malaria-specific antibodies (all species) and malaria antigen (Plasmodium falciparum only) in samples from Venezuelan blood donors (n = 762). All samples were further studied by microscopy and polymerase chain reaction (PCR). The antibody results showed that P. falciparum-infected patients had a lower sample/cut-off ratio than Plasmodium vivax-infected patients. Conversely, a higher ratio for antigen was observed among all P. falciparum-infected individuals. Sensitivity and specificity were higher for malarial antigens (100 and 99.8%) than for antibodies (82.2 and 97.4%). Antibodypositive donors were observed in Caracas, Ciudad Bolívar, Puerto Ayacucho and Cumaná, with prevalences of 1.02, 1.60, 3.23 and 3.63%, samples were observed among the donors. However, our results show significant levels of seropositivity in blood donors, suggesting that more effective measures are required to ensure that transfusion transmission does not occur.
The American journal of tropical medicine and hygiene, 1999
Malaria antibody detection is valuable in providing retrospective confirmation of an attack of malaria. Blood bank screening is another area were malaria serology is potentially useful. In the present study, we tested the presence of antibodies to Plasmodium falciparum in sera from blood bank donors of non-endemic and malaria-endemic areas of Venezuela. Sera from 1,000 blood donors were tested by an indirect immunofluorescent antibody (IFA) assay and an IgG-ELISA for the presence of malaria antibodies using a synchronized in vitro-cultured Venezuelan isolate of P. falciparum as the antigen source. A selected group of positive and negative sera (n = 100) was also tested by a dot-IgG-ELISA. Positive results (reciprocal titer > or = 40) were found in 0.8% and 3.8% of blood donors when tested by the IFA assay and in 0.8% and 2% (optical density > or = 0.2) when tested by the IgG-ELISA in Caracas (non-endemic area) and Bolivar City (endemic area), respectively. The presence of anti...
Malaria Journal
Background: Transfusion with Plasmodium-infected blood represents a risk for malaria transmission, a rare but severe event. Several non-endemic countries implement a strategy for the screening of candidate blood donors including questionnaire for the identification of at-risk subjects and laboratory testing of blood samples, often serology-based, with temporary deferral from donation for individuals with a positive result. In Italy, the most recent legislation, issued in November 2015, introduced the use of serological tests for the detection of anti-Plasmodium antibodies. Methods: In the absence of a gold standard for malaria serology, the aim of this work was to evaluate five commercial ELISA kits, and to determine their accuracy (sensitivity and specificity) in comparison to immuno-fluorescence antibody test (IFAT), and their agreement (concordance of results). Serum samples from malaria patients or from subjects with malaria history (N = 64), malaria naïve patients with other parasitic infections (N = 15), malaria naïve blood donors (N = 8) and malaria exposed candidate blood donors (N = 36) were tested. Results: The specificity of all ELISA kits was 100%, while sensitivity ranged between 53 and 64% when compared to IFAT on malaria patients samples. When tested on candidate blood donors' samples, ELISA kits showed highly variable agreement (42-94%) raising the possibility that the same individual could be included or excluded from donation depending on the test in use by the transfusion centre. Conclusions: These preliminary results indicate how the lack of a gold standard for malaria serology must be taken into account in the application and future revision of current legislation. There is need of developing more sensitive serological assays. Moreover, the adoption of a unique serological test at national level is recommended, as well as the development of screening algorithms based on multiple laboratory tests, including molecular assays.
Malaria Journal, 2017
Background: Transfusion-transmitted (TT) malaria is an alternative infection route that has gained little attention from authorities, despite representing a life-threatening condition. There has been no systematic review of this health problem in American countries. The aim of this study was to describe the clinical and epidemiological characteristics of TT malaria in the Americas and identify factors associated with lethality based on the studies published in the literature. Methods: Potentially relevant papers in all languages were retrieved from MEDLINE and LILACS. Additional articles were obtained from reviews and original papers. Publications on screening of candidate blood donors and on surveillance of TT malaria cases were included. Odds ratios with respective 95% confidence intervals (95% CI) were calculated. Epidemiological characteristics of blood donors of TT malaria cases, including a pooled positivity of different tests for malaria diagnosis, were retrieved. Results: A total of 63 publications regarding TT malaria from seven countries were included, from 1971 to 2016. A total of 422 cases of TT malaria were recorded. Most TT malaria cases were in females (62.0%) and 39.5% were in the ≥61 years-old age group. About half of all cases were from Mexico (50.7%), 40.3% from the United States of America (USA) and 6.6% from Brazil. Gyneco-obstetrical conditions (67.3%), surgical procedures (20.6%) and complications from neoplasias (6.1%) were the most common indications of transfusion. Packed red blood cells (RBCs) (50.7%) and whole blood (43.3%) were the blood products mostly associated with TT malaria. Cases were mostly caused by Plasmodium malariae (58.4%), followed by Plasmodium vivax (20.7%) and Plasmodium falciparum (17.9%). A total of 66.6% of cases were diagnosed by microscopy. Incubation period of 2-3 weeks was the most commonly observed (28.6%). Lethality was seen in 5.3% of cases and was associated with living in non-endemic countries, P. falciparum infection and concomitant neoplastic diseases. Conclusion: There is an important research and knowledge gap regarding the TT malaria burden in Latin American countries where malaria remains endemic. No screening method that is practical, affordable and suitably sensitive is available at blood banks in Latin American countries, where infections with low parasitaemia contribute greatly to transmission. Lethality from TT malaria was not negligible. TT malaria needs to be acknowledged and addressed in areas moving toward elimination.
Scholars journal of applied medical sciences, 2024
Original Research Article Background: Malaria is a parasitic disease transmitted to humans through the bite of a female mosquito (Anopheles). however, blood transfusion, which is a life-saving medical procedure in many settings, represents a potential route of Plasmodium transmission. The objective of this study was to determine the plasmodial parasitemia in blood donors with a view to assessing the quality of the erythrocyte concentrates produced at the National Blood Transfusion Center (CNTS) of Chad. Methods: This was a cross-sectional analytical study involving 271 subjects who came to donate blood at the CNTS in N'Djamena over a period from March 1 to June 1, 2023. After obtaining the tacit and/or informed consent of potential donors, a questionnaire was administered to them to collect sociodemographic data, knowledge and practical attitudes towards malaria. A blood sample was taken from each individual. The following biological analyzes were carried out: Malaria Rapid Diagnostic Test, thick smear, blood smear. Data were entered and analyzed using SPSS software version 26.0, and the Chi square test was used to compare proportions and a logistic regression model to look for risk factors associated with malaria infection. Results: This study reveals that: the most represented age group was that of 18-28 years (68.6%), with a sex ratio of 4.1 in favor of the male sex, family type donors were more represented (73.4%). The prevalence of plasmodial infection was 12.2% with a parasitemia of between 100 and 600 parasites/µL of blood. The species in question was Plasmodium falciparum. A statistically significant association was established between sex, non-use of insecticide-treated mosquito nets, lack of knowledge about malaria and malaria infection. Conclusion: This work showed that the residual transfusion risk of malaria is real at the CNTS. It would therefore be necessary to ultimately adopt an innovative safety strategy including systematic screening of donations for Plasmodium falciparum.
Malaria Journal, 2013
Malaria is a leading cause of mortality in southern Benin. The main causative agent, Plasmodium falciparum, poses a threat on critical transfusions in pregnant women and children. This study's objective was to compare the performance of different malaria screening methods in blood donors in southern Benin, a malaria-endemic country. Blood from 2,515 voluntary blood donors in Benin was collected over a period of 10 months in ethylenediaminetetraacetic acid (EDTA) tubes, which were then classified according to extraction time: long rainy season, short dry season, short rainy season, and long dry season. Microscopic examination was used to count parasites. Parasite density (PD) was expressed as the number of parasites per μL of blood. Pan Plasmodium pLDH detection was assessed by an ELISA-malaria antigen test. Using crude soluble P. falciparum antigens, an ELISA-malaria antibody test detected anti-Plasmodium antibodies. Among the 2,515 blood donors (2,025 males and 488 females) screened, the rate of asymptomatic Plasmodium carriage was 295/2,515 (11.72%, 95% CI: 10.5-13.1%). Males had a higher infection rate (12.4%) than did females (8.8%). Parasite density was very low: between seven and100 parasites per μL of blood was reported in 80% of donors with parasitaemia. Three Plasmodium species were diagnosed: P. falciparum in 280/295 patients (95.0%), Plasmodium malariae in 14/295 (5.0%), and Plasmodium ovale in 1/295 (0.34%). Malaria prevalence in donors was higher during the rainy seasons (13.7%) compared with the dry seasons (9.9%). The use of a highly sensitive assay enabled pan Plasmodium pLDH detection in 966/2,515 (38.4%, 95% CI: 36.5%-40.3%). Malaria antibody prevalence was 1,859/2,515 (73.9%, 95% CI: 72.16-75.6%). Donors' antigenaemia and antibody levels varied significantly (P <0.05) over the course of the four seasons. The highest antigenaemia rate 323/630 (51.3%), was observed during the short rainy season, while the highest antibody prevalence, 751/886 (84.7%), was recorded during the long dry season. Blood donations infected with Plasmodium can transmit malaria to donation recipients. Malaria diagnostic methods are currently available, but the feasibility criteria for mass screening in endemic areas become preponderant. Detection of the pLDH antigen seems to be an adequate screening tool in endemic areas, for this antigen indicates parasite presence. Routine screening of all donated blood would prevent infected blood donations and reduce P. falciparum transmission in critical patients, such as children and pregnant women. This tool would also decrease medical prophylaxis in donation recipients and contribute to lower Plasmodium resistance.
The Incidence of Malaria Parasites in Screened Donor Blood for Transfusion
Malaria Research and Treatment
Malaria is a protozoan parasitic infection of humans resulting from one or more of the five species of the genus Plasmodium and its burden across the world particularly in the tropics is well known. Blood transfusion on the other hand is a necessary intervention in saving lives. However, it can lead to transfusion transmitted infections including malaria if the blood was donated by an infected person. It is therefore important that the blood from donors in malaria prone environment be examined thoroughly for malaria parasites. The objective of this study was to investigate the incidence of malaria parasites in donor blood. A total of 1,500 samples from donors were examined using microscopy, rapid diagnostic test (RDT), and molecular method for malaria parasites. Malaria parasites were detected in forty-eight (48), 49 and 47 of the blood samples using microscopy, RDT, and molecular method respectively. This gave an average prevalence of 3.2%. All the blood groups examined had some ma...
The use of malaria antibody tests in the prevention of transfusion-transmitted malaria
Vox Sanguinis, 2010
The International Forum of Vox Sanguinis is meant to obtain information concerning important and ⁄ or controversial subjects of transfusion medicine. Transfusiontransmitted malaria is severe and often fatal. The measures taken to prevent it in non-endemic areas have been successful, although cases still occur occasionally. However, the number of immigrants from and travellers to endemic areas has increased considerably and is still increasing. Furthermore, new tests have been developed to detect plasmodium antibodies and are used for selected group of donors in various blood centres. Also, tests to detect plasmodium antigens and nucleic acid amplification testing (NAT) for parasite DNA have been developed. It seemed therefore of interest to evaluate the preventive measures taken at present in non-endemic areas. To obtain the relevant information, the following questions were sent to transfusion services.