Toxoplasmosis is a widespread cosmopolitan anthropozoonosis due to a protozoan parasite,
In Sub-Saharan Africa in general and in Côte d’Ivoire in particular,
We performed a cross-sectional study from October 2014 to December 2014, carried out at the site of Abobo which is a fixed collection site that achieves awareness, recruitment, retention of donors, collection, and storage.
Blood samples were taken from all 106 healthy volunteer and nonremunerated blood donors from the site of Abobo city by successive recruitment.
The tests were then carried out in the laboratory of NBTC. Inclusion criteria for the study were (i) having an age between 18 and 60 years, (ii) being healthy, and (iii) having a weight over 50 Kg.
We used a standardized questionnaire through medical software used routinely at the blood bank named Progesa from MakSystem to explore few characteristics of the blood donors, such sex, age, number of previous donations, ABO and Rh blood group, and occupation.
All samples were routinely tested for HIV, HBs Ag, and HCV by ELISA and syphilis by VDRL.
For the detection of anti-
Serological tests for toxoplasmosis were carried out in the laboratory of National Blood Center of Abidjan with commercially available enzyme immunoassay tests
For IgG detection, the test principle is based on indirect ELISA technique in which diluted patient serum samples are allowed to react with coated
For qualitative calculation, we have distinguished between positive and negative results by the determination of the cut-off index (equal to OD of sample/cut-off value). Based on this formula, results lower than 0.9 were considered as negative and those greater than 1.1 considered as positive results. Those results between 0.9 and 1.1 were considered as suspected results and have been reevaluated.
For quantitative calculation of IgG, a standard curve was constructed point to point by plotting the mean absorbance obtained for each of the four-reference standard against its concentration in IU/mL on linear graph paper, with absorbance on the vertical (
For IgM, the test principle is based on antibody capture ELISA technique. The concentration of
To distinguish between positive and negative results the cut-off index was determined: cut-off index = OD of sample/cut-off value.
Based on the above formula, results lower than 0.9 were considered as negative and those greater than 1.1 as positive results. Those results between 0.9 and 1.1 were considered as suspected results and were reevaluated with fresh samples.
Negative results indicate absence of anti-
Positive results after recheck indicate presence of anti-
A positive IgG test with a negative IgM test in a donor was interpreted as a chronic infection. A positive IgM test with a positive IgG test in a donor was interpreted as probability of recent infection.
To assess the risk contamination in endemic situation of a blood donation by
Statistical analysis of the results was made using Excel 2007, Epi-info 7. For calculation of the sample size, we used Schwartz formula
The national Ethical Committee approved this study. The purpose and procedures of the study were explained to all donors, and a written informed consent was obtained from all of them.
Demographics characteristics are described in Table
Distribution of donors according to demographic characteristics.
Number | % | |
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Male | 92 | 86.79 |
Female | 14 | 13.21 |
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18–25 years | 34 | 32.08 |
26–35 years | 40 | 37.74 |
36–45 years | 26 | 24.53 |
>45 years | 6 | 5.66 |
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0 | 8 | 7.55 |
1–5 | 32 | 30.19 |
6–10 | 18 | 16.98 |
11–15 | 12 | 11.32 |
16–20 | 10 | 9.43 |
21–30 | 14 | 13.21 |
>30 | 12 | 11.32 |
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Liberal | 26 | 24.53 |
Employed | 28 | 26.42 |
Unemployed | 12 | 11.32 |
Students | 40 | 37.74 |
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O | 62 | 58.49 |
B | 30 | 28.30 |
A | 12 | 11.32 |
AB | 2 | 1.89 |
Rh D positive | 94 | 88.68 |
Rh D negative | 12 | 11.32 |
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IgG positive | 68 | 64.15 |
IgG negative | 38 | 35.85 |
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IgM positive | 12 | 11.32 |
IgM negative | 94 | 88.68 |
Distribution of donors by the immune profile
Presence of |
Absence of |
Total | ||||
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Number | % | Number | % | Number | % | |
Presence of |
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8 |
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4 |
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12 |
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Absence of |
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60 | 56.60 | 34 | 32.08 | 94 | 88.68 |
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Fourteen (20.59%) subjects had a titer of anti-
A link was observed between gender and IgM positivity (
Distribution of
Distribution of
Frequency donor depending on the number of previous blood donations and the presence of IgM and IgG
Regarding blood group, the presence of IgG and IgM
Distribution of donors according to the ABO-Rh and the presence of IgM and IgG
ABO blood group | Number of blood donors | (%) | Presence of antitoxoplasmic IgG | Presence of antitoxoplasmic IgM | ||
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Number | % | Number | % | |||
O | 62 | 58.49 | 40 | 37.74 | 6 | 5.66 |
B | 30 | 28.30 | 22 | 20.75 | 4 | 3.77 |
A | 12 | 11.32 | 6 | 5.66 | 2 | 1.89 |
AB | 2 | 1.89 | 0 | 0.00 | 0 | 0.00 |
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RhD− | 12 | 11.32 | 4 | 3.77 | 0 | 0.00 |
RhD+ | 94 | 88.68 | 64 | 60.38 | 12 | 11.32 |
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According to occupation, seroprevalence rate of
Distribution of donors depending on the profession and the presence of IgM and IgG
Occupation | Number of blood donors | % | Presence of IgG |
Presence of IgM | ||
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Number | % | Number | % | |||
Liberal profession | 26 | 24.53 | 16 | 23.53 | 0 | 0 |
Employed | 28 | 26.42 | 26 | 38.24 | 2 | 16.67 |
Unemployed | 12 | 11.32 | 4 | 5.88 | 4 | 33.33 |
Student | 40 | 37.74 | 22 | 32.35 | 6 | 50 |
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Total |
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100.00 |
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100.00 |
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100 |
106 blood donors from the site of Abobo were recruited in our work. This site was chosen because it is located in the most populated city of Abidjan and is considered a city combining the highest rate of low-income district of Abidjan.
Demographic features of the blood donors are shown in Table
While 92.45% of donors are regular, 7.5% have no experience of giving blood. Donors who have between one and five previous donations are the most represented with 30.19%. NBTC, through blood safety program, has a policy consisting of retaining the donor for future donations, because a known donor is less at risk than a new donor and an identified donor is a responsible donor [
Concerning the occupation, just over one-third or 37.74% are students. Employees are represented by 26.42%, followed by liberal professions 24.53% and 11.32% unemployed. These data are consistent with existing data on blood donors in Côte d’Ivoire
The average age of donors was 31 years with up to 51 years and minimum 20 years. The majority of donors are between 18 and 45 years of which 40% are between 26 and 35 years.
No seropositivity was found for HIV, hepatitis B and C, and syphilis for the blood donors.
In this study, the
64.15% have
The first investigations of toxoplasmosis in Côte d’Ivoire made by Doucet et al. in 1971 found a seroprevalence of 12% [
If we compare the prevalence obtained in donors with neighboring African countries, we find that very little work is done among blood donors concerning toxoplasmosis. In Mali, on 224 blood donors, 49 (21.9%) have
In west and central Africa, prevalence among the pregnant women ranges from 18.2 to 78% [
In Libya, in north Africa, the authors worked on women who have had spontaneous abortions and found that 38.5% were seropositive; 36 (66.6%) were positive for IgG antibodies, 12 (22.2%) for IgG and IgM antibodies, and 6 (11.1%) for IgM. Moreover, four of the IgG-positive women had a history of repeated abortion [
In France, toxoplasmosis is one of the most prevalent infections with seroprevalence in adults between 20 and 55%, varying according to age, geographic region, and professional category. This prevalence has declined significantly in 30 years with a decline of regular prevalence, currently estimated at 37% [
Somewhere else, different works find global toxoplasmosis prevalence going from 7.4% (Mexico), 9.3% (Taiwan), and 19.3% (Iran) to 53.7% (India) [
Sixty-eight blood donors on the 106 recruited in our study have
The presence of anti-
In a study conducted by Sarkari in Iran, 81 donors in 1480 (5.47%) had anti-
Donors having anti-
The prevalence of anti-
As for female donors, 5.66% prevalence of both IgG and IgM was found. This prevalence was much lower than that found in pregnant women in Côte d’Ivoire [
The sex was not associated with seropositivity for IgG. However, it is difficult to confirm any relationship between gender and
In a global way, in this current study, the more our donors are old, the less the prevalence is high. These data contradict those of Sarkari et al. in Iran and El Mansouri et al. in Morocco [
However, Chiang et al. [
A peak for both IgG and IgM was observed in donors having between zero and five blood donations. This is in perfect harmony with the seroprevalence of markers usually found among blood new donors as HIV antibodies, HBsAg (hepatitis B), and anti-HCV (hepatitis C) antibodies. A new donor is more at risk than a known and identified donor [
We observed that IgM anti-
Havlícek et al. [
One study conducted in 3900 military drivers shows that
In our study, no correlation was found between
The existence of an asymptomatic blood passing certain viruses, bacteria, or parasites leads to a risk of transmission of these agents during a blood transfusion especially patients undergoing multiple transfusion.
Few studies are available on contaminated blood
In Sarkari et al. study in Iran, PCR detected active parasitemia in two (1.9%) of the IgM-positive subjects. The presence of parasitemia revealed by PCR in IgM-positive healthy blood donors ensures the likelihood of transmission of
Presence of organism in blood during the course of infection ensures its transmission through transfusion [
If this risk is currently well controlled for some infectious agents (HIV, HCV, and HBV), it is not sufficiently documented and quantified for
Symptomatic donor is excluded from donating systematically donation at the clinic predonation selection. This risk depends on the exclusion criteria of prospective donors and the likelihood that the donor is infectious and asymptomatic the day of donation.
To study the risk of blood transfusion, Ebrahim Zadeh and Stuart et al. [
In addition, the French Institute of Health Surveillance proposed in 2005 a quantitative estimate of the risk of contamination of a blood donation by infectious agents to assess the risk of contamination of donated blood by the pathogen of toxoplasmosis [
In our study, we applied the mathematical model of the Institute for Public Health Surveillance in France. It was calculated by taking 3% incidence in women of reproductive age living in Yopougon [
The quantitative estimation of risk of contamination of a blood donation by
Items | Low hypothesis | High hypothesis |
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Number of days | 365 | 365 |
Duration of parasitemia (days) | 1 | 21 |
Probability to take a donor in parasitemia stage | 1/365 | 21/365 |
Incidence of infection% | 3 | 3 |
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However, it does not estimate the real risk of transmission to the recipient, as it only takes into account neither the transmission efficiency, nor the effectiveness of process for preparing blood components, nor the recipient immunity. For example, the ability of tachyzoites of
Our manuscript highlights seroprevalence of anti-IgG and IgM
In our study, the risk of transmitting blood components contaminated with
Effective strategies are required to prevent transfusion-transmitted toxoplasmosis. Because of lack of funding in our country, the total number enrolled in our study is small and recommend us to be careful in interpretation.
Toxoplasmosis test does not need to be obligatory; we rather recommend education programmes for blood donors and systematic leucocytes reduced blood for people multitransfused, immunocompromised, and pregnant women
None of the authors has any potential financial conflict of interests related to this manuscript.