Hemoglobin change following first line treatment of uncomplicated falciparum malaria with artemether-lumefantrine and artesunate-amodiaquine in Burkina Faso

¹Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso

^&Corresponding author
Issaka Zongo, Institut de Recherche en Sciences de la santé, Bobo-Dioulasso, Burkina Faso

Introduction    

Anemia defined as hemoglobin less than 11 g/dl for children 0-14 years and less than 13.0g/dl for adult is a public health concern in less developed and endemic countries. It leads to significant damage, with repercussions primarily affecting acquisition of motor and cognitive skills, language development, and the learning process [1,2]. About 40% of world population were anemic in the 1990s [3]. But this situation has improved with 25% of world population affected by anemia in 2010, representing 8.8% of global disability the same year [3,4]. Vulnerable groups include children and women of reproductive age. In Burkina Faso, children less than five years old contribute for 46.7% of the total anemic patients in 2017; on that year, anemia was reported as the second cause of hospital admission [5]. Prevalence and incidence of malaria remain high despite sustained and aggressive efforts to control its burden [2,6]; still it is an important contributor to anemia along with other factors [7-10]. There has been a recent international commitment to fight malaria, thus artemisinin based combination therapies are introduced in the fight against malaria [10]. Hemolytic anemia was described following the use of artemether intramuscular and oral artemether-lumefantrine [11,12]. Interventions aimed at curbing the burden of malaria are likely to reduce the disease related anemia. In this study, we report the hemoglobin change in patients presenting with uncomplicated falciparum malaria, treated with either artemether-lumefantrine or artesunate-amodiaquine and followed up for 28 days.

Methods     

Study site: the study was conducted in two urban public health facilities of Bobo-Dioulasso (sakaby and colsama) in 2016. These facilities serve as sentinel sites for antimalarial drug efficacy monitoring set in conjunction with national malaria control program (NMCP) and the world health organization (WHO) office in Ouagadougou. Each health facility is staffed by nurses (approximately 6 nurses of whom one is the head), mid-wives and essential drugs shop keeper. The sentinel sites offer mainly outpatients care (and refer to the district hospital cases requiring admission), expanded program of immunization (EPI) activities and antenatal care (ANC) services. Health facilities of Colsama and Sakaby cover respectively 35 838 and 38 703 inhabitants in 2015/2016. In these sites, malaria is whole endemic with transmission peak during rainy season (May-October). Plasmodium falciparum and Anopheles Gambiae are the main specie and vector.

Study design and population: this study was designed as an efficacy randomized and opened trial comparing hemoglobin change in patients recruited with uncomplicated falciparum malaria and followed up for 28 days during the peak of transmission from July to November 2016. Participants were randomized to receive either artemether-lumefantrine or artesunate-amodiaquine fixed combination. Randomization code was computer generated and kept with a person not involved directly in the study. All subjects aged 6 months or more and attending Colsama and Sakaby health centers with fever or history of fever in the last 24 hours were referred by a clinician for screening of malaria infection using giemsa stain thick and thin blood smears. Participants with P. falciparum infection at parasite densities between 2000 and 200,000 parasites/μl and hemoglobin >5g/dl were included in the clinical study after they or their parent/guardian signed an informed consent form. Other inclusion criteria were: absence of known adverse events to study drugs, absence of malnutrition even moderated based on mid upper arm circumference measurement (MUAC), absence of non-malarial febrile diseases, and absence of documented malaria treatment in the two weeks prior to enrolment, absence of danger sign or severe malaria.

Follow up procedures: study participants were treated over three days; the first dose of either artemether-lumefantrine or artesunate-amodiaquine was given in the morning; remaining doses were given at home by mothers or any caregiver. Then parents or participants were asked to return to the study clinics on days 3, 7, 14, 21, and 28. At each time point (day 0, 7 and 28), full blood cell count was obtained from each participant who provided 5 ml of venous blood (on fasted patients) on tube with heparin and proceeded immediately or within 2 hours using and automated Petra 60. Participants with hemoglobin level less than 11g/dl for participant up to 14 years and 13.0g/dl from 15 years onward were considered anemic and such as were given ferrous for at least one month. Participants were excluded from further follow up in case of use of other antimalarial drugs, the consent withdrawal and lost to follow up.

Intervention: the study drugs are those used in the national malaria control program for the treatment of uncomplicated malaria in Burkina Faso, either AL or ASAQ. Drug administration was based on weight over three days (first day doses directly observed, the remaining left with mothers for home administration).

Ethics: the study was approved by the ethics committee of the research institute on health sciences (IRSS) in Bobo-Dioulasso prior the onset of the recruitment and participants follow up. Only participants who signed themselves an informed consent form (ICF) and those whose parents signed the ICF for their participation to the study were effectively enrolled.

Sample size and statistical analysis: we anticipated that 136 participants will be needed in each group to assess the efficacy of Artemether-Lumefantrin (AL) versus Artesunate-Amodiaquine (ASAQ) assuming 90% uncorrected cure rate in the ASAQ group (detecting a difference of 15%) with 80% power and significance level of 0.05 accounting for 20% of lost to follow up. Data were entered using Microsoft access software, checked and analyzed using STATA version 130. Baseline characteristics of enrolled participants were summarized; participants in each category (anemic or not) were presented as proportion and compared between drug regimens. Categorical variables were compared using chi-square test while continuous were compared using either independent or dependent t-test. Linear regression was used to assess the hemoglobin gain over the follow up period. Statistical significance level was set to 0.05. For these analyses, anemia was defined as per WHO guidelines [13] with a slight modification that we considered similar definition of anemia through childhood; thus we considered the definition of anemia for children up to 14 years (hemoglobin less than 11 g/dl) and for men from 15 years onward (hemoglobin less than 13.0g/dl).

Results     

Baseline characteristics of enrolled participants: study team was based at public health facilities delivering routine care. Patients not meeting the study inclusion criteria after screening were directly referred to the health facility nurses for further management with routine team and were not recorded in the project´s book. Therefore, 281 participants were enrolled (138 in AL and 143 in the ASAQ groups). Most of patients screened but not enrolled presented low parasitemia or complicated falciparum malaria. Of the enrolled patients, 43% were male in the AL and 56.7% in the ASAQ groups respectively. Mean age was 9.85 years (SD 10.21) in the AL group and 9.42 years (SD 8.33) in the ASAQ group with the median being similar (7.0) in all groups. Mean hemoglobin at entry was similar across groups, 10.73 g/dl for AL and 10.72g/dl for ASAQ. Participant´s baseline characteristics are summarized in Table 1.

Hemoglobin change over follow up period analyzed as proportion

Children 0.5-14 years: at enrollment, 52.99% of patients in the AL and 51.18% in ASAQ groups were anemic. These proportions increased on day 7 (73.5% in the AL group and 75.81% in the ASAQ group) (Table 2). Comparison of proportion either between day 0 or day 7 with day 28 revealed a significant hemoglobin increase in all treatment groups; indeed between day 7 and day 28, we noted a significant relative decrease in the proportion of participants with hemoglobin <11.0g/dl (73.5% to 35.65%, p<0.001) in AL group and in ASAQ group (75.81% to 37.6%, p<0.001). Similar trend was observed between day 0 and day 28 irrespective of the treatment group (52.99% versus 35.65%) in AL and 51.18% versus 37.6% in the ASAQ groups; relative reduction was 32.7% in AL group and 26.5% in ASAQ group, p<0.001, Table 2.

Adults 15 years old or more: the case definition of anemia in adult population used a cut off of 13g/dl; the proportion of anemic individuals remained high throughout follow up (Table 2).

Mean hemoglobin evolution over follow up period

Linear regression: in simple linear regression, one increase of unit in age corresponded to a decrease of 0.024g/dl, 95% CI [-0.110 -0.062], p=0.581 in hemoglobin in participants 0-14 years treated with AL and an increase of 0.021g/dl, 95% CI [-0.059-0.103], p=0.593 in participants treated with ASAQ on day 0 in similar age group. In adult age band, one unit increase in age corresponded to 0.0023 g/dl, 95% CI [-0.043-0.048], p=0.915 increase in hemoglobin in patients treated with AL and 0.0105 g/dl, 95% CI [-0.076-0.097], p=0.798 in ASAQ treated patient

T-test comparison (paired and independent)

Children 0.5-14 years: mean hemoglobin concentration decreased from day 0 to day 7, (10.79g/dl, 95% CI [10.50-11.09] versus 10.06g/dl, 95% CI [9.75,-10.36], and the mean difference was 0.731, 95% CI0.304-1159, p=0.0005) in patients treated with AL. In ASAQ group, mean difference between day 0 and day 7 was 0.699, 95% CI [0.308-1.090], p=0.0003. From day 7 to day 28, the mean hemoglobin concentration has increased with a mean difference of 1.27g/dl 95% CI [0.92-1.62], p<0.001 in AL treated group against 1.42g/dl 95% CI [1.11-1.74], p<0.001 in ASAQ group. Similarly, hemoglobin concentration has increased from day 0 to day 28 in all groups, this increase was of 0.539 g/dl, 95% CI [0.197-0.882], p=0.0001 in AL group and 0.75g/dl, 95% CI [0.38-1.11], p<0.0001 in ASAQ group. Independent t-test revealed no difference between treatment groups over fixed time points (day 0, 7 and 28) during follow up period.

Adult, 15 years and more: in adult age group, mean hemoglobin has changed in a similar fashion over time. Mean change was 1g/dl, 95% CI [0.38-1.62], p=0.0015, [10.41 versus 9.41] between day 0 and day 7, -1.99g/dl, 95% CI [-2.63--1.35], p<0.001, [9.41 versus 11.40] between day 7 and day 28 and finally -0.98g/dl, 95% CI [-1.77-0.19], p=0.0088, [10.41-11.40] between day 0 and day 28 in AL group. In ASAQ group, the change has been 0.77g/dl, 95% CI [0.011-1.55], p=0.02, [ 11.40 versus 10.64] between day 0 and day 7, -0.28g/dl, 95% CI [-1.08-5.13] p=0.23, [10.64 versus 10.92] between day 7 and day 28 and finally 0.49 g/dl, 95% CI [-0.41-1.38], p=0.13, [11.41 versus 10.92].

Magnitude of hemoglobin change per age group: the proportion of participants with anemia per fixed time point and per age group was similar across treatment groups, on day 0 this was 52.99% in AL group compared to 51.18% in ASAQ group, or 73.5% versus 75.81% in ASAQ group on day 7. In general, the proportion of participants with anemia increased between day 0 and day 7 in all treatment groups; these proportions have decreased over time in AL and ASAQ groups between day 0 or day 7 versus day 28 (Table 2). When we stratified into two age bands (0-14 years, and 15 years or more), it appears that almost all adult population had hemoglobin less than 13g/dl; cut off defining anemia in this class of age. At the end of the follow up on day 28, 19 participants over 21 and 16 participants over 16 remained anemic in AL and ASAQ groups respectively.

Severity grade of anemia: at study entry, no severe case of anemia was found; rather most patients in 0-14 years were moderately anemic (Table 3). However, five participants (four in AL and one in ASAQ groups) fell into severe grade for anemia on day 7. During follow up three in AL group and the remaining two respectively fully recovered and emerged into light grade; the unique case in ASAQ group did emerge into light anemia grade by the end of the follow up period (Table 4). In Table 4, severity of anemia in adult participant was described; three participants in this age group were found to have hemoglobin less than 13 g/dl (Table 5). In this group, no patient had hemoglobin less than 5 g/dl; those classified as severe cases had at least 6.0g/dl and were clinically asymptomatic (this does not preclude any biological adverse impact) and have not been indicated for blood transfusion; oral iron ferrous was given for one month; no worsen case was reported up to the end of 28 days follow up.

Anemia and malaria treatment outcomes: overall, 18 participants failed (14 parasitological and 4 clinical failures) over 28 days follow up period in AL group and 4 (2 in parasitological and 2 in the clinical failures) in ASAQ group. In the AL group, of the 18 failures, 11 were anemic on day 0 and this number came down to 8 on day 28, thus a recovery of 38.9%. Apparently, no recovery was noted in ASAQ group as similar number was anemic on day 0 and day 28 but in fact one of the anemic on day 0 recovered on day 28 while the second remained anemic and one participant who was not anemic on day 0 fell into anemic range on day 28. Of adequate clinical and parasitological response in the 0.5-14 year age band, 32.2% (29/90) remained anemic on day 28 in AL group compared to 39.47% (45/114) in ASAQ group.

Discussion     

This report is part of a study aiming at evaluating the efficacy and safety of first line therapies for uncomplicated malaria in Burkina Faso. This study has revealed that anemia has worsened by day 7 and that some participants with adequate clinical and parasitological responses were still anemic. Treatment with acts was often associated with anemia [11,12]. Anemia is common [14,15] and prevalent mostly in sub-Saharan Africa where infectious diseases and iron deficiency are frequent. Clinical malaria or asymptomatic parasite carriage still contributes to anemia in endemic countries of sub-Saharan Africa and despite vigorous and effective measures, the prevalence and incidence of malaria remain high especially in West Africa [16]. The consequence of Plasmodium falciparum invading red blood cells is the infection the lysis and the depletion of Red Blood Cells (RBC) stock stock and subsequently the drop in the related hemoglobin parameter. The contributing role of malaria to anemia is a function of the incidence level but also the parasite density. The study sites were in malaria endemic setting where asymptomatic carriage of parasites is common and the tolerance to the infection up to even high parasitemia exist. In this study, the proportion of anemic patient continued to increase by day 7 and is consistent with previous report [15-17]. The underlying mechanism is not fully understood, but this period of time (day 0-7) is in relation with the continued destruction of already infected RBC even though antimalarial drugs were effective. This study is limited as we did not investigate the other specific causes of anemia however this report has the merit to highlight the frequency of anemia in endemic countries and the trend of the hemoglobin change over time during the follow up period.

Conclusion     

Treatment of uncomplicated malaria with first line therapies has proven to impact the anemia status of participants presenting with malaria, even though, anemia persisted in cured participants at the end of the follow up. This report pointed out first that patients are particularly at risk in the first seven days following the initiation of the treatment; while parasite load is decreasing, anemia got worse. Secondly to confirm that anemia goes beyond malaria and as we progress toward its control, integrated efforts are needed to bring anemia under control.

Competing interests     

The authors declare no competing interests.

Authors' contributions     

IZ contributed to the study design and wrote the first draft of the manuscript, YDC, GO, FN, FAS contributed to data acquisition, interpreted the results, critically reviewed the manuscript and approved the final version, JBO contributed to the study design and critically reviewed the manuscript and approved the final version. All the authors have read and agreed to the final manuscript

Acknowledgments     

This research was conducted as part of the routine national malaria control program monitoring and evaluation of first line therapies efficacy. We thank the nurses and the laboratory technicians who collected the data. We thank also the administration of the health district and health facility of Colsama and Sakaby for their strong collaboration. We are grateful for all parents and children who participated in this study.

Tables     

Table 1: baseline characteristics

Table 2: hemoglobin changes over study follow period

Table 3: severity grading of anemia in children 0-14 years

Table 4: severity grading of anemia in adult (15 years and over)

Table 5: list of participants who fell into severe grade on day 7 and emerged on day 28

References