Plasmodium and Schistosoma haematobium infections as well as haematological parameters in school-aged children in Muyuka-Cameroon: a cross-sectional study on the influence of nutritional status


 Background: School-aged children (SAC) are a high-risk demographic group for infectious diseases and malnutrition. The objective of this study was to assess the burden and the effect of Plasmodium and Schistosoma haematobium infections on the haematological indices in SAC and the confounding influence of malnutrition on the outcomes.Methods: This cross-sectional study was conducted in SAC 4-14 years old living in Ikata, Bafia and Mile 14-Likoko in Muyuka-Cameroon. Anthropometric measures of malnutrition (z-scores < −2 standard deviations below mean) were obtained and blood samples collected were used for detection of malaria parasites by Giemsa-stained blood films using light microscopy and complete blood count analysis using an automated haematology analyser. Urine samples collected were used to detect micro haematuria with the aid of reagent strips and the eggs of S. haematobium by urine filtration technique. Multiple linear regression model was used to examine influence of independent variables on haematological parameters.Results: Out of the 606 SAC examined, the prevalence of single infections with Plasmodium or S. haematobium and co-infection with both parasites was 16.2%, 16.3% and 8.3%, respectively. Overall, malaria parasite (MP), urogenital schistosomiasis, malnutrition, anaemia, haematuria, microcytosis and thrombocytopenia was prevalent in 24.4%, 24.6%, 25.9%, 74.4%, 12.2%, 45.4% and 11.1% of SAC, respectively. A significant linear decline (P = 0.023) in prevalence of P. falciparum infection with the severity of stunting was observed. Factors that significantly (P<0.005) influenced haematological parameters included; haemoglobin: age, stunting and MP; haematocrit: age and MP; white blood cell count: age; red blood cell count; age and MP; lymphocyte counts: stunting; MCV: age; MCH: age and stunting; MCHC: sex, stunting and RDW-CV: sex, age and stunting.Conclusions: Plasmodium and S. haematobium are of public health concern in Muyuka-Cameroon and requires expansion of the existing control measures. Malnutrition, microcytosis and thrombocytopenia are common, and anaemia is a severe public health problem in the community. The interaction between haemoglobin level with malaria parasites, S. haematobium as well as the linear growth index is negative and other interactions indicate systemic inflammation. Hence, the need for regular monitoring to improve the health status of the children.


Background
Malaria caused by protozoan parasites such as Plasmodium falciparum and urogenital schistosomiasis (US) caused by the trematode helminth Schistosoma haematobium impose tremendous public health burdens in tropical and subtropical countries. Both diseases have been associated with poverty and factors such as low socio-economic status, poor sanitation, limited access to safe water, poor education and awareness play a key role in their transmission [1,2,3].
Beyond the pre-school years, school-aged children (SAC) are a high-risk demographic group for infectious diseases and malnutrition. Malaria whose symptoms and signs (anaemia, fever, headaches, vomiting, nausea, abdominal pain, inappetence, bitter mouth, dizziness, and weakness) may be more subtle in partially immune children, is increasingly an important challenge in SAC even though they have attracted relatively little attention as a group in need of special protection measures [4,5]. Previous studies have underappreciated the burden amongst whom the prevalence of infection is habitually higher than that among children less than 5 years old and adults [6,7,8]. Following the scale-up of treated bed nets across the country between 2000 and 2015, a signi cant decrease in the prevalence of malaria cases from 41% to 24.3% was reported in Cameroon [9]. With the changing dynamics of malaria transmission and infection due to interventions which include case management using Artemisinin Combination Therapy (ACT) drugs and vector control through the large-scale distribution of Long-Lasting Impregnated Net (LLINs), monitoring the changes in morbidity in this age group is invaluable.
Like most Neglected Tropical Diseases (NTD) schistosomiasis is a chronic and debilitating illness with the ability to affect child development and productivity. Children aged 5-17 years in developing countries are at highest risk of infection and are the most infected group. Schistosomiasis is likely to cause anaemia, stunting and a reduced ability to learn although, the effects are usually reversible with treatment [10,11,12]. In Cameroon, rural areas are the most affected with the emergence of urban urogenital schistosomiasis in the Mount Cameroon area in Tiko Health District, which can be attributed to the migration of individuals from the con ict hit areas of Kumba, Munyenge and Kotto-Barombi [13]. The prevalence of S. haematobium in the Mount Cameroon area ranges from 25.4%-40.27% although, the annual mass drug administration (MDA) campaigns control strategy in SAC has considerably reduced the egg-patent prevalence of the disease [14,15,16,17]. However, after several rounds of localized MDA campaigns and the fact that transmission dynamics and re-infection patterns post-treatment are complex [18], monitoring the variation of intensity of infection and associated morbidity is crucial in ascertaining the impact of control measures.
Since SAC are often under-represented in community-based cluster surveys, malaria and US burden in this group is poorly de ned. Hence, the objective of this study was to assess the burden and the in uence of infections with P. falciparum and S. haematobium on haematological parameters in SAC and the confounding in uence of malnutrition on the outcomes in order to provide an insight on morbidities associated with co-infections in areas with ongoing interventions in place. The ndings will provide contextual intervention targets in the community to ensure the judicious use of the limited resources in improving the health of the underserved population.

Study area and participants
The study was carried out in the schistosomiasis endemic foci of Ikata, Ba a and Mile 14-Likoko which are three rural localities in the Muyuka Health District. The study sites have been described in detailed by Ebai et al. [19]. Environmental and socio-economic conditions in these areas favour the thriving of the vectors and the transmission of these parasites.
A prevalence of malaria parasite (MP) of 35.5% and US of 34.3% was reported in the area in a study of a cross section of the population [7,14]. Intervention measures in the area include but are not limited to the free distribution of LLINs to pregnant women and children and the mass distribution of mebendazole by the Ministry of Public Health in Cameroon to SAC in schools.
This study was conducted among SAC aged 4-14years of both sexes whose parents consented to their participation in the study. As an inclusion criterion, only children who had resided for at least three months in the study area were enrolled in the study and their participation in the study was voluntary.

Study design, sample size estimation and sampling
This cross-sectional study was carried out between March to June 2015 to coincide with the malaria and schistosomiasis transmission season. This was a repeated cross-sectional study following intervention studies in the previous transmission season [7,14]. The sample size was determined using the formula n = Z 2 pq/d 2 [20], where n was the sample size required; Z was 1.96, which is the standard normal deviate (for a 95% con dence interval, CI); p was 35.3% or 34.3%, the proportion of malaria parasite or US prevalence reported previously in the area [7,14]; q was 1-p, the proportion of MP or US negative; and d was 0.05, the acceptable error willing to be committed. The optimum sample size was estimated to be 349 (359.5+346.3/2). To mitigate against possible loss of samples due to blood clotting and withdrawal from the study, the sample size was increased by 15% for a minimum of 401 SAC. A representative sample from each primary school and study site was obtained by selecting participants via random ballot from each class list.

Implementation of study
The inhabitants were educated on the importance, bene ts and protocol of the study in several reconnaissance visits made to the localities prior to the commencement of the study. Children who presented signed consent forms were enrolled into the study and information on both demography and factors that may be associated with malaria and US were obtained through an interview using a simple structured questionnaire. Clinical evaluation was carried out subsequently where weight, height and temperature were measured. The study involved the collection of venous blood and urine sample for haematological analysis, and microscopic detection of S. haematobium eggs, respectively. Labelled blood and urine samples placed on ice blocks were transported to the University of Buea Malaria Research Laboratory for further analysis.

Questionnaire administration and clinical evaluation
A pre-tested questionnaire was administered to each participant with the aid of the teachers to obtain information on demography, hygienic practices, possible risk factors of Plasmodium and helminth infections as well as malnutrition and anaemia. The ages of participants were obtained from the school register.
The axillary temperature was measured using a digital thermometer and a participant with body temperature ≥37.5°C was considered febrile.
Height was measured to the nearest 0.1cm using a graduated ruler of length 2m. Body mass was measured to the nearest 0.5 Kg using a mechanical scale of capacity 120 Kg (KINLEE® model BR9310), and upper arm circumference was measured to the nearest 0.1cm using a graduated tape. These measurements were used to calculate an array of anthropometric indices used as proxies for malnutrition: weight-for-age (WA: under-weight); height-for-age (HA: stunting); weight-for height (WH: wasting). Anthropometric indices were computed as z-scores based on the WHO growth reference curves using the WHO AnthroPlus for personal computers manual [21]. A child was identi ed as being malnourished if he or she scored < −2 in one of the anthropometric indices. A z-score between < -2 and ≤ -3 was considered as moderate wasting, moderate stunting or moderate underweight while Z scores of < − 3 indicated severe wasting, severe stunting or severe underweight [22].

Malaria parasite diagnosis and full blood count
From each participant, approximately 2ml of venous blood was collected in ethylenediamine tetra-acetate tubes for malaria parasite detection and haematological analysis. Thick and thin blood lms were prepared in situ. The thin blood lms were xed in absolute methanol and together with the thick blood lms were Giemsa stained and examined microscopically following standard procedures [23]. Slides were considered positive when asexual forms and/or gametocytes of any Plasmodium species were observed on the blood lm. All the slides were read twice by two independent microscopists. Malaria parasite per µL of blood was established by counting the number of parasites per 200 leukocytes and multiplying by the persons white blood cell (WBC) count. Parasitaemia was classi ed as low (≤ 500 parasite /µL of blood), moderate (501-5000 parasites/µL of blood) and high (>5000 parasites/µL of blood) [24].
A complete blood count analysis was done using a Beckman coulter counter (URIT 3300) which automatically gave values for red blood cell (RBC), WBC and platelet counts, haemoglobin (Hb), haematocrit (Hct), mean cell volume (MCV), mean cell haemoglobin (MCH), mean cell haemoglobin concentration (MCHC) and red cell distribution width-coe cient of variation (RDW-CV) following the manufacturer's instructions. The classi cation of anaemia (Hb concentration below the WHO reference values for age or gender) and its severity was done in accordance with WHO standards (mild anaemia = 10-10.9 g/dL, moderate anaemia = 7-9.9 g/dL and severe anaemia < 7 g/dL) [23,25].
Urine analysis for haematuria and schistosome eggs Each study participant collected approximately 25 mL of midstream urine into a screw cap vials after a brisk exercise between 10am and 2pm. Gross haematuria was determined by visual observation while micro haematuria was determined with the aid of reagent strips (combistix) following the manufacturer's guide (CYBOW TM 11M a series of Health Mate Ref 0974). Eggs of S. haematobium were detected using the urine ltration technique. Following agitation, 10 mL of urine was drawn using a syringe and ltered through a polycarbonate membrane lter (STERLITECH corporation, USA). The lter membrane was examined microscopically for the presence of S. haematobium eggs as described by Cheesbrough [23]. Schistosome egg density was expressed as the number of eggs in 10 mL urine (e/10 mL) and the intensity of infection was categorised as either light (< 50 e/10 mL) or heavy infection (≥ 50 e/10 mL) [26,27].

Data analysis
Descriptive measures such as the mean and standard deviation (SD), geometric means, frequencies, and proportions were used to summarize data. Differences in proportions between populations were compared using Chi (χ 2 ) test. The attributable risk (AR%) of anaemia caused by malaria, US and stunting was calculated accordingly [28]:

Ethical considerations
The study protocol was reviewed and approved by the Institutional Ethical Review Board hosted by the Faculty of Health Sciences, University of Buea following administrative authorisation from the Regional Delegation of Public Health and Basic Education. The ethical approval reference for the study is 2014/243/UB/FHS/IRB. The study was conducted in accordance with the World Medical Association (WMA) principles as stated in the Declaration of Helsinki. The population was sensitized in their various communities at the beginning of the study. Written informed consent was obtained from all parents/caregivers whose child/children participated in the study after explaining the purpose and bene ts of their participation. Participation was totally voluntary, and a participant could decide to halt their participation in the study at any time without any penalty. Participants who had malaria and or helminths were given rst line treatment as recommended by the national treatment guideline policy for uncomplicated malaria and helminths.

Characteristics of participants
The characteristics of the 606 SAC examined is presented in Table 1. The mean (SD) age of the study participant was 8.94 (2.1) years with no signi cant difference between sex and age. The majority (59.2%) of the SAC were enrolled from the Likoko locality. Clinical pro le of the participants revealed a prevalence of anaemia, malaria parasite, US, haematuria, microcytosis and thrombocytopenia of 74.4%, 24.4%, 24.6%, 12.2%, 45.4% and 11.1%, respectively. While no signi cant difference in prevalence of malaria parasite was observed with sex and age, signi cantly higher prevalence of anaemia was observed in children 4-9 years old (78.5%), US and haematuria in females (28.6%, 14.9%) and thrombocytopenia in those 4-9 years old (13.4%) than their respective contemporaries. The prevalence of microcytosis was signi cantly higher in males (50.7%) and children 4-9years (51.7%). Likewise, the prevalence of malnutrition (25.9%) and its forms such as underweight (6.6%) and stunting (22.9%) varied signi cantly with sex and age with a higher prevalence observed in males and children 10-14 years as shown in Table 1.

Prevalence of single and co-infection
The prevalence of single infection with P. falciparum or S. haematobium and co-infection with both parasites was 16.2%, 16.3% and 8.3%, respectively, with no signi cant variation with sex and age. Signi cantly higher (P< 0.001; P < 0.001 and P = 0.001) prevalence of single infection with S. haematobium (25.9%) and co-infection with P. falciparum and S. haematobium (13.4%) were observed in SAC from the Likoko locality while single P. falciparum infection was observed in Ikata (20.9%), respectively. The higher prevalence observed in the anaemics was not statistically signi cant when compared with their counterparts as shown in Table 2. The prevalence of P. falciparum and S. haematobium was lower in children who presented with fever contrary to the signi cantly higher (P = 0.008) prevalence of co-infection observed in those with fever (13.8%). With regard to malnutrition and its forms, the prevalence of S. haematobium and coinfection was comparable among the different groups unlike that of P. falciparum. The prevalence of P. falciparum was signi cantly lower (P = 0.018, P = 0.006) in those malnourished (10.2%) or the stunted (8.6%) than those normal respectively ( Table 2). Observation from the study demonstrated a signi cant linear decline (χ 2 = 7.516, P = 0.023) in prevalence of P. falciparum infection with the severity of stunting with those normal having the highest prevalence (18.4%) while those with severe stunting had the least (6.5%). No signi cant trend in the prevalence of S. haematobium and co-infection was observed with the severity of stunting even though the prevalence was lowest in those with severe stunting (12.9% and 3.2% respectively) as revealed in Fig.1.
Plasmodium falciparum parasitaemia ranged from 71-33250 parasites /µL of blood while S. haematobium eggs /10 mL of urine ranged from 1-494. Although males, children 4-9 years, the malnourished and those with severe stunting had a higher P. falciparum GMPD/ µL of blood the differences were not statistically signi cant. A similar pattern in the distribution of S. haematobium GMED was observed except for sex with females having a higher GMED (26 eggs/10 mL of urine) than males (20 eggs/10 mL of urine) as shown in Table 3. Of the 148 SAC infected with P. falciparum, the majority (n = 74, 50%) had low parasite density. As shown in Fig. 3 (a), the prevalence of low, moderate and high P. falciparum density was 12.2%, 10.6% and 1.7% respectively and this was lower in malnourished than well-nourished children. In addition, the prevalence of low and moderate P. falciparum density decreased with the severity of stunting. With respect to S. haematobium, the prevalence of low and high egg density was respectively 16.3% and 8.3% and, a comparison with the nutritional status showed no signi cant differences with the severity of stunting ( Fig. 3 (b)).

Effect on haematological parameters
Anaemia was common in the study population (74.  ( Table 4). lymphocyte counts: stunting (P = 0.015); MCV: age (P < 0.001); MCH: age (P < 0.001) and stunting (P = 0.001); MCHC: sex (P = 0.046) and stunting (P = 0.004) and RDW-CV: sex (P < 0.001), age (P = 0.001) and stunting (P = 0.023) as shown in Table 5.  [29] and the persistent transmission of schistosomiasis despite MDA and the burden of schistosomiasis in SAC [15]. In the present study we assessed the burden and in uence of these infections on haematological indices in SAC and the confounding in uence of malnutrition on the outcomes in an attempt to provide some insight on the morbidities associated with co-infections in areas of ongoing intervention strategies.
Findings from the study revealed similar prevalence of both Plasmodium and S. haematobium with most infections being single, light and asymptomatic. A drop in prevalence was observed when compared with ndings of studies carried out in the general population in the same area a year earlier [7,14]. However, in schistosomiasis endemic areas, the outcome of infection with Plasmodium is of growing concern. The prevalence of Plasmodium (24.4%) is lower than the 33.9% observed in a simultaneous study in SAC in non-schistosomiasis endemic area within the same Muyuka Health District [30]. These ndings are, however, comparable with a 26.8% and 27.4% prevalence observed in similar populations in schistosomiasis endemic areas in the West Region of Cameroon [31] and North western Tanzania respectively [32]. While the decrease in the prevalence of infection in this cohort of children may be attributed to longlasting insecticide treated bed net use and its community bene t, although SAC have a propensity to use insecticide treated bed nets less frequently, it's use remains an effective method of malaria control [4,7]. Nonetheless, the interactions in epidemiology in schistosomiasis-endemic foci resulting in lower prevalence of Plasmodium infection when compared with non-endemic foci warrants further investigation.
Observations from the study revealed no signi cant differences in the prevalence of both Plasmodium and S. haematobium with age. On the other hand, urogenital schistosomiasis was more common in females with haematuria being a common manifestation consistent with other studies [33,34]. This higher prevalence in females is consistent with observations made by Noriodea et al. [35] in Nigeria but contrasts those of Mewabo et al. [34] and Njunda et al. [36] in Cameroon and Abdulkareem et al. [37] in Nigeria. Although a higher prevalence of urogenital schistosomiasis in females may be attributed to their higher frequency of contact with infested water, for peri domestic activities, it is worth noting that limited access to safe water and sanitation conditions are implicated in the transmission of both Plasmodium and S. haematobium infections [2,3].
The prevalence of Plasmodium and S. haematobium co-infection in SAC (8.3%) is similar to that reported in Gabon [38], higher in Ghana [39] and lower when compared with some areas in Nigeria [40]. Ikata, Ba a and Mile 14-Likoko in Muyuka-Cameroon are S. haematobium endemic areas due to the presence of an e cient Bulinus snail vector and the use of untreated waterways for domestic, farming and recreational use. Risk of co-infection with Plasmodium in these areas is also high as these areas are part of the holoendemic stratum with high and perennial malaria parasite transmission [41]. Furthermore, environmental variants within the different localities maybe of signi cance accounting for the disproportionate distribution of infections in the localities with most of the co-infections observed in the Likoko locality.
Malnutrition prevalence, underweight and stunting varied signi cantly with sex and age with signi cantly higher occurrence of moderate and severe stunting in males and children 10-14 years. The prevalence of stunting is similar to that observed in SAC in Ghana [42], but higher than that observed in Northern Senegal [43] and in urban Cameroon [44].
The preponderance of linear growth retardation known as stunting in males has been well reported in Sub-Saharan Africa [45,46]. Of note is the lower prevalence of Plasmodium infection and higher GMPD/ µL of blood in those malnourished or stunted with signi cant linear decline in infections with the severity of stunting. Similarly, the lowest prevalence of S. haematobium and co-infections and higher GMED was observed in those with severe stunting. Despite the previous work by Olney et al. [47] which reported higher malaria parasite densities in children with lower height for age indices, Gari et al. [48] reported malaria as a risk factor for stunting although stunting was not associated with subsequent malaria illness. Stunting has been highlighted as a predictor of S. haematobium infection [42]. Whilst it is more likely that the severity of stunted malnutrition may have a negative in uence on parasite density since both infections are transitory and severe stunting is chronic and prolonged nutritional inadequacies are required for it to manifest.
The hallmarks of P. falciparum infection include haematological alterations of which anaemia is the most common [49,50] unlike in infections with S. haematobium and co-infections. The perpetual presence of anaemia in apparently healthy SAC negative for both infections with signi cantly higher occurrence in children 4-9 years old and those with coinfections necessitates caveat in attributing the causality of anaemia to these factors. Although the high prevalence of anaemia in those 4-9 years old could be linked to the high parasite densities of both P. falciparum and S. haematobium and microcytosis observed, the attributable risk of anaemia associated with these infections in the population remains low. Notwithstanding, ndings from the multivariate analysis asserts a negative interaction between haemoglobin level with malaria parasites and S. haematobium as well as the association between haemoglobin and linear growth index.
While anaemia is one of the markers of morbidity associated with schistosomiasis even though it may be masked by anaemia resulting from malaria [51], the prevalence of anaemia in children co-infected with P. falciparum and S. haematobium was very high. This prevalence is similar with those in children in Ethiopia [52] with moderate anaemia being the most common form. Although the aetiology of anaemia is multifactorial, both infections may contribute to anaemia separately or through an interaction effect [51]. Nevertheless, the mechanism of malaria mediated anaemia has been well explained [53,54] while anaemia by urogenital schistosomiasis may arise due to chronic blood loss as the egg penetrates the walls of the urinary tract, extra corporal loss of iron, autoimmune haemolysis and in ammation [55].
Findings from the study revealed that the mean Hct, WBC, lymphocyte and platelet counts, MCV, MCH, MCHC and RDW-CV were comparable amongst those infected with P. falciparum or S. haematobium or co-infection and those not infected. Infections with P. falciparum however, signi cantly lowered the Hb concentration and mean RBC counts. This effect is further bolstered by the signi cant association of P. falciparum with red cell indices including Hb, RBC and Hct in the multiple regression analysis. In line with ndings by Kotepui et al. [50,56], the negative association of P. falciparum infection with these red cell indices is not atypical and may be related to the enhanced destruction of infected and uninfected erythrocytes combined with decreased erythrocyte production leading to malaria related anaemia [57,58].
Observations from the study highlighted age as a signi cant factor in most of the haematological parameters evaluated while sex was found to be associated with MCHC and RDW-CV. Since haematological parameters are interrelated with each other as well as with sex and age, of signi cance is the intricate positive interaction between the anthropometric malnutrition proxies of height-for-age and haematological parameters including haemoglobin, lymphocyte, MCH, MCHC and RDW-CV. As noted in previous studies [59,60], the positive association suggests it is likely that the children suffer from chronic malnutrition (stunting) in addition to anaemia as well as systemic in ammation demonstrated by the relationship with lymphocytes and RDW-CV, an integrative measure of the pathological process. While a decrease in lymphocytes is implicated in infection with malaria parasite and anaemia, the biological function of different cell types including B lymphocytes has been reported to decrease during nutritional de ciencies [50,61,62,63]. Nonetheless, the comparability of stunting to the population attributable risk of anaemia due to malaria and urogenital schistosomiasis demonstrates the ability to which stunting can exacerbate anaemia observed in the children.
Other haematological abnormalities of signi cance observed in the study population included thrombocytopenia, and microcytosis which were higher in SAC 4-9 years old. Furthermore, a higher occurrence of microcytosis was observed in males than females. Thrombocytopenia is commonly found in individuals living in areas endemic for Schistosoma mansoni while, microcytosis and thrombocytopenia is common in individuals with malaria [64,65,66,67]. Its association in individuals with S. haematobium is, however, uncertain. Although the context of interpretation is limited to the few cases of thrombocytopenia observed, ndings from the study demonstrated no statistically signi cant association between platelet counts and parasite densities. It is worthy to note that children in the 4-9 years old age group had the highest parasite densities of both Plasmodium and S. haematobium. On the other hand, the high prevalence of microcytosis in the population may be attributed to the high prevalence of anaemia observed which is partly accounted for by the presence of the parasitic infections and chronic nutritional de ciencies.
The ndings of the study should be viewed in the context of the limitations of the cross-sectional nature of the design which did not provide the changes in the burden and morbidities following control measures that could have been captured in a longitudinal study. Hence, there is a need for further investigations to ascertain the causal relationship between enhanced control interventions and changes in demographic as well as clinical characteristics and burden in this at-risk group to formulate more appropriate public health interventions.

Conclusions
The similarities in the burden of infection with both Plasmodium falciparum and S. haematobium suggests that they are of public health concern in Muyuka-Cameroon and requires the expansion of the existing control measures to reach the vulnerable groups within the population. Malnutrition is common with a signi cantly higher occurrence of moderate and severe stunting in males and children 10-14 years old that likely had a negative in uence on parasite density in both infections. Anaemia is a severe public health problem in the community even amongst non-infected children, and other haematological abnormalities like microcytosis and thrombocytopenia are common. The interaction between haemoglobin level with malaria parasites, S. haematobium as well as the linear growth index was negative even though the attributable risk of anaemia associated with these conditions remains low in the population. Other positive interactions between the linear growth index and haematological parameters indicate the occurrence of chronic malnutrition in addition to anaemia as well systemic in ammation. Hence, there is a need for the regular monitoring of morbidities associated with parasitic infections and nutritional de ciencies to improve the overall health status of the children.

Consent for publication
Not applicable.

Availability of data and materials
All datasets generated and analysed in the current study are presented in the paper and supporting information le.
Competing interests IUNS was involved conceptualization, data curation, supervision, writing of original draft, review and editing of the manuscript; OVO, CBE TRN participated in methodology, laboratory analysis; LF participated in editing and revision of the manuscript; OSMB, HKK, TNA contributed in supervision, editing and revision of the manuscript. All authors read and approved the nal manuscript.