Malaria is preventable and treatable when recommended interventions are properly implemented. Thus, diagnosis and treatment focus on. Children with severe malaria frequently develop one or more of the following symptoms: severe anemia, respiratory distress in relation to metabolic acidosis. Therefore, this study investigated the relationship between asymptomatic malaria , growth status, and the prevalence of anaemia among children aged
Beside the role of the antibodies that are specific to malarial antigens and are exported to erythrocyte membranes, the potential role of the erythrocyte-targeted auto-antibodies and that of complement activation and cytokine imbalances are associated with an increased anaemia severity in children with malaria.
Moreover, recent studies show that hepcidin, a amino-acid protein produced in the liver, is associated with the anaemia of inflammation in humans, where its production is increased fold, resulting in both an impaired iron uptake in the gut and iron sequestration in macrophages GanzMeans The presence of Hz in the cytoplasm of polymorphonuclear leukocytes and monocytes appears to be associated with the severity of the malarial infection, as it seems that cytoplasmic Hz is more frequently found in the complicated malaria cases than in the uncomplicated cases Nguyen et al.
Malaria-related anaemia: a Latin American perspective
Experimental animal models of malarial anaemia - In-depth haematological studies in humans with malarial anaemia pose a number of ethical and technical challenges that preclude invasive procedures, particularly BM analyses over the course of the infection.
The development of experimental animal models is therefore critical for understanding the mechanisms involved in the pathogenesis of severe anaemia. Although some molecular bases of malarial anaemia could be shared by several Plasmodium species, experimental evidence suggests that species-specific factors play significant roles. For example, a larger proportion of the non-infected RBCs are removed by erythrophagocytosis in P. Four rodent malaria parasite species Plasmodium berghei, Plasmodium chabaudi, Plasmodium vinckei and Plasmodium yoeliihave been extensively used to study malaria pathogenesis, including anaemia, due to their distinctive erythrocyte invasion profiles, which are similar to those observed with human parasites Lamb et al.
The relationship between anaemia and malaria: apparently simple, yet controversial.
However, several features, such as anaemia in the presence of hyperparasitaemia and extramedullar erythropoiesis, which are frequently observed in rodents, are rare events in human malarial infections Silverman et al. Anaemia research in rodent models allows immunological studies and manipulations that are more difficult in other animal models, such as primates. Non-human primate models appear to be more relevant in LA, due to their abundance in the region and the availability of several primate colonies.
New World monkeys Aotus and Saimiri have been used extensively for vaccine trials and drug testing using P. Malaria semi-immune Aotus monkeys immunised with merozoite vaccine candidates or exposed to P. In this experimental model, low Hb levels were associated with low reticulocyte counts, suggesting that the ineffective erythropoiesis and removal of non-infected erythrocytes are at least part of the aetiological factors involved Egan et al.
Aotus monkeys that self-control parasite patency or that received anti-malaria treatment exhibited a robust reticulocytosis, indicating a direct effect of the parasite on erythroid progenitors.
Anemia due to Malaria
Interestingly, immunisation of Aotus monkeys with the P. Aotus also appears to be a good model to study the role of hepcidin homeostasis.
Although little is known about the relationship between hepcidin and malarial anaemia, one study developed in Colombia with the Aotus model showed that hepcidin levels decreased throughout the experiment in malaria and mock-infected animals Llanos Regardless of this finding, it remains an area for further research.
Methodologies have been implemented to study the BM compartment in Aotus monkeys experimentally infected with P. Interestingly, on-going studies have confirmed that high numbers of normoblasts are present in BM aspirates, suggesting that erythropoiesis is effective unpublished data Llanos However, the molecular mechanisms involved in severe anaemia in semi-immune Aotus monkeys remain unknown Egan et al. Plasmodium coatneyi and Plasmodium fragile share with P.
Therefore, these parasite species mimic clinical complications of cerebral malaria associated with P. Plasmodium cynomolgi is phylogenetically related to P. The patterns of relapses described in P. Comparative experiments using P. Unfortunately, such studies are restricted to primate centres outside LA. Conclusions and perspectives - Beside the acknowledged importance of anaemia as a cause of morbidity and mortality in Africa and other endemic regions, little is known about its prevalence and burden in the malaria-endemic regions of LA.
The few studies reported from this region appear to indicate that the incidence of severe anaemia is significantly lower than that reported from Africa or Asia.
However, considering that specific haematological changes associated with malaria infection may vary with the level of malaria endemicity Idro et al. The Centre aims, as a priority, to determine the prevalence and severity of haematological manifestations attributable to malaria infection and their association with concomitant immune status, including nutritional factors and hel-minth coinfection.
Although studies would initially cover only Colombia, Panama, Peru and Guatemala, further expansion of malaria research, including anaemia, would be extended to other countries of LA, to the Caribbean region and Brazil. These multi-country regional projects will allow the comparison of pathologies in settings with different malaria transmission intensities in communities with great ethnic, occupational and immune diversities.
Moreover, the availability of the Aotus monkey animal model in several countries of the LA region represents a valuable resource to address important questions regarding malaria pathogenesis that cannot be studied in the human populations.
Indeed, the accessibility to BM aspirates of non-human primates vaccinated with human malaria vaccine candidates opens an interesting new area of research to complement the analyses of the influences of specific antimalarial immune responses in the generation of anaemia.
The anaemia of P. Br J Haematol A study of erythroid progenitor cells in the bone marrow of Gambian children with falciparum malaria. Clin Lab Haematol The deoxyuridine suppression test in severe anaemia following Plasmodium falciparum malaria. Distinct patterns of cytokine regulation in discrete clinical forms of Plasmodium falciparum malaria.
Eur Cytokine Netw Anemia and malaria at different altitudes in the western highlands of Kenya. FY polymorphisms and vivax malaria in inhabitants of Amazonas State, Brazil.
Severe Plasmodium vivax malaria, Brazilian Amazon. Emerg Infect Dis Intraleucocytic malaria pigment and clinical severity of malaria in children. Severe Plasmodium vivax malaria exhibits marked inflammatory imbalance. Dynamics of malaria drug resistance patterns in the Amazon Basin region following changes in Peruvian national treatment policy for uncomplicated malaria. Antimicrob Agents Chemother Demographic risk factors for severe and fatal vivax and falciparum malaria among hospital admissions in northeastern Indonesian Papua.
Am J Trop Med Hyg Manejo en UCI de la malaria falciparum severa y complicada. Bol Soc Peru Med Interna Glutathione reductase activity and its relation with riboflavin levels measured by methemoglobin reduction by cystamine in patients with malaria preliminary report. Ann Saudi Med Cellular and molecular mechanisms of senescent erythrocyte phagocytosis by macrophages.
Comparative hematologic analysis of uncomplicated malaria in uniquely different regions of unstable transmission in Brazil and Colombia. Relation between vitamin B12 and folate status and hemoglobin concentration and parasitemia during acute malaria infections in Colombia. The course of anaemia after the treatment of acute, falciparum malaria. Ann Trop Med Parasitol Anemia in a population from an endemic area of malaria, Rondonia Brazil. Rev Saude Publica Anaemia, iron deficiency and malaria in a rural community in Brazilian Amazon.
Eur J Clin Nutr Vivax malaria in children: Clinica de la malaria complicada debida a P. Estudio de casos y controles en Tumaco y Turbo Colombia. Impact of malaria during pregnancy in the Amazon Region. Rev Panam Salud Publica Malaria, uncinariasis, nutricion y anemia en los tropicos.
Tumour necrosis factor may contribute to the anaemia of malaria by causing dyserythropoiesis and erythrophagocytosis. Simian malarias in man: South American monkeys in the development and testing of malarial vaccines - A review. Mem Inst Oswaldo Cruz 87 Suppl. A retrospective examination of anemia during infection of humans with Plasmodium vivax. Origin and dissemination across the Colombian Andes mountain range of sulfadoxine-pyrimethamine resistance in Plasmodium falciparum. Origin and dissemination of Plasmodium falciparum drug-resistance mutations in South America.
J Infect Dis Anaemia in acute, Plasmodium falciparum malaria in children from Orissa state, India. Plasmodium coatneyi in the rhesus monkey Macaca mulatta as a model of malaria in pregnancy. A Phase II clinical trial of mefloquine in Brazilian male subjects. Bull World Health Organ Risk factors for malaria infection and anemia for pregnant women in the Sahel area of Bandiagara, Mali. Ineffective erythropoiesis in acute human P.
Clinical and laboratory findings of Plasmodium vivax malaria in Colombia, Aotus New World monkeys: Blood transfusion for severe anaemia in children in a Kenyan hospital. The effect of malarial infection on maternal-fetal outcome in Ecuador. J Matern Fetal Neonatal Med The prevalence and relationships of malaria, anemia and malnutrition in a coastal area of El Salvador. Similar cytokine responses and degrees of anemia in patients with Plasmodium falciparum and Plasmodium vivax infections in the Brazilian Amazon Region.
Clin Vaccine Immunol Rev Med Hondur Anemia and iron deficiency in school children, adolescents and adults: Am J Public Health Malaria and nutritional status among pre-school children: A nonhuman primate model for human cerebral malaria: A reticulocyte-binding protein complex of Plasmodium vivax merozoites.
Hepcidin, a key regulator of iron metabolism and mediator of anemia of inflammation. Prevalence of anemia and deficiencies of iron, folic acid and vitamin B12 in an indigenous community from the Venezuelan Amazon with a high incidence of malaria. Arch Latinoam Nutr Plasmodium vivax and mixed infections are associated with severe malaria in children: Acta Med Col Malaria-related maternal morbidity in urban Mozambique.
Anaemia and malaria in Yanomami communities with differing access to healthcare. The limits and intensity of Plasmodium falciparum transmission: The international limits and population at risk of Plasmodium vivax transmission in Overview of malaria control in the Americas. Anticuerpos antifosfolipidos en malaria. Med Interna Caracas From malaria to chemokine receptor: Age, temperature and parasitaemia predict chloroquine treatment failure and anaemia in children with uncomplicated Plasmodium falciparum malaria.
- The relationship between anaemia and malaria: apparently simple, yet controversial.
- There was a problem providing the content you requested
Int J Parasitol Severe malaria in children in areas with low, moderate and high transmission intensity in Uganda. Severe MA is one of the main clinical presentations of severe malaria caused by P.
The aetiology of severe MA in malaria endemic areas may include a number of discrete as well as overlapping features, such as lysis of infected and uninfected RBCs [ 13 ], splenic sequestration of RBCs [ 14 ], dyserythropoiesis and bone marrow suppression [ 15 ], infectious diseases, and chronic transmission of malaria. While haematological insults resulting in moderate and severe anaemia in infection with Plasmodium falciparum have been established [ 16 ], the exact differences in the pathophysiology of anaemia in the various clinical settings, ages, and geographic areas are poorly defined [ 17 ].
In children presenting at a hospital in western Kenya, wasting was associated with increased presentation of MA. In addition the caretakers level of education and occupation significantly correlated with anaemia and MA [ 12 ]. On the other hand, hospital based studies in the Mount Cameroon area indicated severe MA as the main clinical presentation of severe malaria but did not examine sociodemographic or nutritional factors associated with the presentation [ 2 ].
Hence, assessing the influence of some sociodemographic and nutritional indices on the prevalence of MdSA and MA in children will provide valuable information to the health authorities. This will enable informed decision and the appropriate allocation of scarce resources for proper child health management and control of these morbidities.
This study was undertaken to explore the hypothesis that sociodemographic factors and nutritional indices influence the presentation of children in the outpatient department with MdSA and MdSMA. The objectives of the study therefore were to determine the prevalence of falciparum malaria, MA, MdSA, and MdSMA in children at presentation for consultation in general medical outpatient department, evaluate the attributable risk of anaemia caused by malaria, and assess the variation in haematological indices in moderate to severe anaemic and malarial anaemic children.
Materials and Methods 2. Buea has an estimated population of above There are two seasons, the rainy and the dry seasons, which start from mid-March to October and November to mid-March, respectively. The prevalence of malaria parasitaemia in the Mount Cameroon area varies from Study Population The study population included children of both sexes aged 1—14 years, who presented themselves at the Regional Hospital Annex-Buea for consultation during the period of study.
Children who participated in the study came from various localities and altitudes. The altitude was classified as lowland 0— m aslmiddle belt — m asland highland — m asl as reported by Kimbi et al. For the purpose of comparability, patients with a history of antimalarial treatment in the preceding two weeks or who had a blood transfusion three months prior to the start of study or had haemoglobin genotype SS were not enrolled in the study.
Study Design This cross-sectional hospital based study was carried out during the peak malaria transmission season from the month of May to Augustin the Regional Hospital Annex-Buea.
Blood sample was collected from each child for determination of malaria parasite status and full blood count evaluation. The optimum sample size was calculated using the prevalence of P. The sample size was determined using the formula represented the sample size required; was 1. The optimum sample size obtained from the average of both sample sizes was Emphasis was laid on the voluntary participation of the children in the study and on the point that their refusal to participate in the study will in no way affect the treatment quality the children were to receive.
Clinical Evaluation For each child a general clinical evaluation was carried out by the medical personnel in charge. Symptoms and the duration of the symptoms were recorded. Anthropometric parameters such as height and weight were measured using a measuring tape and a weighing scale, respectively. Questionnaire A structured questionnaire was administered to parent or guardian of the child in order to obtain information on demography, socioeconomic status SEStype of accommodation, health-seeking behaviour, access to health facilities, malaria control measures, knowledge on the signs of anaemia, and feeding practices.
The socioeconomic status was classified as poor, average, and rich as described by Kimbi et al. Laboratory Methods Venous blood samples about 4 mL were collected using sterile disposable syringes from children whose parent or guardian signed the assent forms. Thin and thick blood films were prepared and the remaining blood sample dispensed into labelled ethylenediaminetetraacetate EDTA tubes.
The thick and thin blood films prepared on glass slides at the time of blood sampling were stained with Giemsa and examined following standard protocols [ 24 ]. If gametocytes were seen, the count was extended to leukocytes [ 25 ]. Malarial anaemia MA was defined as children with a malaria-positive smear for P.
Continuous variables were summarized into means and standard deviations and categorical variables reported as frequencies and percentages were used to evaluate the descriptive statistics. Parasite density was log transformed before analysis. A multinomial logistic regression model analysis was conducted to evaluate potential determinants of MdSA and MdSMA with age, sex, SES, level of education, altitude, fever, and nutritional status as independent variables.
The odd ratios OR computed was used to evaluate the risk factors. Characteristics of Participants The consent of children at presentation to the general outpatient department in the Regional Hospital Annex-Buea was sought for their participation in the study of the burden of malaria, MdSA, and MdSMA.
As revealed in Table 1 Majority of the children resided in the middle belt The proportion of mosquito bed net MBN use in the studied population was Sociodemographic, altitude, and clinical characteristics of the participants by age and sex. Fever, splenomegaly, malarial anaemia, and malnutrition were observed in The prevalence of anaemia in the studied population was The difference was statistically significant.
Wasting occurred in 6. While the prevalence of wasting was significantly higher in females Falciparum Malaria Plasmodium falciparum occurred in The prevalence of malaria was highest in patients from the lowland A greater proportion of the children had high parasite densities In addition, the prevalence of malaria was significantly higherin children with fever On the other hand, the high prevalence of malaria observed in malnourished children Prevalence of malaria parasite as affected by the status of fever, malnutrition, and splenomegaly.
Monthly Prevalence The prevalence of fever was highest in the month of July However, only the monthly difference in prevalence of MA was statistically significant. Monthly prevalence of fever, malaria parasite, anaemia, and malarial anaemia during the study period. The prevalence of anaemia as influenced by the morbid state is shown in Figure 4. Children with both fever and detectable malaria parasitaemia had a higher prevalence of anaemia Prevalence of anaemia as affected by malaria parasite and fever status.
Prevalence of anaemia as influenced by morbidity status. Moderate to Severe Anaemia and Malarial Anaemia Mild, moderate, and severe anaemia were prevalent in While the prevalence of MdSA and MdSMA was comparable amongst age group, gender, SES, family size, splenic, and nutritional status, and statistically significant differences were observed with the level of education of head of householdaltitude of residenceand fever status and as shown in Table 2.
Explicitly, in comparison with their contemporaries, the prevalence of MdSA was significantly higher in children who came from homes where the head of household had no formal education On the other hand, MdSMA was significantly higher in children who had fever only The multinomial logistic regression model demonstrated that the altitude, more specifically the lowlandand being febrile were significant predictors of MdSA, while being febrile was the only significant factor associated with MdSMA as shown in Table 3.
On the other hand, the AR of moderate to severe anaemia caused by malaria was 9. In addition, the AR of moderate to severe anaemia due to malaria was higher in children of the 11—14 years age group A nonsignificant negative trend was observed between platelet count and malaria parasitaemia.
Discussion This cross-sectional study examines P. The overall malaria parasite prevalence of