DE SILVA, SW2011-02-142011-02-1420012001DE SILVA, SW, A Study of the normal haematological indices and its variations in malaria in a Sri alankan population, University of Colombo UC(MED), 2001: 336p.http://imsear.searo.who.int/handle/123456789/129624Dissertation: M.Phil., University of Colombo: UC(MED), 2001.Malaria, is the world's second most important tropical parasitic disease, and kills more people than any other communicable disease. Malaria is endemic in the dry zone of Sri Lanka and is non endemic in the west zone and central hills of Sri Lanka. In malaria, anaemia is a common accompanying feature and it develops for to five days after the onset of symptoms. Many confounding factors for anaemia such as nutritional deficiencies, parasite infestations, infections, haemoglobinopathies and thalassaemias too are commonly seen in malaria endemic populations. The main objective of the study was to assess the normal haematological indices and its variations due to malaria in a malaria endemic and noneendemic population in Sri Lanka. The other objectives were to determine the proportion of anaemia caused purely by malaria, and by other aetiologies like iron , vitamin B12 an dfolate deficiency, contributing to the anaemia in this population; to characterize the anaemia due to malaria in an endemic population and a non endemic population; to characterize the anaemia in the acutely ill and the chronically ill malatia patients in endemic and non endemic areas and to assess if the anaemia correlated with the degree of severity of the illness; tp assess the degree of anaemia in malaria in relation to the type of Plasmodium parasite involved. A hospital and out patient clinic based descriptive cross sectional study was done on 256 malaria patients, and compared with an age, sex, and BMI comparable control population. The essential clinical, haematological and biochemical tests were performed and compared. In the present study, the nutritional status was considered using the hight, weight, body mass index, educational level and monthly income between the controls and malaria patients, and was found to be comparable (Tables 3.7 to 3.9). A subject deficient in iron/folate/vitamin B12 was supplemented with the deficient factors and assessed after one month. 131/256 (51.2 percent) of all malaria positive patients observed in this study were anaemic. 79/143 (55 percent) of P vivax malaria patients and 52/113 (46 percent) P falciparum positive malaria patients were anaemic. Among malaria patients 52/113 ( 46 percent) P falciparum positive malatia paients were anaemic. Among malaria patients 52/100 (52 percent) of the females and 79/156 51 percent) of the males were anaemic. There was no significant difference in the presence of anaemia between the male and female malaria patients in this study. When compairing the red cell indices between the anaemic malaria patients and controls from the endemic and non-endemic areas a significant depression in the red cell indices were seen confirming depression of erythroid bone marrow function. A significantly increased red cell distribution eidth indicats premature or early release of immature red cells to the circulation but the decreased reticulocyte count indicates a depressed response of the bone marrow to the decreased red cell mass. Comparing the white cell counts in malria patients a significant decrease was observed in the mean total white cell count, mean neutrophil count and the mean lymphocyte count confirming depression of granulopoiesis in the bone marrow in both P vivax and P falciparum malaria patients. Comparison of the platelet indices of malaria patients there was a statistically significant depression of the patelet count and platelectcrit in these patients when compared with the controls. Tjese results confirm that malaria causes depression of erythroid, myeloid and megakaryocyte cell lines in the bone marrow. Since the malaria parasite is an intra-erythrocytic parasite red cells haemolyse earlier than normal red cells, a certain degree of haemolysis is expected to accompany every infection. The degree of the breakdown of red cells is known to be greater in P falciparum malaria since plasmodia are known to attach to the vascular endothelium and multiple infection of each erythrocyte is common in P falciparum infection. However in this study almost the same proportion of anaemia was observed in patients affected with P vivax and P falciparum malaria, 79/143 (55 percent) P vivax malaria patients and 52/113 (46 percent) P falciparum malaria patients (Figure 3.2)(X2=0.045, P\>0.005). It is commonly believed that P falciparum malaria is the more severe form of disease. The present study confirms that P vivax malaria too causes almost the same debility as P falciparum malaria as evidenced by the comparison of clinical features and red cell indices in both groups of patients (Figures 3.3-3.4). The severity of anaemia due tomalaria too is comparable in P vivax and P falciparum malaria as shown in table 3.37(X2-0.03,P\>0.05). The severity of anaemia was greater in the non endemic area compared to the endemic area among malaria patients (Table 3.21 a)(P\<0.01). All the anaemic patients (8/17) from the non endemic area had moderate to severe anaemia when compared with the anaemic patients from the endemic area of whom 51/7(72 percent) had only mild anaemia (Table 3.38)(P\<0.05). IN the endemic area people are exposed to malaria transmission from birth and this confers and disease or clinical immunity within them (Karunaweera et al. 1998). The immunity acquired causes a reduction in the severity of disease and a milder degree of depression of bone marrow function (Karunaweera et al., 1998). To determine the proportion of anaemia caused purely by malaria, the full blood count report and the blood picture of the patients were examined in conjunction with the biochemical tests. Considering the above data it was confirmed that there is iron deficiency anaemia occurring in conjunction with malaria in 13/79(16 percent) of P vivax and 8/52(15 percent) of P falciparum malaria patients. Anaemia of chronic disease was observed in 63/79(80 percent) of P vivax and 42/52(81 percent) of P falciparum malaria patients. Occurrence of vitamin B12 and folate deficiency, was seen in only 2.5 percent of P vivax and 2 percent of P falciparum malaria patients. Severe haemolysis was not a prominent feature in these anaemic malarial patients as has been observed in other studies. Defective iron utilization as indicated by sufficient iron stores, in adequate haemoglobinisation, reduced number of reticulocytes, and normal serum iron levels, with normal serum bilirubin all are seen in these chronic P falciparum malaria patients. This is compatible with the normocytic normochromic blood picture seen in anaemia of chronic disease. The normal red cell, white cell and platelet indices of males and females of the control population were derived and were lower than in the studies on Caucasian and Black populations. This confirms the need for a comprehensive survey to establish the normal haematological indices for Sri Lankans. The study assesses the normal haematological indices of the control population with automated blood cell counting , a new facility in Sri Lanka. The variations in the iron content and the iron stores of normal healthy adults indicate that there is wide variation in the serum ion, serum ferritin, the total iron binding capacity, the haematological indices, and blood picture. It is concluded that malaria produces anemaia through several mechanisms, which are divided into two broad groups of a) increased red cell destruction and b) dimilished red cell production. In this study diminished red cell production due to anaemia of chronic disease was the main cause for the anaemia in these malaria patients. The time and nature of onset of anaemia due to malaria, have varied in the different age groups in several parts of the world. Iron deficiency anaemia also occurs concurrently with malaria adding to the burden of morbidity in this population.en-USUniversity of Colombo, UC(MED): Sri Lanka HELLIS NetworkMalariaPlasmodium falciparumPlasmodium falciparum-bloodMalaria vivax-bloodMalaria, Vivax-complicationsCross-Sectional StudiesThesis