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ISSN-0303-5212 |
| The
Journal of the Pakistan Medical Association Rawalpindi - Islamabad |
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Volume 34, Number 2, July - Dec. 2009 |  |
| Original article | |
| Thrombocytopenia in adults with acute malaria | |
| Ali Hassan Abro, Ahmed Alhaj Saleh, Ahmed Saleh Abdou, Abdulla Mohd Ustadi, Hassan MH Shuri, Rania M Seliem |
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| Objective To compare the incidence and severity of thrombocytopenia in various types of malaria Method This study was conducted from June 2004 to May 2007 at the Infectious Diseases Unit, Rashid Hospital Dubai. The diagnosis of malaria was confirmed by thick and thin film staining and platelet count was performed by automated Beckman Coulter machine. Thrombocytopenia was defined as mild (Plat 50-150x103cells/ul), moderate (Plat 20-50x103cells/ul) and severe (Platelets <20x103cell/ul). Results A total of 110 malaria patients were included and 56 (50.9%) had P. falciparum malaria, whereas, 52 (47.27%) and 2 (1.8%) patients suffered from P.vivax and P. malariae respectively. The mean age was 31.9+9.59 years. The males out numbered the females, 102 (92.72%) vs 8 (7.27%). Overall, 87.27% of the patients were found to have low platelet count. There was no significant difference in the incidence of thrombocytopenia between P.falciparum (91%) and P.vivax (84.62%) cases (p>0.05). However, severe thrombocytopenia was observed in P. falciparum (10.71%) than P.vivax (3.84%) patients. Conclusions In contrast to the previous studies, we did not observe significant difference in the incidence of thrombocytopenia between P.falciparum and P.vivax malaria. Furthermore, the incidence of thrombocytopenia was quite high, which, as to the best of our knowledge has not reported before, particularly in P.vivax patients. (Rawal Med J 2009;34:170-172 ). |
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| Key Words: Thrombocytopenia, P. falciparum, P.vivax, malaria. | |
| INTRODUCTION | |
| An estimated three to five hundred million new cases of malaria occur each year1 and disease is endemic in about 91 countries putting over 40% of world population at risk.2 The well recognized hematological abnormalities associated with malaria include anemia, thrombocytopenia, and atypical lymphocytosis.3 Leucopenia, leukocytosis, neutropenia, monocytosis and eosinophilia have also been reported.4 In particular, thrombocytopenia is considered to be a classical finding and could be encountered even in mild/uncomplicated disease and low platelet may present an important marker for diagnosis of malaria in febrile patients living or visiting an endemic area.5 The aim of this study was to evaluate the incidence and severity of thrombocytopenia in different types of acute malaria in adult patients admitted in Rashid hospital. | |
| PATIENTS AND METHODS | |
| This was a hospital based study conducted from Jun 2004 to May 2007 at the Infectious Diseases Unit of Rashid Hospital Dubai, UAE. The study was designed to include the demographics (age, sex, nationality and history of travel) and clinical information of the patient as well as platelet changes in relation to the type of malaria. Patients with clinical history and/or findings suggestive of chronic liver disease, bleeding disorder, thrombocytopenia, drug intake or conditions which can cause thrombocytopenia were excluded from the study. The diagnosis of malaria was confirmed by thin and thick blood films stained with Leishman,s stain. Platelet count was performed using an automated Beckman Coulter machine. All malaria positive smears were reviewed by a hematologist for identification of species and review of smear for platelets count. Other laboratory investigations were performed when and where it was necessary. Thrombocytopenia was defined as mild (Plat 50-150x103cells/ul), moderate (Plat 20-50x103cells/ul) and severe (Platelets <20x103cell/ul).6 Data was analyzed by SAS Enterprise Guide 4.1. |
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| RESULTS | |
| Out of 110 patients, P.Falciparum malaria was slightly commoner than P.vivax-56 (50.9%) vs 52 (47.27%) respectively, while P. malariae was positive in 2 (1.8%) patients. The mean age of patients was 31.9+9.59 years (range 14-76 years).The males out numbered the females, 102 (92.72%) vs 8 (7.27%). Except for one UAE national, all patients were expatriates who lived in or visited the UAE. Out of 110 patients; 65 (59%) were Indian, 24 (21.81%) Pakistani, 14 (12.72%) Africans and 8 (7.27%) were the other nationals. History of recent travel to a malaria endemic area was positive in the 87 (79%) patients. | |
 Fig.1: Ring forms and a gametocyte diagnostic of P. Falciparum with thrombocytopenia |
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| Overall, 96 (87.27%) patients were found to have low platelet count. The mean platelet count was 77.13+54.71x103cells/ul (range 9-346x103/ul) (Fig.1). Among 56 P. falciparum malaria patients, 51 (91%) had thrombocytopenia and the mean platelets count was 78.96+59.04 x103cells/ul (range 10-364x103/ul), whereas, out of 52 P. vivax patients, low platelet count was observed in 44 (84.61%) patients and mean platelet count was 75.30+50.39x103cells/ul (range 9-280x103/ul) (p>0.05). When severity of thrombocytopenia was compared between the two groups, in P. falciparum cases; 29 (51.78%) had mild, 16 (28.57%) moderate and 6 (10.71%) had severe thrombocytopenia, whereas, in patient with P. vivax, 26 (50%) had mild, 16 (30.76%) moderate and 2 (3.84%) had severe thrombocytopenia (Fig 2). | |
 Fig 2. Platelet changes in P.Falciparum and P. Vivax malaria. |
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| The patients who suffered from P. malariae had normal platelet count. Bleeding tendency was not observed in any of the patients and none required platelet transfusion, even with platelet count as low as 9000cell/ul. In most of the patients, platelet count rose to reference range with in 3-5 days of the treatment. Two patients succumbed to death due to complicated P.falciparum malaria (cerebral malaria). | |
| DISCUSSION | |
| Imported malaria is a common cause of acute febrile illness in the UAE, despite it's classification as a malaria free country by WHO.7 Thrombocytopenia complicates up to 60-80% cases of malaria,8 and its occurrence is an important diagnostic clue for malaria in a febrile traveler returning from a malaria endemic area.9 Although variable degree of reduction in circulating platelet count are consistently reported in the different types of malaria,10,11 severe thrombocytopenia is quite rare in P. vivax malaria.12,13 Platelet counts of 20,000/ul or less have been reported in 1.5% and 8.5% in P. vivax and P. falciparum malaria respectively in large study involving 1500 cases of malaria in India.14 In our study, 87.27% of patients with malaria developed thrombocytopenia, a percentage far higher than that reported by other investigators.15-17 Moreover, there was no significant difference in the incidence of thrombocytotopenia in P. falciparum (91%) and P. vivax (84.61%). We also observed higher incidence of severe thrombocytopenia (P.falciparum-10.71% and P. vivax-3.84%) in our patients in comparison to other investigators.14 In our series, none of our patient had any bleeding tendency even with platelet count of 9000cells/ul, as reported by others.18 The mechanism of thrombocytopenia in malaria is still not well understood but decreased thrombopoiesis,3 peripheral destruction induced by P. falciparum immune complexes generated by malarial antigens leading to sequestration of the injured platelets by macrophages in the spleen,19 and disseminated intravascular coagulation20 have been postulated. In acute malaria infection, platelets are found to be hypersensitive and there is increased concentrations of platelet-specific proteins such as beta thromboglobulin (ßTG), platelet factor 4 (Pf4). Production of thromboxane A2 and prostacyclin also increased.20 The hypersensitive (hyperactive) platelets may enhance hemostatic responses and may be this is why bleeding episodes are rare in acute malarial infections, despite the significant thrombocytopenia.17 |
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| CONCLUSION | |
| The incidence of thrombocytopenia caused by acute malaria in hospitalized adult patients was found to be higher than reported earlier, especially in P.Vivax and no significant difference was observed between P. Falciparum and P. Vivax patients. | |
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| REFERENCES | |
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