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Abstract

Background: Among the several human species of malarial parasites, Plasmodium 

falciparum can cause severe infection and if left untreated, there may be fatal complications. 

Early diagnosis and prompt treatment have been proposed to reduce the morbidity and 

mortality from malaria. Objective: To assess the diagnostic efficacy of antigen detection by 

immunochromatographic test (ICT) at different levels of parasitemia for diagnosis of malaria. 

Materials and Methods: This study was carried out in the department of Microbiology, 

Mymensingh Medical College for a period of one year from July 2005 to June 2006. A total of 

98 clinically suspected malaria patients were included in this study. Peripheral blood films 

(PBF) were examined under microscope and parasite count/µL of blood was performed. 

Subsequently ICT for malaria antigen was done for each case. Results: Out of 59 cases 

positive by microscopic examination of blood films, 54 cases had parasitemia >600 

parasites/µL of blood and all these cases were positive by ICT for malaria antigen. Rest 5 

cases showed parasitemia < 600 parasites/µL of blood and one case was found positive by 

ICT for malaria antigen. Conclusion: Immunochromatographic test can be used for early 

diagnosis of malaria with hyperparasitemia, especially for cerebral malaria.

Keywords: Immunodiagnosis, Severe malaria, Hyperparasitemia

                                                                                   J Enam Med Col 2013; 3(2): 88--90

 

Malaria is a febrile illness caused by four human 

species of the genus plasmodium, which causes more 

deaths worldwide than any other parasitic disease. 

Among the four human species Plasmodium 

falciparum is the most dangerous and is responsible 

for severe malaria.1 

Malaria is a major public health problem in 

Bangladesh. Thirteen, out of 64 districts are seriously 

affected by malaria and among the malaria cases, 

more than 70% are falciparum malaria. The 

emergence and spread of antimalarial drug resistant 

falciparum malaria is worsening the malaria problem 

in Bangladesh.2,3 

Malaria may result in a wide variety of symptoms; 

ranging from no symptoms or very mild symptoms 

to severe disease and even death.4 If falciparum 

malaria is not treated properly, complicated ‘severe 

malaria’ may occur. According to WHO ‘severe 

malaria’ may be defined by at least one of the 

following criteria: absence of detectable, non-

malarious causes of severe anemia, prostration, 

respiratory distress, convulsion, impaired con-

sciousness, hypoglycemia, hemoglobinuria, circula-

tory collapse, renal failure, pulmonary edema and 

combined with the presence of P. falciparum 

‘hyperparasitemia’. The term ‘hyperparasitemia’ is 

Introduction

 

88

Efficacy of Immunodiagnosis of Falciparum Malaria at

Different Levels of Parasitemia

1.   Associate Professor, Department of Microbiology, Enam Medical College, Savar, Dhaka

2.    Professor, Department of Microbiology, Mymensingh Medical College, Mymensingh

3.   Department of Microbiology, Khwaja Younus Ali Medical College, Enayetpur, Sirajgonj

4.   Graded specialist, Department of ENT, Combined Military Hospital, Dhaka Cantonment, Dhaka 

Correspondence Mejbah Uddin Ahmed, Email: mejbahua@gmail.com

Original Article

Mejbah Uddin Ahmed1, Mohammad Akram Hossain2, Abul Hossain Khan3,

Salah Uddin Ahmed4

Journal of Enam Medical College

Vol 3 No 2 July 2013



defined as a parasite density >5% parasitemia 

or >250,000 parasites/µL of blood. Among the 

complications of severe malaria, cerebral 

malaria is the most common. The case fatality 

rate with severe malaria may exceed 20% or 

more.1,3,5 A prompt and accurate diagnosis is 

the key to reduce the sufferings and 

complications. 

Malaria is usually diagnosed clinically and by 

microscopic examination of peripheral blood 

film. Clinical diagnosis may overlap with other 

febrile illnesses. Therefore, diagnosis based on 

clinical grounds should be confirmed by 

laboratory investigations. In addition to 

traditional blood film microscopy, fluorescence 

microscopy, detection of antigen and antibody 

by ICT, enzyme-linked immunosorbent assay 

(ELISA) and molecular techniques are also 

available. Among all the methods, microscopic 

examination of blood film is regarded as the 

‘gold standard’.6,7 This method is relatively 

simple and cost-effective. But it is time 

consuming, needs expert microscopist and 

sensitivity is questionable at low level of 

parasitemia.8 Moreover, in infection with P. 

falciparum, parasites are sequestered in the 

deep capillaries of spleen, liver and bone 

marrow and parasite detection may be missed 

in the blood films due to insufficient number of 

parasites.9 For these reasons, in case of severe 

malaria, especially ‘cerebral malaria’ where 

parasitemia remains high (>2,500 parasites/µL), 

antigen detection by ICT may be an alternative 

choice. Because, this is a rapid test and is able 

to detect low level of parasitemia (60--100 

parasites/µL of blood).6 

In addition to conventional microscopy for 

diagnosis of malaria, a rapid and reliable test 

like ICT for antigen can contribute to reduce 

the mortality and morbidity.  Therefore, this 

study was designed to see the efficacy of ICT 

for detection of antigen at different levels of 

parasitemia. 

Materials and Methods

This study was carried out in the department of 

Microbiology, Mymensingh Medical College 

during the period of July 2005 to June 2006. A 

total of 98 clinically suspected malaria cases 

were selected from Haluaghat Thana Health 

Complex, Mymensingh, Mymensingh Medical 

College Hospital and Community Based Medical College 

Hospital, Mymensingh. Cases were selected clinically on 

the basis of fever with chill and rigor, sweating, 

splenomegaly, hepatomegaly, headache, vomiting, fatigue 

and abdominal discomfort. Relevant history, clinical 

findings and results of laboratory investigations of every 

case was systematically recorded in a predesigned data 

sheet and subsequently analyzed by computer program 

SPSS version 12.0.

Capillary blood from the tip of the finger for thick and thin 

films and intravenous blood for ICT were collected 

aseptically. The slides of thick and thin films were labeled 

and stained with Giemsa stain.5 Parasites were detected 

and counted and subsequently antigen was detected by ICT 

method for each case. 

Results

Out of 98 clinically suspected cases 59 (60.20%) were 

positive by microscopic examination of peripheral blood 

film and among them 55 (56.12%) were positive by ICT 

for antigen (Table I). 

Table I: Rate of detection of malaria by microscopy and 

ICT methods

 Tests Positive Negative

 Peripheral blood film (n = 98) 59 (60.20%) 39 (39.80%)

 ICT for antigen (n = 98) 55 (56.12%) 43 (43.88%)

Table II shows the distribution of parasitemia and their 

relation with ICT for antigen. Parasitemia between 10,000-

49,999 parasites/µL of blood was found in 20 cases. 

Seventeen cases showed parasitemia µL 

of blood. The cases with parasitemia >600 parasites/µL of 

blood were positive by ICT for antigen. Parasitemia 

parasites/µL of blood were found in 5 (8.7%) cases of 

which 1 (20%) was positive by ICT for antigen. 

Table II: Distribution of parasitemia among the 59 

microscopy positive cases and their relation 

with ICT for antigen

 Parasite count/  Number (%) Positive by ICT for antigen (%)
 µL of blood

 >50000 17 (28.81) 17 (100)

 10000–49999 20 (33) 20 (100)

 1000–9999 13 (22) 13 (100)

 601–999 04 (6.77) 04 (100)

 < 600 05 (8.47) 01 (20)

 Total 59 55

 

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Discussion

In the present study, out of 98 clinically suspected 

malaria cases, 59 (60.20%) were positive for 

malarial parasite by microscopic examination of 

peripheral blood film and 57 (58.16%) were 

positive by ICT for antigen. Khan et al in Pakistan 

found 45.5% cases positive by microscopic 

examination of peripheral blood film and 43.2% 

positive by ICT for antigen.10 In our study, 

parasitemia between 10,000-- 49,999/µL of blood 

was found in highest number of cases (20, 33%) and 

17(28.81%) cases with 50,000 parasites/µL of blood. 

In a study in Thailand, Pattanasin et al reported 

highest number of patients (37, 26.24%) had 

parasitemia between 5,000--50,000/µL of blood and 

20 (14.18%) patients had parasitemia >50,000/µL of 

blood.11 We found all 54 (100%) cases with 

parasitemia > 600/µl of blood positive by ICT for 

antigen. Cooke et al from Gambia in 1999 found 

100% cases positive by ICT for antigen with 

parasitemia >500/µL of blood.12 We found one case 

positive by ICT for antigen when parasite count was 

<600 parasites/µL of blood. In a study in Kuwait, 

Iqbal et al found 96% sensitivity when parasitemia 

was >500 parasites/µL and 44% sensitivity when 

parasitemia was <500 parasites/µL.7 Kakkilaya in 

2003 observed that many studies showed >95% 

sensitivity when parasitemia was 500
parasites/µL.13 From the above discussion it is 

observed that some results are consistent with our 

findings and some remarkably differ from the 

present study. These variations of results may be 

because of different places and use of different 

diagnostic kits. 

In conclusion, diagnosis of malaria by ICT is 

simple, easy to perform, can be done as bedside test 

and diagnostic efficacy of ICT is satisfactory. So, 

this method can be used in case of malaria, 

especially for cerebral malaria where urgent 

diagnosis is needed. 

References 

1.   Trampuz A, Jereb M, Muzlovic I, Rajesh M. Clinical 

review: severe malaria. Critical Care 2003; 7(4): 

315–323.

2.   International Center for Diarrheal Diseases and Research, 

Bangladesh. New strategies for treating falciparum 

malaria in Bangladesh. Health and Science Bulletin 

2006; 4: 1--6.

3.    Alam MS, Khan MGM, Chaudhury N, Deloer S, Nazib F, 

Bangali AM et al. Prevalence of anopheline species and 

their Plasmodium infection status in epidemic-prone 

border areas of Bangladesh. Malaria Journal 2010; 9: 2--8.

4.   Stauffer W, Fischer PR.
.
Diagnosis

 
and

 
treatment

 
of

 

malaria
 
in

 
children. Clinical Infectious Diseases 2003; 

37: 1340--1348.
 

5.    Mockenhaupt FP,  Ehrhardt  S, Burkhardt J, Bosomtwe 

SY, Laryeas S, Anemana SD. Manifestation and outcome 

of severe  malaria in children in Northern Ghana. The 

American Journal of Tropical Medicine and Hygiene 

2004; l(2): 167--172.

6.   Moody A. Rapid diagnostic tests for malaria parasites. 

Clinical Microbiology Reviews 2002; 15: 66--78.

7.   Iqbal J, Khalid N, Hira PR. Comparison of two commercial 

assays with expert microscopy for confirmation of 

symptomatically diagnosed malaria. Journal of Clinical 

Microbiology 2002; 40(12): 4675--4678. 

8.  Mankhambo L, Kanjala M, Rudman S, Lema VM, 

Rogerson SJ. Evaluation of the optimal rapid antigen test 

and species-specific PCR to detect placental plasmodium 

falciparum infection at delivery. Journal of Clinical 

Microbiology 2002; 40: 155--158.

9.   Joshi HH. Monoclonal antibody based ELISA: an effective 

diagnostic tool for the diagnosis of falciparum malaria. 

Journal of Nepal Medical Association 2005; 44: 79--83.

10.  Khan SA, Anwar M, Hussain S, Qureshi AH, Ahmad M, 

Afzal S. Comparison of optimal malarial test with light 

microscopy for the diagnosis of malaria. Journal of 

Pakistan Medical Association 2004; 54: 404--408. 

11. Pattanasin S, Proux S, Chompasuk D, Luwiradaj K, 

Jacquier P, Looareesuwan S. Evaluation of a new 

plasmodium lactate dehydrogenase assay for the 

detection of malaria. Transaction of the Royal Society of 

Tropical Medicine and Hygiene 2003; 97: 672--674.

12.  Cooke AH, Doherty T, Chiodini PL, Moody AH, Ries J, 

Pinder M. Comparison of a parasite lactate 

dehydrogenase based immunochromatographic antigen 

detection assay with microscopy for the detection of 

malaria parasite in human blood samples. Am. J. Trop. 

Med. 1999; 60 (2): 173--176.

13. Kakkilaya BS. Rapid diagnosis of malaria. Laboratory 

medicine 2003; 34(8): 602--608.

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