Comparative study of microscopic detection methods and haematological changes in malaria

Quantitative buffy coat (QBC) technique, thick smears, thin smears and conventional buffy coat smears were compared for malarial parasite detection. Of 200 blood samples studied, 70 (35%) samples were positive by QBC technique, 62 (31%) samples by thick smears, 50 (25%) samples by thin smears and only 34 (17%) samples were positive by conventional buffy coat technique. 8 (4%) samples detected by QBC technique alone, had low parasitic index. Haematological analysis was performed on samples positive for malarial parasite. Anaemia was present in 66 (94.28%) samples of which 37 (56.06%) were Plasmodium falciparum, 21 (31.81%) were Plasmodium vivax and 8 (12.12%) had mixed infection (Plasmodium falciparum and Plasmodium vivax). 35 (50%) cases showed normocytic normochromic anaemia. Majority of the samples showed normal total and differential leukocyte count. Thrombocytopenia was found in 49 (70%) samples of which 33 (67.34%) were Plasmodium falciparum.     

Comparison of parasite lactate dehydrogenase based immunochromatographic antigen detection assay (optimal) with microscopy for detection of malaria parasites

This study was done to compare the ability of a newly developed rapid malaria test OPtiMAL, an immunochromatographic antigen detection assay for the diagnosis of malaria using parasite lactate dehydrogenase, against standard microscopy. Blood samples were obtained from 232 patients suspected of having malaria. A total of 122 samples (52.5%) were positive by blood films while 118 (50.8%) were positive by OPtiMAL test. The blood film indicated that 21.4% (26 of 122) of the patients were positive for P. falciparum and 78.6% (96 of 122) were infected with P. vivax. OPtiMAL test showed that 21.2% (25 of 118) were positive for P. falciparum and 78.8% (93 of 118) were infected with P. vivax. This assay had sensitivities of 88.4% and 96.8% compared to traditional blood films for detection of P. falciparum and P. vivax malaria respectively. Thus OPtiMAL test can be used with or without traditional blood film examination for detection of both P. vivax and P. falciparum malaria and can be effectively used for the rapid diagnosis of malaria.     

Detection of four Plasmodium species by genus- and species-specific loop-mediated isothermal amplification for clinical diagnosis

Loop-mediated isothermal amplification (LAMP), a novel nucleic acid amplification method, was developed for the clinical detection of four species of human malaria parasites: Plasmodium falciparum, P. vivax, P. malariae, and P. ovale. We evaluated the sensitivity and specificity of LAMP in comparison with the results of microscopic examination and nested PCR. LAMP showed a detection limit (analytical sensitivity) of 10 copies of the target 18S rRNA genes for P. malariae and P. ovale and 100 copies for the genus Plasmodium, P. falciparum, and P. vivax. LAMP detected malaria parasites in 67 of 68 microscopically positive blood samples (sensitivity, 98.5%) and 3 of 53 microscopically negative samples (specificity, 94.3%), in good agreement with the results of nested PCR. The LAMP reactions yielded results within about 26 min, on average, for detection of the genus Plasmodium, 32 min for P. falciparum, 31 min for P. vivax, 35 min for P. malariae, and 36 min for P. ovale. Accordingly, in comparison to the results obtained by microscopy, LAMP had a similar sensitivity and a greater specificity and LAMP yielded results similar to those of nested PCR in a shorter turnaround time. Because it can be performed with a simple technology, i.e., with heat-treated blood as the template, reaction in a water bath, and inspection of the results by the naked eye because of the use of a fluorescent dye, LAMP may provide a simple and reliable test for routine screening for malaria parasites in both clinical laboratories and malaria clinics in areas where malaria is endemic.     

Malaria diagnosis: standardization of a polymerase chain reaction for the detection of Plasmodium falciparum parasites in individuals with low-grade parasitemia

 In Brazil, no study has been done concerning the detection of malaria parasites by polymerase chain reaction (PCR) related to the diagnosis of Plasmodium falciparum malaria. In the present report we describe a highly sensitive methodology for malaria diagnosis using a nested PCR method based on amplification of the p126 P. falciparum gene detected by simple ethidium bromide staining. The P. falciparum Palo Alto strain (culture samples) was serially diluted in blood from an uninfected donor to a final level of parasitemia corresponding to 10^–8% and was processed for PCR amplification. In each of these dilutions a parasitological examination was performed to compare the sensitivity with that of PCR amplification. Blood samples (field samples) were obtained from 51 malarious patients with positive thick blood smears (TBS) who were living in endemic regions of the Brazilian Amazon. They corresponded to 42 P. falciparum and 9 P. vivax cases, with parasitemia levels ranging from only 16 to 20,200 parasites/μl for P. falciparum disease and from 114 to 11,000 parasites/μl for P. vivax malaria. We demonstrate that the use of nested PCR allows the detection of 0.005 parasites/μl without the use of radioactive material. The use of a 1-ml sample volume and the organic DNA extraction method should be suitable in blood banks and for the evaluation of patients during and after drug treatment. Received: 10 January 1996 / Accepted: 10 April 1996     

Evaluation of rapid immunocapture assays for diagnosis of Plasmodium vivax in Korea

The rapid immunocapture assays, OptiMal and ICT, were evaluated from 87 individuals for the diagnosis of malaria infections directly from whole blood. A total of 87 individuals was examined for malaria parasites by microscopic examination of Giemsa-stained blood smears, and 65 cases were positive for Plasmodium vivax by microscopy. Correspondingly, the OptiMal test identified malaria infection in 45 cases (69.2%) of microscopy positive cases. Of these, two cases were misinterpreted as Plasmodium falciparum, whereas ICT detected P. vivax infection in 29 (44.6%) patients. We would like to propose that rapid immuno capture assays are an easy method that can serve as a useful tool in addition to microscopy for the diagnosis of malaria, but sensitivity is not yet satisfactory for diagnosis of P. vivax in Korea.     

Usefulness of quantitative buffy coat blood parasite detection system in diagnosis of malaria

A rapid test for diagnosis of malaria based on acridine orange staining of centrifuged blood samples in a microhematocrit tube (QBC) was compared with thick and thin peripheral blood smears in 2274 samples. Malaria was diagnosed in 239 (10.5%) patients by Leishman's staining technique and QBC method. The QBC method allowed detection of an additional 89 (3.9%) cases. Thus the prevalence rate of malaria during the study was 14.4%. In 1946 patients who were negative by the QBC technique, the Leishman's stained smears did not provide any help in malaria diagnosis. Analysis of the relative quantity of parasites in the specimens, in the QBC method, revealed that 80 out of 89 QBC positive but smear negative cases, had a very low parasite number (less than 10 parasites per QBC field). Although QBC method was superior to the smear for malarial parasite detection, species identification was not possible in 26 (7.9%) cases by this technique. In 95.7% (n = 314) QBC positive cases, the buffy coat in the QBC tube appeared pigmented (gray to black). The colour of the buffy coat was therefore considered by us as a predictor of positivity and could be taken as an indicator for a careful and more prolonged search for the parasites. Thus, the QBC technique has its advantages in terms of speed, sensitivity and ease, especially in an endemic area as ours, where the level of parasitaemia is low and more than 70 to 80 smears need to be examined per day. However, the age old Romanowsky stains still appear superior for species identification.     

检测滤纸干血滴中间日疟原虫(英文)

从滤纸干血滴上用Chelex处理洗脱下的疟原虫DNA,经套式PCR扩增间日疟原虫SSUrRNA基因特异性121bp片段,分析该方法的敏感性和特异性。37例血样检测结果全部阳性,当原虫密度低至25个原虫/uL血时仍可成功检测到该特异条带,且其它三种人疟原虫(恶性疟原虫,三日疟原虫和卵形疟原虫)血样均为阴性。提示滤纸干血滴与PCR扩增技术相结合,是疟疾诊断或流行病学调查的实用工具。     

套式PCR检测滤纸干血滴中间日疟原虫

从滤纸干血滴上用Ｃｈｅｌｅｘ处理洗脱下的疟原虫ＤＮＡ,经套式ＰＣＲ扩增间日疟虫ＳＳＵｒＲＮＡ基因特异性１２１ｂｐ片段,分析该方法的敏感性和特异性。３７例血栓检测结果一部阳性,当原虫密度低全２５个原虫／ｕＬ血时仍可成功检测到该特异条带,且其它三种人疟原虫（恶性疟虫,三日疟原虫和卵疟原虫）血样均为阴性。提示滤纸干血滴与ＰＣＲ扩增技术相结合,是疟疾诊断或流行病学调查的实用工具。     

Identification of four species of human malaria parasites by fast PCR

Malaria is one of the most prevalent infectious diseases in the world. Accurate identification of four species of human malaria parasite is essential for appropriate treatment. Here, we developed a simple and rapid method of identifying Plasmodium species using a fast polymerase chain reaction (PCR) assay. Based on the previous literature, we amplified small subunit ribosomal RNA genes of four human malaria parasites. To establish a minimum detection limit, a blood sample with a known number of P. falciparum parasites (parasitemia: 3%) was diluted serially(from 0.03% to 0.000003%). We compared the detection limits between single (one-step) PCR and nested (two-step) PCR. Other clinical blood samples, which were infected with P. falciparum (parasitemia: 2.8%), P. vivax (parasitemia: 0.13%), P. ovale (parasitemia: 0.04%), respectively, were also tested by our PCR system. The PCR findings were compared to those of blood film Giemsa staining and rapid diagnostic tests (RDT). The sensitivity of our method is less than one parasite in 1 microl of blood(estimated parasitemia: 0.000003%) for both single PCR and nested PCR, though an increased number of cycles (40 cycles) was required for single PCR. Using clinical samples, it was proven that amplified products by single PCR could clearly distinguish between P. falciparum, P. vivax, and P. ovale. To detect P. vivax and P. ovale, the PCR system was more sensitive than RDT. The total required time for our method was within three to four hours from DNA extraction to PCR detection. Taken together, our method is easier and faster than the previously reported PCR-based malaria parasite identification systems, and is also useful for cases in which diagnosis by Giemsa staining and RDT is difficult.     

Diagnosis of Plasmodium falciparum malaria at delivery: comparison of blood film preparation methods and of blood films with histology

We compared peripheral and placental blood films (made by different techniques) with placental histology for diagnosis of Plasmodium falciparum malaria in pregnancy. Samples from 464 women were examined, of whom 124 (26.7%) had active P. falciparum infection and 148 (31.9%) had past infection. Placental histology was more sensitive (91%) than peripheral blood film (47%) or placental blood film (63%) examination and also detected past infection. Few women had microscopically detectable infection without a positive histology. Infection detected by histology only and past infection were both associated with significantly lower infant birth weight and with lower hemoglobin concentrations compared to the results for uninfected women. Thick blood films were prepared with blood obtained by placental incision or scraping of the incision margin (263 samples) or by washing of placental tissue (235 samples). Each gave similar sensitivities (76 to 78%), specificities (98 to 99%), positive predictive values (92 to 98%), and negative predictive values (93 to 94%); but the median levels of parasitemia were lower for incision samples (840 parasites/ micro l) than scrapings (2,295 parasites/ micro l) (P = 0.02). Placental histology is the most sensitive method for the diagnosis of malaria in pregnancy. Methods for preparation of placental films may affect the density, but not the prevalence, of P. falciparum infection detected.     

Two-site immunoradiometric assay for detection of Plasmodium falciparum antigen in blood using monoclonal and polyclonal antibodies.

Three systems of immunoradiometric assays (IRMAs), a two-site monoclonal antibody sandwich IRMA (MAb-IRMA), two-site polyclonal antibody-monoclonal antibody sandwich IRMA (PAb-MAb-IRMA), and two-site polyclonal antibody sandwich IRMA (PAb-IRMA), were developed to detect low-grade infections with Plasmodium falciparum. The assays showed good correlation with parasitemia when tested against parasites from in vitro cultures (r = 0.996, 0.994, and 0.998 for MAb-, PAb-MAb-, and PAb-IRMA, respectively), with the ability to detect as few as 0.24, 0.67, and 1.82 parasites per 10(7) erythrocytes, respectively. The assays were specific for P. falciparum, since a serially diluted specimen from a patient with vivax malaria with an initial parasitemia of 0.8% and almost all of the undiluted specimens from five other vivax malaria patients were negative. The assays were performed on patients with falciparum malaria before and after treatment with antimalarial drugs. Before treatment, all 24 patients were positive by all three systems of two-site sandwich IRMAs. Two weeks after treatment, 81.8% (18 of 22) of the patients were positive by microscopic examination, but the IRMA positivity rates were 90.9% (20 of 22), 86.4% (19 of 22), and 81.8% (18 of 22) for MAb-, PAb-MAb-, and PAb-IRMA, respectively. Four weeks after treatment, all 19 patients were negative by microscopic examination, but 52.6% (10 of 19) of the patients were still positive with MAb- and PAb-MAb-IRMA and 31.6% (6 of 19) were positive with PAb-IRMA. Comparison between the three systems of IRMA showed that the MAb-IRMA was superior to the other two systems for three reasons. First, it gave a lower count when tested with blood from healthy individuals. Second, it gave a higher count when tested with blood from patients with falciparum malaria. Third, it gave better correlation with parasitemia when blood from falciparum malaria patients was tested. MAb-IRMA is recommended for use for the detection of low-grade P. falciparum infection.     

Detection of asymptomatic malaria infection among the Afghani immigrant population in Iranshahr district of southeastern Iran

Asymptomatic malaria infection is often associated with subpatent level of parasitaemia and normal clinical examination. Such infection becomes a greater cause for concern when involved in blood transfusion and vector transmission. This study was performed to monitor the situation of asymptomatic malaria among the Afghani immigrants and native residents in Iranshahr district, a malaria endemic area in southeastern Iran, by performing conventional light microscopy. Out of 446 samples collected from Afghani immigrant participants, seven (1.6%) thick blood smears were diagnosed as Plasmodium vivax. None of the individuals who tested positive had malaria symptoms and they did not remember having had any malaria signs during the past two years. Out of 496 samples collected from native resident participants, three (0.6%) thick blood smears were detected as P. vivax and Plasmodium falciparum with mild malaria symptoms. An asymptomatic Plasmodium-infected individual can be a source of malaria parasites for transmission of the agents.     

Comparison of the OptiMAL Test with PCR for Diagnosis of Malaria in Immigrants

The OptiMAL test (Flow Inc., Portland, Oreg.), which detects a malaria parasite lactate dehydrogenase (pLDH) antigen, has not been evaluated for its sensitivity in the diagnosis of malaria infection in various epidemiological settings. Using microscopy and a PCR as reference standards, we performed a comparison of these assays with the OptiMAL test for the detection of Plasmodium falciparum and Plasmodium vivax infection in 550 immigrants who had come from areas where malaria is endemic to reside in Kuwait, where malaria is not endemic. As determined by microscopy, 125 (23%) patients had malaria, and of these, 84 (67%) were infected with P. vivax and 36 were infected with P. falciparum; in 5 cases the parasite species could not be determined due to a paucity of the parasites. The PCR detected malaria infection in 145 (26%) patients; 102 (70%) of the patients had P. vivax infection and 43 had P. falciparum infection. Of the five cases undetermined by microscopy, the PCR detected P. falciparum infection in two cases, P. vivax infection in two cases, and mixed (P. falciparum plus P. vivax) infection in one case. Correspondingly, the OptiMAL test detected malaria infection in 95 patients (17%); of these, 70 (74%) had P. vivax infection and 25 were infected with P. falciparum. In this study, 61 (49%) of the 125 malaria cases, as confirmed by microscopy, had a degree of parasitemia of <100 parasites per microl, and 23 (18%) of the cases had a degree of <50 parasites per microl. Our results show that the sensitivity of the OptiMAL test is high (97%) at a high level of parasitemia (>100 parasites/microl) but drops to 59% when the level is <100 parasites/microl and to 39% when it is <50 parasites/microl. In addition, the OptiMAL test failed to identify four patients whose blood smears contained P. falciparum gametocytes only. We conclude that the sensitivity and specificity of the OptiMAL test are comparable to those of microscopy in detecting malaria infection at a parasitemia level of >100 parasites/microl; however, the test failed to identify more than half of the patients with a parasitemia level of <50 parasites/microl. Thus, the OptiMAL test should be used with great caution, and it should not replace conventional microscopy in the diagnosis of malaria infection.     

Evaluation of ParaHITf strip test for diagnosis of malarial infection

This study sought to determine whether dip stick strip test containing antibody for Plasmodium falciparum histidine rich protein-II (PfHRP-II) antigen could be used for identification of P. falciparum and P. vivax malaria in man. The results obtained were also compared with the results of standard microscopic examination. A total of 150 cases were included for the study. Fifty cases were non-febrile cases with no history of malaria acting as control group and the rest 100 cases were having fever and formed the test group. All the cases in the control group was found to be negative for both microscopic examination and strip test. In the test group, all samples that showed positive for P. falciparum by microscopy was also found to be positive for strip test. Whereas, all those samples that were positive for P. vivax in microscopic examination was found to be negative for strip test indicating species specificity of the strip test. In addition, two other cases that were negative for microscopic examination were found to be positive for the strip test. Statistical analysis was done to compare the validity of the results of strip test with that of the results of microscopic examination.     

Detection and species determination of malaria parasites by PCR: comparison with microscopy and with ParaSight-F and ICT malaria Pf tests in a clinical environment

A rapid procedure for the diagnosis of malaria infections directly from dried blood spots by PCR amplification was evaluated with samples from 52 patients. Plasmodium infections were identified with a genus-specific primer set, and species differentiation between Plasmodium falciparum and Plasmodium vivax was analyzed by multiplex PCR. The PCR test with any of the three primer sets was able to detect as few as four parasites per microliter by gel electrophoresis or by nonisotopic paper hybridization chromatography. The diagnoses obtained by PCR correlated closely with those obtained by Giemsa staining except for two samples observed to have mixed P. falciparum-P. vivax infections. These were initially missed by microscopic analysis. In comparison with antigen-capture assays for P. falciparum, the PCR assays were able to detect three infections that were missed by the ParaSight-F test. The PCR test was negative for nine ParaSight-F-positive samples and one ICT Malaria Pf-positive sample, and these were confirmed to be false-positive results. The PCR thus gave no false-negative or false-positive results. Patients undergoing antimalarial therapy were also monitored by the PCR assay. Four of seven patients who were PCR positive for P. vivax at the time of discharge were later readmitted to the hospital with a recurrence of P. vivax infection. We would like to propose that PCR is a sensitive and easy method that can serve as a useful addition to microscopy for the diagnosis and the clinical monitoring of treatment of malaria.     

Malaria rapid diagnostic devices: performance characteristics of the ParaSight F device determined in a multisite field study

Microscopic detection of parasites has been the reference standard for malaria diagnosis for decades. However, difficulty in maintaining required technical skills and infrastructure has spurred the development of several nonmicroscopic malaria rapid diagnostic devices based on the detection of malaria parasite antigen in whole blood. The ParaSight F test is one such device. It detects the presence of Plasmodium falciparum-specific histidine-rich protein 2 by using an antigen-capture immunochromatographic strip format. The present study was conducted at outpatient malaria clinics in Iquitos, Peru, and Maesod, Thailand. Duplicate, blinded, expert microscopy was employed as the reference standard for evaluating device performance. Of 2,988 eligible patients, microscopy showed that 547 (18%) had P. falciparum, 658 (22%) had P. vivax, 2 (0.07%) had P. malariae, and 1,750 (59%) were negative for Plasmodium. Mixed infections (P. falciparum and P. vivax) were identified in 31 patients (1%). The overall sensitivity of ParaSight F for P. falciparum was 95%. When stratified by magnitude of parasitemia (no. of asexual parasites per microliter of whole blood), sensitivities were 83% (>0 to 500 parasites/microl), 87% (501 to 1,000/microl), 98% (1,001 to 5,000/microl), and 98% (>5,000/microl). Device specificity was 86%.     

Real-time PCR for detection and identification of Plasmodium spp

Rapid and accurate detection of malaria parasites in blood is needed to institute proper therapy. We developed and used a real-time PCR assay to detect and distinguish four Plasmodium spp. that cause human disease by using a single amplification reaction and melting curve analysis. Consensus primers were used to amplify a species-specific region of the multicopy 18S rRNA gene, and SYBR Green was used for detection in a LightCycler instrument. Patient specimens infected at 0.01 to 0.02% parasitemia densities were detected, and analytical sensitivity was estimated to be 0.2 genome equivalent per reaction. Melting curve analysis based on nucleotide variations within the amplicons provided a basis for accurate differentiation of Plasmodium falciparum, P. vivax, P. ovale, and P. malariae. For assay validation, 358 patient blood samples from the National University Hospital in Singapore and Evanston Northwestern Healthcare in Illinois were analyzed. Of 76 blinded patient samples with a microscopic diagnosis of P. falciparum, P. vivax, or P. ovale infection, 74 (97.4%) were detected by real-time PCR, including three specimens containing mixed P. falciparum-P. vivax infections. No Plasmodium DNA was amplified in any of the 82 specimens sent for malaria testing but that were microscopically negative for Plasmodium infection. In addition, 200 blood samples from patients whose blood was collected for reasons other than malaria testing were also determined to be negative by real-time PCR. Real-time PCR with melting curve analysis could be a rapid and objective supplement to the examination of Giemsa-stained blood smears and may replace microscopy following further validation.     

Characterization of peripheral blood lymphocyte subsets in patients with acute Plasmodium falciparum and P. vivax malaria infections at Wonji Sugar Estate, Ethiopia

We investigated the absolute counts of CD4+, CD8+, B, NK, and CD3+ cells and total lymphocytes in patients with acute Plasmodium falciparum and Plasmodium vivax malaria. Three-color flow cytometry was used for enumerating the immune cells. After slide smears were stained with 3% Giemsa stain, parasite species were detected using light microscopy. Data were analyzed using STATA and SPSS software. A total of 204 adults of both sexes (age, >15 years) were included in the study. One hundred fifty-eight were acute malaria patients, of whom 79 (50%) were infected with P. falciparum, 76 (48.1%) were infected with P. vivax, and 3 (1.9%) were infected with both malaria parasites. The remaining 46 subjects were healthy controls. The leukocyte count in P. falciparum patients was lower than that in controls (P=0.015). Absolute counts of CD4+, CD8+, B, and CD3+ cells and total lymphocytes were decreased very significantly during both P. falciparum (P<0.0001) and P. vivax (P<0.0001) infections. However, the NK cell count was an exception in that it was not affected by either P. falciparum or P. vivax malaria. No difference was found in the percentages of CD4, CD8, and CD3 cells in P. falciparum or P. vivax patients compared to controls. In summary, acute malaria infection causes a depletion of lymphocyte populations in the peripheral blood. Thus, special steps should be taken in dealing with malaria patients, including enumeration of peripheral lymphocyte cells for diagnostic purposes and research on peripheral blood to evaluate the immune status of patients.     

Performance of the Now Malaria rapid diagnostic test with returned travellers: a 2-year retrospective study in a French teaching hospital

Malaria caused by Plasmodium falciparum remains the major life-threatening parasitic infection in the world. The number of cases in non-endemic countries continues to increase, and it is important that misdiagnosis of malaria should not occur, especially in non-immune travellers, because of the high risk of a fatal outcome. In a retrospective study of 399 sera, the Now Malaria rapid test was compared with the quantitative buffy coat (QBC) test and microbiological examination of thin blood films. Compared with the QBC test and thin blood films, the Now Malaria test had sensitivity and specificity values of 96.4% and 97%, respectively, for the detection of pure P. falciparum infection. A negative predictive value of 99.4% allows this test to be included in diagnostic strategies for patients presenting with clinical suspicion of malaria. Two false-negative results were associated with low levels of parasitaemia in the specimens. Thus, use of the Now Malaria test alone to detect P. falciparum infection in non-endemic countries could lead to misdiagnosis of malaria. This rapid diagnostic test should therefore be performed in association with another prompt traditional method such as examination of thin blood films.     

Feasibility and limitations of acridine orange fluorescence technique using a Malaria Diagnosis Microscope in Myanmar

We studied parasite detectability in thick films by an acridine orange fluorescence technique (AO) to test its applicability and the use of a Malaria Diagnosis Microscope (MDM)-ESL in the detection of parasites, compared to the conventional Giemsa staining method. This study was conducted on 1,390 clinically suspected malaria cases of Thaton township, Myanmar. We found sensitivities of 82.8% for Plasmodium falciparum (P. falciparum) and 100% for Plasmodium vivax (P. vivax) and specificities of 97.1% for P. falciparum and 98.6% for P. vivax. AO had a higher sensitivity than Giemsa-stained films at low levels of parasitemia (< 1,000/microl). AO showed lower sensitivity and higher specificity than the Giemsa method at parasite levels of more than 1,000/microl. The results of using the AO method, achieved by both novice and experienced observers, showed no significant difference and required less practice to perform the test as well as to identify the parasite. The acridine orange fluorescence technique using a malaria diagnosis microscope MDM-ESL series is simple, rapid and cost effective. The microscope is conveniently operable using standard AC power or a 12-V DC car battery, and it is easily convertible to a conventional biological microscope. With the exception of species differentiation, which is not possible with this method, this method would be appropriate for both clinical and epidemiological studies.