Endemic malaria, population movements, and travelers all contribute to presenting the laboratory with diagnostic problems for which it may have little expertise available. Blood samples from 100 patients were obtained with symptoms suggestive of malaria. Understand the transmission and life cycle of malaria parasites. Plasmodium malariae and plasmodium falciparum, which do not cause relapses. The test, which is an antigen capture test detecting trophozoitederived histidine rich proteinii, is simple to perform and provides a definitive answer in about 10 min. For full access to this pdf, sign in to an existing account, or purchase an annual subscription. It involves staining of the centrifuged and compressed red cell layer with acridine orange and its examination under uv light source. Evaluation of falcivax against quantitative buffy coat qbc for the diagnosis of malaria. Rapid diagnostic tests for malaria parasites clinical microbiology.
The country is a holoendemic area with a yearround transmission pattern. Almost a decade ago our diagnostic laboratory implemented an inhouse realtime pcr for the detection of plasmodium dna to diagnose malaria in parallel with conventional diagnostics, i. A qbc test is highly specific and a negative result will enable the patient to avoid a multidrug therapy. This fluorescent test which is done analysing 60ul of blood, by centrifuging the sample in a capillary tube coated with acridine orange is. While malaria is found in more than 87 countries, most infections and deaths happen in africa. Laboratory diagnosis of malariavarious method and its. Quantitative buffy coat qbc test for rapid diagnosis of. The flow charts in different settings for diagnosis and drug selection for the treatment of malaria are as under. Compared with the qbc test and thin blood films, the now malaria test had sensitivity and specificity values of 96. In contrast to other techniques for malaria diagnosis, such as the thick slide, pcr noor et al.
Rapid diagnostic tests for malaria parasites clinical. Multiplex realtime pcr for diagnosing malaria in a non. Microscopy is the most widely used laboratorybased diagnostic test for malaria, and it likely will remain the test of choice for some time. The qbc malaria tube is internally coated with all the necessary reagents and anticoagulants to perform a malaria test in minutes. Delay in diagnosis and treatment is a leading cause of death in malaria patients in the united.
Here we report our experiences and make a comparison between the different diagnostic. What is the role of the quantitative buffy coat qbc. The qbc malaria test is a fluorescence microscopybased malaria diagnostic test embraced by users around the world. Even microscopic diagnosis has gone through a paradigm shift with the development of new techniques such as the quantitative buffy coat qbc method and the partec rapid malaria test. The present study was carried out to compare the efficacy of quantitative buffy coat qbc and rapid diagnostic test rdt with conventional peripheral blood smears. Practical uses of acridine orange fluorescence microscopy of centrifuged blood qbc malaria test tm and the qbcii hematology system tm in patients attending malaria clinics in thailand.
Malaria can be diagnosed by demonstration of the parasitering form,schizonts,gametocytes etc from the peripheral blood film and detection of antigen by imm. It speeds and simplifies malaria detection, with a. A rapid procedure for the diagnosis of malaria infections directly from dried blood spots by pcr amplification was evaluated with samples from 52 patients. Comparative study of peripheral blood microbiology section. The quantative buffy coat qbc is an acridine orange fluorescence staining method, used as a preliminary screening tool for the diagnosis of malaria. However, the microscope is a key tool in the integrated management of disease in resource poor settings, and the optimal role and conditions in malaria patients, a prompt and accurate diagnosis is the key. Evaluation of blood smears, quantitative buffy coat and. Malaria treatment table can be used as a guide for treatment of malaria in the united states. Learn about the different types of tests doctors use to test for malaria in your body and how the exam is performed. These parasites are primarily spread by the bite of infected female anopheles mosquitos. Quantitative buffy coat qbc test 1,3 the qbc test is a new method for identifying the malarial parasite in the peripheral blood.
Malaria in equatorial guinea remains a major public health problem. A total of 387 samples were collected from patients presenting with fever and chills. Previousstudies in ethiopia 2, the philippines 3, thailand 4, and indonesia 5 concerned mainly falciparum malaria or mixed infections of falciparum and vivax malaria. The qbc autoread plus haematology system can change the way you collect and analyse samples. The aim of our study is to determine the sensitivity and the specificity of the qbc tube method in the detection of malaria parasite in a hospital and field setting. The qbc malaria test is a fluorescence microscopybased malaria diagnostic test. Quantitative buffy coat is another direct and rapid test for diagnosis of malaria. Species differentiation is possible in the qbc malaria test. Detection and species determination of malaria parasites.
Recently, many new rapid diagnostic tests like quantitative buffy coat qbc. Diagnosis all plasmodium species are identified and quantified in the qbc malaria tube using the qbc paralens advance system or traditional microscope. With centrifugation, parasites are concentrated at a predictable location. The qbc malaria tube contains a fluorochrome called acridine orange and anticoagulants when a capillary or venous blood sample is added, a precision engineered plastic float is inserted into the qbc malaria tube. It is important to note that the basesalt conversions. More sensitive than giemsa thick films, it can detect as little as one parasite per l of blood and establish diagnosis earlier than thick film in 47% of low parasitemia 10 parasites per l cases. The type of medications that are used to treat malaria depends on the severity of the disease and the likelihood of chloroquine resistance. Rapid mp qbc blood preparation, procedure, cost, normal. Malaria must be recognized promptly in order to treat the patient in time and to prevent further spread of infection in the community via local mosquitoes. Lot of articles written on qbc malaria test and about the sensitivity. Malaria was diagnosed in 60, 72 and 56 patients by leishman staining technique, qbc method and malaria antigen test respectively. In africa, it is rare except in the horn and it is almost. Command responsibility malaria control depends on directed discipline by those in.
Pdf evaluation of falcivax against quantitative buffy. Persuade commanders to enforce malaria preventive measures. Buffy coat qbc test and rapid diagnostic tests rdts are widely used and more sensitive in detecting malaria parasite. Performance of the now malaria rapid diagnostic test with. Department of immunology and parasitology, armed forces research institute of medical sciences, bangkok 10400, thailand. Malaria is an infectious disease caused by plasmodium parasites. In the first place, sensitivity and specificity was measured in. Drug resistance in malaria world health organization.
Advantages to qbc are that less training is required to operate the system than for reading giemsastained blood films, and the test is typically quicker to perform than normal light microscopy. It is based on acridine orange staining of centrifuged peripheral. The qbc malaria test can provide results in just eight 8 minutes, compared to 45 minutes to 2 hours with giemsa thick films. Because results cannot be used to speciate plasmodium, a thin smear must be examined. Pdf application and evaluation of qbc malaria diagnosis in a.
If we dont do the test and the doctor gives us drugs, the sickness may not stop because it may be due to other ailments and not malaria alone. Detection of circulating malariaspecific antigens using rapid diagnostic test rdt, or detection of species specific parasite dna in a sample of peripheral blood using a clia validated polymerase chain reaction test pcr, or detection of malaria parasites in thick or thin peripheral blood films with report of percent parasitemia. Drug resistance and genetic variation has altered many accepted morphological appearances of malaria species, and new technology has. Treatment malaria is treated with antimalarial drugs and measures to control symptoms, including medications to control fever, antiseizure medications when needed, fluids and electrolytes. Malaria chapter 4 2020 yellow book travelers health. The most economic, preferred, and reliable diagnosis of malaria is microscopic examination of blood films because each of the four major parasite species has distinguishing characteristics. Laboratory diagnosis of malaria by conventional peripheral blood. The drug or drug combination recommended for each specific situation are listed in bold on the first line of each box in the adult and pediatric dosing columns. Thin films are similar to usual blood films and allow species identification because the parasites appearance is best preserved in this preparation. Rapid diagnosis of malaria is important for the administration of effective treatment, to reduce the morbidity and mortality. According to the manufacturer, qbc malaria test is 5. Comparative evaluation of a rapid diagnostic test, an. Microscopy has been the gold standard for malaria diagnosis for decades.
Actal artemisininbased combination therapy artemether lumefantrine. The qbc technique has been shown to be a rapid and sensitive test for diagnosing malaria in numerous laboratories settings 15,3235. This speed improvement allows users to increase lab throughput and make the most of their limited resources. Malaria pocket guide includes information to help service personnel. The quantitative buffy coat qbc is a technique that is as sensitive as thick smears. There are four main types of plasmodium p species that infect humans plasmodium vivax and plasmodium ovale, which cause a relapsing form of the disease, and. Malaria is a major international public health problem. Moreover, the qbctechnique hasthe advantage ofspeed, and its sensitivity and specificity are good when comparedwith the gtfmethod. The qbc tubes are internally coated with all the necessary reagents including acridine orange fluorochrome stain and anticoagulants with the exception of the qbc venous tubes. It is prevalent in endemic areas in the middle east, asia, oceania and central and south america. Pdf quantitative buffy coat analysis was used in practical diagnosis situations. The qbc malaria tube contains a fluorochrome called acridine orange and anticoagulants when a capillary or venous blood sample is added, a precisionengineered plastic float is inserted into the qbc malaria tube.
In this technique, two drops of blood, typically obtained from a finger pricked by a metal lancet, are placed on a glass microscope slide. Respondent 01, fgd 4 the test can identify any cause of sickness. The purpose of this study was to determine the prevalence of malaria parasitaemia in blood donors in buea, cameroon, and to evaluate the performance of a rapid diagnostic test rdt, a malaria antibody enzymelinked immunosorbent assay elisa, and a plasmodium lactate dehydrogenase pldh elisa in the detection of asymptomatic malaria. Malaria diagnosis by quantitative buffy coat technique. Plasmodium infections were identified with a genusspecific primer set, and species differentiation between plasmodium falciparum and plasmodium vivax was analyzed by multiplex pcr.
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