MYO MIN THAN 6538214TMTM/D
When working on the field site, the technique that will be most suitable for malaria detection in mosquitoes will depend on several factors, including sensitivity, specificity, speed, cost, and available resources . In this assignment, I will discuss the various techniques and choose the most appropriate technique for malaria detection in mosquitoes in the field.
Mosquito dissection is a simple technique that involves dissecting the mosquito to examine its internal organs, including the midgut, salivary glands, and ovaries [2,3,4]. However, dissection can be time-consuming and requires skilled personnel, making it unsuitable for large-scale malaria surveillance programs in the field .
Immunological techniques such as CSP ELISA and Slot blot Immunoassay (ECL-SB) are suitable for large-scale screening programs and can detect malaria antigens in mosquito samples or antibodies (circumsporozoite protein) in the mosquito’s midgut [4,5]. These techniques are relatively simple to perform, and results can be obtained within a few hours. However, immunological techniques may produce false-positive or false-negative results due to cross-reactivity with other antigens or low-level infections, respectively.
Nested PCR (the standard method of molecular technique) and PCR RFLP (or combining with Cytb-PCR) are highly sensitive and specific molecular techniques that can detect low-level infections and distinguish between different species of the Plasmodium parasite, for instance, can differentiate P.f and P.v [4,6]. However, these techniques require DNA extraction from mosquito samples, primer collection and may be expensive and time-consuming. Nested PCR and PCR RFLP are more suited for research or diagnostic laboratories where more specialized equipment and skilled personnel are available .
In addition, MALDI TOF MS is a promising tool for malaria surveillance programs in the field due to its high sensitivity and specificity, ability to identify different species and strains of the Plasmodium parasite, and minimal sample preparation. MALDI TOF MS can provide results within a few minutes, making it a rapid and cost-effective technique for large-scale screening programs. In addition, the correct classification rate was 98.75% of all mosquitoes tested [4,7].
Therefore, based on the available resources and requirements of the malaria surveillance program in the field, MALDI TOF MS would be the most appropriate technique for malaria detection in mosquitoes. The technique can be performed in a portable laboratory, requires minimal sample preparation, and can provide rapid and accurate results compared to other methods. However, if more specialized equipment and skilled personnel are available, nested PCR and PCR RFLP could also be used for more in-depth analysis and research purposes.
In summary, the choice of technique for malaria detection in mosquitoes in the field will depend on several factors, including sensitivity, specificity, speed, cost, and available resources. While each technique has its advantages and disadvantages, MALDI TOF MS appears to be the most suitable technique for large-scale malaria surveillance programs in the field due to its high sensitivity, specificity, rapidity, and cost-effectiveness. And then nested PCR and PCR RFLP is my second choice if funding support or conditions/ situations are favorable.
1. James S, Takken W, Collins FH, Gottlieb M. Needs for monitoring mosquito transmission of malaria in a pre-elimination world. The American Journal of Tropical Medicine and Hygiene. 2014 Jan 1;90(1):6.
2. Williams J, Pinto J. Training manual on malaria entomology for entomology and vector control technicians (basic level). USAID. Washington, DC. 2012;78.
3. Coleman J, Juhn J, James AA. Dissection of midgut and salivary glands from Ae. aegypti mosquitoes. JoVE (Journal of Visualized Experiments). 2007 Jul 4(5):e228.
4. Jiraporn R. Development of malaria diagnosis in Anopheles mosquitoes. [PowerPoint presentation]. Mahidol University. Department of Medical Entomology. Faculty of Tropical Medicine. [updated 2023 Mar].
5. TIP T. ELISA technical guide and protocols. Thermo Fisher Scientific Inc USA, Bartlesville, OK. 2010.
6. Bass C, Nikou D, Blagborough AM, Vontas J, Sinden RE, Williamson MS, Field LM. PCR-based detection of Plasmodium in Anopheles mosquitoes: a comparison of a new high-throughput assay with existing methods. Malaria journal. 2008 Dec;7(1):1-9.
7. Laroche M, Almeras L, Pecchi E, Bechah Y, Raoult D, Viola A, Parola P. MALDI-TOF MS as an innovative tool for detection of Plasmodium parasites in Anopheles mosquitoes. Malaria Journal. 2017 Dec;16:1-0.