SOP – Malaria Microscopy - NVBDCP

Quality Assurance of Malaria Diagnostic testsChapter 3CURRENT STATUS OF QUALITY ASSURANCE FORMALARIA MICROSCOPY3.1 MicroscopyIt is the most widely used diagnostic test in India, since the inception of a structured malariacontrol programme in our country. It is till today the “Gold Standard” for laboratory diagnosis,yet it does have some disadvantages, the most important being the subjectivity ininterpretation of the result by the examiner.3.2 Strategy of cross-checking of malaria microscopy under NVBDCP• There has been a well established programme for cross verification of the laboratoryresults of microscopy under Dte. of NVBDCP, wherein all the blood smears foundpositive at the Primary Health Centres (PHC) or other peripheral laboratories aresupposed to be cross-checked for parasite species and stage by the designatedcenters. The negative slides are also cross checked as well. It was envisaged thatall positives and 10% of all negative blood smears examined at PHC/ Malaria Clinicwould be cross-checked.• Coding: One of the responsibilities of the Zonal Malaria Officers (ZMO) is the codingof the examined slides. The code number (last digit) for cross checking is issued byZMO (in the first week) of every month, for the negative slides examined in theprevious month. If the code for the month is 5, the slide numbers ending with 5 fromeach section are cross checked.• Cross checking: The PHC/ malaria clinic laboratory technician is supposed tocollect all negative slides examined during the previous month with number endingwith the code digit and dispatch to the concerned cross-checking laboratory by 10 th ofevery month. All positive blood smears are cross checked in the Regional Office ofHealth & Family Welfare (ROH&FW), Govt. of India and State Headquarterlaboratories. Depending on the workload, it is shared 50:50 between theselaboratories. The negative slides are distributed between state/zonal and ROH&FWlaboratories, at the ratio of 8.5: 1.5 between former and latter. Instructions are issuedto the PHC/malaria clinic laboratory to preserve the rest of the slides, until the crosscheckingresults are received back.• Supervision of laboratories for cross checking: In 1975, the expert committee onmalaria recommended very strongly for supervision of efficiency of laboratories. Forthis, there was a provision for posting a supervisory laboratory technician atdistrict/zonal/state laboratories. His function was to visit every PHC laboratory toinspect and conduct on the spot corrections in regard to laboratory records, returns,materials and equipment. He was also supposed to cross-check the laboratoryprocedures and to assist the technicians to improve their efficiency.• Results and feed back: The results of cross-checking were to be sent to theconcerned laboratory by the 10 th of the succeeding month. In case of highdiscrepancy rate i.e., 2% or above, the state programme officer and RegionalSOP – Malaria Microscopy© Copyright to Dte. NVBDCP Only. Any modification are prohibited