<prompt> Answer this question truthfullyWhat are the laboratory results for filariasis?  <response>: <reason> Identification of microfilariae by microscopic examination is the most accuarte diagnostic procedure. Examination of blood samples allows the identification of microfilariae of Wuchereria bancrofti, Brugia malayi, Brugia timori, Loa loa, Mansonella perstans, and M. ozzardi. It is important to time the blood collection with the known periodicity of the microfilariae. The blood sample can be a thick smear, stained with Giemsa or hematoxylin and eosin. For increased sensitivity, concentration techniques can be used. Concentration techniques include centrifugation of the blood sample lyzed in 2 formalin Knotts technique, or filtration through a nucleopore membrane.Capillary fingerstick blood: Since microfilariae concentrate in the peripheral capillaries, thick and thin smears prepared from fingerstick blood are recommended.Thick smears Thick smears consist of a thick layer of dehemoglobinized lysed red blood cells RBCs. Thick smears allow a more efficient detection of parasites increased sensitivity.Thin smears consist of blood spread in a layer such that the thickness decrease.The microfilaria of wuchereria bancrofti is sheathed and measure 240-300 μm in stained blood smears and 275-320 μm in 2 formalin. They have a gently curved body and a tail that is tapered to a point. The nuclear column the cells that constitute the body of the microfilaria is loosely packed; the cells can be visualized individually and do not extend to the tip of the tail. Microfilariae circulate in the blood.Shown below is an image of microfilariae of W. bancrofti in thick blood smears stained with Giemsa.Microfilariae of Brugia malayi are sheathed and in stained blood smears measure 175-230 μm. In 2 formalin they are longer, measuring 240-300 μm. The tail is tapered, with a significant gap between the terminal and subterminal nuclei. Microfilaria circulate in the blood.Shown below is an image of microfilaria of B. malayi in a thick blood smear, stained with Giemsa.Microfilaria of Brugia timori are sheathed and measure on average 310 μm in stained blood smears and 340 μm in 2 formalin. Microfilaria of B. timori differ from B. malayi by a having a longer cephalic space, a sheath that does not stain with Giemsa, and a larger number of single-file nuclei towards the tail. Microfilariae circulate in the blood.Shown below is an image of microfilariae of B. timori in a thick blood smear from a patient from Indonesia, stained with Giemsa and captured at 500x oil magnification.Microfilariae of Onchocerca volvulus are unsheathed and measure 300-315 μm in length. The tail tapers to a point and is often sharply bent. The nuclei do not extend to the tip of the tail. Microfilariae typically reside in skin but may be found in blood or urine during heavy infections, or invade the eye and cause a condition known as river blindness.Shown below is an image of microfilariae of O. volvulus from a skin nodule of a patient from Zambia, stained with hematoxylin and eosin.Detection of the filarial antigens has become one of the sensitive and specific diagnostic procedures to diagnose filariasis. The antigen detecting tests include the following: ELISA Immunochromatographic technique ICT and it includes: Alere filariasis test strip Card-based assay for qualitative resultsBlood microfilariae:Anticoagulated EDTA venous blood 1 ml should be concentrated by one of the following methods: Centrifugation Knotts technique Prepare 2 formaldehyde 2 ml of 37 formaldehyde 98 ml H2O. Mix 9 ml of this 2 formaldehyde with 1 ml of patients venous blood. Centrifuge at 500 × g for 10 minutes; discard supernatant. Sediment is composed of WBCs and microfilariae if present. Examine as temporary wet mounts. Prepare thick and thin smears; allow to dry; dip in absolute methanol before Giemsa staining to enhance staining of microfilariae. Filtration Place Millipore or Nucleopore membrane filter 5 μm pore in filter holder with syringe attachment. Mix 1 ml of venous blood in EDTA with 10 ml of 10 Teepol 610 Shell Co.; allow to stand for several minutes to allow lysis; transfer to a 10 ml Luer-Loc syringe; attach the filter apparatus. Force the solution through the 5 μm pore filter, followed by several syringes of water to wash out the remaining blood, then 1 or 2 syringes full of air to clear excess fluid. Prepare a temporary wet mount by removing the filter and placing it on a glass slide, adding a drop of stain or dye and a coverslip. For permanent preparations, pass 2 to 3 ml of methanol through the filter while it is still in the holder; remove filter and dry it on a glass slide; then stain it with Giemsa stain, horizontally so that the filter does not wash off the slide; coverslip filter before examining. 