Thick vs Thin film comparison
From MalariaETC
Navigation
>Main Malaria Index
>>Thick film - main page
>>>Current page: Thick film vs thin film
Relative merits of thick or thin films in malaria diagnosis
-
Thin film appearances P.falciparum
-
Thick film appearances P.falciparum
There is no single correct choice of staining, essentially the thin film has many advantages in terms of ease of preparation, staining and identification. Non-e BUT the thick malarial film offers superior sensitivity for diagnosis. It is important to appreciate these strengths and weaknesses.
| 1. Sensitivity for detection |
|---|
| Thick film: Higher - can detect lower levels of parasitaemia ~5–10 parasites/µL |
| Thin film: Lower - generally requires ~50 parasites/µL for reliable detection |
| 2. Species Identification |
| Poor: poor - red cell morphology is lost and species-specific features may not be seen |
| Thin film: Good - both parasite morphology and RBC characteristics are assessed |
| 3. Quantification of parasite number |
| Difficult: red cells are not seen so requires estimation and is therefore imprecise |
| Easier: parasites can be counted counted directly and assessed as a proportion of red cells |
| 4. Preparation and staining considerations |
| Less easy: requires air drying and careful spreading and staining to minimise any artefact |
| Easier: films are fixed and stained immediately with clearer morphology of parasites and red cells |