The CDC conducted a survey with the Ministry of Health in Uganda to evaluate the prevalence of filariasis among the local population. Skin snips and blood specimens were collected and sent to a regional laboratory for preparation. Thick blood films were made and stained with Giemsa, and then forwarded to the CDC in Atlanta for evaluation. The objects seen in Figures A–D were seen in low numbers on several of the patients’ smears. The object in Figure A measured 325 micrometers in length; Figure B shows a close-up of one of its ends. The object in Figure C measured 237 micrometers in length. The object in Figure D measured 225 micrometers in length. Fig. A Fig. B Fig. C Fig. D

1. What class of organisms does this parasite belong? (1)

2. Knowing where this organism was found, what is your best guess as to its identity? (1)

3. How are these organisms transmitted? (1)

4. How can this organism be differentiated from the others of this class? (2)