When fully mature, C. silacea and C. dimidiata assume the day-biting tendencies of all tabanids.The bite of the mango fly can be very painful, possibly because of the laceration style employed; rather than puncturing the skin as a mosquito does, the mango fly (and deer fly) makes a laceration in the skin and subsequently laps up the blood. Female flies require a fair amount of blood for their aforementioned reproductive purposes and thus may take multiple blood meals from the same host if disturbed during the first one.Although Chrysops silacea and C. dimidiata are attracted to canopied rainforests, they do not do their biting there. Instead, they leave the forest and take most blood meals in open areas. The flies are attracted to smoke from wood fires and they use visual cues and sensation of carbon dioxide plumes to find their preferred host, humans.A study of Chrysops spp. biting habits showed that C. silacea and C. dimidiata take human blood meals approximately 90% of the time, with hippopotamus, wild ruminant, rodent and lizard blood meals making up the other 10%. Morphology
Adult Loa worms are sexually dimorphic, with males considerably smaller than females at 30–34 mm long and 0.35–0.42 mm wide compared to 40–70 mm long and 0.5 mm wide. Adults live in the subcutaneous tissues of humans, where they mate and produce wormlike eggs called microfilariae.
Studies have sought to delineate the sequence of events following Ivermectin treatment that lead to neurologic SAE and sometimes death, while also trying to understand the mechanisms of adverse reactions to develop more appropriate treatments.In a study looking at mass Ivermectin treatment in Cameroon, one of the greatest endemic regions for both onchocerciasis and loiasis, a sequence of events in the clinical manifestation of adverse effects was outlined.It was noted that the patients used in this study had a L. loa microfilarial load of greater than 3,000 per ml of blood.Within 12–24 hours post-Ivermectin treatment (D1), individuals complained of fatigue, anorexia, and headache, joint and lumbar pain—a bent forward walk was characteristic during this initial stage accompanied by fever. Stomach pain and diarrhea were also reported in several individuals.By day 2 (D2), many patients experienced confusion, agitation, dysarthria, mutism and incontinence. Some cases of coma were reported as early as D2. The severity of adverse effects increased with higher microfilarial loads. Hemorrhaging of the eye, particularly the retinal and conjunctiva regions, is another common sign associated with SAE of Ivermectin treatment in patients with L. loa infections and is observed between D2 and D5 post-treatment. This can be visible for up to 5 weeks following treatment and has increased severity with higher microfilarial loads.Haematuria and proteinuria have also been observed following Ivermectin treatment, but this is common when using Ivermectin to treat onchocerciasis. The effect is exacerbated when there are high L. loa microfilarial loads however, and microfilariae can be observed in the urine occasionally.