In a study done at 5 different co-endemic regions for onchocerciasis and loiasis, doxycycline was shown to be effective in treating over 12,000 individuals infected with both parasites with minimal complications. Drawbacks to using Doxycycline include bacterial resistance and patient compliance because of a longer treatment regimen and emergence of doxycycline-resistant Wolbachia. However, in the study over 97% of the patients complied with treatment, so it does pose as a promising treatment for onchocerciasis, while avoiding complications associated with L. loa co-infections.Human loiasis geographical distribution is restricted to the rain forest and swamp forest areas of West Africa, being especially common in Cameroon and on the Ogooué River. Humans are the only known natural reservoir. It is estimated that over 10 million humans are infected with Loa loa larvae.An area of tremendous concern regarding loiasis is its co-endemicity with onchocerciasis in certain areas of west and central Africa, as mass ivermectin treatment of onchocerciasis can lead to serious adverse events (SAEs) in patients who have high Loa loa microfilarial densities, or loads. This fact necessitates the development of more specific diagnostics tests for Loa loa so that areas and individuals at a higher risk for neurologic consequences can be identified prior to microfilaricidal treatment. Additionally, the treatment of choice for loiasis, diethylcarbamazine, can lead to serious complications in and of itself when administered in standard doses to patients with high Loa loa microfilarial loads. History
The first case of Loa loa infection was noted in the Caribbean (Santo Domingo) in 1770.
Gatifloxacin drops and an eye-patch over ointment were utilized post surgery and there were no complications (unfortunately, the patient did not return for DEC therapy to manage the additional worm—and microfilariae—present in his body). Epidemiology
As of 2009, loiasis is endemic to 11 countries, all in western or central Africa, and an estimated 12–13 million people have the disease. The highest incidence is seen in Cameroon, Republic of the Congo, Democratic Republic of Congo, Central African Republic, Nigeria, Gabon, and Equatorial Guinea. The rates of Loa loa infection are lower but it is still present in and Angola, Benin, Chad and Uganda. The disease was once endemic to the western African countries of Ghana, Guinea, Guinea Bissau, Ivory Coast and Mali but has since disappeared.Throughout Loa loa-endemic regions, infection rates vary from 9 to 70 percent of the population. Areas at high risk of severe adverse reactions to mass treatment (with Ivermectin) are at present determined by the prevalence in a population of >20% microfilaremia, which has been recently shown in eastern Cameroon (2007 study), for example, among other locales in the region.Endemicity is closely linked to the habitats of the two known human loiasis vectors, Chrysops dimidiata and C. silicea.Cases have been reported on occasion in the United States but are restricted to travelers who have returned from endemic regions.In the 1990s, the only method of determining Loa loa intensity was with microscopic examination of standardized blood smears, which is not practical in endemic regions.