Abstract
Mansonella ozzardi infections are common in the riverside communities along the Solimões, Negro and Purus Rivers in the state of Amazonas (AM). However, little is known about the presence of this parasite in communities located in regions bordering AM and the state of Acre. The prevalence rate of M. ozzardi infections was determined in blood samples from volunteers according to the Knott method. A total of 355 volunteers from six riverine communities were enrolled in the study and 65 (18.3%) were found to be infected with M. ozzardi. As expected, most of the infections (25%) occurred in individuals involved in agriculture, cattle rearing and fishing and an age/sex group analysis revealed that the prevalence increased beginning in the 40-50-years-of-age group and reached 33% in both sexes in individuals over 50 years of age. Based on the described symptomatology, articular pain and headache were found to be significantly higher among infected individuals (56 and 65% prevalence, respectively, p < 0.05). Sera from volunteers were subjected to ELISA using a cocktail of recombinant proteins from Onchocerca volvulus to evaluate the specificity of the test in an endemic M. ozzardi region. No cross-reactions between M. ozzardi-infected individuals and recombinant O. volvulus proteins were detected, thus providing information on the secure use of this particular cocktail in areas where these parasites are sympatric.
Highlights
Mansonella ozzardi is a filarial parasite native to the Americas that is widely distributed in the Brazilian state of Amazonas (AM) (Martins et al 2010), which was the first region in Brazil where it was detected (Deane 1949)
The surveyed localities were chosen based on previous field studies revealing the presence of Simulium species such as S. amazonicum and Simulium oyapockense in this region, which are potential vectors of filarial parasites (Nascimento et al 2009) and could serve as risk factors for simuliid-transmitted diseases in the population
M. ozzardi infections are well known along the Purus River and its tributaries (Medeiros et al 2008, 2009, 2011), but no epidemiological studies aimed at determining the presence and dispersion of this species through strategic points on the border of AM and AC have been performed previously
Summary
Monte Verde, which is located on the left bank of this river, exhibited 63% positive samples, whereas on the opposite side of the river, 54.5% of the volunteers in the locality of Praia do Gado presented blood microfilariae of M. ozzardi (p > 0.05). One volunteer from Andaraí, located along the Antimary River, was positive for microfilariae and all of the individuals from Mapinguari presented blood samples that were negative for microfilariae. Vila Antimary and Porto Acre, situated along the Acre River, both presented some infected individuals, with Vila Antimary displaying a higher prevalence rate (p < 0.05). Division of the subjects according to age/sex revealed that among volunteers under 40 years of age, the prevalence of infection was higher in males (p < 0.05), whereas among those aged 40-50 and over 50 years, the prevalence of infection was distributed evenly between the two sexes (p > 0.05). The results obtained via ELISA using the recombinant proteins Ov10, Ov11 and Ov16 coupled to MBP revealed that IgG responsiveness to the cocktail was negative in 354 of the 355 samples tested, with the one exception coming from Porto Acre
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
