Lung fluke (Paragonimus africanus) infects Nigerian red-capped mangabeys and causes respiratory disease

Abstract

Eggs of the lung fluke genus Paragonimus were detected in red-capped mangabeys (Cercocebus torquatus) in Nigeria. We assess the role of these primates as potential sylvatic hosts and the clinical effects of the parasite on monkeys. DNA sequenced from eggs in feces were 100% identical in the ITS2 region to Paragonimus africanus sequences from humans in Cameroon. Paragonimus-positive monkeys coughed more than uninfected monkeys. Experimental de-worming led to reduction in parasite intensity and a corresponding reduction of coughing to baseline levels in infected monkeys. This report provides the first evidence of Paragonimus sp. in C. torquatus, of P. africanus in Nigerian wildlife, and the first molecular evidence of the parasite in African wildlife. Coughing, sometimes interpreted as a communication behavior in primates, can actually indicate infection with lung parasites. Observations of coughing in primates may, in turn, provide a useful mechanism for surveillance of Paragonimus spp, which are re-emerging human pathogens, in wildlife reservoirs.

Paragonimusand paragonimiasis in West and Central Africa: unresolved questions

“…Identification of parasites to the species level can be undertaken in the light of recent taxonomic advances, new discoveries and DNA technologies (Bayssade-Dufour et al ., 2014, 2015; Friant et al ., 2015). This could establish which species of snails, freshwater crabs and crab-eating mammals serve as hosts and help to clarify the life-history traits of this complex pathogen (Table 1).…”

“…The availability of DNA sequence data now makes it possible to identify Paragonimus spp. from metacercariae or indeed from any part of the life cycle: eggs, larval stages and adult flukes (Bayssade-Dufour et al ., 2014, 2015; Friant et al ., 2015). Using molecular data to identify Paragonimus spp.…”

“…is more accurate than past methods that relied on measurements of adult flukes, metacercariae and eggs recovered from sputum or faecal samples, due to parasite morphological plasticity (Voelker and Vogel, 1965; Voelker, 1973; Voelker et al ., 1975). The availability of improved identification methods is especially important as new species have recently been discovered, suggesting there may be many more to find (Bayssade-Dufour et al ., 2014, 2015; Friant et al ., 2015).…”

“…The species of freshwater crab and the Paragonimus sp. that it is infected with, can be established accurately by morphological and molecular analyses (Cumberlidge, 1999; Daniels and Bayliss, 2012; Friant et al ., 2015). This is essential for future research because a great deal of the literature on paragonimiasis in Cameroon, for example, is based on out-of-date morphological identification systems for both the freshwater crabs (species of Sudanonautes ) and the parasites (species of Paragonimus ; Voelker and Sachs, 1977).…”

“…in the stool signals that the animal has adult flukes in its lungs. DNA analysis of parasite eggs is a non-invasive means of identifying the infecting species (Friant et al ., 2015). In comparison, the removal of adult flukes from the lungs of a mammal host requires that the animal be sacrificed and this should only be performed when absolutely necessary (hopefully rarely).…”