Human paragonimiasis in Africa

Abstract

An up-to-date review on human paragonimiasis in Africa was carried out to determine the current geographical distribution of human cases and analyze the animal reservoir, snails and crustaceans which intervene in the local life cycle of Paragonimus species. Two countries, i.e., Cameroon and Nigeria, were mainly affected by this disease, while the distribution of human cases in the other eight states of the intertropical zone was scattered. Infected patients were currently few in number and two Paragonimus species: P. africanus and P. uterobilateralis, were found. The animal reservoir is mainly constituted by crab-eating mammals. The identity of the host snail remains doubtful and was either a prosobranch, or a land snail. Seven crab species belonging to Callinectes, Liberonautes and Sudanonautes genera are able to harbour paragonimid metacercariae. Due to the current low prevalence of human paragonimiasis recorded in Africa and the high cost of wide-scale screenings for this disease, training of technicians in anti-tuberculosis centers would be the most realistic attitude to detect mycobacteria and/or Paragonimus eggs during the same sputum examination. Key words: Paragonimus spp., Africa, human paragonimiasis, intermediate hosts, tuberculosis RésuméUne revue sur la paragonimose en Afrique a été réalisée pour déterminer la distribution géographique actuelle des cas humains et analyser le réservoir animal, les mollusques et les crustacés qui interviennent dans le cycle local des espèces de Paragonimus. Deux pays, à savoir le Cameroun et le Nigeria, sont principalement affectés par cette maladie tandis que la répartition des cas humains dans les huit autres états de la zone intertropicale est dispersée. Les patients parasités sont actuellement peu nombreux et deux espèces de Paragonimus: P. africanus et P. uterobilateralis, ont été identifiées. Le réservoir animal est principalement constitué par des mammifères mangeurs de crabes. L'identité du mollusque hôte reste douteuse et se rapporte à un prosobranche ou à un mollusque terrestre. Sept espèces de crabes appartenant aux genres Callinectes, Liberonautes et Sudanonautes sont capables d'héberger des métacercaires de Paragonimus. En raison de la faible prévalence actuelle de la paragonimose humaine en Afrique et du coût élevé du dépistage à grande échelle pour cette maladie, la formation des techniciens dans les centres anti-tuberculeux serait l'attitude la plus réaliste pour détecter simultanément les mycobactéries ou les oeufs de Paragonimus, lors de l'examen du même crachat.

Potential Pathogens Reported in Species of the Family Viverridae and Their Implications for Human and Animal Health

“…(Baugh, 1962;Casanova et al, 2000); and Paragonimus spp. in a wide range of civet species (Chen, 1959;Dissanaike and Paramananthan, 1961;Sachs et al, 1986;Gang et al, 1999;Aka et al, 2009;Colon and Patton, 2013;Su et al, 2013). The vast majority of platyhelminthes reported for viverrids were identified by examining morphology of different stages within the parasite's life cycle.…”

“…Detailed descriptions of clinical signs seen in viverrids were included in a small number of reports, including an investigation into morbidity or mortality in Viverridae (Roberton et al, 2006), and the documentation of experimental infection of viverrids with SARS CoV (Wu et al, 2005). However, most (Chen, 1959;Dissanaike and Paramananthan, 1961;Sachs et al, 1986;Gang et al, 1999;Aka et al, 2009;Colon and Patton, 2013;Su et al, 2013) Z, zoonotic potential acknowledged; M, platyhelminth affects multiple hosts other than Viverridae. (Hoogstraal and Trapido, 1966;Hoogstraal, 1971;Tanskul et al, 1983;Tolosa and Regassa, 2007;Mediannikov et al, 2012) Rhipicephalus haemaphysaolides Taiwan, Malaysia, India, Vietnam, Myanmar (wild) (Hoogstraal and Wassef, 1985;Hoogstraal et al, 1986) Family Trichodectidae (Chewing lice) Felicola bengalensis…”

No Paragonimus in high-risk groups in Côte d'Ivoire, but considerable prevalence of helminths and intestinal protozoon infections

“…In Africa, paragonimiasis has been mainly reported from the West and Central Equatorial region [2,4]. Cameroon and Nigeria are the most affected countries [5]. Paragonimiasis has a complex life cycle with two intermediate hosts; freshwater snails act as the first intermediate host, whereas freshwater crustaceans serve as the second intermediate host, in which the parasites encyst as metacercariae [1,2,6].…”

Malnutrition Featured During the Nigerian Civil War as both Classical Kwashiorkor and Nascent Paragonimiasis

“…The post-war situation Eggs endowed with this particular shape abounded and were being documented thoroughly [7]. Interestingly, the adult egg-laying worms had never been identified within human beings.…”