Background: Plasmodium vivax (P. vivax) is considered as absent in West/Central Africa because of the high prevalence of Duffy antigen negativity in the local human population. Duffy antigen on red blood cells is the only well-known receptor allowing the entry of P.vivax. However, in recent years, several studies reported P. vivax infections in sub-Saharan Africa among Duffy negative individuals, including two studies performed in the southern part of Cameroon (Centre, South, Littoral, North-West and East Regions). Our research aims to assess the possible circulation of P. vivax and its association with the Duffy genotype among outpatients reporting fever and attending health facilities in Santchou and Dschang Health Districts (West-Cameroon), located at 700 and 1,400 meters above the sea level respectively. Material and methods: Samples collection was performed using dried blood spots during the dry season(December-February) in Dschang andrainy season in Santchou (August-December). All samples were analyzed by molecular conventional methods (PCR) and the Duffy genotyping was assessed for all the P. vivax positive samples. Results: In total, 884 samples were collected and malaria parasite DNA was detected in 247 (27.9%)samples. In particular, 241 cases of Plasmodium mono-infections (212 P. falciparum, 26P. vivax, 2 P. ovale, 1 P. malariae) and 6 cases of co-infections (3 falciparum/vivax,2 faciparum/ovale, 1 falciparum/malariae) were detected. Globally, P. vivaxhas been detected in 29 cases (11.7% of positive samples), mainly from Dschang (n=27) than Santchou (n=2). All the P. vivaxpositive cases have shown a Duffy-negative genotype (-33CC). Conclusions: Our data show, for the first time to our knowledge, the circulation of P.vivax in the West Region of Cameroon among Duffy-negative authoctonous individuals, with a prevalence possibly dependending from altitude and seasonality. Further data are necessary in order to assess the real P. vivax local circulation, as well as to identify Duffy-independent P. vivax erythrocyte invasion pathway. Furthermore, in a public health point of view, it is necessary to improve the local microscopic diagnostic capacity in order to ensure a more effective and safer therapeutic management of vivax malaria attacks and relapses.
Molecular Evidence of Plasmodium Vivax Infection in Duffy-Negative Symptomatic Autochthones Individuals from West Cameroon / DJEUNANG DONGHO, GHYSLAINE BRUNA; Paganotti, GIACOMO MARIA; Sanou Sobze, Martin; Muthoga, Charles Waïtaka; Leabaneng, Tawe; Tiotsia Tsapi, Armand; Mpoame, Mbida; Russo, Gianluca. - ELETTRONICO. - (2017), p. 63162. (Intervento presentato al convegno 6th International Conference on Plasmodium Vivax Reseach tenutosi a Manaus, Brazil nel 11-14 June 2017).
Molecular Evidence of Plasmodium Vivax Infection in Duffy-Negative Symptomatic Autochthones Individuals from West Cameroon
DJEUNANG DONGHO, GHYSLAINE BRUNA;PAGANOTTI, GIACOMO MARIA;RUSSO, Gianluca
2017
Abstract
Background: Plasmodium vivax (P. vivax) is considered as absent in West/Central Africa because of the high prevalence of Duffy antigen negativity in the local human population. Duffy antigen on red blood cells is the only well-known receptor allowing the entry of P.vivax. However, in recent years, several studies reported P. vivax infections in sub-Saharan Africa among Duffy negative individuals, including two studies performed in the southern part of Cameroon (Centre, South, Littoral, North-West and East Regions). Our research aims to assess the possible circulation of P. vivax and its association with the Duffy genotype among outpatients reporting fever and attending health facilities in Santchou and Dschang Health Districts (West-Cameroon), located at 700 and 1,400 meters above the sea level respectively. Material and methods: Samples collection was performed using dried blood spots during the dry season(December-February) in Dschang andrainy season in Santchou (August-December). All samples were analyzed by molecular conventional methods (PCR) and the Duffy genotyping was assessed for all the P. vivax positive samples. Results: In total, 884 samples were collected and malaria parasite DNA was detected in 247 (27.9%)samples. In particular, 241 cases of Plasmodium mono-infections (212 P. falciparum, 26P. vivax, 2 P. ovale, 1 P. malariae) and 6 cases of co-infections (3 falciparum/vivax,2 faciparum/ovale, 1 falciparum/malariae) were detected. Globally, P. vivaxhas been detected in 29 cases (11.7% of positive samples), mainly from Dschang (n=27) than Santchou (n=2). All the P. vivaxpositive cases have shown a Duffy-negative genotype (-33CC). Conclusions: Our data show, for the first time to our knowledge, the circulation of P.vivax in the West Region of Cameroon among Duffy-negative authoctonous individuals, with a prevalence possibly dependending from altitude and seasonality. Further data are necessary in order to assess the real P. vivax local circulation, as well as to identify Duffy-independent P. vivax erythrocyte invasion pathway. Furthermore, in a public health point of view, it is necessary to improve the local microscopic diagnostic capacity in order to ensure a more effective and safer therapeutic management of vivax malaria attacks and relapses.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
