A molecular survey of febrile cases in malaria-endemic areas along China-Myanmar border in Yunnan province, People’s Republic of China

• Published in: Parasite (Paris) 2014, Vol.21, p.27-27
• Main Authors: Zhou, Xia, Huang, Ji-Lei, Njuabe, Metoh Theresia, Li, Sheng-Guo, Chen, Jun-Hu, Zhou, Xiao-Nong
• Format: Article
• Language: English
• Subjects: Adult; Child; China - epidemiology; Diagnosis; Diagnostic Errors; Diagnostic systems; DNA, Protozoan - genetics; Emigration and Immigration; Endemic Diseases; Erythrocytes; False Negative Reactions; Fever - blood; Fever - etiology; Humans; Infections; Malaria; Malaria - blood; Malaria - complications; Malaria - diagnosis; Malaria - epidemiology; Malaria - parasitology; Malaria - transmission; Microscopy; Molecular chains; Myanmar; Myanmar - epidemiology; Nested PCR; P.R. China; Parasite Load; Parasitemia; Parasitemia - diagnosis; Parasitemia - epidemiology; Patients; Phylogeny; Plasmodium; Plasmodium - classification; Plasmodium - genetics; Plasmodium falciparum; Plasmodium knowlesi; Plasmodium malariae; Plasmodium ovale; Plasmodium vivax; Polymerase Chain Reaction; Ribotyping; RNA, Protozoan - genetics; RNA, Ribosomal, 18S - genetics; Sampling Studies; Species Specificity; Surveillance; Transients and Migrants; Vector-borne diseases
• ISSN: 1776-1042; 1252-607X; 1776-1042
• DOI: 10.1051/parasite/2014030

Background: Imported malaria is a major threat to neighboring malaria-eliminating countries such as P.R. China and is difficult to monitor. A molecular survey of febrile patients with a history of traveling abroad along the Myanmar-China endemic border areas from January 2008 to August 2012 was carried out. The rates of infection with species of Plasmodium and compliance of microscopy diagnosis with nested PCR (Polymerase Chain Reaction) results were calculated. Results: Plasmodium genus-specific nested PCR confirmed that 384 cases were positive. Further species-specific nested PCR showed that the rate of Plasmodium vivax infection was 55% (213/384); that of Plasmodium falciparum was 21% (81/384) and 17% (67/384) of cases were co-infection cases of P. vivax and P. falciparum; the remaining 6% (23/384) of cases were caused by other species, such as Plasmodium ovale, P. malaria, P. knowlesi or mixed infections of Plasmodium. In total there was 13% (50/384) false microscopy diagnosis including 6% (22/384) error in species diagnosis and 7% (28/384) undiagnosed cases in co-infection or low parasitemia malaria cases. Conclusions: This study indicates that there are considerable numbers of malaria cases in the China-Myanmar endemic border areas that remain undiagnosed or misdiagnosed by microscopy, especially in low-level and/or complex co-infection cases. It is urgent to develop accurate rapid diagnostic tests and apply PCR confirmation for efficient surveillance. Introduction : Le paludisme importé est une menace majeure pour les pays voisins qui éliminent le paludisme tels que République Populaire de Chine et est difficile à surveiller. Une enquête moléculaire a été réalisée sur des patients fébriles avec une histoire de voyage à l’étranger dans les zones endémiques frontalières Myanmar - Chine de janvier 2008 à août 2012. Les taux d’infection des espèces de Plasmodium et de conformité du diagnostic microscopique et des résultats PCR nichée ont été calculés. Résultats : la PCR nichée du genre Plasmodium a confirmé que 384 cas étaient positifs au genre. La PCR nichée spécifique aux espèces a montré que le taux d’infection à P. vivax était de 55 % (213/384), celui de P. falciparum de 21 % (81/384) et que 17 % (67/384) des cas étaient des cas de coinfection de P. vivax et P. falciparum. Les 6 % restants (23/384) des cas étaient causés par des infections d’autres espèces, telles que P. ovale, P. malariae, P. knowlesi ou des infections de Plasmodium mélangées. Au t