Investigation of polymorphisms in Plasmodium falciparum hrp2, hrp3, aldolase and pldh genes and their impact on the performance of malaria rapid diagnostic tests in Papua New Guinea

@#The World Health Organization (WHO) recommends that parasitological confirmation of clinical malaria diagnosis be performed before antimalarial treatment is administered. Malaria rapid diagnostic tests (RDTs) represent a valuable tool for prompt and efficient diagnosis of malaria in settings where microscopic diagnosis is unavailable or unreliable. Concerns remain, however, that Plasmodium falciparum polymorphisms in the genes coding the antigens detected by RDT could impact on RDT performance. Using field isolates of Plasmodium falciparum, we aimed to characterize genetic variability in histidine-rich proteins 2 and 3 (PfHRP-2 and PfHRP-3), aldolase (ALD) and Plasmodium lactate dehydrogenase (pLDH) genes and to evaluate their impact on the performance of RDT. Pfhrp-2, Pfhrp-3, aldolase and pldh were amplified using polymerase chain reaction (PCR) and sequenced. Genetic variation was observed in pfhrp-2 and pfhrp-3 genes while aldolase and pldh showed high levels of conservation. These findings suggest that RDTs based on pLDH and ALD are reliable in the study settings where there is intense diversity or polymorphisms of histidine-rich protein (HRP). Nevertheless, there is no evidence from this study to suggest that RDTs based on the detection of PfHRP-2 and PfHRP-3 have lower sensitivity in Papua New Guinea (PNG). The results observed in this study will be used to inform the PNG National Department of Health on the continued usage of pLDH/ HRP-2 RDT for malaria diagnosis in PNG.

Shigellosis: A truly neglected disease in Papua New Guinea

@#Diarrhoeal diseases still affect many people, especially children living in impoverished and under-developed settings. In Papua New Guinea (PNG) diarrhoea remains one of the leading causes of hospitalization and a major cause of death. Here, we focus on the role of Shigella in diarrhoeal illness in PNG, and provide an overview of the causative organism and the illness. A review of the available data on the aetiology of diarrhoea in PNG suggests that shigellosis is a major cause of diarrhoeal illness. Since shigellosis can cause protracted and life-threatening illness an appreciation of the burden of shigellosis is important to aid in the development of optimal prevention and control strategies. Treatment strategies for all cases of moderate-severe diarrhoeal illness should centre on rehydration, but where antimicrobial treatment is required consideration should be given to the increasing antimicrobial resistance observed in Shigella isolates in PNG.