Study to Understand Resistance to Malaria in Papua New Guinea

The Papua New Guinea Institute of Medical Research have recruited malaria cases and healthy controls to contribute to Consortial Project 1. These individuals have been collected from Madang province, on the northern coast of mainland Papua New Guinea. Madang province has a population of approximately 300,000 people, the majority of whom live as subsistence famers outside peri-urban areas. Plasmodium falciparum and P. vivax are transmitted with an entomological inoculation rate (EIR) of 50-150 per year. 

Description of study population - Cases

Cases consist of children (5 months-12 years) with signs of severe or uncomplicated malaria. Severe malaria cases were recruited from the Modillion Hospital, the main referral centre for Madang province, during three time periods: 1993-1995, August 2003-April 2004 and October 2006-ongoing. Uncomplicated malaria cases were recruited from community based health clinics and government based primary care clinics around Madang town, matched by age, sex and ethnicity to a severe malaria case collected from October 2006 onwards.

The criteria for inclusion of severe malaria cases varied slightly. For those recruited between 1993-95 the WHO 1990 definition for severe childhood malaria was used. Between 2003-2004 the entry criteria were based on the WHO 2000 definition for severe malaria. In addition, cases had to have resided in Madang province for the previous 12 months. Severe malaria cases collected from October 2006 onwards were included on the basis of the WHO 2000 definitions in addition to the following: parasitaemia (>1000 P. falciparum/mL and >500 P. vivax/mL) and parents from the North Coast (Madang, Morobe and Sepik). Uncomplicated malaria cases were defined by a history of or current fever, with either a positive rapid diagnostic test for malaria or plasmodial parasites.

Description of study population - Controls

Controls consist of apparently healthy children (2 months-12 years) recruited during three time periods: 1993-1995, 2007 and October 2006-ongoing. Controls collected between 1993-1995 were recruited from the community soon after the recruitment of a severe malaria case, individually matched as closely as possible to a case for ethnicity, age, gender and residence.  Controls collected in 2007 were individually matched by age and gender to a severe malaria case collected between 2003-2004, while controls collected from October 2006 onwards have been individually matched by age, gender and ethnicity to a severe malaria case collected from October 2006 onwards. Children with chronic minor skin infections were considered for enrollment as healthy controls during 2007 and October 2006 onwards. Eligible controls had no recent history of malaria and if they had a history of fever, they had a negative rapid diagnostic test for malaria.