Malaria was the most serious endemic disease at the time of European contact. Many local coastal people developed some degree of immunity but European planters and miners, officials and missionaries all suffered from the disease. Non-European laborers and missionary assistants from outside PNG were also seriously affected. In 1900 the German bacteriologist, Robert Koch, studied the effects of quinine on the disease. During World War I quinine was used systematically to treat Australian troops. Between the wars attempts were made to control the disease in the towns by treating the breeding grounds of the malaria-carrying anopheles mosquito. During World War II the Allied troops were successfully treated with mepacrine (atebrin) and experiments were conducted with chloroquine, sulphonamides and proguanil. Between 1942 and 1945 thousands of Japanese soldiers died from malaria.
In spite of stringent administration attempts to control its spread, increased contact between the coast and the highlands in the 1960s resulted in the disease becoming endemic in much of the highlands by the 1970s. The campaign to control malaria included DDT spraying of breeding areas and the distribution of drugs. In 1970 World Health Organization representatives visited PNG to advise on anti-malarial procedures. Attempts made between 1970 and 1990 to eradicate the disease were unsuccessful. Drug-resistant strains of malaria to which the people have no natural immunity appeared in the 1980s. In 1990 malaria was the third most common cause of illness and death and the incidence appeared to be increasing.
Although the overall malaria incidence has declined markedly during the 2008–2012 period (18.2% to 1.6% population parasite prevalence), it still constitutes a significant burden on the health system. The 2016 World Malaria Report (World Health Organization, 2016b) stated that in 2015, there were 297,787 reported confirmed (microscopy and rapid diagnostic tests) cases at health facility level and another 48,644 confirmed cases at community level and 163 reported deaths. The same report estimated the number of cases for 2015 to be at 900,000 (range of 650,000-1,200,000) and an estimated 1200 deaths (range 140-2300. NDoH data confirm that malaria is in the top ten leading causes of hospital and health centre admissions and the second-leading cause of death (Government of Papua New Guinea, 2010c). The entire population is at risk for malaria and 94% live in areas with potentially high transmission (>1 case per 1000 population) (World Health Organization, 2016b). The national proportion of children sleeping under an insecticide-treated bednet is 59%, and there are more male children under 5 years of age sleeping under insecticide-treated bed nets than female children (National Department of Health, 2013b).