Interpret data relating to the incidence and prevalence of infectious disease in populations, for example:

• Mobility of individuals and the portion that are immune or immunised (ACSBL124, ACSBL125)
• Malaria or Dengue Fever in South East Asia

Incidence of Malaria in South East Asia:

• Of the 10 malaria-endemic countries in the South-East Asia Region, 5 reported decreases in malaria cases and incidence rates of ≥75% between 2000 and 2011.
• Bhutan, DPR Korea, Nepal, Sri Lanka and Thailand reported decreases in the number and incidence rate of microscopically confirmed cases of ≥75% since 2000.
• Bangladesh recorded a decrease of 69% in malaria case incidence between 2000 and 2011 and is therefore on track to achieve a decrease of 75% by 2015.
• India has reported a slow but steady decline in case numbers of 36%, and case incidence of 45%, between 2000 and 2010, while continuing to examine more than 100 million blood slides each year.

Prevalence of Malaria in South East Asia:

• In South-East Asia Region approximately 70% of the population of 1.8 billion people is at some risk for malaria, with 26% at high risk: 460 million people inhabit areas with a reported incidence of >1 case per 1000 population per year.
• In the past, the South Asia/Southeast Asia region annually was estimated to contribute about 30% to the estimated 300–500 million global cases of malaria and about 8% of the global 1 million malaria deaths.
• By these WHO calculations, the estimated number of malaria cases in South Asian region are on the order of 90–167 million cases and estimated deaths are on the order of 125,000 per year. The majority of the malaria incidence in South East Asia is contributed by India followed by Indonesia, Myanmar, and Thailand.
• After the national malaria eradication campaigns of 1957–1959, malaria was negligible in the region with only 1037 reported cases and no deaths. During the resurgence phase in the 1960s and 1970s, malaria made a spectacular come-back in the region. At its peak, there were 7.2 million cases with API of 8.8, SPR of 9.7% and P. falciparum representing 14% of the cases. During the 1990s, the reported incidence stabilized to about 2–3 million malaria cases and the reported deaths attributable to malaria increased to 8061 in 1996. This increase in mortality corresponded to the gradual rise in P. falciparum to about 60% of malaria infections. However, as discussed, the true burden of mortality may be higher than reported by the National Malaria Control Programs of the member countries.
• In 2009, a total of 2.7 million cases of malaria were reported in South East Asia (source WHO). Of these, India alone contributed 1.6 million (58%) cases. This was followed by Indonesia with 0.5 million cases (20%). Among the rest of the countries, Myanmar contributed 0.4 million (16%). The other countries together contributed to the remaining 6% of malaria.

Extract from HSC Biology Stage 6 Syllabus. © 2017 Board of Studies NSW.