The science of malaria: Biology , epidemiology & public health

1. Dr. Rebecca Duerst, Program Director for Health Care ELCA Synod Malaria Summit 20-22 March 2014 The science of malaria: Biology, epidemiology & public health

2. Outline • True or False on malaria biology, epidemiology, and public health • Scientific advances in malaria work • Time for Q&A

3. True or False?Biology, Question 1 • Q: Malaria is caused by mosquitos • A: False • Explanation: Malaria is caused by parasites in the genus Plasmodium; it is transmitted by female Anophelesmosquitoes

4. True or False?Biology, Question 2 • Q: There are 4 species of Plasmodia known to cause malaria in humans • A: False • The 4 main species causing human malaria are: • Plasmodium falciparum • Plasmodium ovale • Plasmodium vivax • Plasmodium malariae • A 5thspecies, Plasmodium knowlesi(“nolls-eye”), is now recognized as an important cause of human disease in Southeast Asia; it is responsible for up to 75% of malaria infections in some areas

5. True or False?Biology, Question 3 • Q: The life cycle of Plasmodium parasites is complex • A: True • http://www.cdc.gov/malaria/about/biology a Female Anopheles mosquitoes require a blood meal for egg development. Infected females inject the sporozoite form into a human host. bSporozoites are carried in the bloodstream to liver cells, where they proliferate asexually and release merozoites. cMerozoites invade red blood cells and reproduce asexually; disease clinically manifests as fever & chills. d Then male and female gametocytes are produced and transmitted back to a mosquito, where they fuse to form oocysts that divide into sporozoites. These migrate to the salivary glands.

6. True or False?Epidemiology, Question 1 • Q: Epidemiology is the branch of medicine dealing withphysiology and pathology of the skin • A: False • Epidemiology is the study of distribution and determinants of health-related states / events (including disease), and the application of this study to control diseases and other health problems(WHO)

7. True or False?Epidemiology, Question 2 • Q: Africa carries the majority of the world’s burden of malaria • A: True

8. True or False?Epidemiology, Question 3 • Q: Malaria has no relationship to poverty, HIV&AIDS, climate change, etc. • A: False • www.gapminder.org

9. True or False?Public Health, Question 1 • Q: Despite much progress, malaria is still a major public health concern globally • A: True • 2012 estimated malaria cases: • 207 million • 80% occur in sub-Saharan Africa • 2012 estimated malaria deaths: • 627,000 • 90% occur in sub-Saharan Africa, 77% in children under 5 years of age • An estimated 3.3 million deaths were averted between 2000-2012

10. True or False?Public Health, Question 2 • Q: Focusing efforts only on net distribution is the best strategy for malaria prevention • A: False • WHO promotes integrated approach (“integrated vector management”) including LLINs, IRS, & environmental management, along with education, prompt diagnosis and effective treatment, surveillance, etc. • http://www.npr.org/blogs/health/2014/01/03/257627285/why-ending-malaria-may-be-more-about-backhoes-than-bed-nets

11. True or False?Public Health, Question 3 • Q: Artemisinin (key ingredient in ACT) is still 100% effective throughout the world • A: False • Parasite resistance to artemisinins has been detected in 4 countries in Southeast Asia • Cambodia, Myanmar, Thailand and Viet Nam • In Cambodia, resistance has been found to both components of ACT • Special provisions have been made for DOT with a non-artemisinin-based combination

12. True or False?Final Question • Q: Because malaria is such a focus of global health efforts, extensive, accurate data is available • A: False • There is more uncertainty about malaria than any other disease • Malaria surveillance systems detect <10% of estimated cases - Richard Cibulskis, WHO Global Malaria Programme, 2011

13. New ideas & technological innovations Scientific advances In Malaria Research

14. Testing & Diagnosis:Detection methods • Phone camera microscopes • “CellScope” (relatively expensive) • 1mm glass ball, cardboard, tape • “Origami” microscope (6 March 2014) • http://youtu.be/pBjIYB5Yk2I

15. Testing & Diagnosis:Detection methods • “Matibabu” blood scanner (Swahili for “medical center”) • http://news.discovery.com/tech/videos/phone-app-diagnoses-malaria-video.htm Brian Gitta, Makerere University, Uganda pitches his idea that uses cell phones and light – not needles and blood samples to test for malaria(USAID).

16. Malaria vaccinePrime candidates • PfSPZ (Sanaria) – August, 2013 • 6 volunteers received 5 IV doses each, over 20 weeks • 100% protection, but impractical conditions • RTS,S (GSK) – October, 2013 (18 mo. follow-up) • Protection lasted over 18 months, though waned slightly • Reduced malaria cases in children by nearly half (46%) • Adding a booster dose at 18 months is now being studied • Policy recommendation from WHO is possible in 2015 • http://www.npr.org/blogs/health/2013/10/08/230356317/first-malaria-vaccine-moves-a-step-closer-to-approval

17. DrugsNew targets? • AP2-G protein – February, 2014 • Master switch that triggers activation of genes that initiate the development of gametocytes (only form infectious to mosquitos) • CAX protein – April, 2013 • Transporter that controls calcium level inside cells (Artemisinin interferes with the other Ca+2 transporter) • Parasites die before developing inside mosquito when CAX does not function

18. MosquitosAltering the vector • GM mosquitos (?) • Mosquito blood has proteins that punch holes through the parasite’s membrane • Engineer mosquitos that produce in higher amounts • Wolbachia-infected mosquitos • Bacteria naturally occuring in other species of mosquitos • Confers resistance to malaria (and dengue virus)

19. Thank you!