dr. rebecca duerst, program director for health care elca synod malaria summit 20-22 march 2014
TRANSCRIPT
THE SCIENCE OF MALARIA: BIOLOGY, EPIDEMIOLOGY & PUBLIC HEALTH
Dr. Rebecca Duerst, Program Director for Health Care
ELCA Synod Malaria Summit20-22 March 2014
Outline
True or False on malaria biology, epidemiology, and public health
Scientific advances in malaria work Time for Q&A
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 Anopheles mosquitoes
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 5th species, 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
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. b Sporozoites are carried in the bloodstream to liver cells, where they proliferate asexually and release merozoites. c Merozoites 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.
True or False?Epidemiology, Question 1 Q: Epidemiology is the branch of
medicine dealing with physiology 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)
True or False?Epidemiology, Question 2 Q: Africa carries the majority of the world’s burden of
malaria A: True
True or False?Epidemiology, Question 3 Q: Malaria has no relationship to poverty, HIV&AIDS,
climate change, etc. A: False www.gapminder.org
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
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
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
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
SCIENTIFIC ADVANCES IN MALARIA RESEARCH
New ideas & technological innovations
Testing & Diagnosis:Detection methods Phone camera microscopes
“CellScope” (relatively expensive) 1mm glass ball, cardboard, tape
“Origami” microscope (6 March 2014) http://youtu.be/pBjIYB5Yk2I
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).
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
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
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)
Thank you!