: Malaria remains one of the most important infectious diseases in the world. Transmission of malaria is contingent on the sporogonic development of Plasmodium parasites within mosquitoes. Sporogony is a complex process involving several morphologically distinct life stages and can be described in terms of parasite population dynamics. Most of our knowledge about sporogony comes from laboratory model systems. There are very few studies that have attempted to examine in a rigorous, quantitative fashion the process of sporogony as it occurs in nature. The major hypotheses of this proposal are that 1) parasite sporogony is more efficient in the field than in the laboratory and 2) there are key life stage transitions that determine the probability of sporogonic success within the vector (i.e., developmental bottlenecks). The magnitude and anatomical site of these bottlenecks within the mosquito may differ for different parasites developing in different mosquito species. The objective of this proposal is to use a population dynamics approach to identify the key life stage transitions that most strongly influence the success of Plasmodium falciparum and P. vivax sporogony within indigenous vector populations. The experimental approach will involve controlled mosquito infections with naturally occurring Plasmodium falciparum and P. vivax parasites, using local anopheline species. The parasite populations developing within infected mosquitoes will be sampled throughout sporogonic development and the densities of key parasite life stages (i.e., gametocytes, ookinetes, oocysts and sporozoites) will be quantified. The relative efficiencies of life stage transitions (changes in abundance) and the degree of heterogeneity in mosquito susceptibility to infection (frequency distributions) will be compared among mosquito infections. The proposed studies will be conducted in a small village in western Thailand. Studies are in collaboration with existing U.S. military field research efforts and the Thai Ministry of Public Health in an effort to understand how the population dynamics of sporogony correlate to the epidemiology of local malaria transmission. This project represents the first long-term examination of the natural population dynamics of malaria parasites within their natural vectors and will lead to a better understanding of how plasmodial parasites survive and are maintained within mosquitoes in the field.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI048813-03
Application #
6654878
Study Section
Special Emphasis Panel (ZRG1-TMP (01))
Program Officer
Costero, Adriana
Project Start
2001-09-01
Project End
2005-06-30
Budget Start
2003-07-01
Budget End
2005-06-30
Support Year
3
Fiscal Year
2003
Total Cost
$282,600
Indirect Cost
Name
University of North Dakota
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
102280781
City
Grand Forks
State
ND
Country
United States
Zip Code
58202
Zollner, Gabriela; Sattabongkot, Jetsumon; Vaughan, Jefferson A et al. (2016) LONGITUDINAL EVALUATION OF MALARIA EPIDEMIOLOGY IN AN ISOLATED VILLAGE IN WESTERN THAILAND: I. STUDY SITE AND ADULT ANOPHELINE BIONOMICS. Southeast Asian J Trop Med Public Health 47:341-65
Tanabe, Kazuyuki; Zollner, Gabriela; Vaughan, Jefferson A et al. (2015) Plasmodium falciparum: genetic diversity and complexity of infections in an isolated village in western Thailand. Parasitol Int 64:260-6
Noden, Bruce H; Vaughan, Jefferson A; Pumpuni, Charles B et al. (2011) Mosquito ingestion of antibodies against mosquito midgut microbiota improves conversion of ookinetes to oocysts for Plasmodium falciparum, but not P. yoelii. Parasitol Int 60:440-6
Tkach, Vasyl V; Snyder, Scott D; Vaughan, Jefferson A (2009) A new species of blood fluke (Digenea: Spirorchiidae) from the Malayan box turtle, Cuora amboinensis (Cryptodira: Geomydidae) in Thailand. J Parasitol 95:743-6
Poudel, Shreekanta S; Newman, Robert A; Vaughan, Jefferson A (2008) Rodent Plasmodium: population dynamics of early sporogony within Anopheles stephensi mosquitoes. J Parasitol 94:999-1008
Coleman, Russell E; Sattabongkot, Jetsumon; Promstaporm, Sommai et al. (2006) Comparison of PCR and microscopy for the detection of asymptomatic malaria in a Plasmodium falciparum/vivax endemic area in Thailand. Malar J 5:121
Kuzmin, Yuriy; Tkach, Vasyl V; Vaughan, Jefferson A (2005) Rhabdias kongmongthaensis sp. n. (Nematoda: Rhabdiasidae) from Polypedates leucomystax (Amphibia: Anura: Rhacophoridae) in Thailand. Folia Parasitol (Praha) 52:339-42
Coleman, Russell E; Kumpitak, Chalermpon; Ponlawat, Alongkot et al. (2004) Infectivity of asymptomatic Plasmodium-infected human populations to Anopheles dirus mosquitoes in western Thailand. J Med Entomol 41:201-8