Evidence for transmission of Plasmodium vivax among a duffy antigen negative population in Western Kenya.
We present evidence that a parasite with characteristics of Plasmodium vivax is being transmitted among Duffy blood group-negative inhabitants of Kenya. Thirty-two of 4,901 Anopheles gambiae and An. funestus (0.65%) collected in Nyanza Province were ELISA positive for the P. vivax circumsporozoite protein VK 247. All positives were found late in the rainy season, when An. funestus predominated, and disproportionately many were found at a single village. A P. vivax specific sequence of the SSU rRNA gene was amplified from three of six ELISA-positive mosquitoes. Erythrocytes from 31 children, including 9 microscopically diagnosed as infected with P. vivax, were negative by flow cytometry for the Fy3 or Fy6 epitopes, which indicate Duffy blood group expression. A DNA fragment specific for the C terminus of the gene for P. vivax merozoite surface protein 1 (MSP-1) was amplified from the blood of four of these children and subsequently sequenced from two.
Ryan
Jeffrey R
JR
Walter Reed Army Institute of Research, Washington, DC, USA. Quetzal6E@netscape.net
Stoute
José A
JA
Amon
Joseph
J
Dunton
Raymond F
RF
Mtalib
Ramadhan
R
Koros
Joseph
J
Owour
Boaz
B
Luckhart
Shirley
S
Wirtz
Robert A
RA
Barnwell
John W
JW
Rosenberg
Ronald
R
D000595:Amino Acid Sequence; D000818:Animals; D000852:Anopheles / Q000469:parasitology*; D002648:Child; D016054:DNA, Protozoan / Q000032:analysis; D004375:Duffy Blood-Group System / Q000097:blood / Q000235:genetics / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D004912:Erythrocytes / Q000276:immunology / Q000469:parasitology; D006801:Humans; D007303:Insect Vectors / Q000469:parasitology*; D007630:Kenya; D016780:Malaria, Vivax / Q000097:blood / Q000235:genetics / Q000635:transmission*; D020066:Merozoite Surface Protein 1 / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D010966:Plasmodium vivax / Q000302:isolation & purification*; D015800:Protozoan Proteins / Q000032:analysis; D011956:Receptors, Cell Surface / Q000097:blood / Q000235:genetics / Q000276:immunology
C473745:ACKR1 protein, human; D016054:DNA, Protozoan; D004375:Duffy Blood-Group System; D020066:Merozoite Surface Protein 1; D015800:Protozoan Proteins; D011956:Receptors, Cell Surface; C041595:circumsporozoite protein, Protozoan