Using serological measures to monitor changes in malaria transmission in Vanuatu

Autor: Heidi Reid, Chris Drakeley, Archie C. A. Clements, Jackie Cook, Andrew Vallely, James S. McCarthy, Jennifer Iavro, George Taleo, Melissa Kuwahata
Rok vydání: 2010
Předmět:
Male
Plasmodium vivax
Protozoan Proteins
Antibodies
Protozoan
law.invention
Vanuatu
Seroepidemiologic Studies
law
Prevalence
Malaria
Falciparum
Child
Merozoite Surface Protein 1
Aged
80 and over
Middle Aged
Infectious Diseases
Transmission (mechanics)
Child
Preschool
Adult
medicine.medical_specialty
lcsh:Arctic medicine. Tropical medicine
Adolescent
lcsh:RC955-962
Plasmodium falciparum
Antigens
Protozoan
Enzyme-Linked Immunosorbent Assay
Biology
lcsh:Infectious and parasitic diseases
Young Adult
Environmental health
parasitic diseases
Malaria
Vivax
medicine
Humans
Seroprevalence
lcsh:RC109-216
Seroconversion
Aged
Research
Infant
Newborn
Infant
Membrane Proteins
medicine.disease
biology.organism_classification
Virology
Cross-Sectional Studies
Parasitology
Immunoglobulin G
Tropical medicine
Malaria
Zdroj: Malaria Journal
Malaria Journal, Vol 9, Iss 1, p 169 (2010)
ISSN: 1475-2875
Popis: Background With renewed interest in malaria elimination, island environments present unique opportunities to achieve this goal. However, as transmission decreases, monitoring and evaluation programmes need increasingly sensitive tools to assess Plasmodium falciparum and Plasmodium vivax exposure. In 2009, to assess the role of serological markers in evaluating malaria transmission, a cross-sectional seroprevalence study was carried out in Tanna and Aneityum, two of the southernmost islands of the Vanuatu archipelago, areas where malaria transmission has been variably reduced over the past few decades. Methods Malaria transmission was assessed using serological markers for exposure to P. falciparum and P. vivax. Filter blood spot papers were collected from 1,249 people from Tanna, and 517 people from Aneityum to assess the prevalence of antibodies to two P. falciparum antigens (MSP-119 and AMA-1) and two P. vivax antigens (MSP-119 and AMA-1). Age-specific prevalence was modelled using a simple catalytic conversion model based on maximum likelihood to generate a community seroconversion rate (SCR). Results Overall seropositivity in Tanna was 9.4%, 12.4% and 16.6% to P. falciparum MSP-119, AMA-1 and Schizont Extract respectively and 12.6% and 15.0% to P. vivax MSP-119 and AMA-1 respectively. Serological results distinguished between areas of differential dominance of either P. vivax or P. falciparum and analysis of age-stratified results showed a step in seroprevalence occurring approximately 30 years ago on both islands, indicative of a change in transmission intensity at this time. Results from Aneityum suggest that several children may have been exposed to malaria since the 2002 P. vivax epidemic. Conclusion Seroepidemiology can provide key information on malaria transmission for control programmes, when parasite rates are low. As Vanuatu moves closer to malaria elimination, monitoring changes in transmission intensity and identification of residual malaria foci is paramount in order to concentrate intervention efforts.
Databáze: OpenAIRE
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