Skip to main content
main-content

01.12.2012 | Research | Ausgabe 1/2012 Open Access

Malaria Journal 1/2012

Sero-epidemiological evaluation of changes in Plasmodium falciparum and Plasmodium vivax transmission patterns over the rainy season in Cambodia

Zeitschrift:
Malaria Journal > Ausgabe 1/2012
Autoren:
Jackie Cook, Nico Speybroeck, Tho Sochanta, Heng Somony, Mao Sokny, Filip Claes, Kristel Lemmens, Michael Theisen, Irene S Soares, Umberto D'Alessandro, Marc Coosemans, Annette Erhart
Wichtige Hinweise

Electronic supplementary material

The online version of this article (doi:10.​1186/​1475-2875-11-86) contains supplementary material, which is available to authorized users.

Competing interests

The authors declare that they have no competing interests.

Authors' contributions

JC analysed the data and wrote the paper; NS contributed to the data analysis and paper review; TS supervised all the field work activities; HS contributed to the study design and fieldwork supervision; MS carried out and coordinated the fieldwork; FC supervised the sample processing with ELISA; KL processed all blood samples with ELISA; MT and IS contributed antigen to the project; UDA contributed to the study design, data analysis and reviewed the manuscript; MC contributed to the study design and coordination of all field and laboratory activities and reviewed the paper; AE contributed to the study design, the supervision of the laboratory activities, the data analysis, and reviewed the paper. All authors read and approved the final manuscript.

Abstract

Background

In Cambodia, malaria transmission is low and most cases occur in forested areas. Sero-epidemiological techniques can be used to identify both areas of ongoing transmission and high-risk groups to be targeted by control interventions. This study utilizes repeated cross-sectional data to assess the risk of being malaria sero-positive at two consecutive time points during the rainy season and investigates who is most likely to sero-convert over the transmission season.

Methods

In 2005, two cross-sectional surveys, one in the middle and the other at the end of the malaria transmission season, were carried out in two ecologically distinct regions in Cambodia. Parasitological and serological data were collected in four districts. Antibodies to Plasmodium falciparum Glutamate Rich Protein (GLURP) and Plasmodium vivax Merozoite Surface Protein-119 (MSP-119) were detected using Enzyme Linked Immunosorbent Assay (ELISA). The force of infection was estimated using a simple catalytic model fitted using maximum likelihood methods. Risks for sero-converting during the rainy season were analysed using the Classification and Regression Tree (CART) method.

Results

A total of 804 individuals participating in both surveys were analysed. The overall parasite prevalence was low (4.6% and 2.0% for P. falciparum and 7.9% and 6.0% for P. vivax in August and November respectively). P. falciparum force of infection was higher in the eastern region and increased between August and November, whilst P. vivax force of infection was higher in the western region and remained similar in both surveys. In the western region, malaria transmission changed very little across the season (for both species). CART analysis for P. falciparum in the east highlighted age, ethnicity, village of residence and forest work as important predictors for malaria exposure during the rainy season. Adults were more likely to increase their antibody responses to P. falciparum during the transmission season than children, whilst members of the Charay ethnic group demonstrated the largest increases.

Discussion

In areas of low transmission intensity, such as in Cambodia, the analysis of longitudinal serological data enables a sensitive evaluation of transmission dynamics. Consecutive serological surveys allow an insight into spatio-temporal patterns of malaria transmission. The use of CART enabled multiple interactions to be accounted for simultaneously and permitted risk factors for exposure to be clearly identified.
Zusatzmaterial
Authors’ original file for figure 1
12936_2012_2084_MOESM1_ESM.png
Authors’ original file for figure 2
12936_2012_2084_MOESM2_ESM.bmp
Authors’ original file for figure 3
12936_2012_2084_MOESM3_ESM.bmp
Authors’ original file for figure 4
12936_2012_2084_MOESM4_ESM.bmp
Literatur
Über diesen Artikel

Weitere Artikel der Ausgabe 1/2012

Malaria Journal 1/2012 Zur Ausgabe

Neu im Fachgebiet Innere Medizin

Meistgelesene Bücher aus der Inneren Medizin

2017 | Buch

Rheumatologie aus der Praxis

Entzündliche Gelenkerkrankungen – mit Fallbeispielen

Dieses Fachbuch macht mit den wichtigsten chronisch entzündlichen Gelenk- und Wirbelsäulenerkrankungen vertraut. Anhand von über 40 instruktiven Fallbeispielen werden anschaulich diagnostisches Vorgehen, therapeutisches Ansprechen und der Verlauf …

Herausgeber:
Rudolf Puchner

2016 | Buch

Ambulant erworbene Pneumonie

Was, wann, warum – Dieses Buch bietet differenzierte Diagnostik und Therapie der ambulant erworbenen Pneumonie zur sofortigen sicheren Anwendung. Entsprechend der neuesten Studien und Leitlinien aller wichtigen Fachgesellschaften.

Herausgeber:
Santiago Ewig

Mail Icon II Newsletter

Bestellen Sie unseren kostenlosen Newsletter Update Innere Medizin und bleiben Sie gut informiert – ganz bequem per eMail.

© Springer Medizin 

Bildnachweise