Reliability of School Surveys in Estimating Geographic Variation in Malaria Transmission in the Western Kenyan Highlands

Background School surveys provide an operational approach to assess malaria transmission through parasite prevalence. There is limited evidence on the comparability of prevalence estimates obtained from school and community surveys carried out at the same locality. Methods Concurrent school and community cross-sectional surveys were conducted in 46 school/community clusters in the western Kenyan highlands and households of school children were geolocated. Malaria was assessed by rapid diagnostic test (RDT) and combined seroprevalence of antibodies to bloodstage Plasmodium falciparum antigens. Results RDT prevalence in school and community populations was 25.7% (95% CI: 24.4-26.8) and 15.5% (95% CI: 14.4-16.7), respectively. Seroprevalence in the school and community populations was 51.9% (95% CI: 50.5-53.3) and 51.5% (95% CI: 49.5-52.9), respectively. RDT prevalence in schools could differentiate between low (<7%, 95% CI: 0-19%) and high (>39%, 95% CI: 25-49%) transmission areas in the community and, after a simple adjustment, were concordant with the community estimates. Conclusions Estimates of malaria prevalence from school surveys were consistently higher than those from community surveys and were strongly correlated. School-based estimates can be used as a reliable indicator of malaria transmission intensity in the wider community and may provide a basis for identifying priority areas for malaria control.

[1]  Robert W Snow,et al.  Implementing school malaria surveys in Kenya: towards a national surveillance system , 2010, Malaria Journal.

[2]  R. Snow,et al.  The use of schools for malaria surveillance and programme evaluation in Africa , 2009, Malaria Journal.

[3]  J. Cox,et al.  Association of transmission intensity and age with clinical manifestations and case fatality of severe Plasmodium falciparum malaria. , 2005, JAMA.

[4]  C. Dye,et al.  Heterogeneities in the transmission of infectious agents: implications for the design of control programs. , 1997, Proceedings of the National Academy of Sciences of the United States of America.

[5]  S. Hoffman,et al.  Impact of transmission intensity and age on Plasmodium falciparum density and associated fever: implications for malaria vaccine trial design. , 1995, The Journal of infectious diseases.

[6]  Kevin Marsh,et al.  The changing limits and incidence of malaria in Africa: 1939-2009. , 2012, Advances in parasitology.

[7]  K. Bojang,et al.  Mortality Patterns and Site Heterogeneity of Severe Malaria in African Children , 2013, PloS one.

[8]  B. Greenwood,et al.  The microepidemiology of malaria and its importance to malaria control. , 1989, Transactions of the Royal Society of Tropical Medicine and Hygiene.

[9]  J. Cox,et al.  Estimating medium- and long-term trends in malaria transmission by using serological markers of malaria exposure. , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[10]  D. Conway,et al.  Comparison of surveillance methods applied to a situation of low malaria prevalence at rural sites in The Gambia and Guinea Bissau , 2009, Malaria Journal.

[11]  Std Control Programme.  National Guidelines for HIV Testing and Counselling in Kenya , 2008 .

[12]  Chris J Drakeley,et al.  Heterogeneity in malaria exposure and vaccine response: implications for the interpretation of vaccine efficacy trials , 2010, Malaria Journal.

[13]  W. Youden,et al.  Index for rating diagnostic tests , 1950, Cancer.

[14]  W H TALIAFERRO,et al.  Acquired immunity in malaria. , 1948, Abstracts. International Congress on Tropical Medicine and Malaria.

[15]  G. Glaeske,et al.  Correction factor for the analysis of the hip fracture incidence—differences between age, sex, region, and calendar year , 2012, Wiener klinische Wochenschrift.

[16]  S. Shen,et al.  The statistical analysis of compositional data , 1983 .

[17]  R. Snow,et al.  Relationship between exposure, clinical malaria, and age in an area of changing transmission intensity. , 2008, The American journal of tropical medicine and hygiene.

[18]  L. Lin,et al.  A concordance correlation coefficient to evaluate reproducibility. , 1989, Biometrics.

[19]  S. Brooker,et al.  School-based surveys of malaria in Oromia Regional State, Ethiopia: a rapid survey method for malaria in low transmission settings , 2011, Malaria Journal.

[20]  Teun Bousema,et al.  Dried blood spots as a source of anti-malarial antibodies for epidemiological studies , 2008, Malaria Journal.

[21]  Douglas G. Altman,et al.  Measurement in Medicine: The Analysis of Method Comparison Studies , 1983 .

[22]  David L Smith,et al.  Measuring malaria endemicity from intense to interrupted transmission , 2008, The Lancet. Infectious diseases.

[23]  J. McCarthy,et al.  Using serological measures to monitor changes in malaria transmission in Vanuatu , 2010, Malaria Journal.

[24]  S. Goldwater.  Public Health and Sanitation , 1899, The Indian medical gazette.

[25]  Adrienne M. Lucas,et al.  Does Free Primary Education Narrow Gender Differences in Schooling? Evidence from Kenya , 2012 .

[26]  W C Blackwelder,et al.  "Proving the null hypothesis" in clinical trials. , 1981, Controlled clinical trials.

[27]  Diggory Hardy,et al.  Simulation of malaria epidemiology and control in the highlands of western Kenya , 2012, Malaria Journal.

[28]  Edwin L. Bradley,et al.  Comparing Paired Data: A Simultaneous Test for Means and Variances , 1989 .

[29]  S. Hay,et al.  The uncertain burden of Plasmodium falciparum epidemics in Africa. , 2007, Trends in parasitology.

[30]  K. Marsh,et al.  Serological Evidence of Discrete Spatial Clusters of Plasmodium falciparum Parasites , 2011, PloS one.

[31]  R. Snow,et al.  Use of Rapid Diagnostic Tests in Malaria School Surveys in Kenya: Does their Under-performance Matter for Planning Malaria Control? , 2012, The American journal of tropical medicine and hygiene.

[32]  R. Snow,et al.  The use of insecticide treated nets by age: implications for universal coverage in Africa , 2009, BMC public health.

[33]  S. Brooker,et al.  Can prevalence of infection in school-aged children be used as an index for assessing community prevalence? , 1999, Parasitology.

[34]  A. Hubbard,et al.  Antibodies to Plasmodium falciparum antigens predict a higher risk of malaria but protection from symptoms once parasitemic. , 2011, The Journal of infectious diseases.

[35]  Chris Drakeley,et al.  Serology: a robust indicator of malaria transmission intensity? , 2007, Trends in parasitology.

[36]  John Aitchison,et al.  The Statistical Analysis of Compositional Data , 1986 .

[37]  Pai-Lien Chen,et al.  Correlation of prospective and cross-sectional measures of HIV type 1 incidence in a higher-risk cohort in Ho Chi Minh City, Vietnam. , 2012, AIDS research and human retroviruses.