Serosurveillance for monitoring immunization coverage in DHS July 24, 2015 Bernard Barrère
SAMPLE and BIOMARKERS National sample of 8,400 households In all households: anthropometric measurements and hemoglobin testing among women age and children < 5 In 1/3 households: syphilis testing among all women age and men age In 1/3 households: testing for immunity to tetanus among women and children <5, and immunity (or exposure) to measles among children <5 Madagascar DHS : Overview Measles/Tetanus testing was entirely part of the DHS Blood samples were collected by the DHS teams Testing in the labs was done according to a protocol developed with and approved by DHS Results were analyzed in collaboration with the labs and reported in the Madagascar DHS report
Capillary blood from finger prick was collected on filter paper (DBS) One DBS was sent to the Pasteur Institute in Antananarivo for measles testing One DBS was sent to the Baxter Health Care Lab (MD, USA) for tetanus testing Madagascar DHS : Methodology COVERAGE FOR TETANUS/MEASLES TESTING Blood samples were collected and tested for: 91% of 2,817 eligible women 86% of 1,917 eligible children
Madagascar DHS : Example of Results Distribution of children < 5 according to the Measles test result % Immunized62.8 Not immunized37.2 TOTAL100.0 Proportion immunized according to the Measles test result% Among children months who received measles vaccination before the age of 12 months according to the vaccination card 91.2
SAMPLE and BIOMARKERS National sample of 18,171 households. In all households: anthropometric measurements of women age and children < 5 In 1/2 households: Anemia testing among women age 15-49, men age 15-59, and children age 6-59 months HIV testing women age and men age Malaria testing (RDT and thick smear) among children age months DBS collected from children 6-59 months for PCR test for diagnosis of malaria and for immunity to Tetanus, Rubella, Measles, Mumps, Polio and Varicella. DR Congo DHS : Overview (1)
DR Congo DHS : Overview (2) Immunity testing was not entirely part of the DHS Blood samples were collected by the DHS teams DHS developed programs to log-in the DBS and record the test results, and merged the testing data and survey data But testing in the labs was done independently without any involvement of DHS Initially basic test results were supposed to be reported in the DRC-DHS report released in September No result was available at that time.
Capillary blood from finger prick was collected on filter paper (DBS) The filter papers were sent to UCLA-DRC laboratory at the National Laboratory for Biomedical Research (INRB) in Kinshasa, were they were logged in and divided in three: One DBS remained at the UCLA/INRB lab in Kinshasa for Measles, Mumps, Rubella, Varicella, and Tetanus testing One was sent to CDC Atlanta for polio testing DR Congo DHS : Methodology COVERAGE FOR TESTING AT UCLA/INRB LAB Blood samples were collected and tested for 95.4% of 8,420 eligible children age 6-59 months
DR Congo DHS : Example of Results Proportion immunized according to the Measles test result% Among children months who received measles vaccination according to the vaccination card 69.2 Among children months who received measles vaccination according to mother’s report 58.8 Among children months who received measles vaccination according to the vaccination card or mother’s report 62.1 Among children months who did NOT received measles vaccination 36.6 Among ALL tested children months54.3
On-going survey As part of the on-going Mozambique HIV/Malaria survey, DBS are collected from children age 6-59 months for Tetanus and Hep B testing
Madagascar DHS : Example of Results (3) Distribution of all women according to the Tetanus test result % Fully immunized (for 10 years +) (Tetanus toxoid>0.1 UI/Ml) 61.3 Partly immunized (for 2 years) (Tetanus toxoid >0.01<0.1 UI/Ml) 21.1 Not immunized17.6 TOTAL100.0 Proportion immunized according to the Tetanus test result% Among women who received at least 2 tetanus injections during last pregnancy in the past 5 years 91.6 Among women who received at least 2 tetanus injections in the past 10 years 92.7
Madagascar DHS : Example of Results (2) Distribution of children < 5 according to the Tetanus test result % Fully immunized (for 10 years +) (Tetanus toxoid >0.1 UI/Ml)52.6 Party immunized (for 2 years) (Tetanus toxoid >0.01<0.1 UI/Ml)24.0 Not immunized23.4 TOTAL100.0 Proportion immunized according to the Tetanus test result% Among children months who received three injections of DPT before the age of 12 months according to the vaccination card 91.3
DR Congo DHS : Example of Results (1) Proportion of children 6-59 immunized according to the test result % Measles64.4 Tetanus36.0 Rubella34.4 Mumps22.0 Varicella9.0 Proportion immunized according to the Measles test result% Among children months who received measles vaccination before the age of 12 months according to the vaccination card 91.2
DR Congo DHS : Example of Results (3) Proportion immunized according to the Tetanus test result% Among children months who received tetanus vaccination (3 doses) according to the vaccination card 70.7 Among children months who received tetanus vaccination (3 doses) according to mother’s report 48.6 Among children months who received tetanus vaccination (3 doses) according to the vaccination card or mother’s report 57.5 Among children months who did NOT received tetanus vaccination (0 dose) 17.4 Among ALL children months tested44.3