Serosurveillance for monitoring immunization

coverage in DHS

July 24, 2015July 24, 2015

Bernard BarrèreBernard Barrère

SAMPLE and BIOMARKERS• National sample of 8,400 households• In all households: anthropometric measurements and hemoglobin

testing among women age 15-49 and children < 5• In 1/3 households: syphilis testing among all women age 15-49 and

men age 15-59• 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 2003-04: 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 2003-04: 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 2003-04: Example of Results

Distribution of children < 5 according to the Measles test result

%

Immunized 62.8

Not immunized 37.2

TOTAL 100.0

Proportion immunized according to the Measles test result %

Among children 12-59 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 15-49 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 15-49 and men age 15-59• Malaria testing (RDT and thick smear) among children age 6-59 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 2013-14: Overview (1)

DR Congo DHS 2013-14: 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 2014. 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 2013-14: Methodology

COVERAGE FOR TESTING AT UCLA/INRB LABBlood samples were collected and tested for

95.4% of 8,420 eligible children age 6-59 months

DR Congo DHS 2013-14: Example of Results

Proportion immunized according to the Measles test result %

Among children 12-23 months who received measles vaccination according to the vaccination card

69.2

Among children 12-23 months who received measles vaccination according to mother’s report

58.8

Among children 12-23 months who received measles vaccination according to the vaccination card or mother’s report

62.1

Among children 12-23 months who did NOT received measles vaccination

36.6

Among ALL tested children 12-23 months 54.3

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 2003-04: 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 immunized 17.6

TOTAL 100.0

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 2003-04: 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 immunized 23.4

TOTAL 100.0

Proportion immunized according to the Tetanus test result %

Among children 12-59 months who received three injections of DPT before the age of 12 months according to the vaccination card

91.3

DR Congo DHS 2013-14: Example of Results (1)

Proportion of children 6-59 immunized according to the test result

%

Measles 64.4

Tetanus 36.0

Rubella 34.4

Mumps 22.0

Varicella 9.0

Proportion immunized according to the Measles test result %

Among children 12-59 months who received measles vaccination before the age of 12 months according to the vaccination card

91.2

DR Congo DHS 2013-14: Example of Results (3)

Proportion immunized according to the Tetanus test result %

Among children 12-23 months who received tetanus vaccination (3 doses) according to the vaccination card

70.7

Among children 12-23 months who received tetanus vaccination (3 doses) according to mother’s report

48.6

Among children 12-23 months who received tetanus vaccination (3 doses) according to the vaccination card or mother’s report

57.5

Among children 12-23 months who did NOT received tetanus vaccination (0 dose)

17.4

Among ALL children 12-23 months tested 44.3