Malawi 2015-16

ecorded on the Biomarker Questionnaire and subsequently entered into interviewers’ tablet computers.
The survey protocol, including biomarker collection, was reviewed and approved by the National Health
Sciences Research Committee in Malawi and the ICF Institutional Review Board.
Anthropometry: Height and weight measurements were recorded for children age 0-59 months and
women age 15-49.
Anaemia testing: Blood specimens for anaemia testing were collected from women age 15-49 who
voluntarily consented to be tested and from all children age 6-59 months for whom consent was obtained
from their parents or the adult responsible for the children. Blood samples were drawn from a drop of
blood taken from a finger prick (or a heel prick from children age 6-11 months) and collected in a
microcuvette. Haemoglobin analysis was conducted on-site with a battery-operated portable HemoCue
analyser. Test results were provided verbally and in writing. Parents of children with a haemoglobin level
below 7 g/dl were instructed to take the child to a health facility for follow-up care. Non-pregnant women
and pregnant women were referred for follow-up care if their haemoglobin levels were below 7 g/dl and 9
g/dl, respectively. All households in which anaemia testing was conducted were given a brochure that
explained the causes and prevention of anaemia.
HIV testing: Interviewers collected finger-prick blood specimens from women age 15-49 and men age 15-
54 who consented to laboratory HIV testing. The protocol for blood specimen collection and analysis was
based on the anonymous linked protocol developed for The DHS Program. This protocol allows for the
merger of HIV test results with the sociodemographic data collected in the individual questionnaires after
removal of all information that could potentially identify an individual.
Interviewers explained the procedure, the confidentiality of the data, and the fact that the test results would
not be made available to respondents. If a respondent consented to HIV testing, five blood spots from the
finger prick were collected on a filter paper card to which a barcode label unique to the respondent was
affixed. A duplicate label was attached to the Biomarker Questionnaire. A third copy of the same barcode
was affixed to the dried blood spot transmittal sheet to track the blood samples from the field to the
laboratory.
Respondents were asked whether they would consent to allow the laboratory to store their blood sample for
future unspecified testing. If respondents did not consent to additional testing, it was indicated on the
Biomarker Questionnaire that they refused additional tests on their specimen, and the words “no additional
testing” were written on the filter paper card. Each respondent, whether they provided consent or not, was
given an informational brochure on HIV and a list of nearby sites that provide HIV testing services (HTS).
Blood samples were dried overnight and packaged for storage the following morning. Samples were
collected periodically from the field and transported to the laboratory at the Community Health Sciences
Unit (CHSU) in Lilongwe. Upon arrival at CHSU, each blood sample was logged into the CSPro HIV Test
Tracking System database, given a laboratory number, and stored at -20˚C until tested.
The HIV testing protocol (Figure 1.1) stipulated that blood could be tested only after the questionnaire
data collection had been completed, the data had been verified and cleaned, and all unique identifiers other
than the anonymous barcode number had been removed from the data file.
The testing algorithm calls for testing all samples with the first assay, the Enzygnost Integral II (Siemens)
enzyme-linked immunoassay (ELISA I). All samples that tested positive on the ELISA I are subjected to a
second ELISA (ELISA II), the Murex HIV Ag/Ab combination (DiaSorin). Similar to samples that tested
positive on ELISA I, 5% of the samples that tested negative on the ELISA I are also subjected on the
ELISA II while the other 95% are recorded as negative.
Concordant negative results on the ELISA I and ELISA II are recorded as negative. If the results on
ELISA I and ELISA II are discordant, the two ELISAs are repeated in parallel. If the results remain
4 • Introduction and Survey Methodology