Consecutive pregnant women self-presenting at the selected health care facilities and meeting the eligibility criteria will be invited to participate in the study. After study staff provides full information about the study, pregnant women willing to participate will be asked to sign the informed consent form. They will consent to be interviewed and to provide finger-prick blood. For women younger than 18 years old, additional approval from the parent or legal guardian will be needed if required by local Institutional Review Board (IRB). Participants will be invited to participate at any visit at any trimester.