Mobile health (mHealth) approaches and lessons for increased performance and retention of community health workers in low- and middle-income countries: a review.

BACKGROUND: Mobile health (mHealth) describes the use of portable electronic devices with software applications to provide health services and manage patient information. With approximately 5 billion mobile phone users globally, opportunities for mobile technologies to play a formal role in health services, particularly in low- and middle-income countries, are increasingly being recognized. mHealth can also support the performance of health care workers by the dissemination of clinical updates, learning materials, and reminders, particularly in underserved rural locations in low- and middle-income countries where community health workers deliver integrated community case management to children sick with diarrhea, pneumonia, and malaria. OBJECTIVE: Our aim was to conduct a thematic review of how mHealth projects have approached the intersection of cellular technology and public health in low- and middle-income countries and identify the promising practices and experiences learned, as well as novel and innovative approaches of how mHealth can support community health workers. METHODS: In this review, 6 themes of mHealth initiatives were examined using information from peer-reviewed journals, websites, and key reports. Primary mHealth technologies reviewed included mobile phones, personal digital assistants (PDAs) and smartphones, patient monitoring devices, and mobile telemedicine devices. We examined how these tools could be used for education and awareness, data access, and for strengthening health information systems. We also considered how mHealth may support patient monitoring, clinical decision making, and tracking of drugs and supplies. Lessons from mHealth trials and studies were summarized, focusing on low- and middle-income countries and community health workers. RESULTS: The review revealed that there are very few formal outcome evaluations of mHealth in low-income countries. Although there is vast documentation of project process evaluations, there are few studies demonstrating an impact on clinical outcomes. There is also a lack of mHealth applications and services operating at scale in low- and middle-income countries. The most commonly documented use of mHealth was 1-way text-message and phone reminders to encourage follow-up appointments, healthy behaviors, and data gathering. Innovative mHealth applications for community health workers include the use of mobile phones as job aides, clinical decision support tools, and for data submission and instant feedback on performance. CONCLUSIONS: With partnerships forming between governments, technologists, non-governmental organizations, academia, and industry, there is great potential to improve health services delivery by using mHealth in low- and middle-income countries. As with many other health improvement projects, a key challenge is moving mHealth approaches from pilot projects to national scalable programs while properly engaging health workers and communities in the process. By harnessing the increasing presence of mobile phones among diverse populations, there is promising evidence to suggest that mHealth can be used to deliver increased and enhanced health care services to individuals and communities, while helping to strengthen health systems

A Macaque Model to Study Vaginal HSV-2/Immunodeficiency Virus Co-Infection and the Impact of HSV-2 on Microbicide Efficacy

Herpes simplex virus type-2 (HSV-2) infection enhances the transmission and acquisition of human immunodeficiency virus (HIV). This occurs in symptomatic and asymptomatic stages of HSV-2 infection, suggesting that obvious herpetic lesions are not required to increase HIV spread. An animal model to investigate the underlying causes of the synergistic action of the two viruses and where preventative strategies can be tested under such complex physiological conditions is currently unavailable.We set out to establish a rhesus macaque model in which HSV-2 infection increases the susceptibility to vaginal infection with a model immunodeficiency virus (simian-human immunodeficiency virus, SHIV-RT), and to more stringently test promising microbicides. HSV-2 exposure significantly increased the frequency of vaginal SHIV-RT infection (n = 6). Although cervical lesions were detected in only approximately 10% of the animals, long term HSV-2 DNA shedding was detected (in 50% of animals followed for 2 years). Vaginal HSV-2 exposure elicited local cytokine/chemokine (n = 12) and systemic low-level HSV-2-specific adaptive responses in all animals (n = 8), involving CD4(+) and CD8(+) HSV-specific T cells (n = 5). Local cytokine/chemokine responses were lower in co-infected animals, while simian immunodeficiency virus (SIV)-specific adaptive responses were comparable in naïve and HSV-2-infected animals (n = 6). Despite the increased frequency of SHIV-RT infection, a new generation microbicide gel, comprised of Carraguard(R) and a non-nucleoside reverse transcriptase inhibitor MIV-150 (PC-817), blocked vaginal SHIV-RT infection in HSV-2-exposed animals (n = 8), just as in naïve animals.We established a unique HSV-2 macaque model that will likely facilitate research to define how HSV-2 increases HIV transmission, and enable more rigorous evaluation of candidate anti-viral approaches in vivo

Plasmodium falciparum merozoite surface protein 3 is a target of allele-specific immunity and alleles are maintained by natural selection.

BACKGROUND: Plasmodium falciparum merozoite surface protein (MSP) 3 is an asexual blood-stage malaria vaccine candidate antigen. Sequence polymorphisms divide alleles into 2 major types, but the adaptive and immunological significance of the types has not been defined. METHODS: One hundred one msp3 allele sequences were sampled from 2 populations living in areas where malaria is endemic and were analyzed for evidence of natural selection. Recombinant antigens representing full-length sequences of different allelic types and a relatively conserved C-terminal region were produced, to evaluate immunization-induced antibody responses in mice and protective associations for naturally acquired antibodies in a cohort of 319 Gambian children under surveillance for malaria. RESULTS: Frequency-based statistical analyses indicated that polymorphisms are maintained by balancing selection in each of the 2 populations studied. Immunization of mice with full-length MSP3 antigens induced predominantly type-specific antibodies, and a large proportion of naturally acquired antibodies to MSP3 in humans also discriminated between the alleles. Among Gambian children, antibodies to allele-specific and conserved epitopes in MSP3 were associated prospectively with protection from clinical malaria, even after adjustment for age and for the presence of antibodies to other merozoite antigens. CONCLUSIONS: A vaccine incorporating both major allelic types of this promising candidate antigen could be particularly useful for induction of protective immunity in infants and young children

Dynamics of the antibody response to Plasmodium falciparum infection in African children.

BACKGROUND: Acquired immune responses to malaria have widely been perceived to be short-lived, with previously immune individuals losing immunity when they move from malaria-endemic areas. However long-lived Plasmodium falciparum-specific antibody responses lasting for an individual's lifetime are frequently observed. METHODS: We fit mathematical models of the dynamics of antibody titers to P. falciparum antigens from longitudinal cohort studies of African children to estimate the half-lives of circulating immunoglobulin G (IgG) antibodies and IgG antibody-secreting cells (ASCs). RESULTS: Comparison of antibody responses in the younger Ghanaian cohort and the older Gambian cohort suggests that young children are less able to generate the long-lived ASCs necessary to maintain the circulating antibodies that may provide protection against reinfection. Antibody responses in African children can be described by a model 15 including both short-lived ASCs (half-life range, 2-10 days), which are responsible for boosting antibody titers following infection, and long-lived ASCs (half-life range, 3-9 years), which are responsible for maintaining sustained humoral responses. CONCLUSIONS: The rapid decay of antibodies following exposure to malaria and the maintenance of sustained antibody responses can be explained in terms of populations of short-lived and long-lived ASCs

Duration of Naturally Acquired Antibody Responses to Blood-Stage Plasmodium falciparum Is Age Dependent and Antigen Specific▿ †

Naturally acquired antibody responses provide partial protection from clinical malaria, and blood-stage parasite vaccines under development aim to prime such responses. To investigate the determinants of antibody response longevity, immunoglobulin G (IgG) antibodies to several blood-stage vaccine candidate antigens in the sera of two cohorts of children of up to 6 years of age during the dry seasons of 2003 and 2004 in The Gambia were examined. The first cohort showed that most antibodies were lost within less than 4 months of the first sampling if a persistent infection was not present, so the study of the second-year cohort involved collecting samples from individuals every 2 weeks over a 3-month period. Antibody responses in the second cohort were also influenced by persistent malaria infection, so analysis focused particularly on children in whom parasites were not detected after the first time point. Antibodies to most antigens declined more slowly in children in the oldest age group (>5 years old) and more rapidly in children in the youngest group (<3 years old). However, antibodies to merozoite surface protein 2 were shorter lived than antibodies to other antigens and were not more persistent in older children. The age-specific and antigen-specific differences were not explained by different IgG subclass response profiles, indicating the probable importance of differential longevities of plasma cell populations rather than antibody molecules. It is likely that young children mostly have short-lived plasma cells and thus experience rapid declines in antibody levels but that older children have longer-lasting antibody responses that depend on long-lived plasma cells

Amphotericin B Formulations Exert Additive Antifungal Activity in Combination with Pulmonary Alveolar Macrophages and Polymorphonuclear Leukocytes against Aspergillus fumigatus

Deoxycholate amphotericin B (DAMB) and amphotericin B lipid complex (ABLC) additively augmented the fungicidal activity of pulmonary alveolar macrophages against the conidia of Aspergillus fumigatus. DAMB, ABLC, and liposomal amphotericin B similarly displayed additive effects with polymorphonuclear leukocytes in damaging the hyphal elements of A. fumigatus