Biomedical subjects

Elwyn Chomba

Publications and source records attributed to Elwyn Chomba.

6 recordsLinked to original sources

PubMed2007

The social and economic impact of epilepsy in Zambia: a cross-sectional study.

BACKGROUND: Among the 40 million people with epilepsy worldwide, 80% reside in low-income regions where human and technological resources for care are extremely limited. Qualitative and experiential reports indicate that people with epilepsy in Africa are also disadvantaged socially and economically, but few quantitative systematic data are available. We sought to assess the social and economic effect of living with epilepsy in sub-Saharan Africa. METHODS: We did a cross-sectional study of people with epilepsy concurrently matched for age, sex, and site of care to individuals with a non-stigmatised chronic medical condition. Verbally administered questionnaires provided comparison data for demographic characteristics, education, employment status, housing and environment quality, food security, healthcare use, personal safety, and perceived stigma. FINDINGS: People with epilepsy had higher mean perceived stigma scores (1.8 vs 0.4; p<0.0001), poorer employment status (p=0.0001), and less education (7.1 vs 9.4 years; p<0.0001) than did the comparison group. People with epilepsy also had less education than their nearest-age same sex sibling (7.1 vs 9.1 years; p<0.0001), whereas the comparison group did not (9.4 vs 9.6 years; p=0.42). Housing and environmental quality were poorer for people with epilepsy, who had little access to water, were unlikely to have electricity in their home (19%vs 51%; p<0.0001), and who had greater food insecurity than did the control group. During pregnancy, women with epilepsy were more likely to deliver at home rather than in a hospital or clinic (40%vs 15%; p=0.0007). Personal safety for people with epilepsy was also more problematic; rape rates were 20% among women with epilepsy vs 3% in the control group (p=0.004). INTERPRETATION: People with epilepsy in Zambia have substantially poorer social and economic status than do their peers with non-stigmatised chronic medical conditions. Suboptimum housing quality differentially exposes these individuals to the risk of burns and drowning during a seizure. Vulnerability to physical violence is extreme, especially for women with epilepsy.

Adult↗

PubMed2006

Novel approach for differential diagnosis of HIV infections in the face of vaccine-generated antibodies: utility for detection of diverse HIV-1 subtypes.

Because increasing numbers of HIV vaccine candidates are being tested globally, it is essential to differentiate vaccine- from virus-induced antibodies. Most of the currently tested vaccines contain multiple viral components. As a result, many vaccine recipients give positive results in FDA-licensed HIV serodetection tests. We have identified conserved sequences in Env-gp41 and Gag-p6, which are recognized soon after infection but are not included in most HIV vaccine candidates. A new HIV serodetection assay, the HIV-SELECTEST, was established that distinguishes between vaccine-induced antibodies and seroconversion due to true HIV infections. It is important to make this assay globally relevant, because many clinical trials are conducted around the world where most HIV infections are due to non-B subtype HIV-1. Therefore, the current study examined the reactivity of plasma samples from >3,000 infections with diverse HIV subtypes worldwide. The HIV-SELECTEST performed at >99% specificity and sensitivity. Both recent and established infections with clades A, B, C, D, E, F, G, J, and CRFs were detected. Antibodies elicited by other vaccinations or infections endemic to the clinical trial sites did not react in this assay. Therefore, HIV-SELECTEST could be an important differential diagnostic tool for HIV vaccine trials, blood banks, and population screening worldwide.

AIDS Serodiagnosis↗

PubMed2006

Genetic and neutralization properties of subtype C human immunodeficiency virus type 1 molecular env clones from acute and early heterosexually acquired infections in Southern Africa.

A standard panel of subtype C human immunodeficiency virus type 1 (HIV-1) Env-pseudotyped viruses was created by cloning, sequencing, and characterizing functional gp160 genes from 18 acute and early heterosexually acquired infections in South Africa and Zambia. In general, the gp120 region of these clones was shorter (most evident in V1 and V4) and less glycosylated compared to newly transmitted subtype B viruses, and it was underglycosylated but no different in length compared to chronic subtype C viruses. The gp120s also exhibited low amino acid sequence variability (12%) in V3 and high variability (39%) immediately downstream of V3, a feature shared with newly transmitted subtype B viruses and chronic viruses of both subtypes. When tested as Env-pseudotyped viruses in a luciferase reporter gene assay, all clones possessed an R5 phenotype and resembled primary isolates in their sensitivity to neutralization by HIV-1-positive plasmas. Results obtained with a multisubtype plasma panel suggested partial subtype preference in the neutralizing antibody response to infection. The clones were typical of subtype C in that all were resistant to 2G12 (associated with loss of N-glycosylation at position 295) and most were resistant to 2F5, but all were sensitive to 4E10 and many were sensitive to immunoglobulin G1b12. Finally, conserved neutralization epitopes in the CD4-induced coreceptor binding domain of gp120 were poorly accessible and were difficult to induce and stabilize with soluble CD4 on Env-pseudotyped viruses. These results illustrate key genetic and antigenic properties of subtype C HIV-1 that might impact the design and testing of candidate vaccines. A subset of these gp160 clones are suitable for use as reference reagents to facilitate standardized assessments of vaccine-elicited neutralizing antibody responses.

Gene Products, env↗

PubMed2006

Zambian teachers: what do they know about epilepsy and how can we work with them to decrease stigma?

PURPOSE: Teachers play a central role in determining access to education and may mediate epilepsy-associated stigma. We developed and administered a teacher-specific survey to assess teachers' knowledge, attitudes, behaviors, and practices (KABPs) regarding epilepsy in Zambia and social and demographic determinants of KABPs. METHODS: In 2004, we surveyed 171 teachers in urban and rural regions using a 46-item questionnaire. Knowledge and tolerance composite scores were developed and analyses completed to identify demographic and social determinants of KABPs and evaluate whether generic tolerance questions were associated with stigmatizing practices. RESULTS: The response rate was 93% (n=159). Knowledge regarding epilepsy ranged broadly. Misattribution was evident for etiology (spirit possession 17.3%; contagion 28.2%; witchcraft 16.8%), and individuals with poorer knowledge were more likely to recommend traditional healers (p=0.0004) rather than physicians for epilepsy care. Higher knowledge was associated with higher tolerance (p=0.01). Tolerance was highest among urban residents (p=0.002) and individuals with personal familiarity/experience with epilepsy. More tolerant teachers were less likely to report stigmatizing practices, such as ejecting children with seizures from school. CONCLUSIONS: Teacher-targeted interventions aimed at reducing epilepsy-associated stigma and its sequelae in Zambia should include both an educational component and a social component in which teachers are exposed to a person or persons with the condition. Education programs led by person(s) with epilepsy may be ideal.

Adult↗

PubMed2004

Improved nutritional recovery on an elemental diet in Zambian children with persistent diarrhoea and malnutrition.

The persistent diarrhoea-malnutrition syndrome (PDM) remains a leading cause of morbidity and mortality in hospitals in resource-poor countries. In view of the benefits of elemental or oligomeric feeds in inflammatory bowel diseases, we performed a randomized controlled trial of an exclusive diet of amino acid-based elemental feed (AAF) compared with standard nutritional rehabilitation (based on skimmed milk and then soya) for PDM. Treatment was given for 4 weeks in the malnutrition ward of the University Teaching Hospital, Lusaka, in a single-blind study. Intestinal and systemic infections were treated with routine therapies. The main outcome measures were weight gain, recovery from diarrhoea, and mortality. Two hundred children (106 HIV seropositive, 90 HIV seronegative) were randomized; 155 children completed therapy, 39 died, and six were lost to follow-up. At randomization, they were severely malnourished: median baseline weight-for-age z-score was -4.0 (interquartile range, IQR -4.4, -3.5); 9 per cent were underweight, 23 per cent had marasmus, 47 per cent had kwashiorkor, and 21 per cent had marasmic-kwashiorkor. Weight gain was greater in the AAF group (median gain in weight-for-age z-score was 1.23, IQR 0.89-1.57) compared with the control group (0.87, IQR 0.47-1.25; p=0.002), although calorie intakes were higher in the control group. The increase in haemoglobin concentration was also greater in the AAF group (0.8 g/dl, IQR 0-1.8) than in the control group (0.3, IQR -0.6, -1.6; p=0.04). Diarrhoea frequency and global recovery scores improved equally in both treatment groups and mortality did not differ. A diet of reduced molecular complexity was associated with significantly improved weight gain.

Anthropometry↗

PubMed2004

Priorities for antiretroviral therapy research in sub-Saharan Africa: a 2002 consensus conference in Zambia.

BACKGROUND: A consensus conference was held to discuss priorities for antiretroviral therapy (ART) research in Zambia, one of the world's most heavily HIV-afflicted nations. Zambia, like other resource-limited settings, has increasing access to highly active antiretroviral therapy (HAART) because of declining drug costs, use of government-purchased generic medications, and increased global donations. For sustained delivery of care with HAART in a resource-constrained medical and public health context, operational research is required and clinical trials are desirable. The priority areas for research are most relevant today given the increasing availability of HAART. METHODS: A conference was held in Lusaka, Zambia, in January 2002 to discuss priority areas for ART research in Zambia, with participants drawn from a broad cross section of Zambian society. State-of-the-art reviews and 6 intensive small group discussions helped to formulate a suggested research agenda. RESULTS: Conference participants believed that the most urgent research priorities were to assess how therapeutic resources could be applied for the greatest overall benefit and to minimize the impact of nonadherence and viral resistance. Identified research priorities were as follows:Conference participants recommended that HIV-related clinical care and research be integrated within home-based care services and operated within the existing health delivery structures to ensure sustainability, reduce costs, and strengthen the structures. CONCLUSION: Our consensus was that antiretroviral clinical trials and operational research are essential for Zambia to address the new challenges arising from increasing ART availability. There is global consensus that antiretroviral clinical trials in resource-constrained countries are possible, and the capacity for such trials should be developed further in Africa.

AIDS-Related Opportunistic Infections↗