1
|
Coordination and Management of COVID-19 in Africa through Health Operations and Technical Expertise Pillar: A Case Study from WHO AFRO One Year into Response. Trop Med Infect Dis 2022; 7:tropicalmed7080183. [PMID: 36006275 PMCID: PMC9415043 DOI: 10.3390/tropicalmed7080183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 01/19/2022] [Accepted: 01/26/2022] [Indexed: 11/24/2022] Open
Abstract
Background: following the importation of the first Coronavirus disease 2019 (COVID-19) case into Africa on 14 February 2020 in Egypt, the World Health Organisation (WHO) regional office for Africa (AFRO) activated a three-level incident management support team (IMST), with technical pillars, to coordinate planning, implementing, supervision, and monitoring of the situation and progress of implementation as well as response to the pandemic in the region. At WHO AFRO, one of the pillars was the health operations and technical expertise (HOTE) pillar with five sub-pillars: case management, infection prevention and control, risk communication and community engagement, laboratory, and emergency medical team (EMT). This paper documents the learnings (both positive and negative for consideration of change) from the activities of the HOTE pillar and recommends future actions for improving its coordination for future emergencies, especially for multi-country outbreaks or pandemic emergency responses. Method: we conducted a document review of the HOTE pillar coordination meetings’ minutes, reports, policy and strategy documents of the activities, and outcomes and feedback on updates on the HOTE pillar given at regular intervals to the Regional IMST. In addition, key informant interviews were conducted with 14 members of the HOTE sub pillar. Key Learnings: the pandemic response revealed that shared decision making, collaborative coordination, and planning have been significant in the COVID-19 response in Africa. The HOTE pillar’s response structure contributed to attaining the IMST objectives in the African region and translated to timely support for the WHO AFRO and the member states. However, while the coordination mechanism appeared robust, some challenges included duplication of coordination efforts, communication, documentation, and information management. Recommendations: we recommend streamlining the flow of information to better understand the challenges that countries face. There is a need to define the role and responsibilities of sub-pillar team members and provide new team members with information briefs to guide them on where and how to access internal information and work under the pillar. A unified documentation system is important and could help to strengthen intra-pillar collaboration and communication. Various indicators should be developed to constantly monitor the HOTE team’s deliverables, performance and its members.
Collapse
|
2
|
Leveraging Polio GIS platforms in the African Region for mitigating Covid-19 contact tracing and Surveillance challenges. JMIR Mhealth Uhealth 2021; 10:e22544. [PMID: 34854813 PMCID: PMC8972111 DOI: 10.2196/22544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 02/01/2021] [Accepted: 05/08/2021] [Indexed: 11/18/2022] Open
Abstract
Background The ongoing COVID-19 pandemic in Africa is an urgent public health crisis. Estimated models projected over 150,000 deaths and 4,600,000 hospitalizations in the first year of the disease in the absence of adequate interventions. Therefore, electronic contact tracing and surveillance have critical roles in decreasing COVID-19 transmission; yet, if not conducted properly, these methods can rapidly become a bottleneck for synchronized data collection, case detection, and case management. While the continent is currently reporting relatively low COVID-19 cases, digitized contact tracing mechanisms and surveillance reporting are necessary for standardizing real-time reporting of new chains of infection in order to quickly reverse growing trends and halt the pandemic. Objective This paper aims to describe a COVID-19 contact tracing smartphone app that includes health facility surveillance with a real-time visualization platform. The app was developed by the AFRO (African Regional Office) GIS (geographic information system) Center, in collaboration with the World Health Organization (WHO) emergency preparedness and response team. The app was developed through the expertise and experience gained from numerous digital apps that had been developed for polio surveillance and immunization via the WHO’s polio program in the African region. Methods We repurposed the GIS infrastructures of the polio program and the database structure that relies on mobile data collection that is built on the Open Data Kit. We harnessed the technology for visualization of real-time COVID-19 data using dynamic dashboards built on Power BI, ArcGIS Online, and Tableau. The contact tracing app was developed with the pragmatic considerations of COVID-19 peculiarities. The app underwent testing by field surveillance colleagues to meet the requirements of linking contacts to cases and monitoring chains of transmission. The health facility surveillance app was developed from the knowledge and assessment of models of surveillance at the health facility level for other diseases of public health importance. The Integrated Supportive Supervision app was added as an appendage to the pre-existing paper-based surveillance form. These two mobile apps collected information on cases and contact tracing, alongside alert information on COVID-19 reports at the health facility level; the information was linked to visualization platforms in order to enable actionable insights. Results The contact tracing app and platform were piloted between April and June 2020; they were then put to use in Zimbabwe, Benin, Cameroon, Uganda, Nigeria, and South Sudan, and their use has generated some palpable successes with respect to COVID-19 surveillance. However, the COVID-19 health facility–based surveillance app has been used more extensively, as it has been used in 27 countries in the region. Conclusions In light of the above information, this paper was written to give an overview of the app and visualization platform development, app and platform deployment, ease of replicability, and preliminary outcome evaluation of their use in the field. From a regional perspective, integration of contact tracing and surveillance data into one platform provides the AFRO with a more accurate method of monitoring countries’ efforts in their response to COVID-19, while guiding public health decisions and the assessment of risk of COVID-19.
Collapse
|
3
|
The COVID-19 pandemic: research and health development in the World Health Organisation Africa region. Pan Afr Med J 2021; 35:50. [PMID: 33623575 PMCID: PMC7875729 DOI: 10.11604/pamj.supp.2020.35.2.23628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 05/25/2020] [Indexed: 12/04/2022] Open
Abstract
Concerns have been expressed about the view point of WHO AFRO concerning research for health in the African Region. WHO AFRO considers research a critical component in the improvement of health in the Africa region. Ensuring the effectiveness of our strategies, policies and programmes requires evidence. In the context of the ongoing COVID-19 outbreak, WHO research interests cover key areas of the response. The WHO AFRO consider research as critical in our efforts at protecting people against health emergencies and pandemics like the COVID-19 and ensuring universal access to proven interventions. In view of this, the WHO has taken steps to strengthen capacity for research in the region. The results of these efforts may take time to manifest but will surely do as we persist in our drive, with support from our partners.
Collapse
|
4
|
|
5
|
Correction to: Community participation and private sector engagement are fundamental to achieving universal health coverage and health security in Africa: reflections from the second Africa health forum. BMC Proc 2019; 13:11. [PMID: 31827602 PMCID: PMC6889179 DOI: 10.1186/s12919-019-0182-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
|
6
|
Transformation of World Health Organization’s management practice and workforce to fit the priorities of African countries. Pan Afr Med J 2019; 34:146. [PMID: 32158511 PMCID: PMC7049381 DOI: 10.11604/pamj.2019.34.146.19463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 06/17/2019] [Indexed: 12/02/2022] Open
Abstract
Introduction The WHO Regional Office for Africa developed an evidence-based tool, called the Dalberg tool to guide the functional review and restructuring of the workforce and management of the country offices to better fit the health priorities of Member States. Methods The Dalberg tool was used in conjunction with a series of consultations and dialogues to review twenty-two countries have undergone the functional review. Results: the “core functions” in WHO country offices (WCOs) were identified. These are health coordination, strengthening of health systems, generation of evidence and strategic information management, and preparedness against health emergencies. Results In order to standardize country office functions, categorization of countries was undertaken, based on specific criteria, such as health system performance towards Universal Health Coverage (UHC), health emergencies, burden of communicable and non-communicable diseases, subnational presence and national population size. Conclusion Following the functional review, the staff is now better aligned with country and organizational priorities. For example, the functional review has taken into consideration: (i) the ongoing polio transition planning; (ii) the implementation of the WHO emergency programme in countries; (iii) the investment case for strengthening routine immunization in Africa; and (iv) regional flagship programmes, such as adolescent health and UHC. The delivery of the core functions above will require the hiring of additional capacities and expertise in most country offices if deemed fit-for-purpose.
Collapse
|
7
|
Community participation and private sector engagement are fundamental to achieving universal health coverage and health security in Africa: reflections from the second Africa health forum. BMC Proc 2019; 13:7. [PMID: 31737089 PMCID: PMC6849158 DOI: 10.1186/s12919-019-0170-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Background Inadequate access to quality health care services due to weak health systems and recurrent public health emergencies are impediments to the attainment of Universal Health Coverage and health security in Africa. To discuss these challenges and deliberate on plausible solutions, the World Health Organization Regional Office for Africa, in collaboration with the Government of Cabo Verde, convened the second Africa Health Forum in Praia, Cabo Verde on 26–28 March 2019, under the theme Achieving Universal Health Coverage and Health Security: The Africa We Want to See. Methods The Forum was conducted through technical sessions consisting of high-level, moderated panel discussions on specific themes, some of them preceded by keynote addresses. There were booth exhibitions by Member States, World Health Organization and other organizations to facilitate information exchanges. A Communiqué highlighting the recommendations of the Forum was issued during the closing ceremony. More than 750 participants attended. Relevant information from the report of the Forum and notes by the authors were extracted and synthesized into these proceedings. Conclusions The Forum participants agreed that the role of community engagement and participation in the attainment of Universal Health Coverage, health security and ultimately the Sustainable Development Goals cannot be overemphasized. The public sector of Africa alone cannot achieve these three interrelated goals; other partners, such as the private sector, must be engaged. Technological innovations will be a key driver of the attainment of these goals; hence, there is need to harness the comparative advantages that they offer. Attainment of the three goals is also intertwined – achieving one paves the way for achieving the others. Thus, there is need for integrated public health approaches in the planning and implementation of interventions aimed at achieving them. Recommendations To ensure that the recommendations of this Forum are translated into concrete actions in a sustainable manner, we call on African Ministers of Health to ensure their integration into national health sector policies and strategic documents and to provide the necessary leadership required for their implementation. We also call on partners to mainstream these recommendations into their ongoing support to World Health Organization African Member States.
Collapse
|
8
|
Lujo viral hemorrhagic fever: considering diagnostic capacity and preparedness in the wake of recent Ebola and Zika virus outbreaks. Rev Med Virol 2016; 26:446-454. [PMID: 27593704 PMCID: PMC7169100 DOI: 10.1002/rmv.1903] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 08/03/2016] [Accepted: 08/04/2016] [Indexed: 12/18/2022]
Abstract
Lujo virus is a novel Old World arenavirus identified in Southern Africa in 2008 as the cause of a viral hemorrhagic fever (VHF) characterized by nosocomial transmission with a high case fatality rate of 80% (4/5 cases). Whereas this outbreak was limited, the unprecedented Ebola virus disease outbreak in West Africa, and recent Zika virus disease epidemic in the Americas, has brought into acute focus the need for preparedness to respond to rare but potentially highly pathogenic outbreaks of zoonotic or arthropod‐borne viral infections. A key determinant for effective control of a VHF outbreak is the time between primary infection and diagnosis of the index case. Here, we review the Lujo VHF outbreak of 2008 and discuss how preparatory measures with respect to developing diagnostic capacity might be effectively embedded into existing national disease control networks, such as those for human immunodeficiency virus, tuberculosis, and malaria.
Collapse
|
9
|
Implementation of the World Health Organization Regional Office for Africa Stepwise Laboratory Quality Improvement Process Towards Accreditation. Afr J Lab Med 2016; 5:280. [PMID: 28879103 PMCID: PMC5436392 DOI: 10.4102/ajlm.v5i1.280] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 12/03/2015] [Indexed: 11/21/2022] Open
Abstract
Background The increase in disease burden has continued to weigh upon health systems in Africa. The role of the laboratory has become increasingly critical in the improvement of health for diagnosis, management and treatment of diseases. In response, the World Health Organization Regional Office for Africa (WHO AFRO) and its partners created the WHO AFRO Stepwise Laboratory (Quality) Improvement Process Towards Accreditation (SLIPTA) program. SLIPTA implementation process WHO AFRO defined a governance structure with roles and responsibilities for six main stakeholders. Laboratories were evaluated by auditors trained and certified by the African Society for Laboratory Medicine. Laboratory performance was measured using the WHO AFRO SLIPTA scoring checklist and recognition certificates rated with 1–5 stars were issued. Preliminary results By March 2015, 27 of the 47 (57%) WHO AFRO member states had appointed a SLIPTA focal point and 14 Ministers of Health had endorsed SLIPTA as the desired programme for continuous quality improvement. Ninety-eight auditors from 17 African countries, competent in the Portuguese (3), French (12) and English (83) languages, were trained and certified. The mean score for the 159 laboratories audited between May 2013 and March 2015 was 69% (median 70%; SD 11.5; interquartile range 62–77). Of these audited laboratories, 70% achieved 55% compliance or higher (2 or more stars) and 1% scored at least 95% (5 stars). The lowest scoring sections of the WHO AFRO SLIPTA checklist were sections 6 (Internal Audit) and 10 (Corrective Action), which both had mean scores below 50%. Conclusion The WHO AFRO SLIPTA is a process that countries with limited resources can adopt for effective implementation of quality management systems. Political commitment, ownership and investment in continuous quality improvement are integral components of the process.
Collapse
|
10
|
Epidemiology of Ebola virus disease transmission among health care workers in Sierra Leone, May to December 2014: a retrospective descriptive study. BMC Infect Dis 2015; 15:416. [PMID: 26464285 PMCID: PMC4604711 DOI: 10.1186/s12879-015-1166-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 09/30/2015] [Indexed: 11/14/2022] Open
Abstract
Background Anecdotal evidence suggests that much of the continuing infection of health care workers (HCWs) with Ebola virus during the current outbreak in Sierra Leone has occurred in settings other than Ebola isolation units, and it is likely that some proportion of acquisition by HCWs occurs outside the workplace. There is a critical need to define more precisely the pathways of Ebola infection among HCWs, to optimise measures for reducing risk during current and future outbreaks. Methods We conducted a retrospective descriptive study of Ebola acquisition among health workers in Sierra Leone during May–December 2014. The data used were obtained mainly from the national Ebola database, a cross-sectional survey conducted through administration of a structured questionnaire to infected HCWs, and key informant interviews of select health stakeholders. Results A total of 293 HCWs comprising 277 (95 %) confirmed, 6 (2 %) probable, and 10 (3 %) suspected cases of infection with Ebola virus were enrolled in the study from nine districts of the country. Over half of infected HCWs (153) were nurses; others included laboratory staff (19, 6.5 %), doctors (9, 3.1 %), cleaners and porters (9, 3.1 %), Community Health Officers (8, 2.7 %), and pharmacists (2, 0.7 %). HCW infections were mainly reported from the Western Area (24.9 %), Kailahun (18.4 %), Kenema (17.7 %), and Bombali (13.3 %) districts. Almost half of the infected HCWs (120, 47.4 %) believed that their exposure occurred in a hospital setting. Others believed that they were exposed in the home (48, 19 %), at health centres (45, 17.8 %), or at other types of health facilities (13, 5.1 %). Only 27 (10.7 %) of all HCW infections were associated with Ebola virus disease (EVD) isolation units. Over half (60 %, 150) of infected HCWs said they had been trained in infection prevention and control prior to their infection, whereas 34 % (85) reported that they had not been so trained. Conclusions This study demonstrated the perception that most HCW infections are associated with general health care and home settings and not with dedicated EVD settings, which should provide substantial reassurance to HCWs that measures in place at dedicated EVD facilities generally provide substantial protection when fully adhered to.
Collapse
|
11
|
Development and validation of serological assays for viral hemorrhagic fevers and determination of the prevalence of Rift Valley fever in Borno State, Nigeria. Trans R Soc Trop Med Hyg 2014; 108:768-73. [PMID: 25344695 PMCID: PMC7107251 DOI: 10.1093/trstmh/tru163] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Background Rift Valley fever (RVF) is endemic to the tropical regions of eastern and southern Africa. The seroprevalence of RVF was investigated among the human population in Borno State, Nigeria to determine the occurrence of the disease in the study area in comparison with that of Lassa fever and Crimean-Congo Hemorrhagic fever. Methods Recombinant nucleoprotein (rNP)-based IgG-ELISAs for the detection of serum antibodies against RVF virus (RVFV), Lassa fever virus (LASV), and Crimean-Congo hemorrhagic fever virus (CCHFV) were used to test human sera in Borno State, Nigeria. The presence of neutralizing antibody against the RVFV-glycoprotein-bearing vesicular stomatitis virus pseudotype (RVFVpv) was also determined in the human sera. Results Of the 297 serum samples tested, 42 (14.1%) were positive for the presence of RVFV-IgG and 22 (7.4%) and 7 (2.4%) of the serum samples were positive for antibodies against LASV and CCHFV, respectively. There was a positive correlation between the titers of neutralizing antibodies obtained using RVFVpv and those obtained using the conventional neutralization assay with the attenuated RVFV-MP12 strain. Conclusions The seroprevalence of RVF was significantly higher than that of LASV and CCHF in Borno State, Nigeria. The RVFVpv-based neutralization assay developed in this study has the potential to replace the traditional assays based on live viruses for the diagnosis and seroepidemiological studies of RVF.
Collapse
|
12
|
Abstract
BACKGROUND On March 23, 2014, the World Health Organization (WHO) was notified of an outbreak of Ebola virus disease (EVD) in Guinea. On August 8, the WHO declared the epidemic to be a "public health emergency of international concern." METHODS By September 14, 2014, a total of 4507 probable and confirmed cases, including 2296 deaths from EVD (Zaire species) had been reported from five countries in West Africa--Guinea, Liberia, Nigeria, Senegal, and Sierra Leone. We analyzed a detailed subset of data on 3343 confirmed and 667 probable Ebola cases collected in Guinea, Liberia, Nigeria, and Sierra Leone as of September 14. RESULTS The majority of patients are 15 to 44 years of age (49.9% male), and we estimate that the case fatality rate is 70.8% (95% confidence interval [CI], 69 to 73) among persons with known clinical outcome of infection. The course of infection, including signs and symptoms, incubation period (11.4 days), and serial interval (15.3 days), is similar to that reported in previous outbreaks of EVD. On the basis of the initial periods of exponential growth, the estimated basic reproduction numbers (R0 ) are 1.71 (95% CI, 1.44 to 2.01) for Guinea, 1.83 (95% CI, 1.72 to 1.94) for Liberia, and 2.02 (95% CI, 1.79 to 2.26) for Sierra Leone. The estimated current reproduction numbers (R) are 1.81 (95% CI, 1.60 to 2.03) for Guinea, 1.51 (95% CI, 1.41 to 1.60) for Liberia, and 1.38 (95% CI, 1.27 to 1.51) for Sierra Leone; the corresponding doubling times are 15.7 days (95% CI, 12.9 to 20.3) for Guinea, 23.6 days (95% CI, 20.2 to 28.2) for Liberia, and 30.2 days (95% CI, 23.6 to 42.3) for Sierra Leone. Assuming no change in the control measures for this epidemic, by November 2, 2014, the cumulative reported numbers of confirmed and probable cases are predicted to be 5740 in Guinea, 9890 in Liberia, and 5000 in Sierra Leone, exceeding 20,000 in total. CONCLUSIONS These data indicate that without drastic improvements in control measures, the numbers of cases of and deaths from EVD are expected to continue increasing from hundreds to thousands per week in the coming months.
Collapse
|
13
|
Abstract
Of the 46 countries in the World Health Organization (WHO) African region (AFRO), 43 are implementing Integrated Disease Surveillance and Response (IDSR) guidelines to improve their abilities to detect, confirm, and respond to high-priority communicable and noncommunicable diseases. IDSR provides a framework for strengthening the surveillance, response, and laboratory core capacities required by the revised International Health Regulations [IHR (2005)]. In turn, IHR obligations can serve as a driving force to sustain national commitments to IDSR strategies. The ability to report potential public health events of international concern according to IHR (2005) relies on early warning systems founded in national surveillance capacities. Public health events reported through IDSR to the WHO Emergency Management System in Africa illustrate the growing capacities in African countries to detect, assess, and report infectious and noninfectious threats to public health. The IHR (2005) provide an opportunity to continue strengthening national IDSR systems so they can characterize outbreaks and respond to public health events in the region.
Collapse
|
14
|
Abstract
BACKGROUND In response to the potential threat of an influenza pandemic, several international institutions and governments, in partnership with African countries, invested in the development of epidemiologic and laboratory influenza surveillance capacity in Africa and the African Network of Influenza Surveillance and Epidemiology (ANISE) was formed. METHODS We used a standardized form to collect information on influenza surveillance system characteristics, the number and percent of influenza-positive patients with influenza-like illness (ILI), or severe acute respiratory infection (SARI) and virologic data from countries participating in ANISE. RESULTS Between 2006 and 2010, the number of ILI and SARI sites in 15 African countries increased from 21 to 127 and from 2 to 98, respectively. Children 0-4 years accounted for 48% of all ILI and SARI cases of which 22% and 10%, respectively, were positive for influenza. Influenza peaks were generally discernible in North and South Africa. Substantial cocirculation of influenza A and B occurred most years. CONCLUSIONS Influenza is a major cause of respiratory illness in Africa, especially in children. Further strengthening influenza surveillance, along with conducting special studies on influenza burden, cost of illness, and role of other respiratory pathogens will help detect novel influenza viruses and inform and develop targeted influenza prevention policy decisions in the region.
Collapse
|
15
|
Immunogenicity of Standard‐Titer Measles Vaccine in HIV‐1–Infected and Uninfected Zambian Children: An Observational Study. J Infect Dis 2007; 196:347-55. [PMID: 17597448 DOI: 10.1086/519169] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2006] [Accepted: 02/02/2007] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND Achieving the level of population immunity required for measles elimination may be difficult in regions of high human immunodeficiency virus type 1 (HIV-1) prevalence, because HIV-1-infected children may be less likely to respond to or maintain protective antibody levels after vaccination. METHODS We conducted a prospective study of the immunogenicity of standard-titer measles vaccine administered at 9 months of age to HIV-1-infected and uninfected children in Lusaka, Zambia. RESULTS From May 2000 to November 2002, 696 children aged 2-8 months were enrolled. Within 6 months of vaccination, 88% of 50 HIV-1-infected children developed antibody levels of >or=120 mIU/mL, compared with 94% of 98 HIV-seronegative children and 94% of 211 HIV-seropositive but uninfected children (P=.3). By 27 months after vaccination, however, only half of the 18 HIV-1-infected children who survived and returned for follow-up maintained measles antibody levels >or=120 mIU/mL, compared with 89% of 71 uninfected children (P=.001) and in contrast with 92% of 12 HIV-1-infected children revaccinated during a supplemental measles immunization activity. CONCLUSIONS Although HIV-1-infected children showed good primary antibody responses to measles vaccine, their rapid waning of antibody suggests that measles vaccination campaigns may need to be repeated more frequently in areas of high HIV-1 prevalence.
Collapse
|
16
|
Abstract
Subclinical mastitis, defined as raised milk sodium/potassium (Na/K) ratio, is associated with poor infant growth and, among HIV-infected women, with increased milk HIV viral load. We conducted a longitudinal cohort study in Lusaka, Zambia, in order to investigate the relative importance of several potential causes of subclinical mastitis: maternal infection, micronutrient deficiencies and poor lactation practice. Women (198 HIV-infected, 189 HIV-uninfected) were recruited at 34 weeks' gestation and followed up to 16 weeks postpartum for collection of information on their health, their infant's health, infant growth and infant feeding practices. Milk samples were collected from each breast at 11 postpartum visits and blood at recruitment and 6 weeks postpartum. The geometric mean milk Na/K ratio and the proportion of women with Na/K ratio > 1.0 in one or both breasts were significantly higher among HIV-infected than among uninfected women. Other factors associated with the higher mean Na/K ratio in univariable analyses were primiparity, high maternal alpha(1)-acid glycoprotein (AGP) at 6 weeks, maternal overall morbidity and specific breast symptoms, preterm delivery, low infant weight or length, infant thrush and non-exclusive breast feeding. In multivariable analyses, primiparity, preterm delivery, breast symptoms, HIV status and raised AGP were associated with the raised Na/K ratio. Thus the main factors associated with subclinical mastitis that are amenable to intervention are poor maternal overall health and breast health. The impact of improved postpartum health care, especially management of maternal infections and especially in primiparous women, on the prevalence of subclinical mastitis and its consequences requires investigation.
Collapse
|
17
|
Abstract
In a longitudinal cohort study we investigated factors contributing to breast milk HIV RNA viral load among lactating women in Lusaka, Zambia. Detailed data from 135 HIV-infected women were collected by questionnaires concerning postpartum maternal and infant health and infant feeding practice. Maternal blood was collected during pregnancy and at 6 weeks postpartum. Milk samples collected from each breast at 10 days and 6 weeks postpartum plus a subset collected at other time points were analyzed for HIV RNA viral load. Increased milk viral load was associated in univariate analyses with maternal symptoms of poor health, raised plasma alpha(1)-acid glycoprotein (AGP) at week 6, raised milk sodium/potassium (Na/K) ratio, postpartum need for antibiotics, preterm delivery, and low birth weight infants. In a multiple regression 49% of variability in mean milk viral load was explained by milk Na/K ratio and need for antibiotics, with borderline contributions from plasma AGP and plasma viral load. Maternal blood hemoglobin or receipt of iron supplements and infant feeding variables such as changing the infant's diet by moving from exclusive to nonexclusive breastfeeding or adding solid foods were not associated with milk viral load. Thus maternal health was the main factor contributing to milk viral load. The lack of effect of feeding practices on milk viral load and the previously determined association of poor maternal health with reduced duration of exclusive breastfeeding in this cohort suggest the relation between exclusive breastfeeding and decreased HIV transmission may be secondary to poor maternal health.
Collapse
|
18
|
Increased Risk of Intrauterine Transmission of HIV-1 Associated With Granulocyte Elastase in Endocervical Mucus. J Acquir Immune Defic Syndr 2006; 41:249-51. [PMID: 16394860 DOI: 10.1097/01.qai.0000185576.44215.67] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND One of the remaining challenges in the prevention of mother-to-child transmission of HIV is to reduce the risk of the transmission during pregnancy. It remains to be investigated which factors affect intrauterine HIV transmission and how they can be identified and addressed during pregnancy. METHODS Granulocyte elastase in the endocervical mucus of HIV-positive pregnant women in Zambia was measured, and its association with intrauterine transmission of HIV-1 from the mother to the fetus was investigated. RESULTS The intrauterine transmission rate determined by polymerase chain reaction assay of DNA from neonates at birth was 15.3%. The risk for intrauterine transmission was 8.65-fold higher in women who were positive for granulocyte elastase than in those who were negative. CONCLUSION We suggest that the women showing positive granulocyte elastase at delivery be strongly suspected of having and if having had chorioamnionitis during pregnancy, which could affect the intrauterine transmission of HIV.
Collapse
|
19
|
Socioeconomic and reproductive factors associated with condom use within and outside of marriage among urban pregnant women in Zambia. Afr J Reprod Health 2005; 9:128-36. [PMID: 16623197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
A cross-sectional questionnaire survey was conducted on 470 pregnant women in Lusaka, Zambia. Multivariate analysis revealed school attendance and child deaths as independently significant variables positively associated with HIV seropositivity. Among women with fidelity, HIV prevalence was not significantly lower, and condom use was much lower than among women who were having extramarital affairs. Factors significantly associated with condom use within and outside of marriage differed-age and number of live births within, and sexual transmission knowledge outside of marriage. School attendance was not effective for gaining knowledge on sexual transmission or condom use. Regular own earning was significantly effective for condom use in both groups, irrespective of school attendance. The following should be implemented intensively: effective education on HIV and sex in and out of school before early sexual debut, further implementation of family planning with emphasis on condom use, and empowering women by assisting with their economic independence.
Collapse
|
20
|
Socioeconomic and Reproductive Factors Associated with Condom Use within and outside of Marriage among Urban Pregnant Women in Zambia. Afr J Reprod Health 2005. [DOI: 10.2307/3583419] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
21
|
Predominance of three NF-kappaB binding sites in the long terminal repeat region of HIV Type 1 subtype C isolates from Zambia. AIDS Res Hum Retroviruses 2005; 21:901-6. [PMID: 16225420 DOI: 10.1089/aid.2005.21.901] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Human immunodeficiency virus type-1 (HIV-1) is a leading cause of mortality and morbidity in the world, with almost 46 million people infected globally. HIV-1 subtype C accounts for 55% of these infections. In Zambia, the majority of HIV-1 infections are subtype C. However, to its north most countries have non-subtype C as the most predominant HIV-1 subtype while to its south most of them are predominantly subtype C. The aim of this study was to determine the subtype distribution and to analyze the long terminal repeat (LTR) region of HIV-1 isolates from the northern part of Zambia. We amplified as well as directly sequenced the LTR, gag, and env regions of 78 HIV-1 peripheral blood samples from adult Zambians. Our results show 95% (74/78) of our isolates were HIV-1 subtype C. Furthermore, of the subtype C samples analyzed across the LTR, 61% (25/41) carried 3 NF-kappaB signature binding site sequences.
Collapse
|
22
|
Abstract
Exclusive breastfeeding (EBF) is optimal for infant health and is associated with decreased risk of mother-to-child HIV transmission compared with mixed feeding of breast milk and other foods. To investigate why many women stop EBF before the recommended 6 months, maternal and infant health and infant-feeding data were collected from 177 HIV-infected and 177-uninfected Zambian women regularly from 34 weeks gestation to 16 weeks postpartum. Despite strong support for good breastfeeding practice, only 37% of women were still EBF at week 16. Factors significantly associated with shorter duration of EBF were primiparity, maternal systemic illness, and infant length at 6 weeks. The results suggest that the association of EBF with lower rates of mother-to-child HIV transmission may not be causal but may be secondary to the reduced duration of EBF associated with poor maternal or infant health. Programs supporting EBF should include support for maternal health.
Collapse
|
23
|
Estimating the force of measles virus infection from hospitalised cases in Lusaka, Zambia. Vaccine 2004; 23:732-8. [PMID: 15542196 DOI: 10.1016/j.vaccine.2004.07.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2004] [Accepted: 07/19/2004] [Indexed: 10/26/2022]
Abstract
Estimates of the force of infection (the rate at which susceptible individuals acquire infection) are essential for modelling the transmission dynamics of infectious diseases and can be a useful tool in evaluating mass vaccination strategies. Few estimates exist of the force of infection of measles virus in sub-Saharan Africa. A mathematical model was applied to age-specific recorded hospital admissions between September 1996 and September 1999 to estimate the force of measles virus infection in Lusaka, Zambia. The average force of infection was estimated to be 20% per year (95% confidence intervals (CI) 16.5, 23.5) which was insensitive to varying assumptions about vaccine coverage. The force of infection varied from year to year (P < 0.001) reflecting the cyclic pattern of measles incidence. The estimated probability of a case being hospitalised decreased with age, consistent with less severe disease in older children. Estimates of the force of infection using routinely available data were consistent with those based upon serological surveys in other sub-Saharan African countries.
Collapse
|
24
|
Abstract
Age-related changes in lymphocyte subsets in HIV-uninfected Zambian children are described. The total lymphocyte count and numbers of CD4+ and CD8+ T-lymphocytes declined with increasing age, while the percentage of CD4+ and CD8+ T-lymphocytes changed little during childhood. Girls between the ages of 12 and 71 months had a higher percentage of CD4+ T-lymphocytes and a higher CD4:CD8 ratio than did boys of a similar age.
Collapse
|
25
|
Abstract
Heterosexual transmission accounts for the majority of human immunodeficiency virus-1 (HIV-1) infections worldwide, yet the viral properties that determine transmission fitness or outgrowth have not been elucidated. Here we show, for eight heterosexual transmission pairs, that recipient viruses were monophyletic, encoding compact, glycan-restricted envelope glycoproteins. These viruses were also uniquely sensitive to neutralization by antibody from the transmitting partner. Thus, the exposure of neutralizing epitopes, which are lost in chronic infection because of immune escape, appears to be favored in the newly infected host. This reveals characteristics of the envelope glycoprotein that influence HIV-1 transmission and may have implications for vaccine design.
Collapse
|
26
|
Latency-associated nuclear antigen of Kaposi's sarcoma-associated herpesvirus interacts with human myeloid cell nuclear differentiation antigen induced by interferon alpha. Virus Genes 2004; 27:237-47. [PMID: 14618084 DOI: 10.1023/a:1026391715071] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV)/human herpes virus type 8 (HHV-8) is tightly linked to the development of Kaposi's sarcoma, primary effusion lymphoma (PEL) and some cases of multicentric Castleman's disease. Latency-associated nuclear antigen (LANA) is one of a limited number of KSHV genes consistently expressed in these diseases as well as in KSHV-infected cell lines derived from PEL, and has been shown to play crucial role in persistence of KSHV genomes in the infected cells. In this study, we explored the cellular factors that interact with LANA using yeast two-hybrid screening, and isolated a part of gene encoding human myeloid cell nuclear differentiation antigen (MNDA). MNDA is a hematopoietic interferon-inducible nuclear proteins with a HIN-200 family member with conserved 200-amino acid repeats. Immunoprecipitation assay revealed that LANA interacted with MNDA in a mammalian embryonic kidney cell line. MNDA transcript was undetectable in three PEL cell lines by reverse-transcription polymerase chain reaction, but it was induced by interferon alpha (IFNalpha). Moreover, LANA and MNDA were co-localized in the nuclei of MNDA-expressing PEL cells. Our results suggest that LANA interacts with MNDA in KSHV-infected cells exposed to IFNalpha. Such interaction may modulate IFN-mediated host defense activities.
Collapse
MESH Headings
- Antigens, Differentiation, Myelomonocytic/biosynthesis
- Antigens, Differentiation, Myelomonocytic/genetics
- Antigens, Differentiation, Myelomonocytic/metabolism
- Antigens, Viral/genetics
- Antigens, Viral/physiology
- Base Sequence
- Cell Division
- Cell Line
- Cell Nucleus/immunology
- Cell Nucleus/virology
- DNA, Viral/genetics
- Herpesvirus 8, Human/genetics
- Herpesvirus 8, Human/immunology
- Herpesvirus 8, Human/physiology
- Humans
- Interferon Type I/pharmacology
- Nuclear Proteins/genetics
- Nuclear Proteins/immunology
- Nuclear Proteins/physiology
- Recombinant Proteins
- Sarcoma, Kaposi/immunology
- Sarcoma, Kaposi/virology
- Transcription Factors/biosynthesis
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Two-Hybrid System Techniques
Collapse
|
27
|
HIV/AIDS in Central Africa: pathogenesis, immunological and medical issues. Int Arch Allergy Immunol 2004; 132:183-95. [PMID: 14646379 DOI: 10.1159/000074299] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The estimated worldwide prevalence of human immunodeficiency virus (HIV) infections topped 52.5 million in June 2003, a mere 20 years after the aetiological agent was shown to be a sexually transmissible virus with a predilection for CD4+ T lymphocytes. More than 22 million people have died of the acquired immunodeficiency syndrome (AIDS) and the condition has in one generation become the most devastating and persistent epidemics in recorded history. More than two thirds of the world total of HIV-infected people live in Sub-Saharan Africa. In Central and Southern Africa at least 20% of the adult population is infected. As these adults die, they leave increasing numbers of orphans. Life expectancy at birth declined by 10 years per decade since the late 1980s to 50 years in the late 1990s, and in Botswana it is estimated to be as low as 33 years by 2010. The epidemic is increasing unabated and prospects for a curative or protective vaccine remain remote. The impact on HIV in Africa has been so profound that it influences political, economic, agriculture/food security, social, education, defence, science and health considerations. The medical and in particular immunology communities in Central Africa have the invidious challenge of on the one hand diagnosing the condition, monitoring its impact and contributing to treatment and management efforts. The science and clinical practice of immunology is challenged to find answers to the epidemic, perhaps including a vaccine. In this review we address the peculiarities of the HIV epidemic in Africa, its epidemiology and immunopathogenesis. We address the effect of the epidemic on individual patients, in their homes, workplaces and the knock-on effects on families and friends of the infected. Respective specialists discuss special groups (women, children) that are predominantly seen in Africa. We also discuss the impact of the epidemic on the clinical practice of medicine in general and challenges faced in the introduction of antiretroviral medicines. We also discuss options available for the diagnosis, treatment and monitoring of HIV-infected patients in this region.
Collapse
|
28
|
Plasma vitamin A and E levels of HIV-infectedand HIV-uninfected Zambian women during pregnancy and lactation. Trans R Soc Trop Med Hyg 2003. [DOI: 10.1016/s0035-9203(03)80072-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
|
29
|
Abstract
BACKGROUND AND OBJECTIVES Sexual behavior following voluntary HIV counseling and testing (VCT) is described in 963 cohabiting heterosexual couples with one HIV positive and one HIV negative partner ('discordant couples'). Biological markers were used to assess the validity of self-report. METHODS Couples were recruited from a same-day VCT center in Lusaka, Zambia. Sexual exposures with and without condoms were recorded at 3-monthly intervals. Sperm detected on vaginal smears, pregnancy, and sexually transmitted diseases (STD) including HIV, gonorrhea, syphilis, and Trichomonas vaginalis were assessed. RESULTS Less than 3% of couples reported current condom use prior to VCT. In the year after VCT, > 80% of reported acts of intercourse in discordant couples included condom use. Reporting 100% condom use was associated with 39-70% reductions in biological markers; however most intervals with reported unprotected sex were negative for all biological markers. Under-reporting was common: 50% of sperm and 32% of pregnancies and HIV transmissions were detected when couples had reported always using condoms. Positive laboratory tests for STD and reported extramarital sex were relatively infrequent. DNA sequencing confirmed that 87% of new HIV infections were acquired from the spouse. CONCLUSIONS Joint VCT prompted sustained but imperfect condom use in HIV discordant couples. Biological markers were insensitive but provided evidence for a significant under-reporting of unprotected sex. Strategies that encourage truthful reporting of sexual behavior and sensitive biological markers of exposure are urgently needed. The impact of prevention programs should be assessed with both behavioral and biological measures.
Collapse
|
30
|
Prevalence of drug-resistance-associated mutations in antiretroviral drug-naive Zambians infected with subtype C HIV-1. AIDS Res Hum Retroviruses 2003; 19:151-60. [PMID: 12643279 DOI: 10.1089/088922203762688667] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The ability of HIV-1 to evolve resistance to antiretroviral drugs leads to treatment failure. By nucleotide sequencing of HIV-1 subtype B isolates, amino acids responsible for drug resistance have been identified. Less information is available, however, on the extent and distribution of these amino acids in HIV-1 nonsubtype B viruses circulating mainly in developing countries. More HIV-infected patients in the developing world are now using antiretroviral drugs, and hence there is a need to monitor drug resistance mutations in HIV-1 non-subtype B viruses. This study examines the prevalence of drug resistance mutations in 28 antiretroviral drug-naive HIV-1-infected Zambians. HIV-1 proviral DNA was extracted from peripheral blood mononuclear cells. The region encompassing gag p17 to env C2-V3-C3 was amplified by the polymerase chain reaction followed by direct sequencing. Sequence analyses for drug resistance-associated mutations in th e protease and reverse transcriptase genes, and HIV-1 subtyping, were done. Overall, 92.8% of the generated sequences were HIV-1 subtype C. The generated sequences revealed only secondary associated, but no primary, drug-resistance mutations The most frequent secondary mutations in the protease and RT genes were, respectively, I93L(91.7%), L89M (79.2%), M3611V (79%, 4.2%), and R211K (70.8%), S48T (62.5%). The atypical residues M41N (3.6%) and D67A (3.6%) were detected in the RT gene. This study reveals many naturally occurring polymorphisms in HIV-1 subtype C isolates from antiretroviral drug-naive individuals. Such polymorphisms could lead to rapid treatment failure and development of drug-resistant HIV-1 mutants in individuals undergoing antiretroviral therapy.
Collapse
|
31
|
Abstract
BACKGROUND Accurate information about specific causes of death in African children dying of respiratory illnesses is scarce, and can only be obtained by autopsy. We undertook a study of children who died from respiratory diseases at University Teaching Hospital, Lusaka, Zambia. METHODS 137 boys (93 HIV-1-positive, 44 HIV-1-negative], and 127 girls (87 HIV-1-positive, 40 HIV-1-negative) aged between 1 month and younger than 16 years underwent autopsy restricted to the chest cavity. Outcome measures were specific lung diseases, stratified by age and HIV-1 status. FINDINGS The presence of multiple diseases was common. Acute pyogenic pneumonia (population-adjusted prevalence 39.1%, 116/264), Pneumocystis carinii pneumonia (27.5%, 58/264), tuberculosis (18.8%, 54/264), and cytomegalovirus infection (CMV, 20.2%, 43/264) were the four most common findings overall. The three most frequent findings in the HIV-1-negative group were acute pyogenic pneumonia (50%), tuberculosis (26%), and interstitial pneumonitis (18%); and in the HIV-1-positive group were acute pyogenic pneumonia (41%), P carinii pneumonia (29%), and CMV (22%). HIV-1-positive children more frequently had P carinii pneumonia (odds ratio 5.28, 95% CI 2.12-15.68, p=0.0001), CMV (7.71, 2.33-40.0, p=0.0002), and shock lung (4.15, 1.20-22.10, p=0.03) than did HIV-1-negative children. 51/58 (88%) cases of P carinii pneumonia were in children younger than 12 months, and five in children aged over 24 months. Tuberculosis was common in all age groups, irrespective of HIV-1 status. INTERPRETATION Most children dying from respiratory diseases have preventable or treatable infectious illnesses. The presence of multiple diseases might make diagnosis difficult. WHO recommendations should therefore be updated with mention of HIV-1-positive children. Improved diagnostic tests for bacterial pathogens, tuberculosis, and P carinii pneumonia are urgently needed.
Collapse
|
32
|
Identification of Pneumocystis carinii DNA in oropharyngeal mouth washes from AIDS children dying of respiratory illnesses. AIDS 2002; 16:932-4. [PMID: 11919499 DOI: 10.1097/00002030-200204120-00017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Polymerase chain reaction (PCR) using Pneumocystis carinii-specific primers pAZ 102-H(5'-GTGTACGTTGCAAAGTACTC-3') and pAZ 102-E(5'-GATGGCTGTTTCCAAGCCCA-3') was performed on oropharyngeal washes obtained at autopsy from 22 AIDS children with histologically confirmed P. carinii pneumonia (PCP), and 48 control AIDS children who died from other infections. Fifteen of 22 (68%) PCP samples and none of 48 (0%) control samples had detectable P. carinii DNA (sensitivity 68%; specificity 100%; positive predictive value 100%; negative predictive value 87%). This method requires further validation in clinical practice.
Collapse
|
33
|
Identification of Pneumocystis carinii DNA by polymerase chain reaction in necropsy lung samples from children dying of respiratory tract illnesses. J Pediatr 2002; 140:367-9. [PMID: 11953737 DOI: 10.1067/mpd.2002.122468] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Polymerase chain reaction for Pneumocystis carinii DNA was performed on necropsy lung samples from children by means of P carinii -specific primers.P carinii DNA was identified in 22 of 22 (100%) samples with histologically proven P carinii pneumonia and 13 of 75 (17%) with non-P carinii pneumonia respiratory illness (sensitivity, 100%; specificity, 83%). The low specificity precludes the use of polymerase chain reaction as an alternative to histopathologic diagnosis.
Collapse
|
34
|
Molecular epidemiology of human immunodeficiency virus type 1 transmission in a heterosexual cohort of discordant couples in Zambia. J Virol 2002; 76:397-405. [PMID: 11739704 PMCID: PMC135722 DOI: 10.1128/jvi.76.1.397-405.2002] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Most human immunodeficiency virus type 1 (HIV-1) transmissions in sub-Saharan Africa are believed to occur between married adults who are discordant for their HIV-1 infection status; however, no studies to date have investigated the molecular epidemiology of such transmission events. Here we report the genetic characterization of HIV-1 strains from 149 transmission pairs that were identified prospectively in a cohort of discordant couples in Lusaka, Zambia. Subgenomic gag, gp120, gp41, and/or long terminal repeat regions were amplified by PCR analysis of uncultured blood samples from both partners and sequenced without interim cloning. Pairwise genetic distances were calculated for the regions analyzed and compared to those of subtype-specific reference sequences as well as local controls. Sequence relationships were also examined by phylogenetic tree analysis. By these approaches, epidemiological linkage was established for the majority of transmission pairs. Viruses from 129 of the 149 couples (87%) were very closely related and clustered together in phylogenetic trees in a statistically highly significant manner. In contrast, viruses from 20 of the 149 couples (13%) were only distantly related in two independent genomic regions, thus ruling out transmission between the two partners. The great majority (95%) of transmitted viruses were of subtype C origin, although representatives of subtypes A, D, G, and J were also identified. There was no evidence for extensive transmission networks within the cohort, although two phylogenetic subclusters of viruses infecting two couples each were identified. Taken together, these data indicate that molecular epidemiological analyses of presumed transmission pairs are both feasible and required to determine behavioral, virological, and immunological correlates of heterosexual transmission in sub-Saharan Africa with a high level of accuracy.
Collapse
|
35
|
Abstract
Little is presently known about the specific routes of transmission of Kaposi's sarcoma-associated herpesvirus (KSHV) or human herpesvirus-8 (HHV-8). To investigate whether this agent might be transmitted vertically from mother to infant, we conducted a study on 89 KSHV seropositive mothers and their newborn infants. Thirteen mothers (14.6%) had KSHV DNA detected in their peripheral blood mononuclear cells (PBMC). Two of 89 samples drawn at birth from infants born to KSHV seropositive mothers had KSHV DNA detectable within their PBMC. These findings suggest that KSHV can be transmitted perinatally, but infrequently. Other routes of transmission such as horizontal transmission remain the most likely means of KSHV transmission.
Collapse
|
36
|
Virologic and immunologic determinants of heterosexual transmission of human immunodeficiency virus type 1 in Africa. AIDS Res Hum Retroviruses 2001; 17:901-10. [PMID: 11461676 PMCID: PMC2748905 DOI: 10.1089/088922201750290023] [Citation(s) in RCA: 300] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
More than 80% of the world's HIV-infected adults live in sub-Saharan Africa, where heterosexual transmission is the predominant mode of spread. The virologic and immunologic correlates of female-to-male (FTM) and male-to-female (MTF) transmission are not well understood. A total of 1022 heterosexual couples with discordant HIV-1 serology results (one partner HIV infected, the other HIV uninfected) were enrolled in a prospective study in Lusaka, Zambia and monitored at 3-month intervals. A nested case-control design was used to compare 109 transmitters and 208 nontransmitting controls with respect to plasma HIV-1 RNA (viral load, VL), virus isolation, and CD4(+) cell levels. Median plasma VL was significantly higher in transmitters than nontransmitters (123,507 vs. 51,310 copies/ml, p < 0.001). In stratified multivariate Cox regression analyses, the risk ratio (RR) for FTM transmission was 7.6 (95% CI: 2.3, 25.5) for VL > or = 100,000 copies/ml and 4.1 (95% CI: 1.2, 14.1) for VL between 10,000 and 100,000 copies/ml compared with the reference group of <10,000 copies/ml. Corresponding RRs for MTF transmission were 2.1 and 1.2, respectively, with 95% CI both bounding 1. Only 3 of 41 (7%) female transmitters had VL < 10,000 copies/ml compared with 32 of 93 (34%) of female nontransmitters (p < 0.001). The transmission rate within couples was 7.7/100 person-years and did not differ from FTM (61/862 person-years) and MTF (81/978 person-years) transmission. We conclude that the association between increasing plasma viral load was strong for female to male transmission, but was only weakly predictive of male to female transmission in Zambian heterosexual couples. FTM and MTF transmission rates were similar. These data suggest gender-specific differences in the biology of heterosexual transmission.
Collapse
|
37
|
Emergence of new HIV-1 subtypes other than Subtype C among antenatal women in Lusaka, Zambia. AIDS Res Hum Retroviruses 2001; 17:759-63. [PMID: 11429116 DOI: 10.1089/088922201750237031] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Molecular epidemiology of HIV-1 in Zambia was investigated by direct sequencing of PCR products from samples collected from antenatal attendees in Lusaka, Zambia. One hundred and forty samples were initially screened for HIV, using antibody assays. Thirty-three (23.6%) samples were HIV-1 positive. Sequences of the HIV-1 env gp120 region were obtained from 28 of 33 (85%) HIV-1-positive samples. Twenty-six of the 28 sequences were HIV-1 env subtype C-like as previously reported. However, one HIV-1 env subtype D-like virus and one HIV-1 env subtype G-like virus were identified. This is the first time that these two HIV-1 env subtype viruses have been identified in Zambia, suggesting that more subtypes could be in existence.
Collapse
|
38
|
Hepatitis B virus infection among pregnant women in Zambia. EAST AFRICAN MEDICAL JOURNAL 1995; 72:813-5. [PMID: 8689985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The prevalence of hepatitis B virus (HBV) markers was studied in pregnant women attending antenatal clinics in Zambia. A total of 2,098 pregnant women were recruited into the study at three urban health centres in Lusaka, the capital city and four district hospitals in rural areas of different provinces of Zambia. The overall prevalence of HBsAg was 6.5% (137/2,098), and HBeAg was present in 16.1% (22/137) of those positive for HBsAg. Antibody positive rate (HBsAb and/or HBcAb) was 51.3% in randomly selected HBsAg negative samples. HBsAg positive rate varied between 3.3% and 13.6% in each study sites. Prevalence for both HBsAg and antibodies to HBV were significantly higher in rural areas (district hospitals) than in urban areas (urban health centres in Lusaka). These data show that although HBV is endemic in Zambia, the prevalence varies from region to region.
Collapse
|
39
|
|
40
|
Abstract
A 2-year hospital-based survey of measles infections were carried out at the University Teaching Hospital (UTH) in Lusaka, Zambia from January 1992 to December 1993. During this period, a total of 1066 children with a clinical diagnosis of measles were admitted to the paediatric isolation ward at UTH. Measles cases were seen throughout both 1992 and 1993. However, there was a peak from September to December, 1992. The number of cases decreased with age, and 370 (34.7%) were under 1 year old. It is noteworthy that 203 (19.0%) were less than the 9 months of age which is the recommended time for measles vaccination in Zambia. The overall case fatality rate was 12.6%, and was higher in children aged 0-3 years (14.3%) than in those aged 4 years and above (6.7%). Measles vaccination status could be checked from the child's immunization card for 343 measles cases over 9 months of age, 118 (34.4%) of these having previously received measles vaccine. Vaccinated children had a significantly lower case fatality rate (6.4%) than the unvaccinated group (17.0%). This suggests that while measles vaccine cannot prevent infection, it can reduce the severity of infection.
Collapse
|
41
|
Use of saliva as an alternative to serum for HIV screening in Africa. S Afr Med J 1995; 85:156-7. [PMID: 7777963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Saliva has been recommended as a safe and effective alternative to serum for enzyme-linked immunosorbent assay (ELISA) for HIV antibodies in surveillance programmes in developing countries. We evaluated the use of saliva specimens for detection of HIV antibodies using three different commercially available ELISAs. Saliva specimens from 107 patients selected at random from HIV high-risk (38), medium-risk (27) and low-risk (42) areas of the hospital were screened with the Wellcozyme HIV1 + 2 GACELISA VK61 (recommended for use with saliva), Wellcozyme HIV1 + 2 VK54/55 and Wellcozyme HIV-1 recombinant VK56/57. Of the 107 patients, 50 were positive and 57 negative for antibodies to HIV on confirmatory Western blot testing. For detection of antibodies to HIV in saliva, the Wellcozyme HIV1 + 2 GACELISA VK61 had a sensitivity and a specificity of 98%, the Wellcozyme HIV-1 recombinant VK56/57 a sensitivity and specificity of 96%, and the Wellcozyme HIV1 + 2 VK54/55 a sensitivity of 94% and a specificity of 95%. For detection of antibodies to HIV in serum, the Wellcozyme HIV-1 recombinant VK56/57 had a sensitivity and a specificity of 100%, the Wellcozyme HIV1 + 2 GACELISA VK61 a sensitivity and a specificity of 98%, and the Wellcozyme HIV1 + 2 VK54/55 a sensitivity and a specificity of 96%. This study illustrates that saliva can be used as an alternative to serum for screening for anti-HIV antibodies in African patients.
Collapse
|
42
|
Rotavirus gastro-enteritis in hospitalized children with acute diarrhoea in Zambia. ANNALS OF TROPICAL PAEDIATRICS 1995; 15:39-43. [PMID: 7598436 DOI: 10.1080/02724936.1995.11747747] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The clinical and epidemiological aspects of rotavirus diarrhoea were studied in hospitalized children with acute diarrhoea in Lusaka, Zambia. Two hundred and fifty-six (24.0%) of 1069 children admitted to the study were shedding rotavirus. The rotavirus-positive rate was highest in children less than 1 year of age (37.0%) and it was also high in those less than 6 months old. Rotavirus diarrhoea was seen throughout the year with a higher rotavirus-positive rate in the dry season. In rotavirus-positive diarrhoea patients, more children were dehydrated (82.4%) than in the rotavirus-negative group (56.2%). Rotavirus infection was more common in the children with normal nutritional status (27.6%, 162/588) than in those with malnutrition (19.3%, 93/482). The associated case fatality rate in the rotavirus-positive group was 6.4%, significantly less than in the rotavirus-negative group (OR 0.44, 95% CI 0.24-0.79), and mortality cases were seen only in children less than 2 years old.
Collapse
|