Quantifying the value of viral genomics when inferring who infected whom in the 2014-16 Ebola virus outbreak in Guinea.

Transmission trees can be established through detailed contact histories, statistical or phylogenetic inference, or a combination of methods. Each approach has its limitations, and the extent to which they succeed in revealing a 'true' transmission history remains unclear. In this study, we compared the transmission trees obtained through contact tracing investigations and various inference methods to identify the contribution and value of each approach. We studied eighty-six sequenced cases reported in Guinea between March and November 2015. Contact tracing investigations classified these cases into eight independent transmission chains. We inferred the transmission history from the genetic sequences of the cases (phylogenetic approach), their onset date (epidemiological approach), and a combination of both (combined approach). The inferred transmission trees were then compared to those from the contact tracing investigations. Inference methods using individual data sources (i.e. the phylogenetic analysis and the epidemiological approach) were insufficiently informative to accurately reconstruct the transmission trees and the direction of transmission. The combined approach was able to identify a reduced pool of infectors for each case and highlight likely connections among chains classified as independent by the contact tracing investigations. Overall, the transmissions identified by the contact tracing investigations agreed with the evolutionary history of the viral genomes, even though some cases appeared to be misclassified. Therefore, collecting genetic sequences during outbreak is key to supplement the information contained in contact tracing investigations. Although none of the methods we used could identify one unique infector per case, the combined approach highlighted the added value of mixing epidemiological and genetic information to reconstruct who infected whom.

A rapid assessment of health system preparedness and response to the COVID-19 pandemic in Guinea.

Epidemic-prone diseases have high adverse impacts and pose important threats to global health security. This study aimed to assess levels of health facility preparedness and response to the COVID-19 pandemic in Guinea. This was a cross-sectional study in public and private health facilities/services across 13 Guinean health districts. Managers and healthcare workers (HCWs) from departments in each facility/service were interviewed. Descriptive statistics and comparisons were presented using Pearson's Chi-Squared Test or Fischer exact test. Totally, 197 managers and 1020 HCWs participated in the study. Guidance documents and dedicated spaces for management/isolation of suspected COVID-19 cases were available only in 29% and 26% of facilities, respectively. Capacities to collect (9%) and safely transport (14%) samples were low. Intensive care units (5%), dedicated patient beds (3%), oxygenators (2%), and respirators (0.6%) were almost lacking. While 36% of facilities/services had received infection prevention and control supplies, only 20% had supplies sufficient for 30 days. Moreover, only 9% of HCWs had received formal training on COVID-19. The main sources of information for HCWs were the media (90%) and the internet (58%). Only 30% of HCWs had received personal protective equipment, more in the public sector (p<0.001) and in Conakry (p=0.022). This study showed low levels of preparedness of health facilities/services in Guinea and highlighted a lack of confidence among HCWs who felt unsafe at their workplace. Better governance to improve and maintain the capacity of the Guinean health system to respond to current and future epidemics is needed.

COVID-19 vaccine equity: a health systems and policy perspective.

INTRODUCTION: The global COVID-19 vaccine rollout has highlighted inequities in the accessibility of countries to COVID-19 vaccines. Populations in low- and middle-income countries have found it difficult to have access to COVID-19 vaccines. AREAS COVERED: This perspective provides analyses on historical and contemporary policy trends of vaccine development and immunization programs, including the current COVID-19 vaccination drive, and governance challenges. Moreover, we also provide a comparative health system analysis of the COVID-19 vaccine deployment in some countries from different continents. It recommends that the international Access to COVID-19 Tools Accelerator (ACT-A) partnership requires a strong governance mechanism and urgent financial investment. EXPERT OPINION: All WHO member states should agree on technology transfer and voluntary license-sharing via a commonly governed technology access pool and supported by a just Intellectual Property regime. Contextualized, dynamic understandings and country-specific versions of health systems strengthening are needed to improve vaccine equity in a sustainable matter.

Observatoire communautaire sur l'accès aux services de santé : difficultés du processus de responsabilité sociale en Guinée.

INTRODUCTION: The objective of this study was to identify the factors that influenced the poor performance of the Community Observatory on Access to Health Services (OCASS) project during its implementation from 2014 to 2017 in Guinea and to formulate recommendations for the rest of the project. METHODS: This was a qualitative study using the multipolar performance framework of B. Marchal et al. adapted from the ‘Global and Integral Assessment Model of Health Systems Performance, in acronym EGIPSS, from the Sicotte framework. The data was collected using a spreadsheet created in Microsoft Excel developed according to the four functions of the analytical framework: service delivery, goal achievement, interaction with the environment, and safeguarding values and organizational culture. RESULTS: The absence of an initial assessment of the technical, operational and organizational capacities of the implementing body and the failure to take into account the specific needs of the project in terms of resources (financial, material and human) were decisive in the poor performance of OCASS. Also, the weak involvement of national actors, the Ebola epidemic and the multiplicity of actors around the observatory played a significant role in the failure to achieve the objective of the project. CONCLUSION: Our study revealed that the national context must be taken into account when setting up a social responsibility project and carrying out a basic assessment remains a fundamental step to guarantee its success.

Determinants of Transmission Risk During the Late Stage of the West African Ebola Epidemic.

Understanding risk factors for Ebola transmission is key for effective prediction and design of interventions. We used data on 860 cases in 129 chains of transmission from the latter half of the 2013-2016 Ebola epidemic in Guinea. Using negative binomial regression, we determined characteristics associated with the number of secondary cases resulting from each infected individual. We found that attending an Ebola treatment unit was associated with a 38% decrease in secondary cases (incidence rate ratio (IRR) = 0.62, 95% confidence interval (CI): 0.38, 0.99) among individuals that did not survive. Unsafe burial was associated with a higher number of secondary cases (IRR = 1.82, 95% CI: 1.10, 3.02). The average number of secondary cases was higher for the first generation of a transmission chain (mean = 1.77) compared with subsequent generations (mean = 0.70). Children were least likely to transmit (IRR = 0.35, 95% CI: 0.21, 0.57) compared with adults, whereas older adults were associated with higher numbers of secondary cases. Men were less likely to transmit than women (IRR = 0.71, 95% CI: 0.55, 0.93). This detailed surveillance data set provided an invaluable insight into transmission routes and risks. Our analysis highlights the key role that age, receiving treatment, and safe burial played in the spread of EVD.