African Studies Keyword: Malaria

From nearly any perspective and metric, the effects of malaria on the African continent have been persistent and deep. By focusing on the malady of malaria and the last century of biomedical interventions, Graboyes and Alidina raise critical historical, ethical, and scientific questions related to truth telling, African autonomy, and the obligations of foreign researchers. They provide a condensed history of malaria activities on the continent over the past 120 years, highlighting the overall history of failures to eliminate or control the disease. A case study of the risks of rebound malaria illustrates the practical and moral problems that abound when historical knowledge is ignored. In light of current calls for renewed global eradication efforts, Graboyes and Alidina provide evidence for why historical knowledge must be better integrated into global health epistemic realms.

Sterile tuberculous granuloma in a patient with XDR-TB treated with bedaquiline, pretomanid and linezolid

Drug-resistant tuberculosis (DR-TB) continues to pose a threat to the global eradication of TB. Regimens for extensively drug-resistant (XDR) TB are lengthy and poorly tolerated, often with unsuccessful outcomes. The TB Alliance Nix-TB trial investigated the safety and efficacy of a 26-week regimen of bedaquiline, pretomanid and linezolid (BPaL) in participants with XDR-TB, multidrug-resistant (MDR) TB treatment failure or intolerance. In this trial 9 out of 10 participants were cured. We describe a trial participant with XDR-TB who presented with new-onset seizures soon after BPaL treatment completion. Imaging showed a right temporal ring-enhancing lesion, and a sterile tuberculous granuloma was confirmed after a diagnostic, excisional biopsy. Learning points include management of a participant with a tuberculoma after BPaL completion, efficacy of new medications for central nervous system (CNS) TB and a review of their CNS penetration. This is the first case of pretomanid use in CNS TB.

Evaluation of diagnostic accuracy of eight commercial assays for the detection of rubella virus specific IgM antibodies

Rubella and congenital rubella syndrome are caused by the rubella virus and are preventable through vaccination, making disease eradication possible. Monitoring of progress towards global eradication and local elimination requires high quality, sensitive disease surveillance that includes laboratory confirmation of cases. Previous evaluations of anti-rubella IgM detection methods resulted in the broad adoption of Enzygnost (most recently manufactured by Siemens) enzyme-linked immunosorbent assay (ELISA or EIA) kits within WHO’s global measles and rubella laboratory network but they have been discontinued. This study evaluates seven comparable ELISA methods from six manufacturers (Trinity Biotech, Euroimmun, Clin-Tech, NovaTec and Virion\Serion) as well as one automated chemiluminescent assay (CLIA) from Diasorin. These methods consisted of three IgM capture methods and five indirect ELISA methods. A panel of 238 sera was used for the evaluation that included 38 archival rubella IgM positive sera and 200 sera collected from symptomatically similar cases, such as measles, dengue, parvovirus B19 and roseola. With this panel of sera, the sensitivity of the methods ranged from 63.2% to 100% and the specificity from 80.0% to 99.5%. No single method had both sensitivity and specificity >90%, unless sera with equivocal results were considered to be presumptive positive. Some methods, particularly the Serion ELISA, had a large number of false positives with parvovirus B19 IgM positive sera as well as sera from confirmed measles cases. The performance characteristics identified in this evaluation serve as a reminder to not rely solely on rubella IgM results for case confirmation in elimination settings.

Analysing malaria events from 1840 to 2020: the narrative told through postage stamps

The role played by postage stamps in the history of malaria control and eradication has largely gone unrecognized. Scientific investigators of malaria, especially Nobel laureates, were commemorated with special issues, but the work of the World Health Organization (WHO), which promoted an ambitious and global philatelic initiative in 1962 to support global eradication, is generally overlooked. This review examines the philatelic programme that helped to generate international commitment to the goal of malaria eradication in 1962 and established philatelic malaria icons that had worldwide recognition. Malaria-related postage stamps have continued to be issued since then, but the initial failure of malaria eradication and the changing goals of each new malaria programme, inevitably diluted their role. After the first Global Malaria Eradication Campaign was discontinued in 1969, few Nations released philatelic issues. Since the Spirit of Dakar Call for Action in 1996 a resurgence of postage stamp releases has occurred, largely tracking global malaria control initiatives introduced between 1996 and 2020. These releases were not co-ordinated by the WHO as before, were more commercialized and targeted stamp collectors, especially with attractive miniature sheets, often produced by photomontage. Having a different purpose, they demonstrated a much wider diversity in symbolism than the earlier stylized issues and at times, have been scientifically inaccurate. Nonetheless postage stamps greatly helped to communicate the importance of malaria control programmes to a wide audience and to some extent, have supported preventive health messages.

Variants of SARS Coronavirus-2 and Their Potential Impact on the Future of the COVID-19 Pandemic

The emergence of SARS-CoV-2 variants of concern (VOCs), especially the sweeping spread of the delta variant, and differing public health management strategies, have rendered global eradication of SARS-CoV-2 unlikely. The currently available COVID-19 vaccines, including the inactivated whole virus vaccines, mRNA vaccines, and adenovirus-vectored vaccines, are effective in protecting people from severe disease and death from COVID-19, but they may not confer good mucosal immunity to prevent the establishment of infection and subsequent viral shedding and transmission. Mucosal vaccines delivered via intranasal route may provide a promising direction, which, if given as a third dose after a two-dose series of intramuscular vaccination, likely promotes mucosal immunity in addition to boosting the systemic cell-mediated immunity and antibody response. However, immunity induced by vaccination, and natural infection as well, is likely to wane followed by re-infection as in the case of human coronaviruses OC43, 229E, NL63, and HKU1. It is a challenge to prevent and control COVID-19 worldwide with the increasing number of VOCs associated with increased transmissibility and changing antigenicity. Nevertheless, we may seek to end the current pandemic situation through mass vaccination and gradual relaxation of non-pharmaceutical measures, which would limit the incidence of severe COVID-19. Repeated doses of booster vaccine will likely be required, similar to influenza virus, especially for the elderly and the immunocompromised patients who are most vulnerable to infection.

A predictive analysis on the risk of peste des petits ruminants in livestock in the Trans-Himalayan region and validation of its transboundary transmission paths

Although the Trans-Himalayan region (THR) is an important endemic and rendezvous area of peste des petits ruminants (PPR), monitoring and prevention measurements are difficult to execute because of the rough geographical conditions. Besides, a heterogeneous breeding system and the poor veterinary service of susceptible animals compound the existing problems. Here, we propose a forecasting system to define the key points of PPR prevention and aid the countries in saving time, labor, and products to achieve the goal of the global eradication project of PPR. The spatial distribution of PPR was predicted in the THR for the first time using a niche model that was constructed with a combination of eco-geographical, anthropoid, meteorological, and host variables. The transboundary least-cost paths (LCPs) of small ruminants in the THR were also calculated. Our results reveal that the low-elevation area of the THR had a higher PPR risk and was mainly dominated by human variables. The high-elevation area had lower risk and was mainly dominated by natural variables. Eight LCPs representing corridors among India, Nepal, Bhutan, Bangladesh, and China were obtained. This confirmed the potential risk of transboundary communication by relying on PPR contamination on the grasslands for the first time. The predicted potential risk communication between the two livestock systems and landscapes (high and low elevation) might play a role in driving PPR transboundary transmission.

Understanding childhood immunizations, their serological interpretation and vaccines - A review article

The practice of immunization dates back hundreds of years. Buddhist monks drank snake venom to confer immunity to snake bite and variolation (smearing of a skin tear with cowpox to confer immunity to smallpox) was practiced in 17th century China. Edward Jenner is considered the founder of vaccinology in the West in 1796, after he inoculated an 8 year-old-boy with vaccinia virus (cowpox), and demonstrated immunity to smallpox. In 1798, the first smallpox vaccine was developed. Over the 18th and 19th centuries, systematic implementation of mass smallpox immunization culminated in its global eradication in 1979. Vaccination is when a vaccine is administered to you (usually by injection). Immunization is what happens in your body after you have the vaccination. The vaccine stimulates your immune system so that it can recognize the disease and protect you from future infection (i.e., you become immune to the infection.). Immunization is a proven tool for controlling and eliminating life-threatening infectious diseases and is estimated to avert between 2 and 3 million deaths each year. It is one of the most cost-effective health investments, with proven strategies that make it accessible to even the most hard-to-reach and vulnerable populations. It has clearly defined target groups; it can be delivered effectively through outreach activities; and vaccination does not require any major lifestyle change.

Surveillance of Human Guinea Worm in Chad, 2010–2018

The total number of Guinea worm cases has been reduced by 99.9% since the mid-1980s when the eradication campaign began. Today, the greatest number of cases is reported from Chad. In this report, we use surveillance data collected by the Chad Guinea Worm Eradication Program to describe trends in human epidemiology. In total, 114 human cases were reported during the years 2010–2018, with highest rates of containment (i.e., water contamination prevented) in the years 2013, 2014, 2016, and 2017 (P < 0.0001). Approximately half of case-patients were female, and 65.8% of case-patients were aged 30 years or younger (mean: 26.4 years). About 34.2% of case-patients were farmers. Cases were distributed across many ethnicities, with a plurality of individuals being of the Sara Kaba ethnicity (21.3%). Most cases occurred between the end of June and the end of August and were clustered in the Chari Baguirmi (35.9%) and Moyen Chari regions (30.1%). Cases in the northern Chari River area peaked in April and in August, with no clear pattern in the southern Chari River area. History of travel within Chad was reported in 7.0% of cases, and male subjects (12.5%) were more likely than female subjects (1.7%) to have reported a history of travel (P = 0.03). Our findings confirm that human Guinea worm is geographically disperse and rare. Although the proportion of case-patients with travel history is relatively small, this finding highlights an additional challenge of surveillance in mobile populations in the final stages of the global eradication campaign.

Molecular epidemiology of peste des petits ruminants virus emergence in critically endangered Mongolian saiga antelope and other wild ungulates

Peste des petits ruminants virus (PPRV) causes disease in domestic and wild ungulates, is the target of a global eradication programme and threatens biodiversity. Understanding the epidemiology and evolution of PPRV in wildlife is important, but hampered by the paucity of wildlife-origin PPRV genomes. In this study, full PPRV genomes were generated from three Mongolian saiga antelope, one Siberian ibex and one goitered gazelle from the 2016/2017 PPRV outbreak. Phylogenetic analysis showed that for Mongolian and Chinese PPRV since 2013, the wildlife and livestock-origin genomes were closely related and interspersed. There was strong phylogenetic support for a monophyletic group of PPRV from Mongolian wildlife and livestock, belonging to clade of lineage IV PPRV from livestock and wildlife from China since 2013. Discrete diffusion analysis found strong support for PPRV spread into Mongolia from China and phylogeographic analysis indicated Xinjiang Province as the most likely origin, although genomic surveillance for PPRV is poor and lack of sampling from other regions could bias this result. Times of most recent common ancestor (TMRCA) were June 2015 (95% HPD: August 2014 to March 2016) for all Mongolian PPRV genomes and May 2016 (95% HPD: October 2015 to October 2016) for Mongolian wildlife origin PPRV. This suggests that PPRV was circulating undetected in Mongolia for at least six months before the first reported outbreak in August 2016, and that wildlife were likely infected before livestock vaccination began in October 2016. Finally, genetic variation and positively-selected sites were identified that might be related to PPRV emergence in Mongolian wildlife. This study is the first to sequence multiple PPRV genomes from a wildlife outbreak, across several host species. Additional full PPRV genomes and associated metadata from the livestock-wildlife interface are needed to enhance the power of molecular epidemiology, support PPRV eradication and safeguard the health of the whole ungulate community.