Grand Challenges is a family of initiatives fostering innovation to solve key global health and development problems. Each initiative is an experiment in the use of challenges to focus innovation on making an impact. Individual challenges address some of the same problems, but from differing perspectives.
Federico Costa of the Federal University of Bahia, Brazil, Mitermayer Galvão dos Reis of Fiocruz, Brazil, and Nathan Grubaugh and Albert I Ko of Yale University in the U.S. will establish metagenomic next generation sequencing in clinical settings in an urban region of Brazil classified as an infectious disease ‘hot spot’ to help develop new diagnostics and identify emerging pathogens. Rapid urbanization in Salvador, a metropolitan of 2.9 million inhabitants in Northeast Brazil, has produced a favorable environment for the emergence and spread of infectious diseases, and was the founding site for the recent Zika epidemic. Early detection is critical for preventing disease spread, particularly in Salvador, which is a transport hub and popular holiday destination. However, diagnosis can be challenging in low-resource settings, especially when the causative pathogen is unknown, the disease has diverse symptoms, or a known pathogen starts causing new symptoms. They will collect around 160 clinical samples from patients with suspected infections at a local infectious disease reference hospital and a maternity unit and apply a next generation sequencing approach together with the IDseq analysis platform to identify pathogens from the sequencing data.
Rajeev Shrestha and colleagues at Dhulikhel Hospital, Kathmandu University in Nepal will apply metagenomic, next generation sequencing technology to identify causative pathogens of fatal acute encephalitis to improve diagnosis and treatment. Acute encephalitis syndrome (AES) annually affects over 100,000 individuals in low- and middle-income countries, causing substantial morbidity and mortality. It is a diverse disease caused by over 100 different pathogens, including viruses and parasites, making accurate diagnosis difficult, even in high-resource settings. This hinders prevention and treatment efforts, even though several effective vaccines exist. To better characterize the pathogens causing AES, particularly treatable and emerging ones, they will apply metagenomic, next generation sequencing technology to 60 banked cerebral spinal fluid samples collected from fatal acute encephalitis cases in Nepal as part of a nationwide AES surveillance program that covered 189 hospitals. They will validate and refine their technique using previously validated samples.
Thushan de Silva, Abdul Karim Sesay, Helen Brotherton, and Beate Kampmann of the Medical Research Council in the United Kingdom will locally implement equipment and methods for next generation sequencing of a range of clinical sample types to detect infectious pathogens in hospitalized neonates in low-resource settings. Almost three million children under five years old die each year in sub-Saharan Africa, which is the highest rate globally. A substantial proportion is likely to be caused by pathogenic infections, including multi-drug resistant organisms. However, defining the etiology of neonatal infections, which is crucial for timely and effective treatment and to block disease spread, remains challenging in countries with limited resources. They will test the potential for next generation sequencing to overcome this challenge by conducting a pilot study using clinical samples from around 30 hospitalized neonates within an ongoing clinical trial in a low-resource setting in West Africa. They will optimize protocols on site for detecting pathogens from a range of sample types and develop methods to specifically detect relevant anti-microbial resistant strains. They plan to use the study to install a network of sites across the region that can perform next generation sequencing and share the resulting large datasets with other sites.
Shabir Madhi, Vicky Lynne Baillie, and Courtney Paige Olwagen of Wits Health Consortium in South Africa will use next generation sequencing to identify pathogenic causes of neonatal deaths and stillbirths to help develop new treatments such as vaccines and better prevent disease spread. There are around 2.5 million neonatal deaths annually, and an estimated 2.6 million stillbirths, the vast majority of which occur in low- to middle-income countries. Conventional assays have recently indicated that infectious diseases cause far more of these neonatal deaths and stillbirths than previously thought. They also revealed a worryingly high proportion caused by multi-drug resistant, hospital-acquired infections. They will apply a next generation sequencing approach to 80 archived blood samples from stillbirths obtained in an earlier study and analyze the results using the Global IDseq software platform to identify any novel or unculturable or untargeted pathogens that were not identified using the more traditional microbiological methods. They will also use in silico approaches to analyze virulence factors and antimicrobial resistance profiles of identified pathogens.
Jessica Manning of the National Institute of Allergy and Infectious Diseases and Daniel Parker of the University of California, Irvine in the U.S. are leveraging metagenomic next-generation sequencing technology to control vector-borne and enteric diseases in Cambodia. In Phase I, which coincided with the country's worst ever recorded dengue epidemic, they documented the full range of pathogens carried by wild mosquitoes and in serum samples from around 400 febrile patients in a peri-urban hospital in Kampong Speu Province. They also measured antibody reactivity against mosquito saliva in these patients to locate disease hotspots, which were targeted by control efforts. In Phase II, they will expand their approach to 3,000 patients across three urban hospitals (adult, pediatric and maternity) in the capital, and characterize the prevalence and spread of multi-drug resistant Salmonella typhi to better manage the use of antibiotics. They will also train local laboratory technicians, and use open-source tools to produce maps of the data for health officials to track outbreaks.
Tisungane Mvalo and Gerald Tegha of Lilongwe Medical Relief Fund Trust along with Msandeni Chiume at Kamuzu Central Hospital both in Malawi, Emily Ciccone from the University of North Carolina in the US and Pascal Lavoie of the University of British Columbia in Canada will establish metagenomic next generation sequencing at a research laboratory in Malawi to identify pathogens causing infections in young infants to ensure rapid treatment with appropriate therapy and limit unnecessary antibiotic use. It is estimated that over a quarter of the 2.9 million neonatal deaths that occur each year are caused by infections. Given these high numbers, antibiotic treatment has become the standard practice for all young infants that have a suspected serious bacterial infection. However, a recent study using clinical microbiology approaches only identified an infectious agent in half of suspected cases, suggesting that antibiotics are often being used unnecessarily. They will sequence blood samples taken from infants under three months of age with suspected infections and vaginal swabs from mothers enrolled in an existing study in an urban hospital to identify infectious agents. They will also evaluate the presence of antimicrobial resistance genes and see if they can be linked with maternal vaginal flora. Overall, they aim to characterize the pathogen landscape associated with suspected infectious diseases in young infants.
Cara Brook, Jean-Michel Héraud, and Soa Fy Andriamandimby of the Pasteur Institute in Madagascar, and Jessica Metcalf of Princeton University in the U.S. will establish metagenomic next generation sequencing (NGS) in Madagascar to analyze samples from undiagnosed fever patients and from bats to identify bat-derived viruses that cause human infectious diseases and help develop new diagnostics. It is estimated that up to 75% of emerging human diseases are derived from an animal reservoir. The majority of these zoonoses emerge in low-resource settings in equatorial regions likely due to living conditions and limited access to healthcare. Madagascar has long been geographically isolated, and Madagascan fruit bats are considered potential major sources of several different zoonotic diseases such as Ebola. However, identifying disease-causing viruses using traditional diagnostic methods requires the development of targeted assays and is laborious and inefficient. In contrast, metagenomic NGS is a powerful diagnostic tool that can simultaneously assay many viruses and identify new ones. Their institution serves as a national reference laboratory for several diseases in Madagascar, and to help develop local next generation sequencing and data analysis capacity, they will pilot the approach with a subset of 380 human clinical samples already collected. They will then process an additional 410 human samples for NGS library preparation, sequencing, and pathogen analysis in Madagascar.
Muhammad Imran Nisar, Furqan Kabir, Fyezah Jehan, and Syed Asad Ali of Aga Khan University in Pakistan will employ a metagenomic sequencing approach to better identify bacterial and viral infections, including those caused by novel pathogens, in newborns and infants in Pakistan. Pakistan has the highest neonatal mortality rate in the world. Almost one third of neonatal deaths are thought to be caused by an infectious disease, but accurate diagnosis is challenging in low-resource settings. In a recent study, despite using elaborate detection methods, only 28% of suspected infectious cases could be confirmed. In addition, novel pathogens escape detection because conventional microbiological methods are limited to detecting a predetermined selection. To overcome these limitations, they will establish a metagenomics approach for next generation sequencing with the cloud computing IDseq software to identify the infectious pathogens. They will sequence and analyze 150 archived blood and nasopharyngeal specimens from a previous study and additionally analyze blood and swab samples to be collected from sick newborns and infants with suspected infections over a six-month period at a primary healthcare center in a peri-urban community in Karachi, Pakistan.
James Berkley and Abdi Abdirahman of the University of Oxford in the United Kingdom will test whether metagenomic analysis of clinical samples from patients with suspected infectious diseases can better identify the causative pathogens than current diagnostic methods, to help improve treatment. In Africa and Asia, many severely malnourished infants die after being discharged from a hospital likely due to infectious disease syndromes such as pneumonia, diarrhea, and sepsis. However, the causative pathogen remains unidentified in the vast majority of cases due to the limited sensitivity of current diagnostic methods. Another group highly vulnerable to the limitations of diagnostics currently available in low-resource settings are those with suspected viral encephalitis, which can cause acute seizures and coma. If diagnosed correctly, some of these diseases are treatable. They will use next generation sequencing to perform metagenomic analyses of samples from patients in both groups to identify the causative pathogens, and test whether first isolating extracellular vesicles that may concentrate viral nucleic acids from the samples can improve sensitivity.
Nguyen Thanh Hung and colleagues in Children’s Hospital 1 in Vietnam will implement next generation sequencing to identify the diverse viral causes of encephalitis in children in Vietnam and develop more accurate and rapid diagnostics to improve clinical outcomes. Encephalitis is an inflammation of the brain commonly caused by viral infection and is a major contributor to childhood morbidity and mortality worldwide. Treatment requires rapid diagnosis so that the appropriate antimicrobial therapy can be administered. However, traditional diagnostics are inadequate, and identify less than half of cases. Further confounding accurate diagnosis is the emergence of new and diverse pathogens that cause encephalitis. Next generation sequencing could overcome these challenges by more rapidly sequencing viral nucleic acids than previous methods and at lower costs. They will test this at their 1,600-bed hospital located in Ho Chi Minh City in Vietnam with samples from around 150 children presenting with encephalitis and compare the results with routine diagnostics. Overall, they aim to identify the major causes of encephalitis across Vietnam, map them temporally and spatially, and characterize disease outcomes.