African scientist wins Royal Society Pfizer Award for salmonella research

21 September 2012

A Kenyan scientist who is working to understand a disease that kills around 100,000 people in Africa each year has been awarded the Royal Society Pfizer Award.  Dr Samuel Kariuki, who is conducting research on invasive non-typhoidal salmonella, will receive £60,000 towards a study which aims to provide a better understanding of the transmission patterns of the disease so that a vaccine can be developed.

In Africa invasive non-typhoidal salmonella (NTS) is now a major cause of admission of children to hospital. Although caused by the same variation of bacteria as Salmonella enterica (Typhimurium and Enteritidis) responsible for “food poisoning” and the associated gastroenteritis in western society, in Africa, this is a very different disease. Infections typically present with high fever, without gastrointestinal symptoms and very high case fatality rates (15-25%).

Dr Samuel Kariuki, Chief Research Scientist and Head of Department, Centre for Microbiology Research at the Kenya Medical Research Institute (KEMRI) in Nairobi and the first International Fellow at the Wellcome Trust Sanger Institute (WTSI), has investigated invasive NTS as an emerging and serious disease for children under 5 in Kenya for the last 15 years.

In sub-Saharan Africa, unlike in other regions of the world, invasive forms of NTS are common in HIV-positive adults and non-HIV children, and those with malnutrition, or co-infected with malaria. The strains are typically highly drug resistant. Dr Kariuki, from his various studies utilising basic molecular tools, hypothesised that person-to-person rather than zoonotic transmission was playing a significant role in the epidemiology of NTS. The hypothesis was at first greeted with scepticism from Western scientists but was later proven to be correct due in part to genome analysis of NTS linked to field epidemiology - work carried out by Dr Kariuki in collaboration with WTSI. 

In the last ten years Dr Kariuki has clearly mapped the changing trends in epidemiology over time and his work has attracted the interest of the Novartis Vaccine Global Health Institute which is planning an initiative to develop a salmonella vaccine to target this disease through joint EU funding.

The £60,000 funding from the Royal Society Pfizer Award will help Dr Kariuki and colleagues set up a study to determine the distribution and potential transmission of invasive Salmonella at the Missionaries of Mary hospital in the Mukuru slum settlement in Nairobi where the disease is endemic. Using genomic data mining they will seek to identify antigens in NTS that may be used as targets for vaccine development.

Commenting on his prize and how it will help further research, Dr Samuel Kariuki, said:

“I am indeed very grateful and feel honoured to receive this award. For the last 10 years my team at KEMRI and collaborators at the Sanger Institute have made huge strides in our effort to understand the characteristics of invasive non-typhoidal salmonella (NTS) disease, an endemic, devastating and often fatal illness affecting children in poor resource settings in Kenya and the region. This award will greatly enhance our capacity to study the genetics of disease and host and take us a step closer to developing prevention strategies including vaccine for NTS.”

Professor Martyn Poliakoff, Foreign Secretary of the Royal Society, said:

“This year’s winner, Dr Sam Kariuki, has done outstanding research, contributing to our understanding of non-typhoidal salmonella (NTS) as a major cause of illness and death in children under 5 in Africa and the phenotypes of antibiotic resistance prevalent in NTS. His research takes us a step closer to a possible vaccine. The Royal Society Pfizer Award recognises the valuable research already taking place in Africa, whilst aiming to expand research capacity.  We hope that this award will continue to boost the careers of its winners and the individuals working around them.”

Dr Jack Watters, Vice President of External Medical Affairs at Pfizer, added:

“The delivery of healthcare in the continent of Africa has shown amazing progress in the past decade, especially in the field of HIV/AIDS. However there are still enormous challenges including from non communicable disease in a population which is also benefitting from the longevity revolution. The answers to Africa’s challenges are to be found in Africa which is why the Royal Society Pfizer prize celebrates African researchers delivering first class science in and for Africa where it can make the greatest difference”.

This year sees the Royal Society Pfizer Exceptional Merit Award given for the first time to Dr Martin Ota. He is a clinical immunologist and vaccinologist with the Medical Research Council Unit, The Gambia. His studies are targeted at biomarker discoveries to understand the pathogenesis of tuberculosis and pneumococcal diseases, including clinical trials of novel vaccines to these two pathogens. Dr Martin Ota of the Medical Research Council Unit, The Gambia, has been awarded a £37,000 grant to run a study which will see 200 pregnant women recruited and their infants followed during their first three months of life to better understand the relationship between pneumococcal protein antibody levels and nasopharyngeal carriage of pneumococci in early infancy. His research will be used to help develop better and new vaccines for pneumococcal infections – invasive infections include pneumonia, meningitis and febrile bacteremia; among the common non-invasive manifestations are otitis media, sinusitis and bronchitis.

The award grants as well as a £5,000 personal prize to Dr Kariuki and a £3,000 prize to Dr Ota will be presented at a ceremony on 31 October 2012 at the Royal Society in London.