The global burden of typhoid and paratyphoid fevers: a systematic analysis for the Global Burden of Disease Study 2017
Authors: Jeffrey D Stanaway, Robert C Reiner, Brigette F. Blacker, Ellen M Goldberg, Ibrahim A. Khalil, Christopher E Troeger, Jason R Andrews, Zulfiqar A Bhutta, John A Crump, Justin Im, Florian Marks, Eric Mintz, Se Eun Park, Anita K M Zaidi, Zegeye Abebe, Ayenew Negesse Abejie, Isaac Akinkunmi Adedeji, Beriwan Abdulqadir Ali, Azmeraw T. Amare, Hagos Tasew Atalay, Euripide F G A Avokpaho, Umar Bacha, Aleksandra Barac, Neeraj Bedi, Adugnaw Berhane, Annie J Browne, Jesus L. Chirinos, Abdulaal Chitheer, Christiane Dolecek, Maysaa El Sayed Zaki, Babak Eshrati, Kyle J. Foreman, Abdella Gemechu, Rahul Gupta, Gessessew Bugssa Hailu, Andualem Henok, Desalegn Tsegaw Hibstu, Chi Linh Hoang, Olayinka Stephen Ilesanmi, Veena J Iyer, Amaha Kahsay, Amir Kasaeian, Tesfaye Dessale Kassa, Ejaz Ahmad Khan, Young-Ho Khang, Hassan Magdy Abd El Razek, Mulugeta Melku, Desalegn Tadese Mengistu, Karzan Abdulmuhsin Mohammad, Shafiu Mohammed, Ali H Mokdad, Jean B Nachega, Aliya Naheed, Cuong Tat Nguyen, Huong Lan Thi Nguyen, Long Hoang Nguyen, Nam Ba Nguyen, Trang Huyen Nguyen, Yirga Legesse Nirayo, Tikki Pangestu, George C Patton, Mostafa Qorbani, Rajesh Kumar Rai, Saleem M Rana, Chhabi Lal Ranabhat, Kedir Teji Roba, Nicholas L S Roberts, Salvatore Rubino, Saeid Safiri, Benn Sartorius, Monika Sawhney, Mekonnen Sisay Shiferaw, David L Smith, Bryan L. Sykes, Bach Xuan Tran, Tung Thanh Tran, Kingsley Nnanna Ukwaja, Giang Thu Vu, Linh Gia Vu, Fitsum Weldegebreal, Melaku Kindie Yenit, Christopher J L Murray, Simon I. Hay
Journal: The Lancet Infectious Diseases (2019)

BackgroundEfforts to quantify the global burden of enteric fever are valuable for understanding the health lost and the large-scale spatial distribution of the disease. We present the estimates of typhoid and paratyphoid fever burden from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017, and the approach taken to produce them.MethodsFor this systematic analysis we broke down the relative contributions of typhoid and paratyphoid fevers by country, year, and age, and analysed trends in incidence and mortality. We modelled the combined incidence of typhoid and paratyphoid fevers and split these total cases proportionally between typhoid and paratyphoid fevers using aetiological proportion models. We estimated deaths using vital registration data for countries with sufficiently high data completeness and using a natural history approach for other locations. We also estimated disability-adjusted life-years (DALYs) for typhoid and paratyphoid fevers.FindingsGlobally, 14·3 million (95% uncertainty interval [UI] 12·5–16·3) cases of typhoid and paratyphoid fevers occurred in 2017, a 44·6% (42·2–47·0) decline from 25·9 million (22·0–29·9) in 1990. Age-standardised incidence rates declined by 54·9% (53·4–56·5), from 439·2 (376·7–507·7) per 100 000 person-years in 1990, to 197·8 (172·0–226·2) per 100 000 person-years in 2017. In 2017, Salmonella enterica serotype Typhi caused 76·3% (71·8–80·5) of cases of enteric fever. We estimated a global case fatality of 0·95% (0·54–1·53) in 2017, with higher case fatality estimates among children and older adults, and among those living in lower-income countries. We therefore estimated 135·9 thousand (76·9–218·9) deaths from typhoid and paratyphoid fever globally in 2017, a 41·0% (33·6–48·3) decline from 230·5 thousand (131·2–372·6) in 1990. Overall, typhoid and paratyphoid fevers were responsible for 9·8 million (5·6–15·8) DALYs in 2017, down 43·0% (35·5–50·6) from 17·2 million (9·9–27·8) DALYs in 1990.InterpretationDespite notable progress, typhoid and paratyphoid fevers remain major causes of disability and death, with billions of people likely to be exposed to the pathogens. Although improvements in water and sanitation remain essential, increased vaccine use (including with typhoid conjugate vaccines that are effective in infants and young children and protective for longer periods) and improved data and surveillance to inform vaccine rollout are likely to drive the greatest improvements in the global burden of the disease.FundingBill & Melinda Gates Foundation.