Firdausi Qadri, Farhana Khanam, Xinxue Liu, Katherine Theiss-Nyland et al.
BACKGROUND: Typhoid fever remains a major cause of morbidity and mortality in low-income and middle-income countries. Vi-tetanus toxoid conjugate vaccine (Vi-TT) is recommended by WHO for implementation in high-burden countries, but there is little evidence about its ability to protect against clini...
Katherine Theiss-Nyland, Firdausi Qadri, Rachel Colin-Jones, Khalequ Zaman et al.
BACKGROUND: Typhoid fever illnesses are responsible for more than 100 000 deaths worldwide each year. In Bangladesh, typhoid fever is endemic, with incidence rates between 292-395 per 100 000 people annually. While considerable effort has been made to improve access to clean water and sanitation ser...
Firdausi Qadri, Farhana Khanam, Yiyuan Zhang, Prasanta Kumar Biswas et al.
BACKGROUND: WHO currently recommends a single dose of typhoid conjugate vaccine (TCV) in high-burden countries based on 2-year vaccine efficacy data from large randomised controlled trials. Given the decay of immunogenicity, the protection beyond 2 years is unknown. We therefore extended the follow-...
Birkneh Tilahun Tadesse, Farhana Khanam, Faisal Ahmmed, Justin Im et al.
BACKGROUND: Typhoid fever contributes to approximately 135 000 deaths annually. Achievable improvements in household water, sanitation, and hygiene (WASH) combined with vaccination using typhoid conjugate vaccines (TCVs) may be an effective preventive strategy. However, little is known about how imp...
Farhana Khanam, Golap Babu, Nazia Rahman, Xinxue Liu et al.
A cluster-randomized trial of Vi-TT was conducted in Dhaka, Bangladesh, using JE vaccine as the control. A subset of 1,500 children were randomly selected on 2:1 basis (Vi-TT vs JE) to assess immune response. Blood was collected before vaccination, and on days 28, 545 and 730 post-vaccination and pl...
Justin Im, Farhana Khanam, Faisal Ahmmed, Deok Ryun Kim et al.
Modest improvements in household water, sanitation, and hygiene (WASH) and typhoid vaccination can reduce typhoid risk in endemic settings. However, empiric evaluation of their combined impact is lacking. A total of 62,756 persons residing in 80 clusters in a Kolkata slum were allocated randomly 1:1...
Farhana Khanam, Deok Ryun Kim, Xinxue Liu, Merryn Voysey et al.
Background: A cluster-randomised trial of Vi-tetanus toxoid (Vi-TT) conjugate vaccine conducted in urban Bangladeshi children found a high level of direct protection by Vi-TT but no significant vaccine herd protection. We reassessed the trial using a "fried egg" analysis to evaluate whether herd pro...
Birkneh Tilahun Tadesse, Farhana Khanam, Faisal Ahmmed, Xinxue Liu et al.
BACKGROUND: Typhoid fever, or enteric fever, is a highly fatal infectious disease that affects over 9 million people worldwide each year, resulting in more than 110,000 deaths. Reduction in the burden of typhoid in low-income countries is crucial for public health and requires the implementation of ...
Sophie Kang, Fahima Chowdhury, Juyeon Park, Tasnuva Ahmed et al.
OBJECTIVE: To investigate the association between existing household water quality, sanitation and hygiene (WASH) practices and severe cholera risk in a dense urban slum where cholera is highly endemic. DESIGN, SETTING AND PARTICIPANTS: We assembled a large prospective cohort within a cluster random...
Fahima Chowdhury, Asma Binte Aziz, Faisal Ahmmed, Tasnuva Ahmed et al.
The current global initiative to end Cholera by 2030 emphasizes the use of oral cholera vaccine (OCV) combined with feasible household Water-Sanitation-Hygiene (WASH) interventions. However, little is known about how improved WASH practices and behaviors and OCV interact to reduce the risk of choler...
Abdur Razzaque Sarker, Ashraful Islam Khan, Md Taufiqul Islam, Fahima Chowdhury et al.
Cholera poses a substantial health burden in the developing world due to both epidemic and endemic diseases. The World Health Organization recommends oral cholera vaccines for mass vaccination campaigns in addition to traditional prevention practices and treatments in resource-poor settings. In many...
Shuo Feng, Yiyuan Zhang, Farhana Khanam, Merryn Voysey et al.
BACKGROUND: Typhoid fever remains a substantial public health challenge in low-income and middle-income countries. By 2023, typhoid conjugate vaccines (TCVs) had been introduced in six countries globally, with more than 50 million doses distributed. Now that TCVs are being deployed, there is a need ...
Sadia Rahman, Md Golam Firoj, Se Eun Park, Farhana Khanam et al.
Enteric fever remains a public health challenge. We analyzed data from a cluster-randomized Vi-tetanus toxoid conjugate vaccine trial to compare the epidemiology between Salmonella enterica serovars Paratyphi A, which causes paratyphoid fever, and Typhi, which causes typhoid fever. The overall incid...
Firdausi Qadri, Farhana Khanam, Yiyuan Zhang, Prasanta Kumar Biswas et al.
Faisal Ahmmed, Farhana Khanam, Md Taufiqul Islam, Deok Ryun Kim et al.
BACKGROUND: Salmonella enterica serotype Typhi (Salmonella Typhi) causes severe and occasionally life-threatening disease, transmitted through contaminated food and water. Humans are the only reservoir, inadequate water, sanitation, and hygiene infrastructure increases risk of typhoid. High-quality ...
Nienke Hagedoorn, Shruti Murthy, Christian S. Marchello, Jonathan Williman et al.
Nienke Hagedoorn, Shruti Murthy, Christian S. Marchello, Jonathan Williman et al.
Nienke N. Hagedoorn, Shruti Murthy, Christian S. Marchello, Jonathan Williman et al.
BACKGROUND: Typhoid fever incidence estimates are central to policy decisions on vaccine introduction and investments in non-vaccine prevention and control but are often unavailable. We explored whether prevalence metrics from sentinel studies of community-onset bloodstream infections could accurate...
Yiyuan Zhang, Faisal Ahmmed, Farhana Khanam, Prasanta Kumar Biswas et al.
Background: Indirect protection from the typhoid conjugate vaccine (TCV) has been negligible, possibly due to vaccination being restricted to children, which may have limited the overall vaccine coverage needed to sufficiently interrupt transmission dynamics across endemic populations. In this study...
Nienke N. Hagedoorn, Shruti Murthy, Christian S. Marchello, Jonathan Williman et al.
Abstract Background Typhoid fever incidence estimates are central to policy decisions on vaccine introduction and investments in non-vaccine prevention and control but are often unavailable. We explored whether prevalence metrics from sentinel studies of community-onset bloodstream infections could ...