Typhoid fever remains a substantial infectious-disease burden, with millions of estimated illnesses each year and the greatest incidence concentrated in endemic settings. The latest global estimates put the 2023 burden at 6.2 million cases and 72,000 deaths, while vaccine trials show high protection from typhoid conjugate vaccines in several settings.
Contents
- Global burden by year
- Geography and age
- Severity, diagnosis, and carriage
- Older vaccine types
- Typhoid conjugate vaccine protection
- Travel-associated statistics
Global burden by year
The Global Burden of Disease Study estimated 6.2 million typhoid fever cases worldwide in 2023, with a 95% uncertainty interval of 4.8–8.0 million cases. The same estimate included 72,000 deaths, with a 95% uncertainty interval of 38,000–120,000 deaths, and 5.4 million disability-adjusted life years (DALYs), with a 95% uncertainty interval of 2.8–8.8 million DALYs. These are modeled global estimates, not a simple count of individually reported cases.
For comparison, the WHO Foodborne Diseases Epidemiology Reference Group estimated 7.2 million typhoid illnesses globally in 2021, with a 95% uncertainty interval of 5.6–9.3 million. Its 2021 estimate included 94,700 deaths, with a 95% uncertainty interval of 46,900–161,000, and 7.5 million DALYs, with an uncertainty interval of 3.8–12.9 million. The 2021 and 2023 figures come from different estimation exercises and should not be treated as a direct year-to-year surveillance trend.
| Global measure | 2021 estimate | 2023 estimate |
|---|---|---|
| Illnesses or cases | 7.2 million | 6.2 million |
| Deaths | 94,700 | 72,000 |
| DALYs | 7.5 million | 5.4 million |
Source and scope: WHO Position paper on typhoid vaccines, 2026. Estimates include uncertainty intervals and use different named estimation sources for 2021 and 2023.
The 2021 analysis also used expert elicitation to estimate that 38.1% of typhoid illnesses were foodborne, with a 95% uncertainty interval of 15.5–63.4%. This percentage is an estimate of the foodborne share, not a count of confirmed transmission events.
Geography and age
Incidence varies sharply by setting and by surveillance design. A systematic review of blood-culture-confirmed studies, covering studies available through January 2018 and published in 2019, reported pooled incidence of about 154 illnesses per 100,000 person-years in population-based studies from endemic countries. In hybrid surveillance studies, the pooled estimate was about 142 cases per 100,000 person-years after adjustment for under-ascertainment.
Within population-based analyses, endemic Asian settings had an estimated incidence of about 268 per 100,000 person-years, compared with about 112 per 100,000 person-years in endemic African settings. These are pooled study estimates, so they summarize the included evidence rather than assigning one uniform incidence rate to every country.
An update incorporating datasets published through 2024 found pooled incidence of about 206 illnesses per 100,000 person-years in newer population-based studies and about 133 illnesses per 100,000 person-years in newer hybrid surveillance studies. Because the study sets and methods differ, the older and newer pooled values should be read as evidence summaries, not as a single continuous time series.
Age patterns show that typhoid is not limited to adults. Meta-analyses estimated that 1.3% of illnesses occur before 6 months of age, with a 95% credible interval of 1.0–1.6%; 18.7% occur before 5 years, with a 95% credible interval of 15.7–21.9%; and 55.5% occur before 15 years, with a 95% credible interval of 50.8–59.5%. These are global pooled age-occurrence estimates summarized in the 2026 position paper.
Severity, diagnosis, and carriage
The typical incubation period for typhoid fever is 7–14 days, but the reported range is 3–60 days. Illness may therefore begin outside the immediate period of exposure, so a recent trip can remain clinically relevant when symptoms appear later.
A global systematic review of reports from 1980–2025 found an overall pooled typhoid case-fatality ratio of 2.1% among non-surgical reports, with a 95% confidence interval of 1.7–2.7%. The pooled ratio was 2.7% among children aged 15 years or younger, with a 95% confidence interval of 1.8–4.0%, and 1.8% in mixed-age populations, with a 95% confidence interval of 1.3–2.4%. These pooled values describe reported study populations and are not a prediction for an individual patient.
A systematic review estimated intestinal perforation in approximately 1–2% of typhoid illnesses. Approximately 2–5% of infected people become chronic Salmonella Typhi carriers, according to the WHO epidemiology summary in the 2026 position paper. A carrier estimate describes persistent infection after the initial illness; it is not the same measure as short-term contagiousness during acute disease.
Testing also has measurable limitations. The sensitivity of a single blood culture for typhoid is approximately 55–60%, meaning that one negative culture does not exclude typhoid. Across commonly used rapid or serological assays, average sensitivity was approximately 78–84% and average specificity approximately 77–87% in the Cochrane review summarized by the position paper. Sensitivity measures how often a test detects disease when it is present; specificity measures how often it is negative when disease is absent.
Older vaccine types
Three typhoid vaccine types are licensed globally: live attenuated Ty21a, unconjugated Vi polysaccharide vaccines, and typhoid conjugate vaccines. Their age indications, schedules, and observed protection differ.
Ty21a is licensed for people aged 6 years and older. It is administered in a three-dose oral regimen on alternate days, with four doses used in some national schedules. A systematic review estimated pooled Ty21a efficacy at approximately 45% over 1–3 years, with a 95% confidence interval of 33–55%. Individual field trials reported efficacy ranging from approximately 33% to 67% at three years after vaccination. Studies in Chile found protection of about 62–67% for up to seven years. These figures are study results across specified follow-up periods, not a guarantee of the same duration for every recipient.
Vi polysaccharide vaccines are licensed for people aged 2 years and older and are administered as a single 0.5 mL dose. A systematic review estimated pooled efficacy at approximately 58% over 1–3 years, with a 95% confidence interval of 44–69%. Pre-licensure trials in endemic settings reported efficacy of approximately 60–70% over follow-up periods of up to two years.
Results varied by study location. A cluster-randomized trial in Kolkata, India, found total Vi polysaccharide effectiveness of 61% over two years, with a 95% confidence interval of 41–75%. A cluster-randomized trial in Karachi, Pakistan, found adjusted effectiveness of 31% among recipients aged 2–16 years, with a 95% confidence interval of −28 to 63%. In the prespecified Karachi subgroup aged 5–16 years, effectiveness was 57%, with a 95% confidence interval of 6–81%. The negative lower bound in the full Karachi interval indicates substantial statistical uncertainty around that estimate.
Typhoid conjugate vaccine protection
Four typhoid conjugate vaccines are WHO-prequalified. All are administered as a single 0.5 mL intramuscular dose and contain 25 micrograms of purified Vi capsular polysaccharide. Typbar-TCV and ZyVac TCV are licensed from 6 months through 65 years of age. TYPHIBEV and SKYTYPHOID Multi Inj. are licensed from 6 months through 45 years of age.
Several trials reported high protection over defined periods:
- The Vi-rEPA conjugate vaccine showed 89% efficacy among children aged 2–5 years through 46 months of follow-up in a Viet Nam trial, with a 95% confidence interval of 76–97%.
- A controlled human infection model found 80% Vi-TT efficacy against symptomatic fever with a positive blood culture.
- A Malawi Phase 3 trial found 83.7% Vi-TT efficacy after two years among children aged 9 months to 12 years, with a 95% confidence interval of 68.1–91.6%.
- A Nepal trial found 79.0% Vi-TT efficacy at 24 months among children aged 9 months to 15 years, with a 95% confidence interval of 61.9–88.5%.
- A Bangladesh cluster-randomized trial found 85% total Vi-TT protection over 18 months among children aged 9 months to 16 years, with a 97.5% confidence interval of 76–91%.
The Bangladesh trial also estimated 57% overall protection among all residents of vaccine clusters, with a 95% confidence interval of 45–67%, and 19% indirect protection among unvaccinated cluster residents, with a 95% confidence interval of −12 to 41%. In Malawi, cumulative Vi-TT efficacy was 83.4% after one year, with a 95% confidence interval of 60.1–94.3%.
These results are not interchangeable: they involve different vaccines or formulations, populations, endpoints, trial designs, and follow-up periods. They show why conjugate-vaccine estimates should be reported with their measurement context rather than reduced to one universal percentage.
Travel-associated statistics
U.S. surveillance illustrates how strongly typhoid statistics can be shaped by international travel. Approximately 450 culture-confirmed typhoid cases were reported in the United States in 2019. During 2020–2021, approximately 150–160 cases were reported annually. The figures cover different periods and should not be interpreted as a complete explanation of the change.
The CDC estimates that approximately 85% of U.S. typhoid cases occur among international travelers. More than 70% of U.S. travel-associated cases occur in travelers returning from South Asia, primarily Bangladesh, India, and Pakistan. These figures are from the CDC travel epidemiology summary, whose source page is current through 2025.
An earlier CDC estimate reported an average of about 400 U.S. typhoid cases annually during 2007–2011, with approximately 90% occurring among people returning from foreign travel. That legacy estimate should be read in its original 2007–2011 context and should not be treated as a current annual baseline.
Sources: Typhoid and Paratyphoid Fever, CDC Yellow Book; Updated Recommendations for the Use of Typhoid Vaccine, CDC.