Paratyphoid fever is a bacterial infection caused by Salmonella enterica of the serotypes Paratyphi A, Paratyphi B, or Paratyphi C growing in the intestines and blood.[1] It belongs, together with typhoid fever, to the broader clinical entity of enteric fever.[1][2]
Disease overview
BacterialParatyphoid fever
副伤寒
Evidence-backed informationEN 5/7 applicable sections · ZH 5/7 applicable sectionsUpdated Sep 3, 2026
Paratyphoid fever is a bacterial infection caused by Salmonella enterica serotypes Paratyphi A, B, or C, producing an enteric fever syndrome clinically similar to typhoid fever.[1][2] Transmission occurs via the faecal–oral route, with disease concentrated in regions lacking safe water, sanitation, and hygiene infrastructure.[2] The global burden is substantial, with an estimated 16 million cases and roughly 25,000 deaths attributed to paratyphoid fever annually.[1]
Read the full clinical and epidemiological profile6
Symptoms usually begin 6–30 days after exposure and resemble those of typhoid fever, often beginning with a gradual onset of high fever over several days.[1][2] Weakness, loss of appetite, and headaches are commonly reported, and some patients develop a skin rash with rose-colored spots.[1] Without treatment, symptoms can persist for weeks or months, and life-threatening complications may arise in the second week of untreated illness.[1][2] A proportion of infected individuals can carry the bacteria asymptomatically while remaining capable of transmitting infection to others.[1]
Paratyphoid fever is found across large parts of Asia, Africa, and Central and South America, with many cases acquired in Asian countries, and it occasionally produces epidemics.[1] The disease is more common in less-industrialized countries owing to poverty, poor hygiene, unsafe drinking water, inadequate sewage disposal, and flooding, and unclean food from street vendors helps distribute infection beyond the household.[1] Globally, about 16 million cases occur each year, resulting in approximately 25,000 deaths annually.[1]
Paratyphoid fever is transmitted by the faecal–oral route, most commonly through eating or drinking food or water contaminated with the feces of an infected person, and may occur when a food preparer is infected.[1][2] Humans are the only animals infected, and risk is amplified by poor sanitation among crowded populations.[1] Rarely, transmission may occur via sexual contact.[1]
Prevention centers on ensuring access to safe drinking water, adequate sewage disposal, and improved food and personal hygiene, particularly in settings with poor sanitation or after flooding events.[1][2] While no vaccine is licensed specifically for paratyphoid, typhoid vaccination may provide some cross-protection, and typhoid Vi-conjugate vaccines are cornerstones of broader enteric fever prevention.[1][2] Travelers to endemic areas should adhere to safe food and water practices and observe hand hygiene.[1]
- 1Wikipedia contributors. Paratyphoid fever - Wikipedia [Internet]. Wikipedia. cited 4 Sept 2026.Available from: https://en.wikipedia.org/wiki/Paratyphoid_fever
- 2Kuehn R et al. Enteric (typhoid and paratyphoid) fever. Lancet. 2025 Sep 20. PMID: 40914181. doi: 10.1016/S0140-6736(25)01335-2.PubMed: https://pubmed.ncbi.nlm.nih.gov/40914181/
- A01.1-A01.4
Coverage
Reporting countries and regions
Trends by reporting country
Monthly patterns over time
Research Radar
Recent related research
Genomic epidemiology and antimicrobial resistance reveal local transmission dynamics of enteric fever in Shenzhen, one of the mega cities in China
Journal of Infection
Treatment responses to Azithromycin and Ciprofloxacin in uncomplicated Salmonella Typhi infection: A comparison of Clinical and Microbiological Data from a Controlled Human Infection Model
PLOS Neglected Tropical Diseases
The Burden of Typhoid and Paratyphoid in India: Systematic Review and Meta-analysis
PLOS Neglected Tropical Diseases
A Large Outbreak of Salmonella Paratyphi A Infection Among Israeli Travelers To Nepal
Clinical Infectious Diseases
Literature links are provided for discovery and do not alter or validate the surveillance series above.
Data access
Page dataset index with source links and update metadata.
Official sourcesAuthority, cadence, notes22
Australia NINDSS
Australia
Australian national notifiable diseases surveillance dashboard.
Australia NINDSS — Australian Capital Territory
Australian Capital Territory, Australia
Australian NINDSS monthly state/territory notifications for Australian Capital Territory, kept separate from the Australia national aggregate.
Australia NINDSS — New South Wales
New South Wales, Australia
Australian NINDSS monthly state/territory notifications for New South Wales, kept separate from the Australia national aggregate.
Australia NINDSS — Northern Territory
Northern Territory, Australia
Australian NINDSS monthly state/territory notifications for Northern Territory, kept separate from the Australia national aggregate.
Australia NINDSS — Queensland
Queensland, Australia
Australian NINDSS monthly state/territory notifications for Queensland, kept separate from the Australia national aggregate.
Australia NINDSS — South Australia
South Australia, Australia
Australian NINDSS monthly state/territory notifications for South Australia, kept separate from the Australia national aggregate.
Australia NINDSS — Tasmania
Tasmania, Australia
Australian NINDSS monthly state/territory notifications for Tasmania, kept separate from the Australia national aggregate.
Australia NINDSS — Victoria
Victoria, Australia
Australian NINDSS monthly state/territory notifications for Victoria, kept separate from the Australia national aggregate.
Australia NINDSS — Western Australia
Western Australia, Australia
Australian NINDSS monthly state/territory notifications for Western Australia, kept separate from the Australia national aggregate.
Canada PHAC CNDSS Annual
Canada
Canada is the national jurisdiction; subdivision feeds are registered separately.
Public Health Ontario IDTO Monthly
Ontario, Canada
Ontario-level current-year preliminary monthly case counts from Public Health Ontario's IDTO report.
Finland THL Infectious Diseases Register
Finland
Finland THL Infectious Diseases Register national monthly case counts. The current month is ingested as provisional and the latest three months are refreshed for source revisions.
Hong Kong, China CHP Notifiable Diseases
Hong Kong, China
Hong Kong, China CHP annual notifiable infectious disease CSVs normalized to national monthly totals
JP NIID Weekly
Japan
Japan weekly infectious disease surveillance via NIID/JIHS.
Korea KDCA EID
South Korea
Korea KDCA notifiable infectious disease OpenAPI or portal/KOSIS downloads aggregated to national monthly notification counts.
Norway FHI MSIS Statistics Bank
Norway
Norway FHI MSIS national monthly notifications from the official Allvis frontend API; adapter contract checks guard the unversioned endpoint.
New Zealand PHF Science Monthly Notifiable Diseases
New Zealand
PHF Science (formerly ESR) monthly notifiable disease surveillance data via internal globalID2 crawler
Sweden Public Health Agency SmiNet
Sweden
Sweden SmiNet national monthly reported cases from the official Public Health Agency statistics pages; public release is enabled with closed-month publication and revisable recent-month refreshes.
Singapore CDA Weekly Infectious Diseases Bulletin
Singapore
Singapore national weekly case notifications, combining the official data.gov.sg 2012–2022 CSV history with CDA annual workbooks from 2023 onward; 2023 weekly PDFs are retained as a source fallback.
Taiwan, China CDC NIDSS
Taiwan, China
Taiwan, China monthly notifiable infectious disease open-data CSV feed.
US CDC NNDSS
United States
CDC National Notifiable Diseases Surveillance System provisional data.
US CDC NHSS HIV
United States
CDC NNDSS weekly data plus NHSS annual national HIV diagnoses