National Typhoid and Paratyphoid Fever Surveillance Annual Summary, 2019

Surveillance

Jurisdictions¹ reporting at least one case of Salmonella enterica serotype Typhi, Paratyphi A, Paratyphi B [tartrate negative], or Paratyphi C,² to the National Typhoid and Paratyphoid Fever Surveillance system (NTPFS) during 2019 are shown in Figures 1 and 2. The surveillance system case definitions changed in 2019:

439 Salmonella Typhi cases were reported by 37 jurisdictions (Figure 1).
139 Salmonella Paratyphi cases³ were reported by 27 jurisdictions (Figure 2).

Salmonella Typhi and Paratyphi are bacteria that cause severe and occasionally life-threatening bacteremic illness known as typhoid fever and paratyphoid fever, respectively. This report summarizes all cases of bacterial infection, including those that may be asymptomatic or have atypical clinical presentation.

¹ Includes all 50 states and District of Columbia.
² Two pathotypes of Paratyphi B are recognized, differentiated by the ability to ferment tartrate. The pathotype designated serotype Paratyphi B is unable to ferment tartrate; it causes paratyphoid fever. The other pathotype is designated Paratyphi B var. L(+) tartrate+; it can ferment tartrate and causes uncomplicated gastroenteritis. Only isolates laboratory-confirmed as not able to ferment tartrate are included in this annual summary. Many reports of Paratyphi B detection do not include this information.
³ Seven cases of Salmonella serotype Paratyphi C and two cases of Salmonella Paratyphi without a specified serotype reported.

On This Page

Surveillance
Demographic and Clinical Characteristics
International Travel
Typhoid Fever Vaccine
National Notifiable Diseases Surveillance System
Antimicrobial Resistance
Outbreaks

Read an overview of the National Typhoid and Paratyphoid Fever Surveillance (NTPFS) system [PDF – 2 pages]

Figure 1 Figure 2

Salmonella Typhi cases reported to NTPFS by jurisdiction, 2019 (n = 439)

Download Data [XLS – 474 B]

Salmonella Paratyphi cases reported to NTPFS by jurisdiction, 2019 (n = 139)

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Demographic and Clinical Characteristics of Patients

Demographic and clinical characteristics of patients with Salmonella Typhi and Paratyphi infections are shown in Tables 1 and 2.

The median age of patients with Salmonella Typhi infections was 24 years (range 0 – 78)
The median age of patients with Salmonella Paratyphi infections was 26 years (range 1 – 85)
There were no deaths among patients among patients with Salmonella Typhi or Paratyphi infections

Table 1

Demographic and clinical characteristics of patients with typhoid fever reported to NTPFS, 2018 (n =370)
Characteristic (number with data)	Number	Percent
Age group, years (n = 438) <1	4	<1
1–4	40	9
5–14	90	21
15–24	91	21
25–44	149	34
45–64	53	12
65+	11	3
Female (n = 435)	221	51
Food handler (n = 308)	13	4
Outbreak-associated (n = 367)	18	5
International travel¹ (n = 422)	378	90
Vaccinated² (n = 290)	13	4
Specimen source (n = 430)
Blood	360	84
Stool	61	14
Other	9	2
Hospitalizations³ (n = 432)	360	83
Deaths (n = 409)	0	0

¹ Travel destinations are shown in Table 3a.
² Received typhoid fever vaccination within five years before onset of illness. Of the 13 cases in vaccinated persons, six received only the Vi capsular polysaccharide vaccine (ViCPS) (injection), and two received only the Ty21a oral capsule vaccine. Vaccine type was not reported for the other five.
³ Median length of hospitalization was five days.

Table 2

Demographic and clinical characteristics of patients with paratyphoid fever reported to NTPFS, 2018 (n = 128)
Characteristic (number with data)	Number	Percent
Age group, years (n = 138) <1	0	0
1–4	11	8
5–14	33	24
15–24	22	16
25–44	50	36
45–64	18	13
65+	4	3
Female (n = 136)	65	48
Food handler (n = 91)	5	5
Outbreak-associated (n = 104)	2	2
International travel¹ (n = 123)	118	96
Specimen source (n = 131)
Blood	110	84
Stool	19	15
Other	2	2
Hospitalizations² (n = 136)	99	73
Deaths (n = 123)	0	0

¹ Travel destinations are shown in Table 3b
² Median length of hospitalization was four days.

International Travel

Among the 422 patients with Salmonella Typhi infections whose travel histories were reported, 378 (90%) reported traveling or living outside the United States in the 30 days before illness.
Among the 121 Salmonella Paratyphi infections whose travel histories were reported, 116 (96%) reported traveling or living outside the United States in the 30 days before illness.
Among patients reporting international travel, 335 (89%) patients with Salmonella Typhi infections and 102 (90%) patients with Salmonella Paratyphi infections reported travel to a single destination country (Tables 3a and 3b).
192 (51%) patients with Salmonella Typhi infection and 63 (54%) patients with Salmonella Paratyphi infection associated with travel reported visiting friends or relatives, which was the most commonly reported reason for international travel.

Table 3a

Travel destinations for patients with typhoid fever who reported a single destination country, NTPFS, 2019
Travel Destination	No. (%)
India	145 (43)
Pakistan	56 (17)
Mexico	50 (15)
Bangladesh	24 (7)
El Salvador	21 (6)
Other¹	39 (12)

¹Guatemala (16), Cambodia (2), Haiti (2), Nepal (2), Philippines (2), Burma (1), Dominican Republic (1), Honduras (1), Indonesia (1), Iraq (1), Jamaica (1), Kenya (1), Myanmar (1), Nicaragua (1), Niger (1), Nigeria (1), Samoa (1), Sierra Leone (1), Tanzania (1), United Arab Emirates (1)

Table 3b

Travel destinations for patients with typhoid fever who reported a single destination country, NTPFS, 2019
Travel Destination	No. (%)
India	70 (69)
Pakistan	13 (13)
Bangladesh	8 (8)
Cambodia	4 (4)
Senegal	3 (3)
Other¹	4 (4)

¹Mexico (1), Nepal (1), Vietnam (1), Unknown (1)

Typhoid Fever Vaccine

Download Data [XLS – 67 B]

¹ Figure excludes patients whose typhoid vaccination status was unknown or not reported (n = 149).

National Notifiable Diseases Surveillance System

The National Notifiable Diseases Surveillance System (NNDSS) collects and compiles reports of nationally notifiable infectious diseases, including Salmonella Typhi and Paratyphi cases. NNDSS reports can be found at www.cdc.gov/nndss/data-statistics.

The figure below presents a comparison of Salmonella Typhi case reports submitted to NTPFS and NNDSS in the past five years. Reports submitted to NNDSS can include clinically compatible cases that are epidemiologically linked to a confirmed case but are not laboratory-confirmed.

Comparisons for Salmonella Paratyphi are not provided because, although it was nationally notifiable, it was reported under the case definition for salmonellosis during these years.

Download Data [XLS – 91 B]

Antimicrobial Resistance

The National Antimicrobial Resistance Monitoring System (NARMS) monitors antimicrobial resistance among enteric bacteria (including Salmonella enterica serotypes Typhi and Paratyphi A, Paratyphi B, and Paratyphi C) from humans. Among Typhi, decreased susceptibility to ciprofloxacin (DSC) (Minimum Inhibitory Concentration ≥0.12 µg/mL) has been associated with fluoroquinolone treatment failure. Multidrug-resistant (MDR) is defined as resistance to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole. Resistance to ceftriaxone is an indicator of extensively drug resistant (XDR) Typhi, an emerging public health concern.

Among Salmonella Typhi isolates during 2019:

75% had DSC
15% were MDR
16% were resistant to three or more classes of antibiotics
9% were resistant to ceftriaxone

Among Salmonella Paratyphi A isolates during 2019:

96% had DSC
No isolates were MDR
No isolates were resistant to three or more classes of antibiotics
No isolates were resistant to ceftriaxone

Data are available in NARMS Now, an interactive tool containing antibiotic resistance data from bacteria isolated from humans.

Outbreaks

The Foodborne Disease Outbreak Surveillance System (FDOSS) collects reports of foodborne disease outbreaks from local, state, tribal, and territorial public health agencies. The most recently published annual reports are available at www.cdc.gov/fdoss/annual-reports.

The Waterborne Disease and Outbreak Surveillance System (WBDOSS) collects reports of waterborne disease outbreaks associated with drinking water and recreational water from local, state, tribal, and territorial public health agencies. Reports are available at www.cdc.gov/healthywater/surveillance/surveillance-reports.html.

There were two multistate outbreaks of typhoid fever, resulting in 100 human illnesses. There was one outbreak of paratyphoid fever serotype Paratyphi A, resulting in 24 human illnesses reported in 2019. All outbreaks were linked to international travel.

References

CDC. National Antimicrobial Resistance Monitoring System (NARMS) Now: Human Data. Atlanta, Georgia: U.S. Department of Health and Human Services, CDC. https://wwwn.cdc.gov/narmsnow. Accessed 10/2/2022.

Recommended Citation

Centers for Disease Control and Prevention (CDC). National Typhoid and Paratyphoid Fever Surveillance Annual Report, 2019. Atlanta, Georgia: US Department of Health and Human Services, CDC, 2023

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