No 11 - 2011

Typhoid and Paratyphoid Fever 2008-2010

Clinical manifestation & transmission

Typhoid and paratyphoid fever is caused by Salmonella Typhi and Salmonella Paratyphi A, B and C. Typhoid and paratyphoid fever is notifiable for physicians and laboratories alike, and the Department of Epidemiology sends out reminders for clinical notifications on the basis of laboratory information received through the laboratory surveillance system, Figure 1.

Generally, more laboratory than clinical notifications are received. The number of cases has remained stable during the past 15 years, apart from 1999 when a major outbreak occurred in Turkey which also comprised Danish tourists, EPI-NEWS 38/99 (pdf).

Clinically notified cases

In the 2008-2010 period, a total of 54 cases of typhoid fever and 39 cases of paratyphoid fever were notified,
Table 1.

Mode of transmission - typhoid fever

In line with previous observations, a considerable share (52 %) were infected in Pakistan, India or remaining parts of Asia, Table 2.

A total of 38 of the 54 typhoid cases detected were immigrants, including 13 children < 15 years who were all infected in their countries of origin, including two children from a Congolese family in which five of a total of 16 family members were infected.

A total of 16 Danes were infected with typhoid fever, Table 3.

Three were infected while travelling as tourists in India, including two children below 15 years of age, four were infected in the remaining parts of Asia, including two children below 15 years of age. 

Furthermore, two were infected in Greece, two in Africa and one in South America.

Three Danes were infected in Denmark.

Mode of transmission – paratyphoid fever

A total of 26 (67 %) of the detected cases of paratyphoid fever were acquired in Asia, including 16 in India and Pakistan. Six cases were acquired in Europa, including four cases in Denmark, Table 2.

A total of 19 Danes were infected: 16 during travels abroad, including six in India, two in other parts of Asia, three in Bolivia, two in Africa and one in Russia. In two cases, several possible infection countries were stated.

A total of four Danes, including two children < 15 years, became infected with paratyphoid fever in Denmark.

A total of 19 cases of paratyphoid fever were immigrants, Table 3. All were infected in their countries of origin, including five children < 15 years.

Laboratory-notified cases

Table 4 shows the number of culture-verified cases of S. Typhi and S. Paratyphi A or B diagnosed at Danish departments of clinical microbiology. Cultures should be forwarded to the Department of Microbiological Diagnostics, SSI.

Vaccination status, typhoid fever

Three adult Danes were recorded as vaccinated, but with no statement as to the vaccination year. One of these had typhoid fever.

Commentary

A total of 91 % of the cases of typhoid and paratyphoid fever required admission to hospital and the majority were imported cases.

Vaccination against typhoid fever is recommended for travels to the Indian subcontinent lasting more than two weeks, and for stays with family members and personal contacts in endemic areas, regardless of the duration of stay, EPI-NEWS 6/11 and EPI-NEWS 26/10.

Also see www.ssi.dk/rejser (Danish language).

(C. Kjelsø, S. Ethelberg, Department of Epidemiology and DBMP)

Individually notifiable diseases and selected laboratory diagnosed infections (pdf) 

16 March 2011