Typhoid

Background

Typhoid fever, also known as enteric fever, is an infection caused by the Salmonella typhi bacteria and is transmitted through the ingestion of food or water contaminated by faeces and urine of carriers. Typhoid fever used to be an endemic disease in Singapore, with a fatality rate of 12 percent in the 1950s.¹ Since the 1980s, the incidence of typhoid fever in Singapore has reduced to a level comparable to that of other developed countries.²

Local typhoid cases
It appears that typhoid fever was rare in Singapore before the end of the 19th century.³ However, from the beginning of the 20th century, typhoid fever became more frequent with 353 cases reported in 1907.⁴ Typhoid fever cases steadily increased thereafter with 138 cases and 34 deaths reported in June 1938.⁵

In March 1950, 10 people, mostly school children, died from typhoid fever in Singapore, because of the consumption of contaminated ice cream sold by unlicensed hawkers.⁶ After another outbreak in July 1950, the Municipal Health Department proposed measures to control the sale of ice cream and popsicles by unlicensed hawkers.⁷

In September 1960, 49 cases of typhoid fever were reported on four off-shore islands, and the government conducted an immunisation programme on those islands to curb the outbreak.⁸ In March 1965, after a typhoid outbreak of nine cases in Chung Cheng High School, the Health Ministry stopped the sale of cold, raw and iced food in the school.⁹

Typhoid outbreaks continued into the 1970s. The largest typhoid outbreak in this decade involved 76 cases and 4 carriers in early 1971. This outbreak was detected from a mass screening of over 600 hawkers and food handlers in Geylang Serai.¹⁰

By the early eighties, local typhoid fever and other communicable disease cases in Singapore were on the decline. Typhoid cases fell from 5.9 per 100,000 population in 1980 to 1.2 per 100,000 population in 1989. During this decade, 33 outbreaks with 199 cases were reported.¹¹ Subsequently from 1990 to 2009, 311 local cases of typhoid fever were reported. Since the typhoid outbreak in 1992, all reported local cases occurred singly and sporadically and were no longer spread by chronic carriers.¹²

In August 2019, 18 typhoid cases were reported, all of which had no recent travel history. Although preliminary analysis conducted on the typhoid bacteria samples suggested that the cases could be linked to a common upstream source, this was found not to be the case after further investigation by the Ministry of Health and the Singapore Food Agency.¹³

Imported typhoid cases
On the other hand, the proportion of imported cases of typhoid fever increased from 32 percent in 1980 to 72 percent in 1989.¹⁴ Imported cases comprise local residents who contract the disease while travelling and foreigners who come to Singapore.¹⁵

From 1990 to 2009, 1,388 imported cases of typhoid fever were reported, with an increasing proportion of foreign contract workers. This increase is likely due to the quadrupling of the number of foreign contract workers in Singapore during that period.¹⁶

In 1989, multidrug-resistant Salmonella Typhi emerged, with cases being reported in India, Pakistan and China. Multidrug-resistant typhoid seems to be more severe with a longer fever duration and was largely imported into Singapore by travellers to the Indian subcontinent.¹⁷

Government action
The incidence rate of typhoid fever in Singapore per 100,000 population decreased from 22.8 in 1975 to 5.9 in 1980, 1.2 in 1989, and 0.14 in 2009, a level comparable to that of other developed countries.¹⁸

The Singapore government has taken various measures over the years to bring typhoid fever under control, such as ensuring a high standard of environmental hygiene and sanitation, identifying undetected carriers, licensing food establishments, relocating street vendors to modern food centres, screening and vaccinating public food-handlers, and providing health education. Various nationwide public-health campaigns, such as the 1975 Better Food for Better Health campaign, emphasised the need for food hygiene and sanitation.¹⁹

In addition, the government practises timely epidemiological surveillance, by making the notification of typhoid fever mandatory by law.²⁰



Author
Anasuya Soundararajan



References
1. Albert U Ty et al., “Changing Epidemiology of Enteric Fevers in Singapore,” Annals of the Academy of Medicine, Singapore 39, no. 12 (2010): 889–96.
2. Ty et al., “Changing Epidemiology,” 889–96.
3. “The Public Health in 1886,”Straits Times Weekly Issue, 21 February 1887, 6; “Sanitation in Singapore,” Straits Times Weekly Issue, 21 February 1887, 7. (From NewspaperSG)
4. “Milk Supply Scandals,” Straits Times, 15 September 1908, 7. (From NewspaperSG)
5. “Increase in Cases of Enteric,” Malaya Tribune, 30 June 1938, 12. (From NewspaperSG)
6. “Typhoid Kills Ten in Singapore,” Straits Times, 2 March 1950, 6; “Action to Be Taken against Ice Hawkers,” Straits Times, 7 March 1950, 7. (From NewspaperSG)
7. “Ice Cream Control Plan to Beat Typhoid in Singapore,” Straits Times, 10 July 1950, 4. (From NewspaperSG)
8. “Typhoid: Government Campaign on Four Islands,” Straits Times, 13 September 1960, 4. (From NewspaperSG)
9. “Typhoid Outbreak in Singapore School,” Straits Times, 29 March 1965, 9; “Typhoid: Second Batch of Hawkers Isolated,” Straits Times, 30 March 1965, 4. (From NewspaperSG)
10. T. S. Koh and K. T. Goh, “Enteric Fever Surveillance in Singapore,” Singapore Medical Journal 17, no. 1 (1976): 32–37.
11. F. S. Yew, K. T Goh, and Y. S. Lim, “Epidemiology of Typhoid Fever in Singapore,” Epidemiology & Infection 110, no. 1 (1993): 63–70.
12. Ty et al., “Changing Epidemiology,” 889–96.
13. “Health Ministry, Singapore Food Agency Investigating Recent Increase in Typhoid Cases,” Channel News Asia, 18 August 2019; Chia Shi-Lu, “Spike in Typhoid Cases,” 2 September 2019, Ministry of Health.
14. “More Communicable Diseases Find Their Way to Singapore,” Straits Times, 7 October 1983, 17; “Infectious Diseases Mostly ‘Imported’,” Straits Times, 9 January 1984, 9. (From NewspaperSG)
15. Yew, Goh, and Lim, “Epidemiology of Typhoid Fever,” 63–70.
16. Ty et al., “Changing Epidemiology,” 889–96.
17. H. M. L. Oh, S. K. Chew, and E. H. Monteiro, “Multidrug-resistant Typhoid Fever in Singapore,” Singapore Medical Journal 35 (1994): 599–601.
18. Ty et al., “Changing Epidemiology,” 889–96.
19. T. S. Koh and K. T. Goh, “Enteric Fever Surveillance,” 32–37.
20. F. S. Yew, K. T Goh, and Y. S. Lim, “Epidemiology of Typhoid Fever in Singapore,” Epidemiology & Infection 110, no. 1 (1993): 63–70.

The information in this article is valid as of May 2021 and correct as far as we are able to ascertain from our sources. It is not intended to be an exhaustive or complete history of the subject. Please contact the Library for further reading materials on the topic.