Singapore is an island city state with a population of about 5.6 million. This section presents the highlights of the surveillance and epidemiological investigation findings of the communicable diseases in 2016, including latest additions to the list of notifiable diseases and an evaluation of our national childhood immunisation programme.

CHAPTER 1

OVERVIEW

06POPULATION PROFILE

06COMMUNICABLE DISEASES SITUATION

5

POPULATION PROFILEIn 2016, Singapore had an estimated population of 5.61 million, with a resident population of 3.93 million. The female-to-male ratio in the resident population was 1.04. The ethnic distribution in the resident population showed a Chinese majority of 74.3%, followed by Malays and Indians at 13.4% and 9.1% respectively.

The aging pattern of Singapore’s population is shown in the age pyramid below. The proportion of residents aged 15 to 64 years increased from 71.0% in 1990 to 72.4% in 2016 while the proportion of children under 15 years has steadily declined from 23.0% in 1990 to 15.2% in 2016. Currently 12.4% of Singapore residents are aged 65 years and above, compared to 6.0% in 1990.

Demographic profile (mid-year estimates), 2016

2016Total population 5,607,283Resident population 3,933,559Gender ratio (female to male) 1.04Ethnic distribution (%) Chinese 74.3 Malay 13.4 Indian 9.1 Others 3.2

(Source: Singapore Department of Statistics)

Age distribution of resident population, 2016

OVERVIEW  

INTRODUCTION   This  publication  records  the  extensive  surveillance  and  epidemiological   investigation  activities  undertaken  by  the  Communicable  Diseases  Division  in  2016.    Covering  all  notifiable  infectious  diseases  and  outbreak  findings,  the  epidemiological  features  of  each  of  the  air/droplet-­‐borne,  vector-­‐borne,  food-­‐borne,  blood-­‐borne,  sexually  transmitted   and   other   diseases   are   described.   Also   included   is   an   evaluation   of   our   national   immunisation  programme.       POPULATION  PROFILE    In  2016,  Singapore  had  an  estimated  population  of  5.61  million,  with  a  resident  population  of  3.93  million.  The  female-­‐to-­‐male   ratio   in   the   resident  population  was  1.04.   The  ethnic  distribution   in   the   resident  population  showed  a  Chinese  majority  of  74.3%,  followed  by  Malays  and  Indians  at  13.4%  and  9.1%  respectively.      The  aging  pattern  of  Singapore’s  population   is  shown  in  the  age  pyramid  below.  The  proportion  of  residents  aged  15  to  64  years  increased  from  71.0%  in  1990  to  72.4%  in  2016  while  the  proportion  of  children  under  15  years  has  steadily  declined  from  23.0%  in  1990  to  15.2%  in  2016.  Currently  12.4%  of  Singapore  residents  are  aged  65  years  and  above,  compared  to  6.0%  in  1990.  

Demographic  profile  (mid-­‐year  estimates),  2016   2016 Total  population   5,607,283  

Resident  population   3,933,559  

Gender  ratio  (female  to  male)   1.04  

Ethnic  distribution  (%)    

     Chinese   74.3  

     Malay   13.4  

     Indian    9.1  

     Others    3.2  (Source:  Singapore  Department  of  Statistics)  

Age  distribution  of  resident  population,  2016  

Male Female

Residents (‘000) Residents (‘000)

(Source: Singapore Department of Statistics)  

0 50 100 150 200 0 50 100 150 200

0-4 5-9 10-14 15-19 20-24 25-29 30-34 35-39 40-44 45-49 50-54 55-59 60-64 65-69 70-74 75+

COMMUNICABLE DISEASES SITUATION All notifications of infectious diseases received during the year 2016 have been included in this report. It should however be noted that notifications of cases seeking medical treatment in Singapore for infectious diseases have been excluded from selected morbidity statistics which reflect the status in Singapore citizens, Singapore permanent residents and foreigners residing in Singapore (i.e. non-citizens who have not been granted permanent residence status).

A change since September 2016 has also been made in the Infectious Diseases Act (IDA) whereby six diseases viz. botulism, tetanus, leptospirosis, murine typhus, rabies and Japanese encephalitis were added to the list of notifiable diseases stipulated under the First Schedule.

6

Air/droplet-borne diseasesThe diseases covered in Chapter 2 include Haemophilus influenzae type B disease, hand, foot and mouth disease, influenza, measles, meningococcal infection, mumps, pertussis, pneumococcal disease (invasive), rubella, viral conjunctivitis, and varicella.

In 2016, hand, foot and mouth disease continued to contribute significantly to the burden of air/droplet-borne diseases. There were 42,154 notified cases of this disease, an increase of 49.4% from 28,216 cases in 2015.

A total of 136 measles cases were notified in 2016, compared to 42 cases in 2015. 12 rubella cases were reported in the year, slightly lower than the 15 cases in 2015. There were also 540 notified cases of mumps in 2016, compared to 473 cases in 2015.

Vector-borne diseasesIn Chapter 3, the epidemiological features of chikungunya fever, dengue fever/dengue haemorrhagic fever, leptospirosis, malaria, murine typhus, and zika virus infection are described.

All vector-borne diseases were investigated promptly upon notification. The Ministry worked closely with the National Environment Agency, and intensive vector control operation remained the key strategy for prevention and control of vector-borne outbreaks.

A total of 13,085 dengue fever/dengue haemorrhagic fever cases were notified in 2016, compared with 11,294 cases in 2015. The majority of the cases were infected locally and Dengue virus 2 was the predominant circulating strain. There were also 36 chikungunya fever cases notified in 2016 compared with 42 cases in 2015.

In May 2016, Singapore identified its first imported case of zika virus infection in a traveler returning from Brazil. We subsequently tallied a total of 458 laboratory-confirmed cases, inclusive of a major local outbreak at Aljunied in the second half of the year.

In addition, there were 31 notified cases of malaria in 2016; all had acquired the infection overseas.

Food-borne diseasesChapter 4 covers acute diarrhoeal illness, campylobacteriosis, cholera, enteric fevers, hepatitis A, hepatitis E, salmonellosis, and food poisoning.

Although most cases were sporadic in nature, strict measures were implemented to ensure that high standards of personal, food and environmental hygiene was maintained. These measures were carried out by the Ministry of Health in close collaboration with the National Environment Agency and the Agri-Food and Veterinary Authority of Singapore.

Campylobacteriosis and non-typhoidal salmonellosis contributed significantly to the burden of food-borne illness. There were 442 cases of campylobacteriosis and 2,212 cases of salmonellosis reported in 2016.

The incidence of enteric fevers (typhoid, paratyphoid) showed a 7.9% decrease from 76 cases in 2015 to 70 cases in 2016. There were 48 cases of acute hepatitis A notified in 2016, a decrease of 2.0% compared to 50 cases in 2015.

Blood-borne and sexually transmitted diseasesThe diseases covered in Chapter 5 include hepatitis B, hepatitis C, human immunodeficiency virus infection/acquired immune deficiency syndrome, and other sexually transmitted infections.

The three most common sexually transmitted infections notified in Singapore in 2016 were chlamydia, gonorrhoea and syphilis. The overall incidence rate was 192 cases per 100,000 population. Chlamydia was the most common infection with an incidence rate of 51.7 cases per 100,000 population.

The number of HIV/AIDS infection notifications was 408 in 2016, compared with 455 in 2015.

7

Other diseasesIn Chapter 6, other diseases of public health importance, including legionellosis, leprosy, melioidosis, tuberculosis, healthcare-associated outbreaks, and severe illness and death from possibly infectious causes are described.

In 2016, a total of 2,310 new cases of TB were reported. They comprised 1,617 Singapore residents and 693 long staying foreigners. This represented an increase of 15.5% from 2015.

There were 12 cases of legionellosis and 58 cases of melioidosis notified in 2016. Nine patients died of melioidosis-related conditions giving an overall case fatality rate of 16.1%, compared with 7.3% reported in 2015.

The annual statistics on infectious disease notifications and deaths are presented in the following table:

Childhood immunisationChapter 7 provides the summary of the implementation of the National Childhood Immunisation Programme in 2016. The immunisation coverage among children against TB, hepatitis B, diphtheria, pertussis and tetanus, poliomyelitis, Haemophilus influenzae type b, measles, mumps and rubella, pneumococcal disease and human papillomavirus is included.

Infectious disease notifications and deaths in 2016

Diseases No. of notified cases

No. of deaths+

Morbidity rate*

Mortality rate*

Air/Droplet-borne DiseasesHand, Foot and Mouth Disease 42,154 0 751.8 0Measles 136 0 2.4 0Meningococcal Infection 5 0 0.1 0Mumps 540 0 9.6 0Rubella 12 0 0.2 0Vector-borne DiseasesChikungunya Fever 36 0 0.6 0Dengue Fever/Dengue Haemorrhagic Fever 13,085 12 233.4 0.2Malaria 31 0 0.6 0Zika virus infection 458 0 8.2 0Food-borne DiseasesCampylobacteriosis 442 0 7.6 0Cholera 2 0 0.0 0Hepatitis A 48 0 0.9 0Hepatitis E 74 0 1.3 0Paratyphoid 19 0 0.3 0Salmonellosis 2,212 0 39.4 0Typhoid 51 0 0.9 0Blood-borne and sexually transmitted diseases Hepatitis B 47 0 0.8 0Hepatitis C 24 0 0.4 0HIV/AIDS** 408 72 10.4 1.3STIs 10,767 0 192.0 0Other DiseasesTuberculosis*** 2,310 39 41.2 1.0Leprosy 7 0 0.1 0Legionellosis 12 0 0.2 0Melioidosis 58 3 1.0 0.1

+Source: Registry of Births & Deaths.*Rates per 100,000 population, based on estimated mid-year total population, 2016.

(Source: Singapore Department of Statistics)** Referred to Singaporeans/PR cases.

*** Referred to Singaporeans/PR cases and long staying foreigners.

8

Contributed by Chan Pei Pei, Charlene Tow,

Constance Low, Foong Bok Huay, Han Hwi Kwang, Lalitha Kurupatham,

Marc Ho, Steven Ooi, Tien Wee Siong, Zubaidah Said

Summary of disease notificationsA summary of all the infectious disease notifcations received by the Ministry of Health in Singapore over the 20 year period from 1997-2016 (by number of notifications and by incidence rate per 100,000 population) has been tabulated in the next two pages for readers' easy reference.

9

Year

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

2013

2014

2015

2016

Air/D

ropl

et-B

orne

Dis

ease

sDi

phth

eria

00

00

00

00

00

00

00

00

00

00

Haem

ophi

lus

influ

enza

e ty

pe b

--

-1

50

32

54

11

45

21

106

32

Hand

, Foo

t and

Mou

th D

iseas

e35

813

4414

0864

0251

8716

228

5603

6411

1525

715

282

2000

329

686

1727

830

878

2068

737

125

3174

122

171

2821

642

154

Mea

sles

1413

114

6514

161

5733

9633

2815

1813

4914

838

4614

242

136

Men

ingo

cocc

al in

fect

ion

--

--

413

117

510

56

57

60

39

65

Mum

ps

674

1183

6384

5981

1399

1090

878

1003

1004

844

780

801

631

452

501

521

495

478

473

540

Pertu

ssis

--

--

--

-0

03

3833

138

2924

1721

5785

Pneu

moc

occa

l dise

ase

(Inva

sive)

--

--

--

--

--

--

157

166

148

163

167

147

139

131

Rube

lla36

017

943

231

224

215

288

141

139

9083

180

178

158

110

6448

1715

12Va

ricel

la27

723

2718

331

592

2407

418

220

2712

415

265

2008

324

248

2402

630

548

--

--

--

--

-

Vect

or-B

orne

Dis

ease

sCh

ikung

unya

Fev

er-

--

--

--

--

--

718

341

2612

2210

5918

242

36De

ngue

feve

r/Den

gue

haem

orrh

agic

feve

r43

0052

5813

5567

323

7239

4547

8894

5914

209

3127

8826

7031

4497

5363

5330

4632

2217

018

326

1129

413

085

Mal

aria

421

405

316

266

229

175

118

152

166

181

155

152

172

190

149

143

111

6247

31Zi

ka v

irus

infe

ctio

n-

--

--

--

--

--

--

--

--

--

458

Food

-Bor

ne D

isea

ses

Cam

pylo

bact

erio

sis12

126

934

323

110

550

144

131

241

236

170

177

261

320

372

443

397

435

420

442

Chol

era

1131

1110

82

211

10

71

44

22

22

32

Ente

ric fe

ver

T

ypho

id93

5748

8082

4932

5269

6067

8469

8271

8484

5849

51

Par

atyp

hoid

1923

1521

3425

932

2623

3329

2838

3357

2319

2719

Hepa

titis

A14

913

888

7760

236

5567

9814

688

107

8968

6610

888

7350

48He

patit

is E

1724

2017

324

1724

3631

3554

9011

297

104

5568

5974

Salm

onel

losis

--

-99

198

129

192

345

296

380

309

719

1144

1480

1374

1499

1735

1883

1988

2212

Bloo

d-Bo

rne

& Se

xual

ly T

rans

mitt

ed D

isea

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Hepa

titis

B17

920

514

011

780

6364

9883

9679

8769

6573

5857

4852

47He

patit

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--

--

--

-3

2635

1713

56

32

25

4624

HIV/

AIDS

*17

319

920

622

623

723

424

231

131

735

942

345

646

344

146

146

945

445

645

540

8Se

xual

ly Tr

ansm

itted

Infe

ctio

ns58

0162

5863

1862

5166

8668

9181

7310

697

1104

810

989

1152

312

280

1138

110

742

1115

910

869

1034

710

183

1031

810

767

Othe

r Dis

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sLe

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3779

6552

4046

1721

1916

2522

2521

3124

3717

12Le

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1922

1814

1111

1413

1212

108

1316

1512

63

7M

elio

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114

8177

5934

4498

7862

6162

4060

3431

3634

4258

Tube

rcul

osis

**17

1218

1015

4315

1814

7417

0216

8415

7815

8615

8116

0819

5119

6620

2821

2622

0320

2820

1820

0023

10

* Ref

ers

to S

inga

pore

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PR c

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Ref

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to S

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reig

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from

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f Not

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CTIO

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, 199

7-20

16

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Year

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

2013

2014

2015

2016

Air/D

ropl

et-B

orne

Dis

ease

sDi

phth

eria

00

00

00

00

00

00

00

00

00

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ophi

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10.

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9.4

34.2

35.6

158.

912

5.4

388.

613

6.2

153.

935

7.7

347.

243

5.9

613.

434

6.4

608.

239

9.1

698.

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7.9

405.

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9.8

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6.8

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3.5

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3.7

3.7

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