Malaria and VFRs
The role of travel medicine
Dr Jane N Zuckerman
WHO Collaborating Centre for Reference, Research &
Training in Travel Medicine
Academic Centre for Travel Medicine & Vaccines
Royal Free Travel Health Centre
University College Medical School
UK Travellers 2012
• The number of visits abroad by UK residents fell by
0.5% in 2012, from 56.8 million in 2011 to 56.5
million.
• There is no clear evidence that the fall is driven by
people living in any particular part of the UK.
• Holiday visits, which account for nearly two thirds of
visits abroad, fell by 1.8% while both business visits
and visits to friends or relatives grew.
Source: International Passenger Survey (IPS) - Office for National Statistics
UK residents' visits abroad by purpose 1992-2012
Visits (thousands)
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
Holiday
Business
23,236
5,162
25,133
5,297
27,187
5,614
27,808
6,113
26,765
6,879
29,138
7,166
32,306
8,033
35,023
8,161
36,685
8,872
38,670
8,220
39,902
8,073
41,197
7,892
42,912
8,140
44,175
8,556
45,287
9,102
45,437
9,018
45,531
8,920
38,492
6,887
36,422
6,639
36,819
6,846
36,173
6,956
Visit Friends or
Relatives
Miscellaneous
4,100
1,338
4,457
1,833
4,674
2,155
4,938
2,486
5,502
2,904
6,004
3,649
6,452
4,082
6,598
4,100
7,178
4,102
7,727
3,664
7,870
3,532
8,527
3,807
9,799
3,343
10,648
3,063
11,963
3,184
12,214
2,781
12,392
2,168
11,592
1,643
10,850
1,652
11,594
1,576
11,797
1,612
UK residents visits abroad by purpose 1992 to 2012
Source: International Passenger Survey (IPS) - Office for National Statistics
Public Health England Malaria Report 2013
• There were 1,378 cases of malaria reported in ill returned travellers
to the UK in 2012, including two deaths.
• This is a decrease from the 1,677 cases reported in 2011.
• As in previous years, the majority (73%) were caused by the
potentially life-threatening Plasmodium falciparum and were
acquired in Africa.
• This high proportion of Plasmodium falciparum reflects the fact that
most malaria imported into the UK is acquired in Africa.
• Where region of travel was specified; 49% (669/1,378) of
P.falciparum cases originated from West Africa.
• Among UK malaria cases, where reason for travel was known, over
70% were visiting friends and relatives and the majority of these
travellers had not taken malaria prophylaxis.
Malaria Report 2013
• Probably reflects greater travel to malaria-endemic areas.
• This high proportion of falciparum malaria reflects the fact
that most malaria imported to the UK is acquired in West
Africa.
• The group who continue to be at highest risk of contracting
malaria are those visiting friends and relatives.
• This group are more likely to acquire malaria for a number
of reasons, including:
• not seeking or being unable to access appropriate
medical advice before travel,
• receiving poor advice,
• not adhering to advice, or
• not perceiving themselves to be at risk because the
destination is familiar to them.
Imported malaria cases and deaths
United Kingdom: 1993 - 2012
Imported malaria cases and deaths
United Kingdom: 1993 - 2012
Year *P.falciparum P.vivax P.ovale P.malariae Mixed P unspecified
2012
1002
271
66
32
7
2011
1149
416
77
31
4
2010
1263
350
99
37
12
2009
1179
205
69
36
6
2008
1087
177
76
20
9
1
2007
1139
256 108
30
15
2006
1386
219 106
26
20
2005
1338
258 116
29
10
3
2004
1221
278 121
28
12
2003
1339
206 134
27
15
1
2002
1469
284 134
43
13
2
2001
1576
263 157
37
16
1
2000
1576
322 124
30
16
1
1999
1504
374 113
41
11
2
1998
1388
484 157
26
17
1
1997
1401
790 125
27
20
1
1996
1283
1014 134
35
33
1
1995
1112
742 143
29
29
1994
1178
501 125
44
39
1993
1048
708 116
20
30
-
Total
1378
1677
1761
1495
1370
1548
1758
1754
1660
1722
1945
2050
2069
2045
2073
2364
2500
2055
1887
1922
Deaths
2
8
7
6
6
5
8
11
5
16
9
9
16
14
7
13
11
4
11
5
Imported malaria cases by species and region
of travel, United Kingdom: 2012
Geographic
*P.falciparum P.vivax
area
West Africa
669
1
East Africa
112
11
Central
43
1
Africa
Southern
45
2
Africa
North Africa
Africa 18
1
unspecified
Asia§
7
213
Far East/SE
4
Asia
Central/South
3
America
Middle East
1
Oceania
4
Not given
107
31
Total
1002
271
P.ovale
P.malariae
Mixed
44
7
16
8
4
2
P
unspecified
-
7
1
-
-
52
3
2
-
-
52
-
-
-
-
-
1
1
-
-
21
-
-
-
-
220
-
-
-
-
4
-
-
-
-
3
4
66
4
32
1
7
-
1
4
147
1378
Total
734
140
Imported malaria cases by reason for travel,
United Kingdom: 2011
Population group
*P.falciparum P.vivax P.ovale P.malariae Mixed P unspecified
Visiting family in
452
124
24
6
4
country of origin
Holiday travel
47
11
6
4
Foreign visitor ill while
72
35
3
1
in UK
New entrant
36
60
3
Business/professional
66
7
6
5
travel
UK citizen living
27
1
abroad
Foreign student
28
40
6
1
studying in the UK
Civilian sea/air crew
British armed services
1
Children visiting
2
parents living abroad
Other
Not stated
419
138
28
14
Total
1149
416
77
31
4
-
Total
610
68
111
99
84
28
75
1
2
599
1677
Some Evidence
• Where the history of taking anti-malarial medication was
obtained, 84 %of cases had not taken prophylaxis.
• Of those who had malaria diagnosed in the UK, where
ethnicity was known, 136 were reported as white British,
compared with 938 who were reported as African or of
African descent and 395 reported as Asian or of Asian
descent.
• The burden of falciparum malaria in particular falls heavily
on those of African ethnicity, and this group is important to
target in pre-travel advice.
• Some groups are at particular risk of acquiring malaria and
are not being reached by health messages about the
importance of anti-malarial prophylaxis.
HPA Malaria Report 2012
Malaria and UK Travellers
• Under-reporting of malaria cases in the UK is known.
• A capture-recapture study estimated that the
surveillance system captured 56% of cases.
• Ethnic minority travellers visiting friends and relatives
are at particular risk of acquiring malaria
• Once acquired the risk for mortality is significantly
higher in holiday travellers.
• There is a strong association between increasing age
and mortality.
• Therefore elderly travellers should be considered a
particular risk group.
VFRs & Travel Health
• More migrant families travel to countries of their ethnic origin, where
malaria is endemic, contributing to the increasing incidence of
imported malaria
• Failure to comply with prophylaxis or to seek travel health advice
mostly explains the increased risk of exposure and cases of malaria in
travellers, particularly those visiting friends and relatives.
• Historically, the problem for travel health practitioners recommending
malaria prophylaxis for travel to Africa and Asia has been the adverse
publicity regarding this treatment.
• In addition, many people visiting friends and relatives underestimate
their risk of exposure to travel related illness, especially malaria,
despite not having lived in an endemic area for many years.
• This is a dangerous presumption.
• Other reasons for the reported increase include inaccessibility of travel
health advice, over the counter purchase of inappropriate prophylaxis,
and purchase of inexpensive (and sometimes counterfeit prophylaxis)
at the destination.
UK Travel Patterns
• With travel predicted to grow to nearly 1.6 billion international arrivals
by 2020, travellers will be at increased risk of exposure.
• The increase in cases of imported malaria is not unexpected. It
reflects the increase in the number of visits abroad together with a
150% increase in UK residents travelling to malaria endemic areas
during the past decade.
• One notable change is that with improved vector control in Asia, most
cases are now acquired in Africa.
• As severe acute respiratory syndrome showed, 21st century threats
to global public health and travel are inextricably interlinked, and they
present ready opportunities for the rapid spread of infectious disease
• Although people visiting friends and relatives are at particular risk &
form the largest group returning with malaria, business and holiday
travel also account for a percentage of cases.
What Can We Do?
• A significant decrease in imported cases of P vivax reported after
travel to the Indian subcontinent, a result of successful vector
eradication in many urban areas.
• Pursuing a similar policy and achieving the millennium goals in
Africa may reduce the incidence of malaria in endemic areas and
improve the health of populations, while also reducing the risk of
malaria to travellers, all of which may negate the necessity for
prophylaxis in the future.
• What else can we do? Healthcare practitioners involved in
advising travellers about preventing malaria should follow the
clear and concise guidelines on malaria prevention for UK
travellers.
• Studies of people visiting friends and relatives aimed at
identifying the pertinent factors such as cultural beliefs,
knowledge, and attitude towards malaria prevention would help
understand how best to impart health education through targeted
communication and the use of innovative techniques.