Candidatus neoehrlichia mikurensis

7/3/2014
Natural history of ’Candidatus Neoehrlicha
mikurensis’

Martin Andersson,

Molecular Ecology and Evolution Lab (MEEL),
Lund University, Sweden

First cases in 2010: Sweden (Welinder-Olsson
et al., 2010), followed by cases in
Switzerland, Germany and the Czech Republic
(Fehr et al., 2010; von Loewenich et al., 2010;
Pekova et al., 2011).

7 human cases from China (Li et al., 2012).

•
Fever (11/11)
•
Localized pain in muscle/joints (8/11)
•
Blood cloth or other vascular events (6/11)
First detected in ticks in the Netherlands (Schouls
et al., 1999).
PCR detection in Japan, given the provisional
name ’Candidatus Neoehrlicha mikurensis’
(Kawahara et al., 2004).
’Candidatus Neoehrlicha lotori’, in raccons
North-America (Dugan et al., 2005).
•
More males than females (8/11)
•
Median age 67
•
Less than half recalled tick bite
•
Immune supressive treatment (10/11)
•
Lacking spleen (8/11)
Picture by Lars Råberg
LDA Conference 2014 - Martin Andersson
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7/3/2014
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The world-wide economic loss
is estimated to be billions of
dollars annually.
Ticks surpass all other arthropods
in the variety of microorganisms
they transmit.
The world-wide economic loss
is estimated to be billions of
dollars annually.
Ticks surpass all other arthropods
in the variety of microorganisms
they transmit.
Despite this, the full diversity of
infectious agents transmitted by
ticks are still incompletely known.
LDA Conference 2014 - Martin Andersson
Reservoir hosts
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’Candidatus Neoehrlichia mikurensis’ in
rodents, Sweden.
12.5%
Herseby
0% (n=45)
Häglinge
4.9%
9.3%
Revinge
3.8%
(n=53)
Hemmeströ
Istaby
Andersson and Råberg 2011, Emerging
Infectious Diseases.
• 949 I. ricinus (adults and
nymphs).
• Real-time PCR assay targeting the
groEL gene of ‘Candidatus N.
mikurensis’
• Overall prevalence 6.0%
• Co-infection with B. afzelii in 2.1% of the
ticks, which is significantly more than
expected under random co-occurrence.
Andersson et al., 2013 Vector-Borne
and Zoonotic Diseases
Reservoir hosts
Occurs in bank voles, field voles, yellow-necked mice and in wood
mice. Not found in shrews in this study.
12.5% (n=40)
Herseby
0% (n=45)
Häglinge
4.9% (n=64)
9.3% (n=623)
3.8% (n=53)
Hemmeströ
Revinge
Istaby
Andersson and Råberg 2011, Emerging
Infectious Diseases.
LDA Conference 2014 - Martin Andersson
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7/3/2014
Candidatus Neoehrlichia mikurensis
60
3/5
60
50/98
4/8
50
40
50
35/98
Prevalence (%)
Prevalence (%)
Borrelia afzelii
30
11/46
17/82
20
4/46
10
0
30
10/46
20
10
0
May
2/5
40
1/47
0
37/82
June
August
September
May
June
Andersson et al., 2014. Appl. Environ.
Month
August
0
September
Andersson et al., 2014. Appl. Environ.
Microbiol.
Microbiol.
‘Candidatus N. mikurensis’, genetic relatedness
of the 16s r RNA gene, shown as a haplotype
network
10
Ca N. mikurensis
Japan
9
Mean number of ticks
1/46
1/47
0
8.0/82
8
Ca N. mikurensis
China
7
6
Ca N. mikurensis
Japan
5.3/98
4.7/46
5
4
Ca E. walkerii
Italy
3
2
1.3/47
1.3/46
1.8/8
1
0
Ca N. lotori
USA
Ca N. mikurensis Sweden
Germany, Switzerland
4.0/5
Ehrlichia spp.–like Schotti
variant The Netherlands
Ca N. mikurensis
Russia
0
May
June
August
Month
September
Andersson et al., 2014. Appl. Environ.
Microbiol.
Andersson and Råberg 2011, Emerging
Infectious Diseases.
Neighbor-joining tree of “Candidatus Neoehrlichia mikurensis” inferred from 874 bp of the groEL
gene sequences (A) using the maximum composite likelihood method.
Li H et al. Appl. Environ. Microbiol. 2013;79:1024-1027
LDA Conference 2014 - Martin Andersson
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7/3/2014
• Neoehrlichia does occur in
Romania.
• Co-infection with Borrelia afzelii
Conclusions
• Spread througout most of
Europé, UK?
• Prevalence in I. ricinus typically
6-7%
• Co-infection with B. afzelii
LDA Conference 2014 - Martin Andersson
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7/3/2014
Lund:
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Lars Råberg
Kristin Scherman
Nadège Zaghdoudi-Allan
Dagmar Clough
Barbara Tschirren
Melissa Lemoine
The Swedish Research Council
International:
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Lidia Chitimia
Jean Tsao
Gerhard Dobler
Bronislava Víchová
The Royal Physiographic Society in Lund
The Lund Animal Protection fund
Picture by Petr Kotlik
LDA Conference 2014 - Martin Andersson
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