Held in Sweden, February 2-4 2016, this was organised by the Norwegian Tick Research Network (NorTick) and the Swedish tick research network SNÄFF (Sveriges NÄtverk av Fästing Forskare). A Nordic conference on Ticks and Tick-borne diseases bringing together the leading scientists of that field in Norway, Denmark, Sweden and Finland.
NordTick in numbers:
- 113 delegates – scientists, doctors and students
- 9 different countries represented, though most from Norway and Sweden
- 9 presentations on ticks
- 8 presentations on Lyme disease diagnosis
- 4 on LB treatment
- 1 on experience of a LB clinic
- 1 on Anaplasma in sheep
- 2 on Babesia in ticks and cattle
- 3 on TBE
LDA probably asked about 10% of the questions, so in addition to our poster, we made our contribution to the debates. When someone strayed into ascribing symptoms to psychiatric disorders, Sandra (in case you had forgotten – a consultant psychiatrist) stepped in to put them straight. We were welcomed by people we had previously met at other international conferences and it was very useful to be able to renew these relationships. We were told at the end that several people had commented how good it was to have us there.
Prof Jean Tsao from Michigan describing the research trying to understand the spread of Lyme Borreliosis in N America. Remember that small rodents are a principal reservoir of LB and that any one mouse does not live for very long. It is their reproductive capacity which leads to their abundance and this has the effect of amplifying the prevalence of the Borrelia bacteria which they carry. Normally the nymphs are active first in the season and in having their blood meal they pass Borrelia on to the host so that the later larvae pick it up – this increases infection. If larvae hatch earlier then they have more chance of feeding on an uninfected host and this can decrease Borrelia transmission. Some strains of B burgdorferi only persist for a few weeks in the host. Read more here
Ulrika Bergvall described how they had shown that ticks do attach to roe deer in winter – they are not necessarily dormant. She showed a video of how they captured deer, removed all ticks, tagged them and then repeated the process later in the winter.
Peter Wilhelmsson reported on a study examining migrating birds as hosts – 85% of breeding birds in Sweden are migratory. Between 2001-2009 they found 5-14% of the birds they surveyed were carrying ticks. More than 40% of the ticks were on Robins! Of 1117 ticks analysed 26% were infected with B burgdorferi sl. They also carried B miyamotoi and Candidatus Neoehrlichia mikurensis – the latter yet to be found in the UK but maybe on its way!
Ram Dessau opened the section on Borrelia and Borrelia infections with a talk titled “Denmark Laboratory Essentials for the diagnosis of Lyme borreliosis”, so we were prepared for a lecture. He made some surprising statements – “Why disregard the ELISA? Blots are not so sensitive and have no cut-off.” He was in favour of using blots with a scoring system for the bands and believes the VlsE antigen “does most of the job” as reported in a paper he co-authored.
He claimed that we do not need better tests! Several of the following speakers, however, contradicted that.
Dag Nyman from the Åland Group for Borrelia Research, in his talk on Diagnostics of neuroborreliosis argued that the case definitions in the European EFNS guidelines for LNB should be abandoned as they depend heavily on clinical findings and serology, leaving many ‘possible’ cases who then seek treatment elsewhere. They use CXCL13 in spinal fluid to help improve diagnosis.
Tamara van Gorkom from The Netherlands described a study looking at T cell responses in people with continuing symptoms after IV treatment for LNB. Of the 38 patients 60% reported some continuing symptoms and these patients had a significantly higher number of Borrelia-specific T cells then those with no symptoms. This study raised questions about the sensitivity and specificity of T cell tests in diagnosis of Lyme disease, since 28.6% of those with active Lyme neuroborreliosis tested negative and 19% of healthy volunteers tested positive. There also appeared to be some cross reactivity with Helicobacter pylori infections.
Sørlandet Hospital, in collaboration with the Norwegian patient group NLBF has a number of projects under the BorrSci initiative “Lyme borreliosis; a scientific approach to reduce diagnostic and therapeutic uncertainties.” One of these is to trial six weeks versus two weeks doxycycline treatment. Because of the small number of patients this study may not have enough power to detect a difference. Some of the work planned by the BorrSci initiative uses the JLA top 10 uncertainties which LDA presented to the NorTick conference in 2014. International collaboration works! We asked whether they would like some UK patients but Sweden has agreed to collaborate. We discussed doxycycline failures and asked whether blood samples were being tested for doxycycline concentrations – no, but they will be in the biobank for when more money becomes available.
Kristine J. N. Forselv also from Sørlandet Hospital reported on a study to improve the diagnostic sensitivity of PCR in LNB. They found that using at least 2 ml of CSF and analysing the sample within 1 day improved the sensitivity.
Sigurdur Skarphedinsson described the first year experience from the Clinical Centre for Emerging and Vector-borne Infections at Odense in Denmark. This is what we could do with in the UK! It opened in October 2014 to provide coordinated diagnosis and treatment, initially concentrating on Lyme Borreliosis. It incorporates infectious diseases specialists with neurologists and clinical microbiologists and also has the ability to call on expertise in rheumatology, immunology and dermatology. They are creating a research database and biobank. So far they have had 105 patients of whom 39% had LNB and 5% Anaplasmosis. 49% of patients referred to them for possible borreliosis were given other diagnoses – none of which were CFS/ME! (See our report on Lyme disease in a British referral clinic for a UK comparison) 30% of those seen in this Danish clinic were referred from other regions of Denmark for a second opinion and 19% had already sought alternative diagnosis and treatment abroad, mainly Germany.
Ram Dessau gave his second presentation and proceeded to pull apart a few not particularly robust papers about persistence of B burgdorferi in order to try to show that LB does not persist. A great many of the delegates were really surprised by his forceful presentation and nobody raised any questions – we all thought “what’s the point of questioning someone like that”! He argued that case studies should not be used as proof, and one wonders what he thinks of case studies showing persistence of Ebola virus.
Happily, the poster session followed so we were able to follow up with a number of people. Ram Dessau unfortunately did not stop for a discussion with us, but he knows what we think as we have discussed it with him before now!
Knut Eirik Eliassen described a study investigating the incidence of tick bites and EM in 4 Norwegian counties. They reported an average incidence of EM of 449/100,000 inhabitants – much higher than they had expected. They also found that 20% of people with a tick bite were given antibiotic prophylaxis and a high proportion of patients with EM had an (unnecessary) blood test. Their findings seemed to replicate those of the Scottish study in Aberfeldy, since they found that the rate of EM was roughly 22 times that of laboratory confirmed diagnoses.
Knut Eirik also described a randomised controlled trial comparing 3 treatments for erythema migrans: doxycycline, phenoxymethylpenicillin and amoxicillin. There were no treatment failures and no significant difference in the treatments. 20% of the EMs took more than 5 weeks to disappear completely. Biopsies of EM were taken in order to find the Borrelia species infecting patients. 104/150 were seropositive – 81% of those successfully analysed were B afzelii, 15% B garinii and 4% B burgdorferi ss. There is more analysis to come and full details of the study will be published. They had made the punch biopsy of the EM optional as they thought it might put patients off, but >80% of patients agreed to a biopsy. Evidence that patients are generally keen to contribute to research.
Matilda Lövmar described a Swedish project looking at Babesia species in ticks removed from humans because knowledge of Babesia is low in Sweden. Out of 967 ticks 33 were found positive for Babesia. 49% of those carried B venatorum, 40% B microti and 10% B divergens. About half the ticks also carried Borrelia. 5 individuals reported symptoms and one of these was seropositive for Babesia. 4 other individuals were seropositive. The point was made that with this substantial incidence of Babesia in ticks, babesiosis should be considered in Sweden when someone falls ill following a tick bite.
All in all a very interesting conference. The UK has many similarities with Nordic countries –
- a lack of awareness amongst doctors about tick-borne diseases
- many worried patients
- a disbelief amongst doctors and public health officials in chronic LB
Some differences too:
- they have about 4 times the incidence of Borrelia in their ticks
- they have a higher incidence of other tick-borne diseases than the UK
- they have a much higher Borrelia sero-positive rate. People have been exposed before and test positive even if they are not ill. So LB serology tests are less useful than in the UK.
- it was clear that a lumbar puncture is thought essential for a diagnosis of Lyme neuroborreliosis, which implies that they do not recognise LNB as causing peripheral neuropathy. We found this surprising, but there is clearly a Scandinavian wish to separate Lyme borreliosis and neuroborreliosis, though whether this was to justify IV treatment we couldn’t discover.
- they can get 100 tick-borne disease specialists in a room to have scientific discussions. How many could we muster?!
It was a great conference and we shall work on facilitating something similar in the UK to encourage discussion of tick-borne diseases. We do have researchers and we need to encourage their collective voice, and not only at the LDA conference.
Read the poster we presented at this conference “Lyme Borreliosis – A model for improved diagnosis“