Minutes of Meeting on Lyme Disease And Related Issues in Manitoba

January 11, 2000, Room A106, Chown Building

Participants:

Dr. S. Moses (Minute Taker)

Dr. H. Artsob

Dr. R. Lindsay

Mr. J. Christie

Mrs. E. Wood

Dr. J. Kettner

Mr. P. White

Mr. A. Jonasson

Apologies:

Dr. T. Galloway

______________________________________________________________________

1) Tick Collection and Identification Program (Passive Surveillance)

Dr. Lindsay reported the results of the tick collection and identification program for 1999. His report is attached to these minutes. In brief, there were 67 I. Scapularis ticks identified, which compares with only 23 in 1998. Seven of these ticks were positive for B. burgdorferi on PCR, all taken from domestic dogs or cats. Only one of the ticks was alive at the time of examination, and B. burgdorferi was cultured from it. In 1998, one of the 23 I Scapularis ticks identified was positive for B. burgdorferi, and it was taken from a road-killed dear. There was also one B. burgdorferi positive I. Scapularis tick identified in 1996.

Mr. Christie reported on his sampling of road-killed dear for ticks in 1999, and his report is also attached. Three I Scapularis ticks were identified from about 165 deer, of which one was positive for B. burgdorferi on PCR.

Thus altogether, since 1996, there have been l0 B. burgdorferi positive I. Scapularis ticks identified in Manitoba: 8 from domestic animals and 2 from road-killed deer.

2) Active Surveillance of Small Mammals

Dr. Lindsay reported on the active surveillance of small mammals for ticks in 1999, and a copy of his report is attached to these minutes. Several animals were identified and examined at various locations. No I. Scapularis ticks were found on 516 animals examined, but 25 ticks of other species were identified in September from animals at Delta Marsh, East Selkirk and Marchand.

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Blood was drawn from 381 small mammals, primarily deer mice, and altogether 14 of these had positive IFA results at titre 1:32 or higher. However, only one of these was confirmed positive for B. burgdorferi on Western blot. This was a deer mouse from Delta Marsh examined in September.

Other active surveillance activities included dragging for ticks near Ste. Genevieve in October. This area was chosen because five I. Scapularis infested dogs had been identified in the area during the 1999 tick collection and identification program. No ticks were identified by dog sampling or on a sentinel dog.

3) Clinical Surveillance

Dr. Moses reported that there had been one case of Lyme Disease reported to Manitoba in 1999 that met the provincial (and national) surveillance case definition. Dr. Kettner pointed out that there was one aspect of the case that did not meet the case definition: as the patient did not seek medical attention until about two months after the tick bite, the rash which appeared after the tick exposure was not observed by a physician. Dr. Moses indicated that he felt that the description of the rash as reported by the patient was consistent with an erythema migrans type rash, and as all other aspects of the case were “classic” for an acute B. burgdorferi infection, it was decided that the case should be counted.

Although physicians are asked to report clinical cases of Lyme Disease to Manitoba Health, even if they do not meet the surveillance case definition, they rarely do so. It should also be noted that physicians are advised by Manitoba Health to treat cases which are felt or suspected to be Lyme Disease prior to laboratory confirmation. To get a better idea of the extent to which Lyme Disease is being diagnosed clinically in Manitoba, a search was made of the Manitoba Health physician claims database, and the results are attached to these minutes. As can be seen, in the four years from April 1, 1995 - March 31, 1998, physicians filled out claims on 435 unique individuals with a diagnosis of.Lyme disease, and there was a sharp increase in 1998.

Dr. Artsob asked whether the geographic location of these cases could be mapped, and Dr. Moses indicated that he would try to have this done in the near future.

4) Case Definition

There was considerable discussion around the adequacy of the case definition for Lyme Disease, and several individuals felt that it was time for a national review of the case definition, in the light of new information that has emerged over the past decade. There was a feeling that the case definition, in an attempt to have maximal specificity, did not have sufficient sensitivity. There is also concern though that the case definition should not be entirely lacking in specificity, as it is not desirable to have large numbers of false positives. It was suggested that Manitoba Health should write to Health Canada (LCDC),

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suggesting that a national conference be convened to review the case definition and other important issues around Lyme Disease.

5) Future Research Plans

Manitoba Health, the University of Manitoba and the CSCHAH (LCDC) plan to continue the passive surveillance program in the year 2000. In addition, LCDC will screen all I. scapularis ticks identified for evidence of infection with the agent of human granulocytic ehrlichiosis. LCDC will also continue active small mammal surveillance at several sites during the spring, and at those sites and possibly others in the autumn.

Mrs. Wood indicated that she felt that Manitoba Health should fund additional active surveillance, possibly by contracting Mr. Christie to undertake more mammal trapping.

6) Laboratory Reporting

Mrs. Wood felt that more detailed laboratory results of B. burgdorferi testing should be reported to physicians, not simply final negative and positive determinations. This would include reporting the actual screening test and control values, and possibly a report on the Western blot bands. Dr. Artsob and Dr. Moses indicated that they would investigate how other laboratories, particularly those in the United States, report B. burgdorferi testing to physicians.

It was pointed out by Mrs. Wood and others that the negative laboratory test information received by physicians may be a dis-incentive to report clinical cases, or more importantly, to treat them.

7) Communications

Mr. White indicated that he would review the information presented at the meeting with a view to developing a communications strategy. Clearly, the information gleaned in 1999 must be communicated to physicians and the general public, and the most effective and efficient means of doing so need to be worked out.

The Manitoba Health fact sheets will need to be revised to reflect the new information, and Mrs. Wood offered to make suggestions in this regard. Mrs. Wood also noted that she will be making a presentation at the Wellness Exposition in April and asked whether Manitoba Health could present information there as well. Dr. Moses offered to coordinate such information to be presented there. It will be important to have the revised Manitoba Health fact sheets ready by then.

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8) Action Items

The following summarizes the action items from the meeting:

8.1 Manitoba Health to write to Health Canada (LCDC) regarding a national consensus conference on the surveillance case definition for Lyme Disease and related issues.

8.2 Tick collection and identification program to continue in 2000.

8.3 Active surveillance of small mammals to be continued by LCDC.

8.4 Manitoba Health to review issue of funding additional small mammal surveillance.

8.5 LCDC to screen all I. scapularis ticks identified for evidence of infection with the agent of human granulocytic ehrlichiosis.

8.6 Manitoba Health and LCDC to investigate laboratory reporting of Lyme Disease in other jurisdictions.

8.7 Manitoba Health to map Lyme Disease cases reported in physician claims database.

8.8 Manitoba Health to develop a draft communications strategy for Lyme Disease, to be reviewed and discussed by all stakeholders.

8.9 Mrs. Wood to make suggestions for revisions to Manitoba Health fact sheets:

8.10 Manitoba Health to prepare information for the Wellness Exposition.

9 Date of Next Meeting

Dr. Moses will call another meeting of this group once progress has been made related to the above items, probably in late February or early March.