Interrupting transmission of Lyme borreliosis by targeting a reservoir for vaccination: a longitudinal study of a field site in North America

Barbour, Alan (1), Jean Tsao (2); Jonas Bunikis (1); Maria Luna (1); Durland Fish (2)

1. Dept Microbiol and Mol Genetics, Univ Calif Irvine, USA
2. Dept Epidemiol, Yale University, USA

In the northeastern United States the principal tick vector of Borrelia burgdorferi, the Lyme borreliosis agent, is Ixodes scapularis, and a major reservoir is the white-footed mouse Peromyscus leucopus. We undertook a longitudinal field study of B. burgdorferi, I. scapularis, and P. leucopus in a hardwood forest site in Connecticut, United States with the aims to investigate the following: (1) the incidence and dynamics of infection and immunity in P. leucopus, (2) the population structure of B. burgdorferi in vector and reservoir, and (3) the effect of immunizing the mice in a controlled trial with recombinant OspA protein on prevalence of B. burgdorferi infection of nymphs collected the following year.

Previous studies had indicated that vaccination of infected mice with OspA would prevent establishment of B. burgdorferi infection of larvae that subsequently fed on the immunized mice. We used the following techniques to assess the prevalence of infection of and immunity to B. burgdorferi and to identify the species and genotype of Borrelia: (a) immunoassays with whole cells of B. burgdorferi and purified OspA protein, (b) quantitative polymerase chain reaction with specific probes for B. burgdorferi and a newly-discovered spirochete related to B. miyamotoi in I. scapularis ticks, and (c) multi-locus DNA sequencing of PCR amplifications of the intergenic spacer between the 16S and 23S ribosomal RNA genes, as well as the ospA, ospC, and p66 genes for outer membrane proteins.

The results to date include the following: (i) Almost all P. leucopus become infected with B. burgdorferi during the transmission season and at an incidence of approximately 0.2 infections per mouse per week throughout the season. (ii) Antibody to OspA was rare among naturally-infected mice in baseline studies of the field site but was detectable in approximately 80% of the mice in grids in which recombinant OspA was administered. (iii) Both B. burgdorferi and the B. miyamotoi-like spirochete are prevalent in I. scapularis and P. leucopus at the study site. (iv) By multi-locus sequence typing here were at least 9 different genotypes (strains) of B. burgdorferi in ticks and mice at the field site, but only one genotype of the B. miyamotoi-like spirochete was detected. (v) A lower prevalence of B. burgdorferi in nymphal I. scapularis collected the year after immunization was associated with residence in grids subjected to OspA immunization.

Figure legend. Possible methods for prevention of Lyme borreliosis through intervention at different points in the cycle of Borrelia burgdorferi in northeastern United States among three stages of Ixodes scapularis ticks and tick hosts. The strategy of targeting vaccinations against B. burgdorferi to the reservoir rodent Peromyscus leucopus is the topic of the study.

Keynote speaker - Andersson S et al.: Phylogeny and Distribution of Vector-Borne Pathogens: What to Expect from Genomics?

Keynote speaker - Barbour A et al.: Interrupting transmission of Lyme borreliosis by targeting a reservoir for vaccination: a longitudinal study of a field site in North America

Keynote speaker - Broman T et al.: Campylobacter jejuni and wild birds

Keynote speaker - Broman T et al.: Natural reservoirs and vectors of Francisella tularensis in Sweden

Keynote speaker - Fouchier R: Influenza virus zoonoses

Keynote speaker - Fouchier R: A Novel Corona Virus Causing Severe Acute Respiratory Syndrome

Keynote speaker - Lundström J: Intercontinental dispersal and local adaptation of a mosquito-borne bird virus

Keynote speaker -Stervander M: Research activities and possibilities at Ottenby Bird Observatory

Bladh L et al.: Rapid detection and quantification of RNA of Crimean-Congo Hemorrhagic Fever Virus by Real-Time Reversed Transcription-PCR

Dahlgren D et al.: Survival of Campylobacter jejuni within Acanthamoeba polyphaga; a possible transmission route.

Ehrenborg C et al.: Genetic diversity over short geographic distances and no host specificity among Bartonella grahamii infecting woodland rodents of central Sweden

Ekerfelt C et al.: Involvement of cytolytic immune cells in human Lyme borreliosis - indication of intracellular persistance of the Borrelia spirochete?

Ekstrom J-O et al.: Characterization of the Ljungan virus

Haglund M: Characterization of human TBEV-strains from Sweden and a short review of the phylogenetic relationships within TBEV and Louping Ill.

Jarefors S et al.: Suppressed response to Borrelia-antigen in patients co-exposed to Borrelia burgdorferi and Anaplasma phagocytophila

Johansson M et al.: Development of molecular diagnostics for Orthopoxvirus

Mirazimi A et al.: Phatogenesis and the role of innate immunity in emerging patogen (Crimean Congo Heamorraghic fever virus)

Nejedla P et al.: A Six-year study of the presence of Borrelia burgdorferi s.l. in Ixodes ricinus ticks in the town park of Brno, Czech Republic.

Olsson G et al.: Hot zones in time and space on human hantavirus infections in northern sweden

Palo T et al.: Changing climate and emerging infectious diseases

Persson T et al.: Biological mosquito control in Sweden and risk assessment for non-target wetland insects

Schäfer M et al.: Biological diversity versus risk for mosquito nuisance and disease transmission in constructed wetlands

Shinikar S et al.: Genetic analysis of Crimean-Congo Hemorrhagic Fever virus in Iran

Skarphedinsson S et al.: Detection by PCR of Anaplasma in Danish Roe deer

Vostal K et al.: A Five-year Study of the Presence of Borrelia and Antibodies to Borrelia in Small Rodents.

Widhe M et al.: Borrelia specific IFN-γ and IL-4 secretion in CSF and blood during the course of Human Lyme Borreliosis: relation to clinical outcome

You E et al.: Host Immune Mechanisms in Recurrent Lyme Erythema Infection with Focus on the Cytokines Interleukin-4, Interferon-gamma and Interleukin-10

Zakovska A et al.: Spirochaetes and pathogenic Borrelia burgdorferi s.l. in mosquitoes (larvae and adults) in the Czech Republic