Concomitant Infection Decreases the Malaria Burden but Escalates Relapsing Fever Borreliosis
2010 (English)In: Infection and Immunity, ISSN 0019-9567, E-ISSN 1098-5522, Vol. 78, no 5, 1924-1930 p.Article in journal (Refereed) Published
About 500 million cases of malaria occur annually. However, a substantial number of patients who actually have relapsing fever (RF) Borrelia can be misdiagnosed with malaria due to similar manifestations and geographic distribution of the two diseases. More alarmingly, high prevalence of concomitant infections with malaria and RF Borrelia has been reported. Therefore, we used a mouse model to study the effects of such mixed infection. We observed a 21-fold increase in spirochete titers, whereas the numbers of parasitized erythrocytes were reduced 15-fold. This may be explained by polarization of the host immune response towards the intracellular malaria parasite, resulting in unaffected extracellular spirochetes and hosts that succumb to sepsis. Mixed infection also resulted in severe malaria anemia with low hemoglobin levels, even though the parasite counts were low. Overall, co-infected animals had higher fatality rate and shorter time to death than both malaria and RF single infection. Furthermore, secondary malaria infection reactivated a quiescent RF brain infection, which is the first evidence of a clinically and biologically relevant cue for reactivation of RF Borrelia infection. Our study highlights the importance of investigating concomitant infections in vivo to elucidate the immune responses that are involved in the clinical outcome.
Place, publisher, year, edition, pages
American Society for Microbiology , 2010. Vol. 78, no 5, 1924-1930 p.
Immunology in the medical area Infectious Medicine
IdentifiersURN: urn:nbn:se:umu:diva-32816DOI: 10.1128/IAI.01082-09ISI: 000276778700013PubMedID: 20145098OAI: oai:DiVA.org:umu-32816DiVA: diva2:306212