Immune Monitoring of Paediatric Patients Infected with Rickettsia rickettsii, Ehrlichia canis and Coinfected

Abstract

In 2021, 273 Rocky Mountain spotted fever cases were reported nationwide in Mexico. In Chihuahua City, fourteen samples were obtained from children suspected of rickettsial infection. The analysis of samples (January to December 2021) showed prevalence rates of 28.5%, 43%, and 28.5% for Rickettsia rickettsii, Ehrlichia canis, and both pathogens in coinfection, respectively. The analysis of clinical haematological and biochemistry analytes showed alterations; 100% of the children had elevated liver enzymes and coagulation times, 64% showed leukocytosis due to neutrophilia, 55% had thrombocytopenia, lymphopenia, and hypoalbuminemia, and 45% showed normocytic normochromic anaemia. Statistically significant differences were observed in the expression of the chemokines IL-8, RANTES, CXCL9/MIG, and CXCL10/IP-10 across the coinfected and control groups, and the difference in IP-10 expression was significant for patients infected by R. rickettsii compared to the control group. Additionally, significant differences were observed for expression levels of IL-1β, IL-6, IL-17, IFNγ, and TNFα among the R. rickettsii-positive group compared to the control group. On the other hand, the coinfected group exhibited modified levels of IL-6, IL-8, and IL-10 compared with the control group. Finally, significant differences were observed for CD8+ T lymphocyte subpopulations between individuals positive for R. rickettsii and those positive for E. canis.

Rickettsia rickettsii and Rickettsia typhi in hospitalized children diagnosed with Pediatric Multisystemic Inflammatory Syndrome in Merida, Yucatan

“… 16 In addition, it is important to evaluate other interleukins such as IL-1 and IL-6 as prognostic factors in cabinet studies, in which IL-1B in particular has been linked to inflammasomes as well as IL-6. 17 This data would be relevant in conjunction with laboratory studies. Inflammatory markers such as D-dimer or interleukins, along with identification of the rickettsia group involved (SFG or TG), may serve as prognostic factors, especially in hyper- endemic areas.…”

Clinical and pathological factors associated with Ehrlichia canis in companion dogs

“…This bacterial species has a tropism for monocytes, lymphocytes, and macrophages [1] and more than 800 hosts have been reported, including humans. E. canis mainly affects the Canidae family, however, human infection has been described in Venezuela, Panama, and recently in North Mexico [2][3][4]. The pathogen, is transmitted by Dermacentor variabilis and the brown dog tick Rhipicephalus sanguineus [5].…”