Etiologies of Zoonotic Tropical Febrile Illnesses That Are Not Part of the Notifiable Diseases in Colombia

Pathogens associated with ticks (Acari: Ixodidae) and mammals in the Orinoquia region of Colombia: An approach to understanding vector-pathogen-host interactions

The hard tick clade (Ixodidae) currently comprises 762 species worldwide (266 Prostriata and 496 Metastriata). A quarter of hard ticks are found in the Neotropical region, and 42 species have been documented in Colombia. Ixodidae species are important vectors of pathogens such as bacteria, helminths, protozoa, and viruses. In tick-borne diseases, vertebrate hosts perform an important role in the transmission, maintenance, and spread of pathogens. Colombia ranks sixth among countries with the highest mammal biodiversity, with a total of 548 species, where some of these species may be involved in pathogen transmission cycles with ticks as vectors. This research evaluated the presence of two genera of bacteria (Borrelia and Rickettsia) and the protozoan (Babesia) in ticks and mammals in the Orinoquia region of Colombia, establishing interaction networks. The information comes from 734 mammals (655 wild and 79 domestic), belonging to 59 species. Tick infestation (n = 1,805) was found with 14.85 % (n = 109) of the examined mammals and corresponds to nine tick species confirmed morphologically and molecularly. To detect pathogens 272 ticks were collected while feeding on 96 mammals; samples from 93 mammals were analyzed. The presence of borreliae from the relapsing fever group (RFG) and the Lyme disease group (LDG) were detected. Rickettsia spp. was detected in ticks and mammals, while Babesia bigemina was only detected in ticks. This research is the first to address the prevalence of zoonotic pathogens in domestic and wild mammals infested with hard ticks in the Department of Arauca, Colombia. Considering that reporting cases of infections with Babesia, Borrelia, and Rickettsia in Colombia is not mandatory, their impact on public health cannot be estimated. This highlights the importance of continuously detecting, confirming, and identifying these and other important pathogens within the "One Health" framework, as they have a significant economic and medical-veterinary impact globally.

Molecular surveillance of microbial agents from cattle-attached and questing ticks from livestock agroecosystems of Antioquia, Colombia

Ticks are obligate ectoparasites and vectors of pathogens affecting health, agriculture, and animal welfare. This study collected ticks from the cattle and questing ticks of 24 Magdalena Medio Antioquia region cattle farms. Genomic DNA was extracted from the specimens (individual or pools) of the 2088 adult ticks collected from cattle and 4667 immature questing ticks collected from pastures. The molecular detection of Babesia, Anaplasma, Coxiella and Rickettsia genera was performed by polymerase chain reaction amplification and subsequent DNA sequencing. In a total of 6755 Rhipicephalus microplus DNA samples, Anaplasma marginale was the most detected with a frequency of 2% (Confidence Interval- CI 1.68-2.36), followed by Babesia bigemina with 0.28% (CI 0.16-0.44), Coxiella spp. with 0.15% (CI 0.07-0.27), and Rickettsia spp. with 0.13% (CI 0.06-0.25). Molecular analysis of the DNA sequences obtained from the tick samples revealed the presence of Coxiella-like endosymbiont and R. felis. These results demonstrated the diversity of microorganisms present in R. microplus ticks predominantly associated with cattle and questing ticks from livestock agroecosystems, suggesting their role as reservoirs and potential biological vectors of these microorganisms on the studied sites. Also, it emphasizes the need to combine acarological surveillance with clinical diagnoses and control strategies on regional and national levels.

Etiological characterization of acute undifferentiated febrile illness in Apartadó and Villeta municipalities, Colombia, during COVID-19 pandemic

Background

Acute undifferentiated febrile illness (AUFI) is one of the leading causes of illness in tropical regions. Although malaria is the most important cause, other pathogens such as Dengue (DENV), Leptospira and recently, Coronavirus Disease 2019 (COVID-19) have gained importance. In Colombia, few studies aimed to identify the etiology of AUFI. Most of them performed in Apartadó and Villeta municipalities, identifying the active circulation of several pathogens. Thus, we conducted a cross-sectional study in these municipalities to characterize the etiologies of AUFI during COVID-19 pandemic.

Methods

An active surveillance was conducted between September and December 2021 in local hospitals of Apartadó and Villeta municipalities. Febrile patients were enrolled after voluntarily agreeing to participate in the study. Ten different etiologies were evaluated through direct, serological, molecular and rapid diagnostic methods.

Results

In Apartadó a confirmed etiology was found in 60% of subjects, DENV (25%) being the most frequent, followed by leptospirosis (16.7%), malaria (10%), COVID-19 (8.3%), spotted fever group (SFG) rickettsiosis (6.7%) and Chikungunya (1.7%). In Villeta, a specific etiology was confirmed in 55.4% of patients, of which SFG rickettsiosis (39.3%) was the most frequent, followed by leptospirosis (21.4%), DENV (3.6%) and malaria (1.8%). No cases due to Mayaro, Yellow Fever, Oropouche and Venezuelan Equine Encephalitis viruses were detected.

Conclusion

We confirm the relevance of dengue fever, leptospirosis, SFG rickettsiosis, COVID-19 and malaria as causes of AUFI in the municipality of Apartadó, and highlight the great importance of SFG rickettsiosis as the main cause of AUFI in the municipality of Villeta.