Seasonal Differences in Cyclospora cayetanensis Prevalence in Colombian Indigenous People

Abstract

Fecal-orally transmitted cyclosporiasis is frequent in remote resource-limited settings in Central and South America with poor hygiene conditions. In this study, we aimed at assessing seasonal effects on the epidemiology of colonization or infection with C. cayetanensis in Colombian indigenous people living under very restricted conditions. In the rainy season between July and November and in the dry season between January and April, stool samples from indigenous people with and without gastrointestinal symptoms were collected and screened for C. cayetanensis applying in-house real-time polymerase chain reaction (PCR). In the rainy season and in the dry season, positive PCR results were observed for 11.8% (16/136) and 5.1% (15/292), respectively, with cycle threshold (Ct) values of 30.6 (±3.4) and 34.4 (±1.6), respectively. Despite higher parasite loads in the rainy season, fewer individuals (2/16, 12.5%) reported gastrointestinal symptoms compared to the dry season (6/15, 40%). In conclusion, considerable prevalence of C. cayetanensis in Colombian indigenous people persists in the dry season. Low proportions of gastrointestinal symptoms along with higher parasite loads make colonization likely rather than infection.

Seasonal Patterns of Enteric Pathogens in Colombian Indigenous People—A More Pronounced Effect on Bacteria Than on Parasites

“…A situation of higher proportions of gastrointestinal pathogen detections in the dry season was, in contrast, never observed. This is well in line with previous reports indicating increased disease activity of infectious gastroenteritis during the rainy season in tropical settings [1][2][3][4][5][6][7][8][9][10] and thus confirms those previous findings.…”

“…In Japan, modellings of potential cost savings due to reduced numbers of inpatient gastroenteritis cases as likely beneficial consequences of global warming have been conducted [28], underlining the medical-economic relevance of the topic. In Indigenous Wiwa communities in North-Eastern Colombia, a differentiated pattern with a proportion of seasonality-associated effects deserving further discussion could be recorded in the present study, confirming previous findings with focus on C. cayetanensis [4].…”

“…Decades before, U.S. American armed forces had a similar experience with seasonality of tropical gastroenteritis at a military base on the Philippines [2,3]. In the Colombian Indigenous Wiwa population, an increased rate of Cyclospora cayetanensis infections was observed in the rainy season as well [4], confirming an inconsistently reported seasonality of cyclosporiasis [5][6][7]. For other coccidian parasites like Cryptosporidium spp., similar associations with the rainy season have been reported from the tropics [8].…”

Direct and Indirect Proof of SARS-CoV-2 Infections in Indigenous Wiwa Communities in North-Eastern Colombia—A Cross-Sectional Assessment Providing Preliminary Surveillance Data

“…In general, however, we did not record increased disease severity in participants with active infections, nor signs of relevant sequelae in convalescent individuals with detectable SARS-CoV-2-specific antibodies. The observed generally mild to moderate clinical COVID-19 courses could be (a) attributed to the young average age of our study population, (b) based on previous reports linking the poor living conditions of the indigenous to numerous infections [ 25 , 29 , 30 ] resulting in a well-regulated antiviral immune response, (c) attributed to the fact that severely ill patients would not have been able to walk for up to six hours to reach the closed screening facility, (d) based on the cultural educations which condemn complaining of mild to moderate symptoms and/or (e) based on the severe local stigmatization associated with SARS-CoV-2 infections, so symptoms are preferred to be concealed. Consequently, information on actual disease severity may not be free of bias.…”

New Developments in PCR-Based Diagnostics for Bacterial Pathogens Causing Gastrointestinal Infections—A Narrative Mini-Review on Challenges in the Tropics

“…Next to asymptomatic colonization [ 114 , 115 , 116 ], persistence of DNA of successfully treated and already cleared infections [ 24 ] can also account for positive PCR results without association to symptomatic gastroenteritis. DNA clearance from stool, either by excretion or nucleases, is a stochastic process and contradicting reports of DNA persistence duration after cleared infections between a few days and several weeks within the complex stool matrix exist [ 113 , 117 ].…”