It has been suggested that high altitude can reduce the infectivity and case fatality rate of COVID-19. We investigated the relationship between altitude and the COVID-19 pandemic in Colombia. Epidemiological data included the number of positive cases, deaths, and the case fatality rate of COVID-19. In particular, we analyzed data from 70 cities with altitudes between 1 and 3,180 m. Correlations and linear regression models adjusted to population density were performed to examine the relationship and contribution of altitude to epidemiological variables. The case fatality rate was negatively correlated with the altitude of the cities. The incidence of cases and deaths from COVID-19 had an apparent correlation with altitude; however, these variables were better explained by population density. In general, these findings suggest that living at high altitude can reduce the impact of COVID-19, especially the case fatality rate.

: Leptospirosis is an acute febrile disease that mainly affects developing countries with tropical climates. The complexity and magnitude of this disease is attributed to socioeconomic, climatic, and environmental conditions. In this study, in a 10-year period from 2008 to 2017, the relationship between human leptospirosis cases and climatic factors in Cartagena de Indias, Colombia were evaluated. Monthly leptospirosis cases, climatic variables, and macroclimatic phenomena (El Niño and La Niña) were obtained from public datasets. Local climatic factors included temperature (maximum, average, and minimum), relative humidity, precipitation, and the number of precipitation days. Time series graphs were drawn and correlations between cases of leptospirosis and climatic variables considering lags from 0 to 10 months were examined. A total of 360 cases of leptospirosis were reported in Cartagena during the study period, of which 192 (53.3%) were systematically notified between October and December. Several correlations were detected between the number of cases, local climatic variables, and macroclimatic phenomena. Mainly, the increase of cases correlated with increased precipitation and humidity during the La Niña periods. Herein, seasonal patterns and correlations suggest that the climate in Cartagena could favor the incidence of leptospirosis. Our findings suggest that prevention and control of human leptospirosis in Cartagena should be promoted and strengthened, especially in the last quarter of the year.

The epidemiology of the coronavirus disease (COVID-19) has been scarcely described in individuals under 18 years old, particularly during the first months of the pandemic. The study aimed to describe the COVID-19 epidemiology in the Colombian department of Bolívar from March 2020 to April 2021 among individuals under 18 years. Furthermore, we explored whether the use of data generated by a Bolívar reference laboratory captures the departmental epidemiology. Two information sources were used; the national COVID-19 surveillance system and the Bolívar COVID-19 reference laboratory. In using a population-based ecological approach and information from confirmed symptomatic cases, epidemic curves and heat maps were constructed to assess the COVID-19 dynamics and patterns by sex, age, and residence (Cartagena vs. 45 other municipalities). The COVID-19 incidence was comparable between males and females but varied by age group, being higher in children aged 10 years and older. Cartagena had a significantly higher number of cases and experienced early epidemic peaks. Our analyses suggest that information generated by the reference laboratory does not capture the COVID-19 departmental epidemiology, despite conducting population-based surveillance across Bolívar. The study provides a retrospective characterization of the COVID-19 epidemiology in an understudied population and information that may be useful for future evidence-based responses.

: In Colombia, human leishmaniasis is endemic in rural areas, with increasing reports of outbreaks and cases in urban areas. Cartagena, an urban city in the Colombian Caribbean with a wildland-urban interface, faced its first local cases between 2011 and 2015. Despite reports, visceral leishmaniasis (VL) remains neglected and understudied and almost devoid of active surveillance. Here we report the epidemiological and molecular surveillance of Leishmania species in humans, domestic dogs, and sandflies at the wildland interface in two poverty-stricken neighborhoods of Cartagena. In October 2021, we conducted a surveillance study in the El Toril and La Quinta neighborhoods. Blood samples were collected from 150 healthy humans and 77 domestic dogs for Leishmania species testing by using molecular tools. Five human samples (3.3%) tested positive for Leishmania, one case in El Toril and four cases in La Quinta. The Leishmania donovani complex was detected in three human samples, and all dog samples tested negative for Leishmania. CDC light traps placed for three consecutive days in peridomiciliary areas of the Leishmania-positive case in El Toril allowed the capture of seven females of Lutzomyia dubitans, but none tested positive for Leishmania. Multiple attempts to conduct entomological surveillance in La Quinta were unsuccessful because of non-study-related issues. Our findings contribute to the characterization of the epidemiology of VL in Cartagena, revealing possible neglected cryptic infections in two neighborhoods with an urban-wildland interface.