Surveillance of Salmonella enterica serovar  Typhi in Colombia, 2012–2015

Abstract

Salmonella Typhi (S. Typhi) is the causative agent of typhoid fever; a systemic disease affecting~20 million people per year globally. There are little data regarding the contemporary epidemiology of typhoid in Latin America. Consequently, we aimed to describe some recent epidemiological aspects of typhoid in Colombia using cases reported to the National Public Health Surveillance System (Sivigila) between 2012 and 2015. Over the four-year reporting period there were 836 culture confirmed cases of typhoid in Colombia, with the majority (676/836; 80.1%) of reported cases originated from only seven departments. We further characterized 402 S. Typhi isolates with available corresponding data recovered from various departments of Colombia through antimicrobial susceptibility testing and molecular subtyping. The majority (235/402; 58.5%) of these typhoid cases occurred in males and were most commonly reported in those aged between 10 and 29 years (218/402; 54.2%); there were three (0.74%) reported fatalities. The overwhelming preponderance (339/402; 84.3%) of S. Typhi were susceptible to all tested antimicrobials. The most common antimicrobial to which the organisms exhibited non-susceptibility was ampicillin (30/ 402;7.5%), followed by nalidixic acid (23/402, 5.7%). Molecular subtyping identified substantial genetic diversity, which was well distributed across the country. Despite the diffuse pattern of S. Typhi genotypes, we identified various geographical hotspots of disease associated with local dominant genotypes. Notably, we found limited overlap of Colombian genotypes with organisms reported in other Latin American countries. Our work highlights a substantial burden of typhoid in Colombia, characterized by sustained transmission in some regions and limited epidemics in other departments. The disease is widely distributed across the country and associated with multiple antimicrobial susceptible genotypes that appear to be restricted to Colombia. This study provides a current perspective for typhoid in Latin

A Prolonged Outbreak of Enteric Fever Associated With Illegal Miners in the City of Matlosana, South Africa, November 2020–September 2022

“…Complications were noted among 9 of the 30 interviewed cases. When compared with other studies, the rate of complications was higher in this outbreak [ 34–36 ], most likely due to delayed presentation [ 22 , 37–39 ]. Over 70% of Zama Zamas in South Africa are illegal immigrants [ 40 ], which may result in hesitancy to seek health care.…”

A genomic snapshot of Salmonella enterica serovar Typhi in Colombia

“…This collection comprised 60 unique PFGE profiles ( Fig 1 and S1 Table ), including the most commonly circulating restriction patterns in Colombia (e.g., COINXX.JPPX01. 0008-0083-0115)[ 18 ]. Twelve isolates also originated from eight outbreaks confirmed by the health authorities (A-H; 8, 4, 24, 9, 5, 2, 6, and 8 patients per outbreak respectively) (Figs 1 and S1 ); more than one isolate were included from two of these outbreaks (D and G).…”

“…Pulsed Field Gel Electrophoresis (PFGE) is the conventional method for studying the genetic relationship between S. Typhi isolates in Latin America [16]. Using this method, we recently found that some S. Typhi isolates from Colombia shared indistinguishable PFGE patterns with organisms from Argentina, Chile, Perú, Venezuela, Brazil, and Guatemala, indicative of the circulation of common "continental" genotypes [17,18]. However, PFGE has limited discriminatory power to support subtyping and cannot identify genotype 4.3.1, other emerging genotypes, or AMR genes.…”

Human Salmonellosis: A Continuous Global Threat in the Farm-to-Fork Food Safety Continuum

“…The overwhelming preponderance (339/402; 84.3%) of S. Typhi were susceptible to all tested antimicrobials. The organism showed the most resistance against ampicillin (30/402;7.5%), followed by nalidixic acid (23/402, 5.7%) [154].…”