Invasive Salmonellosis in Humans.

Area of Science:

• Microbiology
• Infectious Diseases
• Genetics

Background:

• Human salmonellosis is primarily caused by Salmonella enterica subspecies enterica.
• Infections manifest as enteric fever, gastroenteritis, bacteremia, or extraintestinal focal infections.
• Disease outcomes are influenced by the pathogen, dose, and host immune and genetic factors.

Purpose of the Study:

• To review current knowledge on Salmonella serovars causing invasive human disease.
• To explore the interplay between pathogen genetics and host factors in salmonellosis.
• To discuss the population biology of invasive Salmonella.

Main Methods:

• Literature review of existing studies on Salmonella enterica.
• Analysis of associations between serovar genetics and human infection types.
• Examination of host factors and pathogen characteristics.

Main Results:

• Serovars Typhi and Paratyphi A show clear links between serovar genetics and systemic human infection.
• Nontyphoidal Salmonella (NTS) like Typhimurium and Enteritidis cause frequent infections likely due to exposure.
• Some Typhimurium strains in Africa may be host-adapted to humans, particularly in HIV-infected individuals.

Conclusions:

• Understanding the genetic background of Salmonella serovars is crucial for predicting invasive disease.
• Further research is needed on host-pathogen genetics for serovars Paratyphi B and C.
• The heterogeneity within serovars like Typhimurium requires careful consideration in population biology studies.