LETTERS TO THE EDITOR
Microbes, Infection and Chemotherapy ISSN: 2789 - 4274 https://doi.org/10.54034/mic.e1375
Salmonella enterica serovar Typhi infection: a public health problem in Latin America and the automated microbiological methods
Max R. Batista Araújo1,*, Luisa Ferreira Seabra2,#, Lincoln Oliveira Sant'Anna3,**, Louisy Sanches dos Santos4,##
1Operational Technical Nucleus, Microbiology, Hermes Pardini Institute. Vespasiano, Minas Gerais, Brazil.
2Operational Technical Nucleus, Microbiology, Hermes Pardini Institute. Vespasiano, Minas Gerais, Brazil.
3Department of Microbiology, Immunology and Parasitology, Faculty of Medical Sciences, Rio de Janeiro State University, Rio de Janeiro, Brazil.
4Department of Microbiology, Immunology and Parasitology, Faculty of Medical Sciences, Rio de Janeiro State University, Rio de Janeiro, Brazil.
Corresponding author: E-mail:max_barau@hotmail.com
Orcid ID: *https://orcid.org/0000-0002-3293-8496, #https://orcid.org/0000-0001-7848-5974, **https://orcid.org/0000-0002-6933-8961, ##https://orcid.org/0000-0002-5303-6395
Submitted: march 03, 2022
Reviewed: march 07, 2022
Approved: march 09, 2022
Dear Editor
We recently received a letter to the editor (1) about our recent clinical case published in this journal (2). The public health problems faced in Brazil and other Latin American countries are recurrent and involve multiple causes. Some determinant factors in health are related to the configuration of health quality. There is still regional heterogeneity and we could even think of a geopolitical fatalism. Access to health systems, for example, is not the same for the entire population even within the same State/Province. Regarding the diagnosis of pathologies, the situation is similar, since not all districts have the same access, the same quality and the same medical-outpatient-hospital care. In this context, typhoid fever stands out as a disease that has already caused major problems to the general population, and despite presenting a certain decrease, remains a matter of concern. The current typhoid fever incidence is directly related to sanitary conditions, reflecting the social disparities that are widely present in Latin American countries.
The present study didn´t aim to describe the disease itself, a knowledge widely described in the medical literature, not even to make an overview of public health, because is not our primary activity area, we also didn´t intend to evaluate the performance of automated diagnostic, since we are facing a clinical case (2).
Thus, what we intended was to describe a case of Salmonella enterica serovar Typhi infection that could have been neglected or inadequately reported, along with the advantages of automated microbiological methods to improve systemic infection diagnosis.
Regarding the infection, there is no doubt that Salmonella enterica serovar Typhi was the real causative pathogen. The patient clinical manifestations, the sanitary conditions of the environment along with two positive blood culture presenting the same microorganism allows us to affirm that it wasn´t contamination. Nevertheless, there was extensive discussion among the professionals involved, obtaining the data and analyzing the clinical information.
Automated blood culture provides, safety results and practicality to the routine, as it increases operational efficiency by presenting a safe technique of continuous monitoring and standardized workflow, in addition to a considerable cost reduction. In this context, it is important to highlight: low sample volume, allowing a greater number of samples without impairing patient's blood volume or microorganism growth; positive and negative alarms; temperature controllers, to ensure incubation stability; user-programmable reading times; graphs representing the results, performed from a primary algorithm and measured by two secondary algorithms, with sample positivity time; easy visualization of positive vials by color difference; indicator of reactive positivity to CO2 and pH changes, doubling the efficiency, reducing positivity time; polymeric adsorption resin and cationic resin in the same vial, ensuring a greater bond with antibiotics and increased positivity of samples (3).
Several studies in the literature confirm the relevance of the use of an automated blood culture system. "The data are in line with the evidence raised in the literature, reinforcing the greater sensitivity of the automated blood culture method. The higher cost with an automated method can become a great economy in the use of antimicrobials, besides contributing to a better prognosis in the case of systemic infections" (3).
Finally, in relation to MALDI-TOF mass spectrometry, there is a growing bibliography regarding its usefulness and great performance for the diagnosis of infectious pathologies and in particular in Salmonella enterica serovar Typhi (4,5). Other representative works published previously, will also be interesting to clarify and mitigate any doubts.
We thank you for reading our work and for the questions presented. It is beyond price our interest in science and studies that, above all, seek to contribute to health professionals/scientific research performance.
Conflict of interest
The authors declare that they have no conflict of interest.
Funding
Funding information is not applicable. No funding was received.
References
1. Mungmunpuntipantip R, Wiwanitkit, V. Correspondence on " Identification of Salmonella enterica serovar Typhi ". Microbes Infect Chemother. 2022; 2: e1363.
2. Batista-Araújo MR, Ferreira-Seabra L, Oliveira-Sant'Anna L, Sanches-dos-Santos L. Identification of Salmonella enterica serovar Typhi strain from a young Brazilian patient: the relevance of automated microbiological methods for the rapid diagnosis of systemic infections. Microbes Infect Chemother. 2022; 2: e1295.
3. Guareze GM, Bordignon JC. Estudo comparativo entre hemocultura automatizada e manual em um laboratório do sudoeste do Paraná, Brasil. RBAC. 2016;48(3):223-8 Available in: http://www.rbac.org.br/wp-content/uploads/2016/11/ARTIGO-6_RBAC-48-3-2016-ref.-266-com-gr%C3%ADficos.pdf. Access in: 02/21/2022.
4. Li G, Sun J, Pan S, Li W, Zhang S, Wang Y, et al. Comparison of the Performance of Three Blood Culture Systems in a Chinese Tertiary-Care Hospital. Front Cell Infect Microbiol. 2019 Aug 7;9:285. doi: 10.3389/fcimb.2019.00285.
5. Osa M, Belo MC, Dela Merced Z, Villanueva AMG, Mauhay J, Celis A, et al. Performance of MALDI-TOF Mass Spectrometry in the Philippines. Trop Med Infect Dis. 2021 Jun 26;6(3):112. doi: 10.3390/tropicalmed6030112
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