Research Article - (2025)Volume 9, Issue 2
Introduction: Salmonella is a bacterium that can cause illness in humans, ranging from gastroenteritis to serious systemic infections. However, its diagnosis remains a challenge for developing countries. Delayed or incorrect diagnosis of Salmonella infections can have negative consequences on the vital prognosis of patients and significant medical costs for the healthcare system. The aim of this study was to evaluate selected hepatic and renal biochemical markers that can be used to optimise monitoring and manage this disease.
Methods: This was a cross-sectional study conducted between April and June 2024 in 166 volunteer who gave their consent in Bafoussam Regional Hospital and Mifi District Hospital. A questionnaire was given to each participant on admission, followed by stool and blood sampling. Following stool culture and biochemical tests, the participants were seperated into positive and negative groups. Hepatic and renal biochemical markers were evaluated using standard methods from commercial kits and automated biochemical analysers. Statistical analyses were performed using SPSS version 22 software.
Results: At the end of this study, 18/166 cases of Salmonella infections were observed, representing a prevalence of 10.8%. Clinical manifestations such as fever, vomiting, abdominal pain, headache and loss of appetite were strongly associated with the disease (95% CI>1). Student's test showed that alanine aminotransferase, aspartate aminotransferase, C-reactive protein, direct and total bilirubin were significantly elevated in the infected patients, particularly the elders (P<0.003), indicating liver damage.
Conclusion: The results of this study highlight the burden of Salmonella infections and the need to reinforce prevention and epidemiological surveillance measures in this region. Analyses of hepatic biochemical markers showed the severity of these infections, highlighting the fact that, it is important to carefully monitor these parameters in order to optimize the management of infected patients.
Infection; Salmonella; Hepatic markers; Renal markers
Salmonella infection is a condition caused by a gram-negative bacteria called Salmonella. This bacterium causes gastrointestinal infection through contaminated food and water [1]. When it occurs in humans, it can take two main forms, namely gastroenteritis (or non-typhoid salmonellosis) and enteritis fever (or typhoid salmonellosis), which is the most severe form of the disease [2]. They represent a public health challenge and have a significant impact on the global economy [3]. Symptoms typically include fever, vomiting, diarrhoea/constipation, abdominal pain, nausea, asthenia and headache [4].
According to the WHO, between 11 and 20 million people suffer from typhoid fever per year in developing countries, due to precarious hygiene and sanitation conditions, with limited access to good drinking water and appropriate advanced treatments. It causes 128 to 161 thousand deaths, 70% of which are children [1,5]. In addition, there are an estimated 93.8 million cases of gastroenteritis worldwide each year, with around 155,000 deaths per year [3].
The management of salmonellosis is increasingly complex in countries with limited resources, such as Cameroon. Reference tests for diagnosing the disease, such as blood culture and stool culture, are often outdated in some of the country’s clinics and hospitals. The widal serological test, although used in almost all health facilities for the sole diagnosis of typhoid serotype, excluding all other potentially diagnosable serovars, remains not very sensitive or specific for the diagnosis of this disease [6]. Faced with these challenges, the diagnosis of the disease when it is present may be delayed or erroneous, leading to severe complications in the organism. This is why it is necessary to explore alternative methods of managing these Salmonella infections.
Systemic infection caused by Salmonella can have harmful consequences within the body's functional organs such as the liver and kidney, among others [7]. In view of this particularity of the bacterium, the search of the biochemical parameters of the liver and kidneys released into the blood when the bacterium passes through the blood will serve as a witness of the damage caused by the latter and can therefore be used to optimize the follow-up and management of affected patients.
The present study was carried out to determine the prevalence of Salmonella infections in patients who came for consultation either in the Bafoussam Regional Hospital or the Mifi District Hospital, furthermore characterize the clinical signs of infected patients, and evaluate certain hepatic and renal biochemical markers in Salmonella-infected patients.
Design and study population
This was a cross-sectional study conducted in two health facilities in the town of Bafoussam in Cameroon, namely the Bafoussam Regional Hospital (HRB) and the Mifi District Hospital (HDM). Participants, regardless of sex or age, coming for a medical visit to one of these health structures, were solicited for the study. Participants with or without clinical signs of the disease were included in the study. The following clinical signs were considered: Fever, diarrhoea/constipation, vomiting, abdominal pain, fatigue and loss of appetite. The non-inclusion criteria concerned individuals with malaria, diabetes, viral hepatitis, a history of chronic disease, including liver or kidney disease, alcohol addiction and medication that may interfere with biochemical markers. Eligible participants gave their consent by signing the consent form and afterward received a questionnaire which they answered. A stool and blood sample were collected from each patient after the questionnaire was answered. A total of 166 participants were enrolled in this study and patients who had a negative stool culture result were considered a control group.
Data and sample collection procedure
Data were first collected using a questionnaire administered to the participants. Variables collected included sociodemographic characteristics, medical history and clinical manifestations. A quantity of stool sample was collected with a sterile spatula and deposited in a wide mouth sterile jar from each participant for stool culture in search of Salmonella. To assess the biochemical parameters, approximately 5 ml of venous blood was collected from all study participants by venipuncture at the elbow crease using a needle adapted to a vacutainer body. The blood collected was placed in anticoagulant-free tubes which were protected from light and centrifuged after 30 minutes at 3000 rpm for 5 minutes. The serum obtained was separated from the clot in Eppendorf tubes and stored at -20°C until biochemical analysis.
Isolation and identification of the bacterium
Stool analysis was performed within 2 hours of collection. A quantity of stool was homogenized with 10 ml of enrichment broth (Selenite F Borth broth) and incubated aerobically at 37°C for 18 to 24 hours for enrichment. After the enrichment step, aliquots of the stool suspensions were inoculated on SS agar selective culture medium and incubated at 37°C for 18-24 hrs. After 24 h of incubation, suspect colonies (colorless with black centers) were identified using the API 20E gallery.
Evaluation of some hepatic and renal biochemical markers
Biochemical parameters were analyzed such as Alanine Aminotransferase (ALT), Aspartate Aminotransferase (AST), direct bilirubin, total bilirubin, urea and creatinine were analyzed on the Rayto-Chemary 120 automaton using standard commercial chemical analysis kits (Monlab Test®). C-reactive Protein (CRP) was quantified on a fluorecare reader using the commercial fluorerare® kit.
Statistical analysis
Data were entered and analyzed using SPSS version 22 software application. Descriptive analyses were used to determine the prevalence of Salmonella infections among patients at the two healthcare facilities. A binary logistic regression test was used to establish an association between Salmonella infection and clinical manifestations. ANOVA test followed by the student’s t test were used to compare the difference in mean hepatic and renal biochemical markers between Salmonella-positive and Salmonella negative patients. The biochemical marker values were expressed as a mean ± standard deviation. A significance level of 5% (p<0.05) and a confidence interval (95% CI) were used to interpret the results.
Sociodemographic characteristics of the study population
The study sample comprised a total of 166 participants. The mean age (± standard deviation) of the respondents was 35.81 ± 22.99 years, with extremes of 2 and 90 years. Bacteriological analysis of stool identified 18 cases of Salmonella infection, representing a prevalence of 10.8%, all female with 7.2% of patients aged 46 years and over. The Mifi district hospital was the most represented with 18 (10.8%) cases (Table 1).
| Characteristics | Frequency (n=166) | Salmonellosis n (%) | |
| Negative 148 (89.2) | Positives 18(10.8) | ||
| Age (35.81 ± 22.99) | |||
| 0-15 years | 36 | 30 (18.1) | 6 (3.6) |
| 16-45 years old | 72 | 72 (43.4) | 0 (0.0) |
| 46 years and older | 58 | 46 (27.7) | 12 (7.2) |
| Gender | |||
| Female | 120 | 102 (61.4) | 18 (10.8) |
| Male | 46 | 66 (27.7) | 0 (0.0) |
| Place of residence | |||
| Bafoussam | 134 | 122 (73.5) | 12 (7.2) |
| Foumbot | 2 | 0 (0.0) | 2 (1.2) |
| Mbouda | 22 | 18 (10.8) | 4 (2.4) |
| Foumban | 4 | 4 (2.4) | 0 (0.0) |
| Buea | 4 | 4 (2.4) | 0 (0.0) |
| Occupation | |||
| Farmer | 22 | 18 (10.8) | 4 (2.4) |
| Pupil | 40 | 32 (19.3) | 8 (4.8) |
| Student | 36 | 36 (21.7) | 0 (0.0) |
| Housewife | 36 | 30 (18.1) | 6 (3.6) |
| Laboratory technician | 4 | 4 (2.4) | 0 (0.0) |
| Saleswoman | 2 | 2 (1.2) | 0 (0.0) |
| Driver | 8 | 8 (4.8) | 0 (0.0) |
| Electrician | 2 | 2 (1.2) | 0 (0.0) |
| Teacher | 6 | 6 (3.6) | 0 (0.0) |
| Mason | 2 | 2 (1.2) | 0 (0.0) |
| Pastor | 2 | 2 (1.2) | 0 (0.0) |
| Nurse | 2 | 2 (1.2) | 0 (0.0) |
| Carpenter | 2 | 2 (1.2) | 0 (0.0) |
| Health facility | |||
| HRB | 80 | 80 (48.2) | 0 (0.0) |
| HDM | 86 | 68 (41.0) | 18 (10.8) |
| Note: n=Frequency, %=Percentage, HRB=Bafoussam Regional Hospital, HDM=Mifi District Hospital | |||
Table 1: Distribution of patients socio-demographic characteristics.
Clinical manifestations associated with Salmonellosis
Statistical analysis using binary logistic regression showed a positive association between Salmonella infection and clinical manifestations such as fever 16 (9.6%), vomiting 12 (7.2%), abdominal pain 16 (9.6%), headache 14 (8.6%) and loss of appetite 8 (4.8%) (P<0.05), at a 95% confidence interval (Table 2).
|
Clinical manifestations |
Frequency (n=166) |
Salmonellosis n (%) |
OR |
P-value |
IC 95% |
||
|
Negative |
Positive |
||||||
|
Fever |
With |
72 |
56 (33.7) |
16 (9.6) |
13.43 |
0.018 |
1.56-110.73 |
|
Without |
94 |
92 (55.4) |
2 (1.2) |
||||
|
Diarrhoea |
With |
60 |
48 (28.9) |
12 (7.2) |
4.16 |
0.057 |
0.95-18.10 |
|
Without |
106 |
100 (60.2) |
6 (3.6) |
||||
|
Constipation |
With |
46 |
42 (25.3) |
4 (2.4) |
0.72 |
0.698 |
0.13-3.75 |
|
Without |
120 |
106 (63.9) |
14 (8.4) |
||||
|
Vomiting |
With |
34 |
22 (13.3) |
12 (7.2) |
11.45 |
0.002 |
2.48-52.72 |
|
Without |
132 |
126 (75.9) |
6 (3.6) |
||||
|
Abdominal pain |
With |
70 |
54 (32.5) |
16 (9.6) |
13.92 |
0.015 |
1.65-117.42 |
|
Without |
96 |
94 (56.6) |
2 (1.2) |
||||
|
Asthenia |
With |
48 |
40 (24.1) |
8 (4.8) |
2.16 |
0.285 |
0.52-8.85 |
|
Without |
59 |
54 (65.1) |
5 (6.0) |
||||
|
Headache |
With |
34 |
20 (12.0) |
14 (8.4) |
22.4 |
0 |
1.56-110.73 |
|
Without |
132 |
128 (77.1) |
4 (2.4) |
||||
|
Loss of appetite |
With |
26 |
18 (10.8) |
8 (4.8) |
5.77 |
0.021 |
0.95-18.10 |
|
Without |
140 |
130 (78.3) |
10 (6.0) |
||||
|
Note: n=Frequency, P-value=Significance threshold, CI=Confidence Interval, OR=Odds Ratio |
|||||||
Table 2: Clinical manifestations associated with Salmonellosis.
Comparison of the means of biochemical abnormalities between sick and healthy patients according to age group
Analysis of biochemical markers showed that Salmonella-infected patients had an average, significantly elevated level of C-reactive Proteins (CRP), Alanine Aminotransferase (ALT) in the 0-15 age group. In addition, Aspartate Aminotransferase (AST), direct bilirubin and total bilirubin were significantly higher in the elderly group (46 and over), compared to non-infected participants (P<0.003). However, there was a moderate elevation of CRP, AST and direct bilirubin in the elderly group (46 and over) compared to the reference value. Furthermore, creatinine and urea levels in both groups were normal and the difference in mean was not statistically significant (p-value>0.05) (Table 3).
| Biochemical markers | Age range | Reference values | Salmonellosis (n=166) | P-value | |
| Negative (n=148) | Positive (n=18) | ||||
| CRP (mg/L) | 0-15 years | <6 | 5.93 ± 3.10 | 80.05 ± 56.24 | 0 |
| 16-45 years old | 5.10 ± 3.04 | … | |||
| 46 year over | 6.41 ± 3.05 | 72.40 ± 54.33 | 0 | ||
| AST (UI/L) | 0-15 years | F: <31 M: <35 |
30.14 ± 14.18 | 42.59 ± 17.63 | 0.198 |
| 16-45 years old | 30.31 ± 14.50 | … | |||
| 46 and over | 34.87 ± 10.78 | 59.92 ± 30.46 | 0.003 | ||
| ALT (UI/L) | 0-15 years | <42 | 8.47 ± 6.94 | 44.36 ± 7.34 | 0 |
| 16-45 years old | 8.62 ± 7.60 | … | |||
| 46 and over | 11.24 ± 9.34 | 47.27 ± 12.71 | 0 | ||
| Bilirubin D (mg/dL) | 0-15 years | <0.3 | 0.32 ± 0.24 | 0.24 ± 0.08 | 0.121 |
| 16-45 years old | 0.34 ± 0.20 | … | |||
| 46 and over | 0.33 ± 0.15 | 0.84 ± 0.35 | 0 | ||
| Bilirubin T (mg/dL) | 0-15 years | <1.0 | 0.77 ± 0.28 | 0.68 ± 0.07 | 0.595 |
| 16-45 years old | 0.76 ± 0.28 | … | |||
| 46 and over | 0.71 ± 0.33 | 1.42 ± 0.83 | 0.003 | ||
| Urea (g/L) | 0-15 years | (0.10-0.50) | 0.18 ± 0.13 | 0.26 ± 0.02 | 0.32 |
| 16-45 years old | 0.19 ± 0.15 | … | |||
| 46 and over | 0.17 ± 0.08 | 0.22 ± 0.05 | 0.19 | ||
| Creatinine (mg/L) | 0-15 years | (5-13) | 5.70 ± 1.50 | 5.79 ± 0.88 | 0.996 |
| 16-45 years old | 8.13 ± 2.29 | … | |||
| 46 and over | 8.36 ± 2.04 | 9.64 ± 2.50 | 0.205 | ||
| Note: n=Frequency, CRP=C-Reactive Protein, AST=Aspartate Aminotransferases, ALT=Alanine Aminotransferase, T=Total, D=Direct, M=Male, F=Female | |||||
Table 3: Comparisons of means biochemical abnormalities between sick and healthy patients.
The aim of this study, carried out at the Bafoussam Regional Hospital and the Mifi District Hospital, was to evaluate some hepatic and renal biochemical markers in patients with Salmonella infection in order to identify biomarkers that are potentially predictive of the disease and that can be used to optimize the follow-up and management of patients with this infection.
The results of the present study indicate that the prevalence of Salmonella infections among these patients is 10.8%, showing that enteric Salmonella infections are also common in the town of Bafoussam. This rate is close to that of Awung et al. [8] who in a study in the Bamenda district health zone in Cameroon, noted a prevalence of 8.70% of Salmonella infections. This relatively high prevalence underscores the high burden of this bacterial infection in our region.
Clinical data revealed that fever, vomiting, abdominal pain, headache and loss of appetite were closely associated with Salmonella infection in this study with a P-value of less than 5%. These clinical signs are characteristic of systemic Salmonella infection. These results are close to that of Lefebvre et al. [9] in Senegal, who showed that fever, vomiting, abdominal pain, headache were predictive signs of Salmonella serovar Typhi; and that of Kashosi et al. [10] who noted an association between Salmonella and the appearance of symptoms such as fever, vomiting, abdominal pain.
The results of the Analysis of Variance (ANOVA) confirmed by the student’s t test showed that Salmonella infection in these patients led to significant disturbances in hepatic markers, particularly in elderly subjects. There was a marked increase in transaminases (ALT, AST), a significant rise in CRP and an increase in total and direct bilirubin. These results are close to those of Etouke et al. [6] who noted hyperalanine aminotransferase, total hyperbilirubinemia, direct hyperbilirubinemia and C-reactive hyperprotein in the case of typhoid salmonellosis and to that of Ndukaku et al. [11] who showed that transaminases (ALT, AST) were very high in people with Salmonella serovar typhi. Also, Albayrak et al. [12] noted elevations in ALT, AST, CRP, total bilirubin and direct bilirubin in patients with typhoidal salmonellosis. Increased Alanine Aminotransferase (ALT) and Aspartate Aminotransferase (AST) clearly indicate liver damage. In addition, the significant rise in CRP underlines the presence of an important systemic inflammatory process. Increase direct bilirubin is the result of biliary tract involvement, which may translate into cholestatic jaundice. Increase total bilirubin suggests hemolysis and accumulation of direct bilirubin in the blood. Also, the moderate elevation of CRP, AST and direct bilirubin levels observed in elderly Salmonella negative elderly patients may be the result of another pathological condition or of their deficienct immune status.
The markers (urea and creatinine) of renal function in this study were within the reference range. This indicates the renal function is preserved in this context. This result is not the first, since a previous study showed that creatinine and urea levels remain within physiological norms in cases of Salmonella ser. typhi [13]. However Etouke et al. [6] and Ndukaku et al. [11] reported high levels of these markers in their studies.
This study was conducted over a limited period. It focused on the detection of Salmonella spp. in stool samples, without further characterization of the serotypes. The small sample size in the various study variables limited the scope of statistical analysis. Other markers of liver function were not measured.
This study contributed to a better understanding of the prevalence of Salmonella infections in patients who came for consultation at the Bafoussam Regional Hospital and the Mifi District Hospital, the associated clinical symptoms and their influence on biochemical markers in the liver and kidneys. The results of this study showed that 10.8% of patients were affected by this disease cases, with clinical symptoms such as fever, vomiting, abdominal pain, headache and loss of appetite. In addition, these infections disrupt certain hepatic biochemical markers by causing significant elevations of alanine aminotransferase, aspartate aminotransferase, C-reactive protein, direct bilirubin and total bilirubin, mostly in elderly patients. These results underline the burden of this disease and biochemical markers related to liver function, should be used to reinforce monitoring and optimize the management of this disease in case of severe infection.
Ethical approval for this study was obtained from the Western Region Human Health Research Ethics committee (CRERSHOuest) (ref: N°/436/27/03/2024/CE/CRERSH-OU/VP). Written informed consent was obtained from each participant for voluntary participation and for the publication of all their data.
The authors do not have any conflicts of interest.
Y.N.J.D. was the field investigator, developed data collection tools; collected, analyzed, and interpreted data; drafted and reviewed the manuscript. G.S.S.N. designed and supervised the study, conceptualized the protocol and reviewed the manuscript.
No funding was received for this research.
The authors warmly thank all the participants in the study, the administration of the Bafoussam Regional Hospital (HRB) and the Mifi District Hospital for facilitating the implementation of this project.
Additional supporting information can be obtained upon demand from authors.
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Citation: Djomo YNJ, Njateng GSS (2025) Some Hepatic and Renal Biochemical Markers Associated with Salmonella Infections in Patients Consulting at the Bafoussam Regional Hospital and the Mifi District Hospital, West-Cameroon: Cross-sectional Study. J Clin Microbiol Antimicrob. 09:224.
Received: 26-May-2025, Manuscript No. JCMA-25-37483; Editor assigned: 29-May-2025, Pre QC No. JCMA-25-37483 (PQ); Reviewed: 12-Jun-2025, QC No. JCMA-25-37483; Revised: 22-Aug-2025, Manuscript No. JCMA-25-37483 (R); Published: 29-Aug-2025 , DOI: 10.35248/JCMA. 25.09.224
Copyright: © 2025 Djomo YNJ, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Sources of funding : No funding was received for this research