Clinical and Radiologic Profile of Acute Lower Respiratory Tract Infections in Hospitalized Children in the Bamenda Regional Hospital ()
1. Introduction
Acute lower respiratory tract infections (ALRTIs) refer to infections affecting areas of the respiratory system below the larynx, including tracheitis, bronchitis, bronchiolitis, and pneumonia [1]. Although significant progress has been made over the years—thanks to improvements in vaccination programs, nutrition, socioeconomic conditions, and control of the HIV epidemic [2]—ALRTIs still represent the primary cause of death in children under the age of five, excluding the neonatal period. Globally, these infections are responsible for more than 20% of pediatric deaths, with pneumonia alone accounting for up to 15% of under-five mortality [3]. It is estimated that between 11 and 20 million children are hospitalized annually due to ALRTIs, and over 2 million die as a result [4].
The burden of ALRTIs is particularly severe in low-income regions, especially sub-Saharan Africa, which accounts for over half of global cases. Reported prevalence in these settings varies between 1.6% and 60.1%, with an associated mortality rate of approximately 15%. In Cameroon, recent data indicate a national ALRTI prevalence of 11.5% [5]. A 16-year mortality review in Northern Cameroon found that children accounted for 67% of all deaths, with ALRTIs—predominantly pneumonia—being the leading cause (24%), followed by malaria (21%) and diarrheal illnesses (19%) [6]. On average, children under five years’ experience about five episodes of ALRTIs annually, most of which are mild and self-limiting. However, ALRTIs are still responsible for 20% - 40% of hospitalizations and 30% - 50% of outpatient visits in paediatric health settings [7]. These infections significantly contribute to childhood morbidity and mortality, influenced by environmental, socio-demographic, and cultural determinants.
Timely identification of clinical symptoms and interpretation of radiological signs are key to early diagnosis and effective intervention. Despite the significant burden of ALRTIs in young children globally, limited data exist in Cameroon regarding their clinical and radiologic presentation. This study, titled “The Clinical and Radiologic Profile of ALRTIs in Hospitalized Children,” aims to describe the diagnostic features, associated risk factors, and outcomes of ALRTIs among hospitalized children, thereby enriching current understanding and guiding more effective prevention and management strategies.
2. Materials and Methods
This cohort study was conducted in the pediatric unit of the Bamenda Regional Hospital over a five-month period, from January 1st to May 31st, 2024. Ethical approval was granted by the hospital’s review board, and written informed consent was obtained from all parents or guardians before participation. The sampling frame comprised all children aged 3 months to 16 years who presented to the paediatric unit with clinical features suggestive of acute lower respiratory tract infections (ALRTIs) during the study period. A total of 111 children were initially recruited. Of these, six were excluded: two because caregivers declined consent, two due to incomplete clinical records, and two because chest radiographs were of insufficient quality for interpretation. This left 105 children who were included in the final analysis. Children with pre-existing chronic cardio-respiratory conditions such as asthma, congenital abnormalities, or bronchopulmonary dysplasia were excluded a priori to avoid confounding by underlying disease. Data collection involved face-to-face interviews with caregivers or patients (where applicable), clinical examination of the children, review of their medical records, and interpretation of chest radiographs by a radiologist. To minimize information bias, the radiologist was blinded to detailed clinical data, having access only to age and sex of the child. ALRTI diagnoses were confirmed by a paediatrician, and patient outcomes were recorded at discharge. Information on socio-demographics, clinical findings, comorbidities, and radiologic characteristics was gathered using a structured questionnaire. The data was securely stored in coded electronic format and entered into CSPro version 7.3. For statistical analysis, the data was exported into R software version 4.2.3. Associations were considered statistically significant at a p-value of less than 0.05.
3. Results
A total of 111 children were recruited for the study; 105 children were included in the analysis and 6 children excluded. A total of 105 children diagnosed with acute lower respiratory tract infections (ALRTIs) were included in the study. The majority of the children (48.6%) were aged between 7 and 36 months, followed by those above 60 months (28.6%). Infants under 6 months constituted 8.6% of the sample, while children aged 37 - 60 months represented 14.3%. In terms of gender distribution, 58.1% of the children were male and 41.9% female. With respect to place of residence, a larger proportion of the children (61.9%) resided in urban areas, compared to 38.1% from rural settings. Regarding parental education, 46.7% of mothers had attained secondary education, 33.3% had tertiary education, and 20.0% had only primary education. Similarly, most fathers (49.5%) had completed secondary education, while 35.2% and 15.2% had primary and tertiary education respectively. Notably, the vast majority of mothers (88.6%) were older than 20 years, with only 11.4% below this age (See Table 1).
Table 1. Sociodemographic characteristics of the children.
Variable |
Frequency (n) |
Percentage (%) |
Age group in months |
|
|
<6 |
9 |
8.6 |
7 - 36 |
51 |
48.6 |
37 - 60 |
15 |
14.3 |
>60 |
30 |
28.6 |
Gender |
|
|
Male |
61 |
58.1 |
Female |
44 |
41.9 |
Residence |
|
|
Rural |
40 |
38.1 |
Urban |
65 |
61.9 |
Level of education of mother |
|
|
Primary |
21 |
20.0 |
Secondary |
49 |
46.7 |
Tertiary |
35 |
33.3 |
Level of education father |
|
|
Primary |
37 |
35.2 |
Secondary |
52 |
49.5 |
Tertiary |
16 |
15.2 |
Age of the mother (in years) |
|
|
<20 |
12 |
11.4 |
>20 |
93 |
88.6 |
The most common type of acute lower respiratory tract infection (ALRTI) among the children studied was pneumonia, accounting for 81.0% of cases with a prevalence of 19.3%. This was followed by bronchiolitis (10.5%, prevalence 2.5%) and bronchitis (8.6%, prevalence 2.1%). Overall, ALRTIs had a total prevalence of 24.0% among the hospitalized children, highlighting pneumonia as the predominant clinical form (See Table 2).
Table 2. Prevalence of ALRTI.
Type of lower respiratory tract infection |
Frequency(n) |
Percentages |
Prevalence |
Pneumonia |
85 |
81.0 |
19.3 |
Bronchiolitis |
11 |
10.5 |
2.5 |
Bronchitis |
9 |
8.6 |
2.1 |
Total |
105 |
100.0 |
24.0% |
The most frequent found symptoms are shown in Figure 1 below. The bar chart shows that cough (100%) and fever (93.3%) were the most common symptoms among children with ALRTIs, followed by difficulty in breathing (69.5%) and noisy breathing (52.4%). Less frequent symptoms included refusal to feed (35.2%), vomiting (28.6%), chest pain (19%), and convulsions (10.5%) (See Figure 1).
Figure 1. Symptoms of ALRTIs.
The most predominant syndromes were systemic inflammatory response syndrome (69.5%) and respiratory distress syndrome (42.9%) (See Figure 2).
Figure 2. clinical syndromes of ALRTIs.
More than half of the patients had alveolar consolidation (96.7%, n = 70), on CXR, followed by bronchial thickening at 38.1% (n = 40) (See Figure 3).
Figure 3. Findings on CXR of children admitted for ALRTIs.
Bilateral lung involvement was the most frequent in our participants (45%, n = 37), followed by right lung involvement at 39.6% (See Figure 4).
Figure 4. Localizations of lesions on CXR.
The analysis of factors associated with severity of ALRTIs showed no statistically significant association for age group, sex, residence, or maternal education. Although children aged > 60 months appeared more likely to have non-severe ALRTIs, the odds ratio (OR = 1.50, p = 0.651) was not statistically significant. Similarly, female sex (OR = 1.93, p = 0.191) and urban residence (OR = 0.70, p = 0.481) were not significantly associated with disease severity. The level of maternal education also showed no significant difference between severe and non-severe groups. However, maternal age > 20 years was significantly associated with reduced odds of severe ALRTIs (OR = 0.27, 95% CI: 0.08 - 1.01, p = 0.043), suggesting that children born to older mothers may have a lower risk of developing severe forms of the disease (See Table 3).
Table 3. Association between sociodemographic variables and severity of acute lower respiratory tract infections (bivariate analysis).
Variable |
Severe n (%) |
Non-severe
n (%) |
OR (95% CI) |
p-value |
Age in months |
|
|
|
|
<6 |
7 (8.2) |
2 (10.0) |
— |
|
6 - 36 |
44 (51.8) |
7 (35.0) |
0.56 (0.11 - 4.24) |
0.515 |
36 - 60 |
13 (15.3) |
2 (10.0) |
0.54 (0.05 - 5.29) |
0.575 |
>60 |
21 (24.7) |
9 (45.0) |
1.50 (0.29 - 11.4) |
0.651 |
Sex |
|
|
|
|
Male |
52 (61.2) |
9 (45.0) |
— |
|
Female |
33 (38.8) |
11 (55.0) |
1.93 (0.72 - 5.27) |
0.191 |
Residence |
|
|
|
|
Rural |
31 (36.5) |
9 (45.0) |
— |
|
Urban |
54 (63.5) |
11 (55.0) |
0.70 (0.26 - 1.92) |
0.481 |
Mothers level of education |
|
|
|
|
Primary |
18 (21.2) |
3 (15.0) |
— |
|
Secondary |
37 (43.5) |
12 (60.0) |
1.95 (0.54 - 9.32) |
0.346 |
Tertiary |
30 (35.3) |
5 (25.0) |
1.00 (0.22 - 5.34) |
> 0.999 |
Mothers age |
|
|
|
|
<20 |
7 (8.2) |
5 (25.0) |
— |
|
>20 |
78 (91.8) |
15 (75.0) |
0.27 (0.08 - 1.01) |
0.043 |
OR = Odds Ratio, CI = Confidence Interval, Non-severe ALRTI: Cough and/or difficult breathing with tachypnea for age, but without danger signs. [Tachypnea thresholds: ≥50 breaths/min (2 - 11 months), ≥40 breaths/min (12 - 59 months], Severe ALRTI: Cough and/or difficult breathing plus at least one danger sign.
Among the various risk factors assessed, malnutrition showed a statistically significant association with severe ALRTIs (p = 0.025), with children who were malnourished being more likely to develop severe disease. Gastroenteritis also showed a borderline significant association (p = 0.049). Other comorbidities, including meningitis, HIV, sickle cell disease (SCD), and low birth weight, were not significantly associated with severity. Additionally, vaccination status, exposure to secondary smoke, exclusive breastfeeding, and family size (overcrowding) did not significantly influence the severity of ALRTIs. Although most children had up-to-date vaccinations and were exclusively breastfed, these factors did not show a protective effect against disease severity in this study (See Table 4).
After adjusting for confounding factors in the multivariate analysis, maternal age above 20 years was found to be significantly protective against severe ALRTIs (AOR = 0.21, p = 0.030), indicating that children of older mothers had lower odds of developing severe illness. Malnutrition emerged as a significant risk factor for severity, with malnourished children being nearly twice as likely to develop severe ALRTIs compared to well-nourished children (AOR = 1.91, p = 0.045). In contrast, gastroenteritis did not retain a significant association in the adjusted model (AOR = 0.84, p = 0.825), suggesting its effect was not independent when other variables were considered (See Table 5).
Table 4. Association between comorbidities, environmental factors and acute lower respiratory tract infection (bivariate analysis).
Variable |
Severe
n (%) |
Non-severe,
n (%) |
OR (95% CI) |
p-value |
Malnutrition |
|
|
|
|
Yes |
20 (23.5) |
1 (5.0) |
— |
|
No |
65 (76.5) |
19 (95.0) |
0.85 (0.16 - 20.4) |
0.025 |
Meningitis |
|
|
|
|
Yes |
8 (9.4) |
2 (10.0) |
— |
|
No |
77 (90.6) |
18 (90.0) |
0.94 (0.21 - 6.54) |
0.936 |
HIV |
|
|
|
|
Yes |
4 (4.7) |
1 (5.0) |
— |
|
No |
81 (95.3) |
19 (95.0) |
0.94 (0.13 - 18.9) |
0.956 |
SCD |
|
|
|
|
Yes |
3 (3.5) |
2 (10.0) |
— |
|
No |
82 (96.5) |
18 (90.0) |
0.33 (0.05 - 2.63) |
0.242 |
Gastroenteritis |
|
|
|
|
Yes |
11 (12.9) |
3 (15.0) |
— |
|
No |
74 (87.1) |
17 (85.0) |
0.84 (0.23 - 4.020 |
0.049 |
Vaccination up to date |
|
|
|
|
Yes |
72 (84.7) |
17 (85.0) |
— |
|
No |
13 (15.3) |
3 (15.0) |
0.98 (0.21 - 3.36) |
0.974 |
Secondary smoker |
|
|
|
|
Yes |
10 (11.8) |
3 (15.0) |
— |
|
No |
75 (88.2) |
17 (85.0) |
0.76 (0.20 - 3.63) |
0.693 |
Exclusive breastfeeding |
|
|
|
|
Yes |
73 (85.9) |
18 (90.0) |
— |
|
No |
12 (14.1) |
2 (10.0) |
0.68 (0.10 - 2.78) |
0.628 |
Birthweight |
|
|
|
|
<2500 |
16 (18.8) |
4 (20.0) |
— |
|
>2500 |
69 (81.2) |
16 (80.0) |
0.93 (0.29 - 3.57) |
0.904 |
Family size |
|
|
|
|
Overcrowding |
35 (41.2) |
10 (50.0) |
— |
|
Undercrowding |
50 (58.8) |
10 (50.0) |
0.70 (0.26 - 1.88) |
0.474 |
OR = Odds Ratio, CI = Confidence Interval, Non-severe ALRTI: Cough and/or difficult breathing with tachypnea for age, but without danger signs. [Tachypnea thresholds: ≥50 breaths/min (2 - 11 months), ≥40 breaths/min (12 - 59 months], Severe ALRTI: Cough and/or difficult breathing plus at least one danger sign.
Table 5. Factors associated with severity of ALRTIs (multivariate analysis).
Variable |
Bivariate analysis |
Multivariate analysis |
OR (95% CI) |
p value |
Aor |
p value |
Mothers age (>20 years) |
0.27 (0.08 - 1.01) |
0.043 |
0.21 (0.05 - 0.88) |
0.030 |
Malnutrition |
0.85 (0.16 - 20.4) |
0.025 |
1.91 (0.97 - 3.76) |
0.045 |
Gastroenteritis |
0.84 (0.23 - 4.02) |
0.049 |
0.84 (0.20 - 4.52 |
0.825 |
OR = Odds Ratio, CI = Confidence Interval.
The outcomes of the study revealed that the vast majority of children diagnosed with ALRTIs were successfully treated and discharged (97.1%), while 3 children (2.9%) unfortunately died, indicating a relatively low but significant mortality rate associated with severe cases (See Table 6).
Table 6. Outcome on discharge.
Outcome |
Frequency (n) |
Percentage (%) |
Discharged |
102 |
97.1 |
Death |
3 |
2.9 |
4. Discussion
The occurrence of acute lower respiratory tract infections (ALRTIs) among children admitted to Bamenda Regional Hospital was 24.0%. This elevated rate may be attributed to the fact that the research was conducted during the dry season (January to March), characterized by dry, cold, and dusty environmental conditions. Our results align closely with prevalence figures reported by Abduk-Aziz et al., which documented rates of 23.7% in Burundi, 24.2% in Ghana, and 23.4% in Sierra Leone [5]. However, this is lower compared to the 40.3% prevalence found in Ethiopia by Birhanu et al. [8], likely due to differences in the age groups studied, larger sample sizes, and varying study contexts, as well as the 57.5% rate reported in Congo by Owusu et al., possibly influenced by socioeconomic and living condition disparities [5]. Our observed prevalence is higher than that reported by Tazinya et al. in Bamenda (17.35%) [6], 17.4% in Cameroon’s Far North region, and 9.5% in the Northwest region based on Demographic and Health Surveys [9].
Pneumonia was the predominant form of ALRTI, with a prevalence of 19.3%, closely matching the 19.4% reported for Cameroon’s Northwest region by Tchatchou [10] and 19% found in India by Matthew et al. [11]. Bronchiolitis was the second most frequent ALRTI, occurring in 2.5% of cases, consistent with Addisu et al.’s report of 1.9% [12]. This contrasts with a higher 28% reported by Nandimalla et al. in India, which may reflect differences in study populations, as their cohort predominantly consisted of infants, who are more susceptible to bronchiolitis [13]. Bronchitis prevalence was low at 2.3%, comparable to 2% reported by Alok et al. in India [14] and 3% by Birhanu et al. in Ethiopia [8], who noted that most bronchitis cases tend to be mild and treated on an outpatient basis, with fewer requiring hospitalization.
The chief symptoms observed among hospitalized children with ALRTIs were cough (100%), fever (93.3%), and difficulty breathing (69.5%). These symptoms likely arise due to a combination of airway obstruction, immune response, and age-related vulnerability [15]. Similar symptom prevalence was reported by Nandimalla et al. in India (100%, 96.5%, and 92% respectively) [13] and by Alok et al. (96.5%, 93%, and 80%) [14]. Among clinical signs, tachypnea was most frequently recorded (85.7%), followed by hypoxia (42.9%). Most children also exhibited systemic inflammatory response syndrome (85.7%), consolidation syndrome (69.5%), and respiratory distress syndrome (42.9%), reflecting the body’s immune reaction to infection and fluid accumulation in the lungs. To our knowledge, no other studies have documented similar detailed findings.
Chest X-rays were abnormal in 87.6% of patients, with 13.4% showing normal results. The normal radiographs may be explained by the viral etiology of many ALRTIs, as viral infections often produce less pronounced lung consolidation compared to bacterial infections, resulting in either normal or minimally altered X-rays [16]. This abnormal rate is higher than the 70% reported by Bourama et al. in Mali, who noted 30% normal X-rays [17], and substantially exceeds the 42% pathological X-rays found by Bach et al. in children with lower respiratory infections [18]. These discrepancies may stem from differences in radiologists’ expertise and interpretive variability. The most common radiological abnormalities observed were alveolar consolidation (66.7%), bronchial wall thickening (38.1%), and pleural effusion (9.5%). These figures surpass those reported by Alok et al. in India (26%, 8%, and 4%, respectively) [14], but contrast with Bourama et al. in Mali, who observed higher bronchial thickening (75.4%) but lower alveolar consolidation (25.7%) and pleural effusion (0.9%) [17], with no clear explanation provided for these differences.
Bilateral infiltrates were present in 44.3% of cases, similar to the 40.5% reported by Alok et al. in India [14]. This bilateral pattern is likely due to children’s smaller airways, which facilitate the spread of infection throughout both lungs, compounded by immature immune systems leading to more extensive lung involvement [19].
Our bivariate logistic regression identified maternal age, malnutrition, and gastroenteritis as significant factors associated with severe ALRTIs. After adjusting for confounders in multivariate analysis, only maternal age and malnutrition remained significantly linked to severe disease. Children of mothers younger than 20 years faced higher risks of severe ALRTIs, potentially due to younger mothers’ limited experience and knowledge regarding childcare, hygiene, and nutrition—key factors in preventing ALRTIs. Additionally, younger maternal age is linked to a higher incidence of low birth weight infants, who have immature immune defenses and greater susceptibility to respiratory infections. Similar findings were reported by Azad et al. in Bangladesh [20] and Cardoso et al. in Brazil [21].
Malnutrition also showed a strong association with severe ALRTIs, likely because it compromises immune function, increasing vulnerability to infections. This relationship has been underscored in studies by Harley et al. in South Africa [22], Alok et al. in India [21], and Azad et al. in Bangladesh [20].
In this study, 97.0% of children improved, with a mortality rate of 3.0%. The low death rate may reflect the urban origin of most patients, facilitating better access to quality healthcare and timely treatment, thus improving outcomes. This is comparable to the 2.9% mortality found by Alok et al. in India, who also had a predominance of urban patients [14]. Conversely, higher mortality rates have been reported—12.8% by Harley et al. in South Africa where many children were admitted to intensive care [22], and 11.6% by Mohammadreza et al. in Iran, where delayed medical care was common [15]. Early identification of severe symptoms, proper management of comorbid conditions like malnutrition, and parental education are crucial to further reducing mortality.
5. Conclusion
ALRTIs affected 24.0% of hospitalized children in this study. The primary clinical manifestations were cough, fever, and difficulty breathing, with systemic inflammatory response syndrome, consolidation syndrome, and respiratory distress syndrome being the most prevalent syndromes. Radiologically, alveolar consolidation, bronchial thickening, and pleural effusion were the dominant findings. Maternal age under 20 years and acute malnutrition were significant risk factors for severe ALRTIs after multivariate adjustment.
6. Study Limitations
This research only included hospitalized cases, which may overestimate disease severity and affect prevalence calculations. Furthermore, no cultures were performed to identify causative pathogens of severe ALRTIs. Lastly, chest radiographs were interpreted by a single radiologist, which could introduce interpretation bias. The study was conducted exclusively during the dry season, a period associated with higher respiratory infection incidence; this may have led to an overestimation of ALRTI prevalence and limits the generalizability of results across all seasons.
Conflicts of Interest
The authors declare no conflicts of interest.