Determinants of community-acquired pneumonia among children aged from 2 to 59 months in Fitche General Hospital: a case control study

Background: Globally, every 39 seconds a child dies because of pneumonia. Pneumonia is one of the most common causes of morbidity and mortality among under-ve children in sub-Sahara African countries. The deaths of children from pneumonia diseases are more frequent than any other infectious disease. Risk factors of pneumonia were not completely identied in Ethiopia, particularly in the study area. Therefore, this study aimed to identify the determinants of community-acquired pneumonia among children aged from 2 to 59 months. Methods: Institutional based unmatched case-control study was employed among 246 (123 cases and 123 controls) participants in Fitche General Hospital March 2018. Data were collected using a pre-tested and standardized questionnaire, and anthropometric measurements. A systematic random sampling technique was used to select control and cases were selected consecutively. Data were analyzed using Statistical Package for Social Science Version 20. Multivariable binary logistic regression analysis was performed, and variables with a P-value <0.05 were considered statistically signicant. Results: Cases of 123 children diagnosed with pneumonia and controls of 123 children without pneumonia were brought to Fitche General Hospital (FGH). Malnutrition [AOR=2.85, 95% CI:(1.61,6.08)], children who were not exclusive breastfeeding in the rst six months of their life [AOR=3.22, 95% CI: (1.61, 5.52)], number of occupants more than 5 people who live in one house [AOR=2.01, 95% CI: (1.04, 4.65)], use of charcoal for cooking in the house [AOR=1.56, 95% CI: (1.04,4.18)] and use of wood for cooking in the house [AOR=2.59, 95% CI:(1.22,6.46)] were signicantly associated with community-acquired pneumonia. Conclusion: This study identied malnutrition, children who were not exclusive breastfeeding in the rst six months of their life, number of occupants more than 5 people who live in one house and use of wood and charcoal for cooking in the house were found among the major risk factors for pneumonia.

Intervention targeted to early identifying and treating malnutrition, encouraging exclusive breastfeeding practices, and preventing use of wood and charcoal for cooking in the child house is compulsory for children well being.

Background
Globally, pneumonia is one of the leading causes of morbidity and mortality among under-ve years of children. 1 Pneumonia is an acute respiratory infection that affects the human lungs; the lungs are made up of small sacs called alveoli, which lled with air when every person breathes. 2 When an individual has pneumonia, the alveoli are lled with pus and uid, which makes breathing painful and limits oxygen intake. 3 Worldwide, Pneumonia is one of the leading killers of children every 39 seconds and accounted for 800,000 deaths of under-ve children every year. 4 In low-resourced countries, pneumonia responsible for greater than 150 million new cases and 1.3 million preventable deaths each year. 1,5 In south Asia and sub-Saharan Africa, pneumonia kills an estimated 922,000 children in 2015 which 15% of all deaths are under ve years old. 6 Ethiopia ranked 27 th in under-ve mortality with 119 deaths per 1,000 live births. 7 Almost one in every ten babies born in Ethiopia does not survive to celebrate the rst birthday. 8 Pneumonia, diarrhea, malaria, measles, AIDS, and sepsis are the most common diseases that causing under-ve deaths, 85% in Africa and 90% in Ethiopian. 6 In Ethiopia, pneumonia is a leading single disease killing under-ve children. 9 Annually around 3,370,000 children encounter pneumonia contributing 20% of deaths for under-ve children. 10 In our previous ve-year retrospective study on mortality of pediatrics, pneumonia was the rst rank of the top ten diseases of mortality. 11 Pneumonia has many possible causes, but the most common etiology of community-acquired pneumonia in children under-ve years of age are bacteria and viruses. The most common causes of bacterial pneumonia are Streptococcus pneumoniae, causing more than 76% of bacterial pneumonia cases. 12,13 Approximately 73% of community-acquired pneumonia in children is caused by viruses; Respiratory syncytial virus is the predominant viral pathogen of childhood pneumonia, accounting for 28% of incidence in under-ve children. 14 On the other hand, deaths from pneumonia are higher in poor rural communities as a result of household air pollution, which depend on solid fuels (wood, dung or charcoal) for cooking or heating, overcrowded homes, and less likely to be immunized against measles and whooping cough, exposure to tobacco smoke, and malnutrition. 6, [15][16][17][18] The mortality of children is easily preventable and treatable through simple and cost-effective interventions. 19 Immunization, exclusive breastfeeding, appropriate complementary feeding, and proper hygiene are among preventive method [20][21][22] while the administrations of amoxicillin and/or antibiotic treatment are the curative methods which can save lives of children. 19 In Ethiopia a few studies done and little is known about the risk factors of community-acquired pneumonia. 17 However, evidence-based identifying risk factors, appropriate intervention, and accurate methods of child health care are relatively scarce in North Shoa Zone Oromiya region. So far, there are no studies done regarding the determinant of pneumonia and interventions among under-ve children in the study area. Therefore, this study aimed to identify the determinant of community-acquired pneumonia among children aged from 2 to 59 months at FGH.

Study Design, Setting and Period
An institutional-based unmatched case-control study design was used to assess the determinants of pneumonia in children aged between 2 to 59 months at FGH March 2018. Fitche General Hospital is a 102 bed Hospital located approximately 114 km from Addis Ababa in the Fitche District of the North Shoa Zone of Oromiya. It is one of the government hospitals in the Oromiya Regional State. It serves more than 1.6 million people and is a referral center for 57 Health Centers and 297 Health Posts from North Shoa Zone.

Study population
The study population consisted of children aged between 2 to 59 months and their mothers or caregivers at FGH with pneumonia (case) and those who come without pneumonia (control). The study enrolled mothers or caregivers of children aged between 2 to 59 months that are cases and controls.
Cases were de ned as a child aged 2 months to 59 months who received a positive diagnosis of pneumonia by trained pediatricians according to the World Health Organization (WHO) Integrated Management of Childhood Illness (IMNCI) guideline adopted by Ethiopian government. [23][24][25] Controls were defined as a child aged 2 months to 59 months who brought to FGH with other than respiratory complaints (who came for immunization and growth monitoring service). Cases and Controls were recruited within the same facilities, period, and age group. The study excluded children belonging to the same household either cases or controls and mothers or caretakers who have hearing impairments.
Sample size calculation and sampling procedure Sample size was determined using Epi Info version 7.2 software Stat Calc menu for unmatched case control study. By considering a 95% con dence level, 80% of Power, 1:1 ratio of controls to cases, 23.8% percent of controls exposed, 2.25 odds ratio, and 41.3% percent of cases with exposure. Through reviewing previous studies, the overcrowding is an exposure variable for pneumonia that gave the highest sample size 123 of cases and controls. 16 The total estimated number of pneumonia patients (cases) for six months was 792 from the pediatric outpatient department (OPD) and the emergency department. Taking the average number of pneumonia cases per month (792/6 = 132), all cases were selected consecutively during data collection until the required number of cases was obtained. Conversely, 5,178 controls from growth monitoring and expanded program of immunization (EPI) units were visited in the last six months based on the registration book. The average number of controls for one month (5,178/6 = 863) and the sampling fraction of control was (863/123=7). A systematic random sampling technique was used to select the study control every seven intervals. The rst participant was selected by the lottery method from 1 st to 7 th and continued every other control until we nalized the calculated sample size.

Data collection tools and procedures
Data were collected by four trained professional nurses using face-to-face interviews with a pre-tested and standardized questionnaire. The questionnaires were developed objectives based on a different literature review. 16,17,18 It contains socio-demographic factors (age of the child, sex of child, residence, marital status of mother or caregiver, educational status of the mother or caregiver, religion, monthly income), and house factors (radio or TV in the house, number of house room and number of participants who live in the same house, the type of oor, and type of roof). It also contains childhood illnesses (history of vaccination, history of measles infection, history of HIV, and previous history of acute respiratory tract infections were reviewed from the child document). Additionally, the questionnaires contain indoor pollution factors (type of fuel energy used, cigarette smoker in the house, presence of kitchen, kitchen detached from the main house), nutritional status (exclusive breastfeeding and malnourished), and place of delivery were assessed. The questionnaire adopted by the English language and translated to the local language (Affan Oromo and Amharic), and back translation was done to see the consistency of the questionnaire. Pretest was done among a sample of 24 (12 cases and 12 controls) children age between 2 to 59 months at Kuyu General Hospital in the North Shoa Zone of Oromia region. The collected data were analyzed, reviewed and correction made for the nal version of the questionnaire.
Anthropometric measurement was done using a standardized and calibrated measuring tools for weight (recorded using analog weight scale to the nearest 0.1 grams) and height (to the nearest 0.1 centimeters), and mid-upper arm circumference (MUAC) was also measured using a MUAC tape-record to the nearest 0.1 centimeters. The outcome was measured according to the de nition of WHO for pneumonia, age between 2 to 59 months with symptoms of cough or di cult breathing and fast breathing and/or chest in-drawing. 20 Data processing and analysis The collected data were cleaned and checked for completeness; then it was entered, compiled, and analyzed by using the Epi Info for data entry and SPSS software for analysis. Percentages and simple frequencies of the given data were calculated for each variable to describe the ndings. Additionally, tables were used to assist data presentation. Bivarible logistic regression analysis was carried out to select variables for multivariable binary logistic regression. Variables with P value ≤ 0.2 in the bivariable analysis were included in a multivariable logistic regression analysis to control the confounding effect among the variables. In multivariable analysis, a p-value of less than 0.05 was considered statistically signi cant, and adjusted odds ratios with 95% CI were calculated to determine the association.

Results
Greater than three-fourth of cases and controls were between 2 to 23 months old. Majority 71(57.7%) of cases and 83(67.5) of controls were living in urban areas. Males were the majority 55.3% of cases and 52.0% of controls. Greater than one-third 42(34.2%) of cases and one-fourth 35(28.5%) of controls were mothers or caregivers who were illiterate. Greater than three-fth of study participants had earned monthly income more than 750 Ethiopian birr (table 1).
The majority of the study participants, 84(68.3%) of cases, and 79(64.2%) of control were fully vaccinated and 63.4% of cases and 85.4% controls had exclusive breastfeeding. Eighty-seven of 123 cases and 106 of 123 controls delivered at health facilities and 100(81.3%) of cases and 103(83.7%) of controls of mothers or caregivers had exposed their child to sunlight properly. Twenty-nine (23.6%) of cases and nine (7.3%) controls had malnourished and 4.9% of cases and 6.5% of controls had a history of measles infection. Thirty-nine percent of cases and 43.1% of controls had a history of upper respiratory tract infection (table 2). Table 3 shows that the potential house and indoor pollution-related risk factors for pneumonia among the study participants. More than half of the study participants had a radio, but half of them did not have television. Forty-eight cases and 37(30.1%) of controls were living in two rooms, and greater than half of the cases were living in houses occupied 3 to 5 occupants. Among the types of cooking fuels used, wood was the most common type of fuel used in cases 78(63.4%) and controls 54(43.9%). Greater than twothirds of cases and three-fth of controls were living in houses with their oor being soiled. The majority of study participants were used iron sheets in their house roofs. Cigarette smoking had practiced in the study participant's house among 22% of cases and 14.6% of controls. Greater than one-fourth of cases and one-fth of controls kitchens were not detached from the main house (table 3).

Factors associated with community-acquired pneumonia
Variables that ful ll bivariate criteria or p-values less than 0.2 were simultaneously included in multivariable logistic regression. The number of occupants who live 3 to 5 in one house and home delivery were variables that adjusted in multivariable logistic regression (

Discussion
Acute respiratory infection, particularly community-acquired pneumonia is the foremost cause of death in resource limited-countries in children aged between 2 to 59 months. Identifying and addressing the risk factors for pneumonia are potentially open to appropriate intervention of public health importance. In this study, risk factors have been trying to identify which may have implications for health intervention programs.
Nutritional de cits may result from any combination of insu cient caloric intake, lack of protein, and inadequate levels of micronutrients. 26 We found malnutrition was signi cantly associated with community-acquired pneumonia. This is in line with the study done in Southwest Ethiopia. 17 This may be due to impaired immunity caused by poor micronutrition and macronutrition. A previous study has been reported that impaired cellular immunity in malnourished children makes them more prone to respiratory tract infections. 27 Inadequate nutrition in-utero and during infancy and early childhood is closely linked to lifelong immune de ciencies and acute respiratory infections. 28,29 Acute respiratory infections generally occur more frequently, last longer, and are more severe in malnourished children. 30 Typically, the mucous membranes and other mechanical structures designed to keep the respiratory tract clear are impaired, and the immune system has not developed properly in children. 3,31 We found that not exclusive breastfeeding was signi cantly associated with pneumonia. This result is in line with WHO comparative impact assessment of child pneumonia in 2009 which is a 15 times greater risk of death from pneumonia if not breastfeeding in the rst 6 months. 32 Breastfeeding has great bene ts for children to prevent health problems and built all systems. Maternal-milk used for transferring to infants maternal innate immune components (lactoferrin, lysozyme, secretory IgA), in uences of breast milk on immune-system matures, and enhancement of the antibody response to pathogens. 33 It offers vital protection against pneumonia-related mortality. The study suggests that children who are not breastfeeding could be at greater risk than children who are either exclusively or even partially breastfeeding. 22,34 This shows that not exclusively breastfeeding can be the risk factors for the development of child illness.
Crowding favors the propagation of microbial agents of respiratory tract infections that have been easily transmitted through family living in one house. Colonization of the respiratory tract of children by potential pathogens is almost universal in resource-limited countries. 2 In our study, more than 5 occupants living in the same house of children were found signi cantly associated with communityacquired pneumonia. This nding is similar to studies done in Southwest Ethiopia, and Northwest Ethiopia. 17,18 Also case-control study done in Brazil found that a linear increased the risk of pneumonia mortality with increasing people in a child's bedroom and an increasing number of occupants in the house. 35 Other studies conducted in the Northwest of Ethiopia and Pakistan were not found an association between pneumonia and the number of occupants in one house. 36, 37 This is due to different in socio-demographic factors and number of occupants.
Our results suggest that a child whose parents used wood and charcoal for cooking was statistically signi cant with pneumonia. This study is in line with the study nding from WHO that show increased household pollution contributed to increasing lower respiratory infection mortality. 38 Exposure to indoor household solid fuel used for cooking and the proliferation of cheap fossil-fuel-based energy has led to much greater exposure to community-acquired pneumonia in low resourced countries. 38,39 In resourced countries socio-demographic index, indoor air pollution tends to decrease as cooking shifts from biofuels to natural gas and electric stove. As a result, there is a small association with lower respiratory infection risk. 40 Despite this improvement in lower respiratory infection, improving air quality is a worthwhile goal for cognitive development, asthma, and other respiratory and cardiac outcomes. 41 Limitation of the study First, this study is limited in terms of generalizability since the study was conducted in restricted to Fitche General Hospital setting. The second limitation could be the diagnosis of pneumonia, which was based on the clinical WHO IMNCI classi cation guideline, which could introduce misclassi cation bias. Thirdly, the participants were questioned mainly about the socio-demographic characteristics, housing condition, child care practice, maternal awareness, and events that have happened not more than two weeks ago related to the child illness to minimize recall bias but still, there could be.

Conclusion
This study suggested that malnutrition, children who were not exclusive breastfeeding in the rst six months of their life, the number of occupants more than 5 people who live in one house and use of wood and charcoal for cooking in the house were found among the major risk factors for developing community-acquired pneumonia for children aged from 2 to 59 months. Even though, pneumonia is an easily preventable disease, nevertheless, it still remains the leading cause of morbidity and mortality, especially in the aged between 2 to 59 months of children. Furthermore, intervention targeted to early identifying and treating malnutrition, encouraging exclusive breastfeeding practices, and preventing use of wood and charcoal for cooking in the child house is compulsory for children well being.

Declarations
Ethics approval and consent to participate Ethical consideration: This study was conducted in accordance with the Declaration of Helsinki. Ethical approval was gained from Salale University College of Health Sciences Ethical Review Committee; regarding written and ngerprint consent, the privacy and con dentiality of the patients, risk and bene t analysis of the study (Ref.No. CHERC/025/2018, February 20/2018 was approved. A formal letter of request for permission was submitted to FGH and permission was granted. All subjects were asked voluntary for informed written and ngerprint assent from mothers or caregivers of children after they were introduced to the purpose of the study. All the reasons why the subject was chosen and why the research was done and the right to withdraw at any time from the study were explained to the study subjects. Additionally con dentiality of all the data to be gained will be seriously maintained.

Consent for publication N/A
Availability of data and material The data for this study are cannot be made publically available at the present time. It will be made available from the corresponding author when reasonable request.

Competing interests
The authors declare that they have no competing interests.

Funding
This research work is funded by Salale University. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Authors' contributions
All authors contributed to data analysis, drafting or revising the article, gave nal approval of the version to be published and agreed to be accountable for all aspects of the work.