ORIGINAL

Niger J Paed 2015; 42 (3):188 –193

Ahmed PA

Yusuf KK

Dawodu A

Childhood acute lower respiratory

tract infections in Northern

Nigeria: At risk factors

DOI:http://dx.doi.org/10.4314/njp.v42i3.3

Accepted: 2nd March 2015

Abstract: Background: Child-

hood Acute Lower Respiratory

Tract Infection (ALRTI) remains

an important public health prob-

lem in the developing world, with

significant morbidity and mortal-

ity a challenge. An understanding

of risk factors in the development

of childhood ALRTI may offer

clues to prevention of the disease;

identify conditions that lead to

progression to severe disease,

complications and even death in a

child receiving treatment.

Results: A total of 50 children

aged 2-60 months were enrolled,

92.0 % had pneumonia while 8.0%

had bronchiolitis. 86.0% of pneu-

monia subjects were 24months and

below, while all those with bron-

chiolitis were infants. 43(86.0%)

of subjects were hospitalized in the

rainy season. The weights for

height z score was less than minus

2 in 12 (24.0 %) of the subjects.

Significant risk factor for ALRTI

was the use of kerosene and solid

fuel for domestic cooking, 33

(66.0%), p value 0.0001; Mortality

was four percent among the in-

fants.

(

)

Ahmed PA

Yusuf KK, Dawodu A

Department of Paediatrics,

National Hospital Abuja.

Nigeria.

Email: ahmedpatience@yahoo.com

Aim: to determine risk factors for

ALRTI among Under five chil-

dren hospitalized.

Methods: A prospective study of

children aged 2-60 months admit-

ted into hospital with diagnosis of

pneumonia and bronchiolitis from

November 2011 to September

We conclude that younger age

under 24 months and exposure to

hydrocarbon and biomass from

indoor pollution was contributing

risk factors for ALRTI in Under

five children.

2

012 at the National Hospital,

Abuja, Nigeria. With a question-

naire data on socio- demographic

and potential risk factors for AL-

RTI were obtained.

Key words: Acute lower respira-

tory tract infection, risk factors,

hospitalization, under-five.

6

Introduction

15 years . The WHO Child Health Epidemiology Refer-

ence Group (CHERG) estimated the median global inci-

dence of clinical pneumonia to be 0.28 episodes per

Acute lower respiratory tract infection (ALRTI),

primarily pneumonia and bronchiolitis remains a major

cause of childhood morbidity and deaths worldwide

Of the estimated 7.6 million deaths in children younger

than five years worldwide in 2010, infectious diseases

caused 68 percent (5·970 million), with the largest per-

centages due to pneumonia; 18percent, 1·575 million

Approximately one-half of children younger than five

7

child-year . This equates to an annual incidence of 150.7

1

, 2

.

million new cases, of which 11-20 million₇(7-13%) are

severe enough to require hospital admission .

Several definite risk factors have been attributed to

ALRTI, that include low birth weight for age of less

than 2500 grams, prematurity, incomplete immunization

against common childhood diseases especially within

the first 12months of life, malnutrition of weight -for -

age- z -score ≤ 2, lack of exclusive breast feeding in the

first six months of life, indoor air pollutants from

domestics biomass fuel, presence of coughing sibling₈_-(₁s₂)

1, 2

.

years of age with community-acquired pneumonia

3

(

CAP) would requ₄ ire hospitalization .

Oyejide CO et al gave an acute respiratory tract infec-

tion annual incidence rate of 6.1 to 8.1 episode per

year in under five children from a low socioeconomic

5

community in Nigeria, and Yilgwan CS et al reported

at home, overcrowding in bedrooms and schools

.

that 50 percent (39/78) of the children admitted with

ARIs were under five children. In a large community-

based study conducted by Denny and Clyde, the annual

incidence rate of pneumonia was 4 cases per 100 chil-

dren in the preschool-aged group, 2 cases per 100 chil-

dren aged 5-9 years, and 1 case per 100 children aged 9-

Other likely risk factors are parental experience as care

giver, presence of concomitant disease such as sickle

cell anaemia, asthma, HIV/AIDS, diarrhoea diseases and

zinc deficiency, while possible risk factors are maternal

education, rainfall (humidity) and altitude (cold

weather), vitamin A deficiency, attendance to day care,

1

89

8

-12

outdoor pollution and birth order . These risk factors

for ALRTI could be further categorized as either envi-

ronmental or constitutional. Maternal education, expo-

sure to fumes/ smoke, exposure to siblings with respira-

tory infections and dampness in the home as environ-

mental, while constitutional determinants would include

were recorded. Weight and height were measured and

weight for age and height for age - z- score calculated

using WHO standards chart for children aged 0-5 years.

All subjects were followed up for at least 6months after

discharged from admission at the paediatric respiratory

clinic of the department. Informed written or oral con-

sent was obtained from the parents and the study was

approved by the National Hospital Abuja Ethics Com-

mittee. Data was analyzed and means, standard devia-

tion, percentages and tables described for continuous

variables, and categorical variables were described using

a Chi square test with a p value level of 0.05 set as sig-

nificant.

13

gender, atopic predisposition and ethnicity .The agents

for most bronchiolitis and pneumonias in children pre-

senting for emergency care are respiratory syncytial

virus (RSV), Streptococcus pneumonia (SP), and Hae-

mophil₇u_-₁s₂influenzae type b (HiB) outside the neonatal

period . Most children treated with ALRTI have mild

to moderate disease and are treated as outpatients with

full recovery. However, when pneumonia is severe or

very severe, hospitalization is indicated, especially

among young infants in the presence of danger signs and

compromised immunity, to reduce mortality. Mortality

rates from respiratory tract infections are not only more

prevalent but more severe, accounting for more than 2

million deaths annually with pneumonia being the num-

Results

A total of 50 children aged 2 to 60 months were re-

cruited for the study. 50 (M 24, F 26) were admitted and

treated for ALRTI (pneumonias 46, bronchiolitis 4). The

four subjects with bronchiolitis were aged 10 weeks (F),

three months (M, F) and seven months old (M). Of the

22 males with pneumonia, 14(63.6%) were aged 2-

8, 14

ber one killer of children in developing societies

.

The aim of this study therefore was to determine associ-

ated risk factors for ALRTI among hospitalized Nigerian

children.

1

2months; 7(31.8%) 13- 24 months; while of the 24

females, 14(58.3%) were aged 2-12months and 8

33.3%) were aged 13- 24months. Forty three (86.0%)

(

Subjects and Methods

of the study subjects were aged 24months and below,

with none above 49 months. The mean ± SD weights

and heights for subjects aged 2-12months was 7.06

±1.30kg and 65.81 ± 6.20cm for all males and 6.73

±1.97kg and 65.63 ±7.39cm for females. The weights

and heights distribution for both males and female did

not show any significant differences (tables 1and 2).

Seven (29.2%) of the males had a weight for height z

score < -2.0, while 5(19.2%) of the females had weight

for height z score < - 2.0. The peak period of ALRTI

hospitalization was between the months of May to Octo-

ber, height of the rainy season, with 43(86.0%) admis-

sions.

The study was prospective and descriptive of children

aged 2 to 60 months old, conducted from November

2

011 to September 2012 at the National Hospital Abuja,

Nigeria. The hospital is a 350-bed hospital with 80 pe-

diatric beds that provides care for the general public,

both inpatient and₅outpatient care. The calculated mini-

1

mum sample size was 34. The statistical analysis was

both descriptive and inferential at 95% confidence inter-

val, zset at 1.96; p, prevalence taken as 4.35% (Yilgwan

5

CS et al report on ALRTI in under five children) d,

tolerable error at 0.05. A total of 50 children were en-

rolled consecutively with a diagnosis of ALRTI by the

principal investigator or a colleague paediatrician. Acute

lower respiratory tract infection was diagnosed in a child

with history of fever, cough, fast or difficult breathing,

chest wall in drawing and abnormal auscultation lung

finding (crackles/ crepitations or bronchial breath

sounds)₈_,₁w₆_-₁i₈th or with an abnormal chest radiographic

Table 1: Age, Sex and Weight Distribution of ALRTI Subjects

Ages

months)

No

(%)

Male

Mean ±SD

Wt(kg)

Female

Mean± SD

Wt(kg)

P

value

95% CI

(

2

1

-12

28(56)

15(30)

7.06 ±1.3

6.73±1.97

0.5376

0.8637

.033(-0.7559 –

to 1.4159)

0.1(-1.1336 to

3-24

9.1±1.17

9.59±1.02

1.3336)

finding

. Chest radiograph finding were evidence of

2

5-36

5(10)

2(4)

13.5±0.3

14±0

11.6±2.26

12.5±0

0.3432

1.9(-7.7435 to

-7.7485)

abnormal pulmonary parenchyma disease as docu-

mented by a radiologist. Patients with recurrent wheeze

or previous admissions for pneumonia were excluded in

view of possible asthma, recurrent pneumonia cases or

tuberculosis. Tachypoea was defined as respiratory rate

of 50 breaths per minute or more for children 2-12

months and 40 breaths per minutes or more for children

37-48

The weight distribution of the males and female subjects did

not show any significant difference in table 1

Table 2: Age, sex and height distribution of ALRTI subjects

17

Ages

month

s)

No (%)

Male Mean

±SD

Ht(cm)

Female Mean±

SD

Ht(cm)

P

value

95%CI

aged above 12 months to 60 months . Pulse oximeter

measures less than 90% oxygen saturation was defined

(

17

as hypoxia . Upon recruitment, with a structured ques-

tionnaire for each subject, information on the subject’s

age, sex, immunization status, breastfeeding history,

including parental educational level and occupation,

family religion, housing type and exposure to smoke

2

1

2

3

-12

28(56)

15(30)

5(10)

2(4)

65.81±6.2

80.29±6.65

94±4

65.63±7.39

81.43±6.67

94±1.63

0.9454

0.7461

1

0.18(-5.1683

to 5.5283)

3-24

5-36

7-48

-1.14(-8.5857

to 6.3057

0.0(-7.7435 to

7.7485)

105±0

103±0

1

90

The Height distribution of the males and female subjects did

not show any significant difference in table 2.

insertion for drainage. Repeat chest radiograph at four

weeks follow up showed complete resolution of paren-

chyma lesions. There were two deaths, a male and fe-

male, from pneumonia, aged six months and below

Overall breast feeding rate was 96.0, p value <05; 15

(

30.0%) were exclusively breast fed for 6months and

(

table5).

mean duration for ever breastfeeding was 9.12 ± 5.55

months. 92.0%, p value <0.5; had completed immuniza-

tion for age according to the National Programme of

Immunization (NPI) schedule. 4(8.0%) of family mem-

bers had a history of smoking tobacco, use of multivita-

min supplementation, 10(20%); while use of kerosene or

fire wood/ coal as cooking fuel was 66.0%; p value <

Table 4: Socio- economic as risk factors for ALRTI in

Subjects

2

Variable

Mean ± SD; N

(%)

x

P value

0.3726

Mother’s Age (years)

Father’s Age (years)

Parental Education

Primary

30.80 ± 6.06

38.63 ± 7.17

1.976

0

.05. The religion of the families were 13(26.0%) Islam,

and 37(74.0%) Christians; p value 0.0022. Housing

types was 94.0% western; p value <0.05; 43(86%) of the

families were urban settlers (table 3).

Father

4(8)

Mother

7(14)

Secondary

Father

Mother

14(28)

12(24)

Table 3: Risk and benefit Factors for ALRTI

Tertiary

2

Variable

No 50

(%)

x

P value

95%CI

Father

32(64)

Mother

31(62)

Number of people in the

home

5.70 ± 2.56

Ever breastfed

48(96) 29.524 <0.0001*

0.8654 to

0.9889

1

5(30%had ex

Bf for

months)

Rooms in the home

2.10 ± 1.18

No in home

1-3

6

8(16)

>

SEC1

SEC2

SEC3

3-≤6

6

30(60)

12(24)

26(52)

16(32)

8(16)

Immunization

46(92) 28.227 <0.0001*

0.3297 to

0

.596

2

x

P value

0.300685

Smoker in the

house

4(8)

0.973

0.3304

0.0315 to

0.1884

7.2234 ,df

6

Multivitamin

usage

Kerosene/wood 33(66) 9.084

usage

10(20) 4.867

<0.0001*

0.1124 to

0.3304

0.2159 to

0.4683

SEC –socioeconomic levels 1, 2, and 3. *The socioeconomic

status show a significant difference; (p<0.05) as shown in table

4

Christianity

Islam

Mud

37(74)

13(26) 3.1

3(6)

0.0022*

Table 5: Distribution of the Clinical features

Clinical features

Western

Urban

47(94) 4.7

43(86)

<0.0001*

Number

50

49

Percent

100

98

Fever

Cough

Semi urban

Rural

1(2)

6(12)

Crackles

49

98

Fever

Chest in-drawing

Pallor

46

17

4

44

55.54 ± 15.69

92

34

8

*

Significant, (p<0.05) shown in table 3

The mean maternal age was 30.80 ± 6.06 years, while

2.0% of the fathers and 67.0% of the mothers had edu-

Cyanosis

7

Abnormal Chest xray

Tachypoea (cycles/min)

Mean ±SD

88

cational level post secondary, while average number of

people in the homes was 5.70 ± 2.56, and 30(60.0%)

having >3-≤6 person per room. 26 (52.0%) families

were from socioeconomic classes (SEC) 1, 16(32.0%)

SEC2 and 8(16.0%) SEC3, p value 0.30068, x 7.2234,

df 6 (table 4).

Heart rate (beats/min) Mean

135.56 ±19.10

±SD

2

Pneumonia

Bronchiolitis

Deaths

46

4

2

92

8

4

Major clinical features were fever, cough, chest crack-

les, tachypoea and tachycardia with abnormal chest x-

ray findings shown in table 5. Mean ± SD respiratory

rate (RR) was 55.54± 15.69 for all patients. The RR was

significantly higher for those below 12 months,

Table 6: showing the Respiratory rate (RR) and Heart rate

HR) of the age groups of the children with ALRTI

(

Ages

-12 months

12-59months

Mean RR

N

Std. Deviation

Fisher’s exact

Sig

2

61.43

48.05

28

22

15.074

13.311

10.747

0.002*

>

Total

Ages

55.54

50

N

15.690

(

p=0.002) shown in table 6. Mean heart rate (HR) for all

Mean HR

138.93

131.27

Std. Deviation

17.668

Fisher’s exact

2.020

Sig

0.162

patients were 135.56 ± 19.10. HR was not significantly

difference between the ages 2-12 months and 12-59

months.

2

-12 months

12-59months

Total

28

22

>

20.392

135.56

50

19.104

Forty four (88.0%) patients had abnormal chest radio-

graphs. Two had repeated convulsions with Spo2 levels

below 85.0%. Pneumothorax, emphysema and pleural

effusion were found in two each, who had chest tube

*

with ALRTI (p=0.002), while HR was not significantly differ-

ent between the children ages 2-12 months with those age 12-

The RR was significant for the children 12 months and below

5

9 months shown in table 6.

1

91

Discussion

feeding followed by continued breast feeding and an

appropriate complementary feeding has been shown to

protect young infants against respiratory tract infections,

while a lack of breast feeding predisposing young in-

This report was hospital based to investigate risk factors

associated with ALRTI. Acute lower respiratory tract

infection, mainly pneumonias and bronchiolitis have

been previously highlighted as a common cause of

childhood morbidity and mortality encoun₁_,t₂e_,₅r_-e₈d_,₁₁i_,n₁₇_,₂s₀e_,₂v₁-

8

-12

.

fants to pneumonias and diarrhea diseases

Com-

pared with breastfed infants, formula-fed infants have

been shown to face higher risks of infectious morbidity

in the first year of life, because they lack specific and

innate immune factors provided in human milk which

protect against infection, particularly against the com-

mon respiratory pathogens, such as H₄_,₂a₅emophilus influ-

eral children emergency care settings

Similar to other reports

percent of children with pneumonia aged two years and

below, while bronchiolitis remaining a disease of in-

fancy. In the Yilgwan CS et al report on 39 Under five

children hospitalized with acute respiratory infections

.

this report had 86

5

,12,17, 20- 22

,

2

enzae and Streptococcus pneumonia . Reported vac-

cination rates among study subjects was over 90 percent

(p value <0.05), mainly covering the six antigens used in

the National programme on immunization schedule. An

effective immunization would be expected to protect

children from respiratory tract infections such as pertus-

sus and measles and invasive diseases. However, the

immunization coverage during the period of study did

not include the routine use of pentavalent vaccine that is

inclusive of pneumococcal antigens and Heamophilus

influenza type b. These agents have been shown to con-

tribute significant₈l_,₁y₁_,₂to₆ childhood pneumonias and other

(

ARIs), bronchiolitis was among infants; while those

with pneumonia were mostly 0-11 months old,

2.1percent; 12- 36 months, 72.7 percent and all (100

4

5

percent) aged 36 months . Our report did not record any

patient above 49months old. Symptoms of fever, cough,

fast and difficult breathing, convulsions; with signs of

tachypnoea, tachycardia, chest in-drawing and crackles,

and abn₅_,o₈r_,₁m₆_,₁a₉l chest x-ray findings, were similar to other

reports

recommends the use of increased respiratory rate as

early sign for diagnosis of pneumonias . The mean ±

SD respiratory rate in this series was 55.54 ± 15.69 for

all patients and 61.43 ±15.07 for 2-12months olds (p

value 0.002).

. The World Health organization (WHO)

17

invasive diseases

, Evidence show that a significant

reduction in pneumonias can be achieved with the penta-

valent vaccine in children and HIV positive individu-

26,27

als

.

This report show that tachypoea was significant for

ALRTI in the 28 (56.0%) patients aged 2-12months

when compared to those above 12months. A rapid respi-

ration in infants should be considered a high point for

suspicion and early treatment of ALRTI in infants. This

view is supported by the WHO guideline for diagnosis

and management of childhood acute respiratory infec₂-₂

The socio-economic class of the parents was not a sig-

nificant risk factor in this report (p value 0.30065). This

can be deduced from the findings of over 65 percent of

mothers having post secondary education, non- over-

crowded living conditions as 76 percent of home have

one to six persons in a room, and 52 percent families are

of upper social class, who mainly are urban dwellers,

living in western type housings. Only 24 percent having

more than six occupants in a room. Exposure to indoor

smoke from use of hydrocarbon and solid domestic fuel

was found a significant environmental risk for respira-

tory tract infections , though exposure to passive smok-

ing from tobacco use was low. Other environmental risk

factors such as role of day care and siblings contact were

not assessed in the present study as limitations. The

rainy season weathers are associated with drop in ambi-

ent temperatures when most of the patients were en-

rolled (86.0 percent). Home dampness in the presence of

moulds, water leakages, and moisture on walls and ceil-

ing were not assessed, but a few families in the present

study lived in mud type housing and in rural settings

which would contribute to dampness during the rainy

season.

17

tions . However, an earlier report by Tagbo BN et al

on 101 children of which 52 (51.5percent) had radio-

logical evidence of pneumonia, 38 (73 percent) had res-

piratory rate ±50/minutes, while 43 (83 percent) had

respiratory rate ±40/minutes. They found respiratory

rate to be least reliable as an indicator of pneumonia in

children 2-11 months (p value >0.005). They suggested

that it was due to wide variation in respiratory rates in

the younger child compared to those aged 12-35 months

13

(

p value <0.005) where it was highly sensitive predictor

of pneumonia. An abnormal radiological finding in pa-

tients with pneumonia was found in 44 (88 percent) in

this report. This is much higher than the WHO reported

3

4.3 percent rate for clinical diagnosis of radiographic

pneumonia in child₃ren presenting to a pediatric emer-

2

gency department . Severe pneumonia with danger

signs were seen among the subjects. The presence of

severe or very severe disease is an indication for hospi-

This report shows that some of the ALRTI patients were

stunted, with weight for height z score less than minus

two. Malnutrition has been highlighted as a significant

cause of childhood illnesses that include pneumonia.

This can be as micronutrient or macronutrient deficien-

cies. Vitamin D has been shown to both increase the

severity and overall prevalence of acute lower respira-

tory infections and is an important factor in determining

the mortality rates from severe forms of respiratory

17

talization in childhood pneumonia . However, hospi-

talization can be affected by parents’ care seeking be-

havior, access to hospitals, financing, and medical pro-

fessionals’ threshold for admission wh₆ ich varies widely

1

within and across geographic settings .

Breastfeeding rate was over 90 percent, (p value <0.05)

with exclusive breast feeding of six months in 15

28

infections .

(

30.0percent). An adequate period of exclusive breast

1

92

Another earlier report found vitamin D deficiency in

consistently higher among younger children aged less

than 18 months .

2

9

12

infants exclusively breast fed . Micronutrients deficien-

cies may be multiple, many of which function as cofac-

tors or regulatory molecules in immune or₀inflammatory

3

cascades (e.g. vitamins C, D, selenium) . However,

these deficiencies will further predispose to anaemia in

childhood. This supports the several micronutrient inter-

ventions programs in use to both protect and prevent

children from developing acute lower respiratory infec-

tions. The aetiology of malnutrition in the present study

was not assessed. Thirty four percent of the study sub-

jects had clinical pallor which would contribute to mal-

nutrition. There were two deaths among infants with

very severe pneumonia. Sewlyn et al also reported that

the incidence and case-fatality of ALRTI were

Conclusion

Young age of less than 24months, exposure to solid

fume from indoor pollutants, are important risk factor

for subjects with ALRTI among those hospitalized.

Conflict of interest: None

Funding: None

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