Management of community acquired pneumonia (CAP) in children: Clinical practice guidelines by the Paediatric Association of Nigeria (PAN

The Paediatric Association of Nigeria first published management guideline for community-acquired pneumonia in 2015 and covered available evidence at that time. This update represents a review of available recent evidence statements regarding the management of pneumonia in children, while at the same time incorporating relevant materials from the first edition of the guideline. The guideline is developed to assist clinicians in the care of children with CAP. The recommendations provided in this guideline may not be the only approach to management, since there are considerable variations among children in the clinical course of CAP.The goal of this guideline is to reduce morbidity and mortality rate of CAP in children by providing recommendations that may be relevant in assisting clinicians to make timely diagnosis and institute appropriate antibiotic therapy of children with CAP. Summarized below are recommendations made in the new 2021 CAP guideline. As part of the recommendations, the quality of the evidence is provided and the grade of the recommendation indicated.The details of the background, methods and evidence summaries that support each of these recommendations can be found in the full text of the guideline.

Risk of congenital cardiovascular anomalies in patients with non-syndromic orofacial cleft: A preliminary case-control study.

BACKGROUND: Orofacial clefts (OCs) are one of the most common craniofacial anomalies and are reported to be associated with congenital cardiovascular anomalies (CCAs). However, there is paucity of data in African populations on the risk of CCAs in OC patients compared to the general population. AIMS: This study aims to determine the odds of congenital cardiovascular anomalies in patients with OC compared to the general population. SUBJECTS AND METHODS: A case-control study design was used. Case subjects were non-syndromic OC subjects, while controls were non-syndromic subjects without OC. All subjects were thoroughly assessed by a pediatric cardiologist for CCAs; and grouped by OC phenotypic type (cleft lip and/or alveolus, cleft lip and palate, cleft palate only and Tessier cleft). Statistical analysis was done using STATA version 14 (College Station, Texas), and significance was placed at P value ≤0.05. RESULTS: A total of 120 subjects (60 cases and 60 controls) were enrolled in the study. In total, 23.3% of the subjects had CCAs. Among the case group, 40% had CCAs compared to 6.7% in the control group. Patent foramen ovale (18.3%) and atrial septal defects (10.0%) were the most common type of CCAs in cases, respectively. Further, cases had significantly higher odds of CCAs compared to controls (OR: 9.3; CI: 2.8, 39.4). CONCLUSIONS: Our finding reveals that the odds of CCAs are significantly higher in patients with OC than the general population. Future studies could assess the effect of CCAs on surgical outcome.

Blood pressure to height ratio as a screening tool for prehypertension and hypertension in adolescents.

BACKGROUND: Current methods of detection of childhood hypertension are cumbersome and contribute to under-diagnosis hence, the need to generate simpler diagnostic tools. The blood pressure to height ratio has recently been proposed as a novel screening tool for prehypertension and hypertension in some populations. We evaluated its applicability in our environment. MATERIALS AND METHODS: The weights, heights, and blood pressure measurements of 2364 apparently healthy adolescents were determined. Sex-specific systolic and diastolic blood pressure to height ratios (SBPHR) and (DBPHR) were calculated, and their ability to detect prehypertension and hypertension was determined using receiver operating curves. Discriminatory ability was measured by the area under the curve (AUC) and optimal cutoff points along the curve were determined. P < 0.05 was considered statistically significant. RESULTS: The SBPHR and DBPHR were similar across all age groups and sexes. The AUC of SBPHR and DBPHR for diagnosing prehypertension and hypertension by sex was >0.95 for both diastolic and systolic hypertension in both sexes. It ranged between 0.803 and 0.922 for prehypertension and 0.954-0.978 for hypertension indicating higher accuracy for hypertension. Sensitivity was higher for systolic and diastolic hypertension (90-98%) compared with prehypertension (87-98%). Specificity was lower than sensitivity across all categories of hypertension and prehypertension (0.64-0.88%) though higher for hypertension (0.75-0.88) compared with prehypertension (0.64-0.75). CONCLUSION: BPHR is a useful screening tool for prehypertension and hypertension in black adolescents. Accuracy increased with higher degrees of hypertension.

National neonatal resuscitation training program in Nigeria (2008-2012): a preliminary report.

BACKGROUND: Routine institutional training of doctors and nurses on newborn resuscitation have commenced, to improve the quality of resuscitation available to high-risk babies, in Nigeria, as a means of reducing newborn deaths in the country. Perinatal asphyxia contributes to 26% of newborn deaths in Nigeria. Perinatal asphyxia results when babies have difficulty establishing spontaneous respiration after birth. MATERIALS AND METHODS: Between 2008 and 2012, doctors and nurses drawn from all the geo-political zones were trained using the Neonatal Resuscitation Training (NRT) manual of the American Heart Association and the American Academy of Pediatrics. Questionnaire-based, cross-sectional surveys of doctor and nurse trainees from the six geo-political zones in Nigeria were conducted eight months after the primary training, to evaluate the post-training neonatal resuscitation activities. RESULTS: Over the period of study, 357 doctors and 370 nurse/midwives were primarily trained in NRT. The overall ratio of step down training was 1:22 with 1:18 for doctors and 1:26 for nurses. In 2008, the delivery attendance rates were 11 per doctor and 9 per nurse/midwife. These rates increased to 30 per doctor and 47 per nurse in 2012. Between 88 and 94% of the doctors and between 72 and 93% of the nurses successfully used bag and mask to help babies breathe in the post-training period. The nurses used bag and mask for infant resuscitation more frequently, compared to doctors, with the rate fluctuating between two-to-one and four-to-one. Over the years, 87 to 94% of the doctors and 92 to 97% of the nurses/midwives trained other birth attendants. CONCLUSION: The NRT in Nigeria is well-subscribed and the frequency of secondary training is good.

Postural hypotension in type 1 diabetes: the influence of glycemic control and duration of illness.

BACKGROUND: Postural hypotension (PH) indicates the presence of cardiac autonomic neuropathy and in diabetes mellitus (DM) is associated with adverse outcome. Nonetheless, PH has been rarely characterized in young persons in Sub-saharan Africa where suboptimal care of DM is prevalent. AIMS: The aim of the study was to determine the prevalence of PH in young patients with type 1DM and its relationship with the duration of DM and glycemic control. SETTINGS AND DESIGN: It was a cross-sectional, case control study carried out in the pediatric out-patient clinic. MATERIALS AND METHODS: Each study participant had blood pressure (BP) measured in the supine and standing positions. Glycated hemoglobin (HbA1c) levels were determined and disease duration was documented. STATISTICAL ANALYSIS: The mean BP in the different positions was determined. The occurrence of PH, duration of disease and HbA1c levels was determined with logistic regression analysis. RESULTS: A total of 26 diabetic subjects and 26 age and sex matched controls were studied. 12 (46.2%) diabetic subjects had evidence of PH while none of the controls had PH. Diabetic subjects with PH had significantly longer duration of DM than those diabetics without PH (6.79 ± 4.81 vs. 2.83 ± 2.36, P = 0.023). The mean HbA1c level was similar in both groups of diabetic subjects (9.79 ± 2.07 vs. 9.17 ± 2.35). On logistic regression, age, duration of disease, HbA1c level and body mass index were not significant predictors of PH. CONCLUSION: PH is common in young persons with type 1 DM, with higher frequency in those with long standing disease.

Double-chambered right ventricle: an uncommon congenital heart disease. Case report and literature review.

A double-chambered right ventricle (DCRV) is a rare congenital heart disease and an uncommon cause of congestive cardiac failure. An anomalous muscle band divides the right ventricle into two cavities, causing variable degrees of obstruction. Echocardiography is considered a useful method for the diagnosis of this pathology, especially in children. An eight-year-old patient with a small ventricular septal defect (VSD) and double-chambered right ventricle presented with a history of palpitations, easy fatigability and recurrent fever. On presentation, she had features of congestive cardiac failure. A complete diagnosis was initially missed with transthoracic two-dimensional (2-D) echocardiography but later obtained based on transthoracic 2-D echocardiography with Doppler facility. This was confirmed with cardiac catheterisation. The patient was referred for surgical correction, which was successful. Due to the rarity of this condition and the consequences of missing the diagnosis, we present this case in order to highlight the rarity of this congenital heart disease in childhood.

Diagnostic usefulness of N-terminal pro-brain natriuretic peptide among children with heart failure in a tertiary hospital in Lagos, Nigeria.

BACKGROUND: N-terminal pro-brain natriuretic peptide (NTproBNP) is useful in the diagnosis and management of adult patients with heart failure. OBJECTIVE: The objective of the study was to determine the usefulness of NT-proBNP in diagnosing congestive heart failure (CHF) in children and its correlation with left ventricular ejection fraction (LVEF) and clinical heart failure score. METHODS: Plasma NT-proBNP was measured in 28 children with CHF and age matched controls. Heart failure assessment was done using modified Ross score and all had echocardiography done. RESULTS: Mean plasma NT-proBNP of children with CHF (377.86±1026.49pg/mL) was significantly higher than that of controls (353.61±328.50 pg/mL) (p<0.001). A plasma NT-pro BNP of 951pg/mL was used as the cut off value for heart failure. The sensitivity, specificity, negative and positive predictive values were 57%, 96%, 69% and 94% respectively. NT-pro BNP levels showed a high positive correlation with the modified Ross score (r= 0.502; p<0.001) but low correlation with LVEF (r= -0.137; p>0.3). CONCLUSION: Our findings indicate that measuring NT-pro BNP may be useful as a diagnostic tool in congestive cardiac failure in children. The fact that its levels also correlated positively with modified Ross score thereby objectively determining severity of heart failure suggests that this biomarker may also be useful as an evaluation tool in congestive cardiac failure in children.

Prospective audit of perinatal mortality among inborn babies in a tertiary health center in Lagos, Nigeria.

BACKGROUND: The perinatal mortality rate remains an important indicator of maternal care and maternal health and nutrition, and also reflects the quality of obstetric and pediatric care available. The causes of most of the perinatal deaths are preventable, thus making it important to identify the risk factors in each health environment. OBJECTIVE: The aim was to prospectively audit the perinatal mortality and associated risk factors in a tertiary health facility in a developing country. MATERIALS AND METHODS: Data for all consecutive deliveries in the labor ward complex of Lagos University Teaching Hospital (LUTH) between June 2002 and November 2002 were obtained from the patients' record and by interviewing the mothers using a questionnaire. The babies were followed up for 7 days post delivery. RESULTS: There were 51 (8.5%) perinatal deaths made up of 43 (7.1%) stillbirths (15 fresh and 28 macerated) and 8 (6.1%) early neonatal deaths giving a perinatal mortality rate of 84.6/1000. Maternal factors that significantly affected perinatal deaths were maternal age, parity, antenatal care booking and the hospital where the mother was booked for antenatal care, number of previous child deaths, and complications of pregnancy. Mode of delivery and complications of labor were the significant intrapartum factors. Fetal factors that influenced perinatal deaths were fetal presentation, birth weight, and Apgar scores at 1 and 5 min. When multiple logistic regression (multivariable analysis) of perinatal mortality on possible risk factors was done, only the Apgar score at 5 min, birth weight, and parity were significant risk factors. CONCLUSION: The study shows a high perinatal mortality rate with majority of perinatal deaths occurring before the delivery. Significant risk factors are a low Apgar score at 5 min, low birth weight, and high parity.

Prospective Audit of Perinatal Mortality among Inborn Babies in a Tertiary Health Center in Lagos; Nigeria

Background: The perinatal mortality rate remains an important indicator of maternal care and maternal health and nutrition; and also reflects the quality of obstetric and pediatric care available. The causes of most of the perinatal deaths are preventable; thus making it important to identify the risk factors in each health environment. Objective: The aim was to prospectively audit the perinatal mortality and associated risk factors in a tertiary health facility in a developing country. Materials and Methods: Data for all consecutive deliveries in the labor ward complex of Lagos University Teaching Hospital (LUTH) between June 2002 and November 2002 were obtained from the patients' record and by interviewing the mothers using a questionnaire. The babies were followed up for 7 days postdelivery. Results: There were 51 (8.5) perinatal deaths made up of 43 (7.1) stillbirths (15 fresh and 28 macerated) and 8 (6.1) early neonatal deaths giving a perinatal mortality rate of 84.6/1000. Maternal factors that significantly affected perinatal deaths were maternal age; parity; antenatal care booking and the hospital where the mother was booked for antenatal care; number of previous child deaths; and complications of pregnancy. Mode of delivery and complications of labor were the significant intrapartum factors. Fetal factors that influenced perinatal deaths were fetal presentation; birth weight; and Apgar scores at 1 and 5 min. When multiple logistic regression (multivariable analysis) of perinatal mortality on possible risk factors was done; only the Apgar score at 5 min; birth weight; and parity were significant risk factors. Conclusion: The study shows a high perinatal mortality rate with majority of perinatal deaths occurring before the delivery. Significant risk factors are a low Apgar score at 5 min; low birth weight; and high parity

Echocardiographic findings among children with sickle cell anaemia at the Lagos University Teaching Hospital.

BACKGROUND: Few studies documenting the echocardiographic findings of patients with sickle cell anaemia have been reported from Africa despite the high prevalence of the disease on the continent. AIMS AND OBJECTIVES: The present study aimed to determine echocardiographic cardiac dimensions and haemodynamic parameters of children with homozygous sickle cell anaemia (SCA), in steady state at the Lagos University Teaching Hospital (LUTH). MATERIALS AND METHODS: Sixty children with SCA and sixty age and sex matched controls with ages ranging from 1-15 years were studied. Their cardiovascular functions were determined by echocardiographic examination. RESULTS: Mean age of SCA patients and controls were 95.41 ± 49.06 months and 95.45 ± 50.9 months respectively (p = 0.97). Mean left atrial dimension (LA), left ventricular end diastolic diameter (LVEDD), left ventricular end systolic diameter (LVESD), left ventricular posterior wall thickness (LVPW), Interventricular septal thickness (IVS) and left ventricular mass (LVM) in SCA patients were significantly larger than those of controls (p < 0.001 for each parameter). Left ventricular fractional shortening (FS) and ejection fraction (EF) were within acceptable normal limits although significantly lower in SCA patients (p < 0.001). The mean haemoglobin concentration in the subjects (77.23 ± 12.88) was significantly lower than in the controls (121 ± 16.09) (p < 0.001). Each direct echocardiographic parameter (LAD, AO, LVEDD, LVESD, IVS, LVPW and LVM) correlated significantly with age in both groups while left ventricular functional parameters (FS and EF) did not in both groups. Chamber dimensions, LVPW, FS and EF were inversely correlated with haemoglobin concentration in the subjects.

Echocardiographic Features of Rheumatic Heart Disease in Lagos

Rheumatic heart disease (RHD) is a global scourge; resulting in significant morbidity and mortality. Our aim is to report on the prevalence; and complications of RHD; as documented by echocardiography in a Nigerian tertiary health facility. We performed a retrospective study of RHD patients; who had trans-thoracic echocardiography studies within the 2 year period of January 1st 2001-December 31st 2002. Data obtained included age; sex and echocardiographic diagnoses; and parameters. Of the 987 patients; 53 had chronic RHD; thus; the prevalence was 5.4. Male female ratio was 1: 1.8 and their average age was 30.1 years. Commonest indication for study was congestive heart failure (68). One; two and three valves were affected in 45 (85); 7 (13); and 1 (2) respectively. Valves involved were mitral - 49 (93); aortic - 18.6; and tricuspid 2 (7.5) respectively. Mixed mitral stenosis/regurgitation (42) was the commonest lesion; and complications included right ventricular overload (20); thromboembolic risk (20); and heart failure (70). RHD is still prevalent in Lagos; Nigeria and associated with grave complications. Valvular involvement remains unchanged as the mitral valve still is the most commonly affected valve but there seems to be an increasing prevalence of mixed mitral valve disease thus making management more challenging. Comprehensive hospital registers for rheumatic heart disease and community based studies are needed to establish the current prevalence

Congenital heart diseases associated with identified syndromes and other extra-cardiac congenital malformations in children in Lagos.

BACKGROUND: Congenital heart diseases are commonly associated with other extra cardiac congenital malformations. OBJECTIVE: To identify congenital heart diseases associated with identified syndromes and other extra cardiac congenital malformations in children in our hospital. METHODS: A prospective descriptive study done on children with congenital malformations referred to the Lagos University Teaching Hospital, Nigeria (LUTH) for echocardiographic evaluation. A thorough 2D assessment of the chambers, septa, heart vessels and concordance of the atrium and ventricle and the great vessels was made. Echo-cardiographic data obtained included M mode direct measurements of dimensions of left atrium, aortic root, right ventricular outflow tract, left ventricle in diastole/systole, wall thicknesses--right ventricular wall, interventricular septum, left ventricular posterior wall. Fractional shortening was derived from M mode data. Final diagnosis of the congenital heart disease was recorded. RESULTS: A total of 101 children with congenital malformations had echocardiography studies done as part of their clinical evaluation, 15 (14.9%) were neonates, 53 (52.5%) infants 25 (24.8%) were aged one to five years and 8 (7.9%) were above five years of age. Recognised syndromes were seen in 69 (68%) cases. Down syndrome with 54 children contributed 78.3% of those with known syndromes. Other identified syndromes and associations were Marfan's, Noonan's, Edwards, Prune Belly, Apert, Ellis-van Creveld syndrome and congenital rubella syndrome. Congenital heart diseases were detected in 73 (72.3%) patients while 28 (27.7%) had no heart defect. The commonest identified congenital heart disease was ventricular septal defect affecting 30 (29.7%) patients. CONCLUSION: Congenital heart diseases are common in children with congenital malformations. Down syndrome was the most common malformation and the congenital heart disease most associated with the congenital malformations was ventricular septal defect. This study emphasizes the need for cardiac assessment of children with congenital malformations.

Marfan syndrome: a study of a Nigerian family and review of current cardiovascular management.

BACKGROUND: Marfan's syndrome is a connective tissue disorder inherited as an autosomal dominant disorder. It causes a myriad of distinct clinical problems, of which the musculoskeletal, cardiac, and ocular system problems predominate. Nearly 50 percent of patients have to undergo aortic surgery in their lifetime resulting in reconstruction or replacement of the aortic root or total of this vessel's parts. OBJECTIVE: To describe a Nigerian family with multiple cases of Marfan syndrome and discuss current cardiovascular management of the syndrome. MATERIALS: Detailed history, clinical and laboratory investigations including ophthalmologic assessment and echocardiography were carried out on all members of a nuclear family of a child who reported with complaints of poor eye sight later diagnosed to have Marfan syndrome. RESULTS: Diagnosis of Marfan syndrome was made in three members of the nuclear family--a father and his two children following eye examination of one of the children. Afollow up cardiovascular assessment revealed that the father required aortic surgery while the two children also had aortic root dilatation. CONCLUSION: This report underlines the importance of a detailed history, physical examination and family study in patient assessment. Current cardiovascular management in Marfan syndrome involves a blocker therapy and an annual cardiovascular evaluation involving clinical history, examination and echocardiography. Prophylactic aortic surgery should be considered when aortic diameter at the sinus valsalva exceeds 50 mm.

Structural heart disease in children in Lagos: profile, problems and prospects.

OBJECTIVES: Structural heart disease (SHD) contributes significantly to the health burden of children in Nigeria, unfortunately comprehensive cardiovascular programme including definitive surgery is currently not available locally. This may have contributed to the paucity of research in paediatric cardiology. Available epidemiologic data are limited and mostly outdated. We studied the current distribution SHD in Lagos and compared findings with reports elsewhere. Problems and prospects associated with cardiovascular care at the study site were highlighted. MATERIALS AND METHODS: Children referred from public and private health facilities for cardiovascular evaluation including echocardiography between January 2004 and December 2005 were studied. PDA in premature babies, PFO and post surgical SHD were excluded. Proportions and relative frequencies of different heart lesions were calculated and analysed using appropriate statistics. RESULTS: Congenital heart disease (CHD) significantly outnumbered acquired heart disease (AHD) (p=0.0001) in these children aged 4 weeks to 15 years (mean age = 3.8 +/- 2.5 years); the relative frequencies were VSD (41.7%), VSD (41.7%), ASD (20.2%), TOF (11.8%), AVCD/ECD (7.0%), PDA (5.7%), PS (3.1%), single ventricle and TGA (2.2%) each. PS was dominant in males, while septation defects were dominant in females. Pericarditis with effusion (31%), RHD (28.6%), myocarditis (14.3%) and dilated cardiomyopathy (14.3%) were the commonest AHD. CONCLUSION: Contrary to previous hospital reports CHD rather than RHD and other AHD are dominant in some African settings like Lagos, and their relative frequencies are similar to reports elsewhere. The wide range of children with diverse native CHD is a reflection of non-availability of definitive surgical facilities locally. Regional and International collaboration could be mutually beneficial.

Holt-Oram syndrome with hypoplastic left heart syndrome in an African child.

This report illustrates the rare association of Holt-Oram syndrome with hypoplastic left heart syndrome hitherto unreported in an African child. The above association is highlighted as this child and the only other case reported in a Caucasian were diagnosed post mortem. The need for early cardiovascular and genetic evaluation or simple detailed family history to aid counselling is also emphasised.

Outcome of low birth weight neonates in a tertiary health care centre in Lagos, Nigeria.

The records of all low birth weight (LBW) neonates admitted into the Neonatal Unit of the Lagos University Teaching Hospital (LUTH) from January 1997 to December 2001 were retrospectively analysed in order to determine the outcome and risk factors associated with mortality. There were 535 LBW admissions of which 411(76.8%) survived while 124(23.2%) died. The birth weight specific mortality rate for the < 1000g neonates was 818 per 1000, 451 per 1000 for the 1000-1499g, 216 per 1000 for the 1500-1999g, and 67 per 1000 for the 2000-2499g neonates (X2 = 127.70, p = 0.0001). Primary indications for admission were neonatal sepsis (25.2%), perinatal asphyxia (23.0%) and neonatal jaundice (19.6%) with case fatality rates of 20.0%, 34.1% and 10.5% respectively (X2 = 34.24, p = 0.00001). Death occurred within 48 hours of admission in 45.2% of subjects and by the 7th day, 72.6% had died (X2 = 70.07, p = 0.0001). Significant risk factors associated with mortality were birth weight [OR 4.24, 95% CI = 3.14-5.72] and category of LBW [OR 2.79, 95% CI = 1.65-4.69]. Sex, twinning, booking status and mode of delivery had no significant influence on mortality. Since the provision of adequate intensive care for these vulnerable infants remains a major challenge in countries with poor resources, efforts should be intensified to implement effective strategies for the reduction of low birth weight deliveries.

The impact of an intervention to change health workers' HIV/AIDS attitudes and knowledge in Nigeria: a controlled trial.

The aim of the study was to improve health workers' skills and confidence in dealing with patients with HIV disease and increase attention to patients' human rights. A longitudinal controlled trial was carried out in which one Nigerian state served as the intervention site and the adjacent state served as the control site for an intervention and dissemination of training in clinical management, health education, and attitudinal change toward patients with HIV disease. The intervention group n=1072, control group n=480. Following initial questionnaire-defining focus groups, nurses, laboratory technologists and physicians in all base hospitals in the intervention state were trained by influential role models who attended the initial training. Data were collected in all sites pre-training and 1 y later. Hierarchical multiple regression analysis controlling for baseline data, and orthogonal factor analysis to define scales were used. Data showed significant positive changes after 1 y in the intervention group on perception of population risk assessment, attitudes and beliefs about people with HIV disease, less fear and more sympathy for and responsibility toward HIV patients, and an increase in self-perceived clinical skills. There was increased willingness to treat and teach colleagues about people with HIV. Clinician fear and discrimination were significantly reduced, and the climate of fear that was associated with HIV was replaced with a professional concern. There was increased understanding of appropriate psychosocial, clinical and human rights issues associated with HIV treatment and prevention. This intervention, targeting health workers in an entire state and using HIV/AIDS information, role modeling, diffusion of training and discussions of discrimination and human rights, significantly affected the perception of risk groups and behaviors, perceived skills in treatment and counseling, reduced fears and increased concern for people with HIV disease, and improved the climate of treatment and prevention of HIV disease compared with a control state.

Acute bacterial meningitis in a developing country: diagnosis related mortality among paediatric patients.

OBJECTIVES: To evaluate the effect of late diagnosis and other factors on outcome of paediatric bacterial meningitis (BM) and recommend appropriate intervention. DESIGN: Case series. SETTING: University of Calabar Teaching Hospital, Calabar, Nigeria. SUBJECTS: 62 consecutive BM patients aged two months to 16 years admitted between 1991 and 1994. MAIN OUTCOME MEASURES: Mortality rate. RESULTS: Diagnostic difficulties experienced in 58% of cases and other factors resulted in delayed diagnosis and high mortality (20 to 47%). CONCLUSION: Only elimination of the identified inadequacies in management can significantly reduce the BM-related high mortality in developing countries.