Acute laryngotracheobronchitis in Nigerian children.

In a prospective study of cases of severe acute respiratory infections seen at the University College Hospital, Ibadan over a 30-month period, 39 cases were found to have acute upper airway obstruction; out of this number, acute laryngotracheobronchitis (croup) accounted for 35 (90%). The ages of the 35 ranged from 2 to 53 months with 86% being less than 3 years old, while there was a male preponderance (M:F ratio, 1.7:1). Croup was associated with bronchopneumonia in 29%, measles in 2.9%, and with both in 40% of the 35 cases. The mean respiratory rate in patients in whom croup co-existed with measles and pneumonia was significantly higher than that in patients with croup alone (P < 0.001). Six (55%) of the eleven viral identifications made were Parainfluenza virus types 1-3, while Respiratory syncytial virus was identified in three patients. Of the 18 blood cultures done, only one was positive, yielding Klebsiella pneumoniae in a two-year old undernourished child with associated measles and bronchopneumonia. Mortality was 11%; all the four children who died had associated bronchopneumonia, which complicated measles infection in three. The findings in this study support the view that antibiotic therapy is not routinely indicated in the management of croup. Furthermore, measles and bronchopneumonia were identified as indicators of poor prognosis requiring extra care in management.

Acute bronchiolitis in tropical Africa: a hospital-based perspective in Ibadan, Nigeria.

In a 30-month prospective study of severe acute lower respiratory infections in hospitalized pre-school Nigerian children, acute bronchiolitis was diagnosed in 67 cases; 19 (28.4%) and 2 (3.0%) of these had concomitant pneumonia or croup, respectively. The peak prevalence was in the wet (rainy) season (May-October). The male/female (M:F) ratio in infants < or = 6 months was 2.9:1, differing significantly from the 1.1:1 in older subjects (P = 0.04). None of the subjects had severe malnutrition. Neither a high fever (> or = 39 degrees C), nor tachypnea on admission was significantly correlated with co-existing pneumonia. Of the 29 subjects in whom it was possible to explore viral immunofluorescence studies and/or serodiagnosis, we identified 26 viral identifications in 18 (62.1%) cases; 6 (20.7%) had > or = 2 viruses. Respiratory syncytial virus was identified in 11 (38.0%) of the 29 cases, and parainfluenza virus (PIV) types 1, 2, and 3 in 10 (34.5%). PIV type 3 accounted for 7 cases, including 3 with bacteremia. Bacterial isolates were made in 9 (21.4%) of 42 blood cultures and in the only lung aspirate; Staphylococcus epidermidis and Staphylococcus aureus accounted for 4 and 3 cases, respectively. Although bacteremia was 2.9 times more common in cases with co-existing pneumonia or croup, the respective frequency of virus-positive cases and that of bacteremia was not significantly different between cases with bronchiolitis alone and those with associated pneumonia or croup. No deaths were recorded, but subjects aged > 6 months had a significantly shorter hospital stay than those < 6 months old (P = 0.02). Despite the limited sample size, our findings reflect the etiological importance of the paramyxoviruses and the seasonal pattern of bronchiolitis in tropical Africa.

Microbial inciters of acute asthma in urban Nigerian children.

BACKGROUND: In tropical Africa the role of microbial agents of acute respiratory infections in acute exacerbations of bronchial asthma remains largely unexplored. However, empirical antibacterial therapy is frequently initiated in moderate to severe cases of acute asthma with symptoms of acute respiratory infection. A study was set up to determine how often acute respiratory infection is associated with acute asthma, to identify the associated pathogens, and to proffer appropriate therapeutic suggestions. METHODS: Over a 16 month period, 86 episodes of acute asthma were studied for clinical and laboratory features of acute respiratory infection at the University College Hospital (UCH), Ibadan. Virological diagnosis was based on immunofluorescence studies of nasopharyngeal aspirates and/or serological tests using the microtitre complement fixation technique. Throat swabs and blood were cultured for bacterial agents. RESULTS: Of the 64 cases who presented with rhinorrhoea, 51 (79.7%) were pyrexial (T > or = 37.6 degrees C). Inflammatory changes (frequently interstitial streakiness) were identified in 10 (19.6%) of the 51 chest radiographs; only two of these had lobar shadowing. Significant bacterial isolates were made in only three (3.5%) of the throat swabs and two (2.4%) of the blood cultures from the 86 cases; none had clinical septicaemia. On the other hand, 55 viral agents were identified from 39 (53%) of the 74 subjects studied; 16 (41.0%) had dual viral identifications. Respiratory syncytial virus (RSV) accounted for 20 (36.4%) identifications, parainfluenza virus (PIV) type 3 for 15 (27.3%), and influenza type A (Flu A) for 12 (21.8%). Viral identifications were significantly higher in infants and preschool subjects (< 5 years) and in those presenting with either rhinorrhoea or pyrexia. CONCLUSIONS: The results of this study underscore the importance of viral upper respiratory infections in asthma exacerbations in a tropical setting. The paucity of clinical and investigative features of bacterial acute respiratory infection suggests that there is little rationale for routine antibiotic cover in children with acute exacerbations of asthma in the tropics.

Respiratory syncytial virus--associated lower respiratory diseases in hospitalised pre-school children in Ibadan.

An analysis of the features of lower respiratory diseases (LRD) associated with Respiratory Syncytial Virus (RSV) in 21 children aged 1-23 months, indicated that the clinical features did not differ appreciably from those described for LRD due to other infective agents. It was however, remarkable that none of the children was grossly malnourished, neither was there any death. The final respiratory diagnoses were bronchiolitis alone (6 cases), bronchopneumonia (6 cases), empyema/pleural effusion (3 cases, including one with bronchopneumonia), lobar pneumonia (3 cases, including one with associated bronchopneumonia). Streptococcus pneumonia and Klebsiella pneumoniae respectively, were isolated from blood culture in the two cases with lobar pneumonia alone. One child had laryngotracheobronchitis (croup) alone and another, croup associated with bronchiolitis and bronchopneumonia. Radiologically, the single most common lesion was patchy consolidation (8 cases) followed by hyper-inflation (6 cases); in one case, there was no observable lesion on the chest radiograph. All the 6 children who had bronchiolitis alone were aged 12 months and below, and were well nourished; conversely, 8 of the 12 children with pneumonia alone or in addition to other lesions and both children with pleural effusion, were older than 12 months and underweight. Other viral agents were identified in 8 (38%) of the cases. Complications included heart failure in 4 cases and a combination of anaemia and heart failure in one child with empyema. In a child with symptom complex and radiological features suggestive of acute obstructive lower respiratory infection with immunofluorescence evidence of RSV infection, age and nutritional status are important factors in determining the need for antibiotic therapy pending the outcome of bacterial cultures.

Acute lower respiratory infections in hospitalised urban pre-school Nigerian children: a clinical overview.

One hundred and three hospitalised urban pre-school Nigerian children aged 2 weeks to 4 years with various acute lower respiratory tract infection (ALRI), were studied prospectively over a 9- month period (August 1985 - April 1986). Overlapping seasonal peaks, corresponding to the rainy/early harmattan months of August through November were most noticeable for the two major viral ALRI syndromes namely, bronchiolitis and croup. The overall M:F ratio was 1.1:1, but a corresponding ratio of 1.6:1 was recorded in the infants. The commonest ALRI symptoms were cough, breathlessness and fever while chest wall retraction, nasal flaring, tachypnoea and auscultatory crepitations were the most frequently recognised physical findings. Grunting respiration was recognised in 26 patients, majority of whom had pleural effusion and/or severe bronchopneumonia. Bronchopneumonia was the single commonest ALRI diagnosis, recorded alone or in combination with another lower respiratory syndrome, in 64 (61.2%) of the 103 cases. The croup:bronchiolitis: pneumonia ratio was 1:2.3:8.3. Nasopharyngitis was recorded in 42 (40.7%) of cases, and was frequently associated with the presumably viral ALRI syndromes of croup and bronchiolitis. Pleural effusion, frequently purulent, was the commonest respiratory complication, while heart failure and anaemia were the most frequently recognised associated conditions, found predominantly in patients with pneumonia and bronchiolitis. There was an overall ALRI case-fatality of 7.8%, representing 8 deaths, in 3 of whom measles was a co-morbid condition. All the 8 deaths had a final diagnosis of pneumonia with or without other ALRI syndromes/associated complications. While subjects with complicating pleural effusion recorded the longest mean duration of hospitalisation, those with bronchiolitis had the shortest duration of hospitalisation and no death. The epidemiologic, as well as the diagnostic and therapeutic implications of our observations are discussed.

Staphylococcal lower respiratory infection in children.

A prospective study of staphylococcal lower respiratory infection in 31 children aged 1-48 months has shown that radiologically, patchy consolidation was the single most common lesion, followed by pleural effusion with or without pneumothorax. Although the mean respiratory rate was 65/minute, it was below 50/minute in 8 cases. Complications include heart failure in 9 cases and severe anaemia necessitating blood transfusion in 9 others, seven (78%) of whom had pleural effusion. Finally diagnoses were bronchopneumonia alone in 16 (52%) cases, pyopneumothorax alone in 6 (19%), pyopneumothorax plus pneumonia in 5 (16%), pleural effusion in 2 (6%) cases and one case each of lobar pneumonia alone and a combination of lobar and bronchopneumonia. Staphylococcus aureus was isolated from the blood in 8 (62%) of 13 children with pleural effusion, indicating a need to consider parenteral antibiotic administration in the initial management of children with staphylococcal pleural effusion. Three (9.7%) patients died; they were all malnourished children who did not receive antibiotics prior to presentation; they all had bronchopneumonia, positive blood cultures and respiratory rates of 60/minute.

Bacterial aetiology of acute lower respiratory infections in pre-school Nigerian children and comparative predictive features of bacteraemic and non-bacteraemic illnesses.

In a 9-month surveillance of the microbial agents causing acute lower respiratory infections (ALRI) in hospitalized preschool Nigerian children, 24 bacterial isolates were made from 22 (33 per cent) out of 66 blood cultures, including seven (70 per cent) of the 10 cultures from subjects with pleural effusion. Of the 24 positive isolates, Staphylococcus aureus accounted for 14 (58 per cent), Klebsiella pneumoniae for four (17 per cent), Streptococcus pneumoniae and Staphylococcus albus for two (8 per cent) each, and Haemophilus influenzae for only one case. Seven subjects had a mixed aetiology, comprising one bacteraemic case with measles and six with concomitant viral identifications. Sixteen cases, 10 (63 per cent) of whom were malnourished, had two or more pathogens, including 10 with multiple viruses. Bacterial isolates from the throat, were not significantly predictive of the ALRI aetiology. Overt malnutrition, empyema, and anaemia, were significantly commoner in bacteraemic cases (P < 0.03, 0.01, and 0.05), while rhinorrhoea and crepitations were each associated with the non-bacteraemic ones. (P = 0.05 and < 0.05). A similar association was shown between rhinorrhoea, wheezing/rhonchi and the mixed aetiological group (P < 0.05 and 0.05, respectively). The case-fatality in bacteraemic subjects, was 9 per cent and was 2.1 times higher than that for non-bacteraemic cases, in whom a shorter mean duration of admission was recorded. In developing countries, the need for periodic local surveillance of ALRI pathogens, as a prerequisite for evolving rational antimicrobial policies, is emphasized. Our findings underscore the predictive importance of malnutrition as a risk-factor of severe bacteraemic ALRI, frequently associated with multiple pathogens. The relative usefulness of blood culture in identifying bacterial agents of ALRI is discussed.

Viral pathogens of acute lower respiratory infections in pre-school Nigerian children and clinical implications of multiple microbial identifications.

In a prospective study of acute lower respiratory infections (ALRI), at the University College Hospital, UCH, Ibadan, 35 viral pathogens were identified by immunofluorescence (IF) techniques from 24 (68.6%) respiratory specimens from 35 hospitalised pre-school children. The respiratory diagnoses comprised croup, bronchiolitis, pneumonia and pleural effusion. The viral identifications comprised 14 (40.0%) of parainfluenza virus type 3, 10 (28.6%) of respiratory syncytial virus (RSV), 5 (14.3%) of influenza virus type A, 4 (11.4%) of parainfluenza virus type 1 and 2 (5.7%) of influenza virus type B. Two or more viral agents were identified in as many as 10 (41.7%) of the 24 IF positive secretions, 8 (80.0%) of which were obtained from children with features of protein energy malnutrition. Twenty subjects had both virological and bacteriological analyses, in 8 (40.0%) of whom co-existing bacteraemia was identified. Four (50.0%) of these blood culture positive subjects, also had features of overt malnutrition. Neither the age nor the sex was significantly related to the viral identifications (P > 0.81 & 0.35 respectively). Similarly, the final respiratory diagnoses were not significantly related to the viral identifications despite the seemingly suggestive relationship between a diagnosis of croup and parainfluenza identifications as well as that between pneumonia and RSV/parainfluenza type 3 identifications. It is concluded that the high proportion of positive viral identifications is a pointer to the importance of viruses as possible primary etiological agents of ALRI in countries of the West African sub-region and perhaps in developing countries of other tropical subregions. The multiplicity of microbial identifications (viruses and bacteria), seen in malnourished children, may explain the clinical severity of ALRI in the same group of children. The usefulness of IF as a rapid diagnostic tool, as well as the potential implications of our findings on ARI control in developing countries, are discussed.

Host factors and acute lower respiratory infections in pre-school children.

The relationship between certain host-related variables and the short-term outcome of hospitalization for severe acute lower respiratory infections was studied prospectively in a cohort of 103 pre-school Nigerian children. The respective mean ages of those with bronchiolitis and croup were 3.2 months and 18.9 months while the corresponding M:F ratios were 2.5:1 and 1:1. It was highly significant that all the eight children that died were malnourished (P less than 0.01). Furthermore, malnourished subjects with pleural effusion, in whom bacteraemia was common, stayed longest in hospital while subjects with bronchiolitis and croup, in whom malnutrition was distinctly uncommon, had the shortest duration of admission. Multiple microbial identifications and bacteraemia were common in malnourished subjects with ALRI. Mortality was significantly higher in older children (P less than 0.05), but sex, immunization/breast-feeding status and co-existing measles or pertussis, were individually neither related to the admission outcome nor the duration. It is concluded that malnutrition is a strong predictor of ALRI-related death in the pre-school child. The significance of bacteraemia and multiple microbial identifications in malnourished children, and the ARI-control implications of the study are discussed.

The association of household pollutants and socio-economic risk factors with the short-term outcome of acute lower respiratory infections in hospitalized pre-school Nigerian children.

In a 9-month study of acute lower respiratory infections (ALRI), the short-term prognostic implications of socio-economic and household risk factors were examined in 103 hospitalized pre-school Nigerian children. Seventy-nine (77%) subjects were potentially exposed to the combustion products of kerosene stoves, 16 (16%) to wood smoke and five (5%) to the products of cooking gas combustion. Only 17 subjects (17%) were exposed to household cigarette smoke. A highly significant association (p < 0.005) was shown between household cooking fuel and the outcome of hospitalization: five (63%) of the eight who died were potentially exposed to wood smoke. The duration of hospitalization was only significantly associated with paternal income (p < 0.05). None of the other domestic risk factors was significantly related to outcome or duration of admission. These findings suggest an association between an adverse outcome of ALRI and domestic exposure to wood smoke. While the hospital-based source will not allow definite conclusions, the present findings underscore the need for community-based studies. The implications for future strategies of ARI control are discussed, with suggestions.

Plasma vitamin C (ascorbic acid) levels in asthmatic children.

Plasma concentration of ascorbic acid was determined in fifty-one asthmatic children and a group of matched controls. The mean ascorbic acid level of 0.54 mg/100 ml among the asthmatics was significantly lower than a mean of 0.84 mg/100 ml for controls (P less than 0.001). Ascorbic acid level was directly related to the socio-economic class (SC) since asthmatic children from SC I, II and II had significantly higher ascorbic acid levels than those from SC IV and V. There was however, no relationship between the plasma ascorbic acid level and atopy, frequency of asthmatic attacks over the previous 12 months and the duration of asthma. It is postulated that if plasma ascorbic acid level was related to the susceptibility to viral respiratory tract infections, the observed low level of the vitamin in the asthmatics would make them more liable to such infections which are capable of precipitating acute asthmatic attacks. Confirmation of our results would indicate the need for regular ascorbic acid supplement in some children with bronchial asthma.

Serum alpha 1-antitrypsin levels in asthmatic children.

Serum levels of alpha 1-antitrypsin (AAT) were determined by an enzymatic assay method in fifty-five asthmatic children and in the same number of controls. The mean AAT level was significantly lower in asthmatics (1.65 mumol/min/ml) than in controls (2.0 mumol/min/ml) (P less than 0.02). A significantly higher proportion of asthmatics than controls (P less than 0.05) had levels below 2.1 mumol/min/ml which is the lower limit of normal, thus suggesting a higher prevalence of partial (heterozygous) AAT deficiency in the asthmatics. There was no relationship between the mean AAT levels and age, duration of asthma or frequency of asthmatic attacks. Although there is some controversy about the relationship between heterozygous AAT deficiency and pulmonary disease, severe (homozygous) AAT deficiency has been linked with emphysema which is also a complication of asthma. There was however, no evidence of emphysema in either the asthmatic child or the control who had no detectable serum AAT. There were three asthmatics whose chest radiographs showed hyperinflation, but had a mean AAT level that was not significantly different from that in those without such changes. Further studies, including phenotype determination in a larger group of asthmatic children, are required in order to determine the prevalence of both homozygous and heterozygous AAT deficiencies which may be risk factors in the development of emphysema and other pulmonary complications of asthma.

Electrocardiograms in children with bronchial asthma.

Electrocardiograms (ECG) from 124 asthmatic children were analysed with a view to defining the cardiac complications of bronchial asthma. Thirty-three percent of the patients had airway obstruction when the ECG were recorded; yet none had any significant cardiac arrhythmia. The P waves and P-R interval were each normal in all but one patient. One patient had right-ventricular hypertrophy (RVH), but in twenty-five others (20%) R waves suggestive of left-ventricular hypertrophy (LVH) were recorded in V5-6. The ST segment was elevated in seventeen patients (14%) and depressed in twelve others (10%), most of whom had suffered from severe asthma for 3 or more years. These findings confirm the rarity of RVH in bronchial asthma, and also imply that serious arrhythmias in asthmatic children should not be perfunctorily ascribed to airway obstruction; other causes of arrhythmia should be sought. We advise that beta-agonist bronchodilators should be cautiously prescribed to asthmatic Africans who may be rendered more susceptible to the arrhythmogenic tendency of such drugs by an underlying LVH.

Serum IgG, IgA and IgM in asthmatic children.

Serum levels of immunoglobulins G, A and M were determined in forty-five asthmatic children and in the same number of controls. Mean IgG and IgA levels in the asthmatics were not significantly different from those in the controls. Conversely, mean IgM values in female controls and all the controls taken as a group, were significantly higher than those in their asthmatic counterparts. There was no relationship between severity of asthma and the mean levels of the various immunoglobulins. However, the mean IgG value in asthmatic children with positive skin sensitivity tests was significantly higher than the mean value in those who had negative reactions. It is concluded that the serum levels of these immunoglobulins are of limited value in either the diagnosis of asthma or in the grading of its severity.

Ventilatory capacity in Nigerian school children.

Forced expiratory volume in one second (FEV1.0) and forced vital capacity (FVC) were determined in 1001 healthy Nigerian school children, aged between four and 16 years. The results were analysed with respect to the ages, heights, weights and body surface areas of the subjects. Among the variables used, weight showed the best correlation with FEV1.0 in both sexes and with FVC in males. Conversely, height showed the best correlation with FVC in females. However, the differences between these correlations were not significant. The median values obtained were lower than those reported in caucasian children at all height levels, but similar to the only available data in the literature for African children. Median FEV1.0 and FVC values were higher in males than in females at most ages, particularly the younger ones. Formulae for the medians and corresponding 2.5 and 97.5% points have been produced, using either height or weight as independent variable.

Observations on some aetiological factors in Burkitt's lymphoma.

A prospective study of the socio-economic status and physical growth of seventy-six children aged 3-10 years, with Burkitt's lymphoma (BL), has revealed that most of the patients were from the lowest socio-economic classes. Majority of the fathers were farmers, labourers or petty traders. The BL children were, as a group, significantly lighter in weight and shorter than controls. It is postulated that although the weights were probably adversely affected by the illness itself, the shorter heights which were most likely present before the onset of the illness, indicated chronic undernutrition. This, together with a low level of immunization would predispose the children to frequent infections, including malaria. Frequent infections would thus condition the reticuloendothelial system to be more susceptible to the lymphoproliferative properties of the EB virus, resulting in malignant changes such as Burkitt's lymphoma.

Ascaris and bronchial asthma in children.

Skin tests with the Ascaris antigen were carried out in 270 children with bronchial asthma and 220 controls. Faecal and sputum specimens were also examined for helminths. Twenty-seven per cent of the asthmatic children had positive reactions to the Ascaris antigen compared with 8% of controls (P less than 0.001). The positive reactions were, however, not related to the sex of the patients, severity of asthma, the presence of Ascaris ova in the faeces or the blood eosinophil counts. Larvae of helminths were not found in sputum specimens examined. While the present study indicates a possible association between Ascaris and asthma in children, further studies, including provocation tests and controlled anthelminthic drug trials, are required to confirm, as well as elucidate this association. It is however, suggested that routine screening for helminthiasis be undertaken in asthmatic children in the tropics and deworming carried out in those with positive results.

Plasma cortisol responses to cortrosyn treatment in asthmatic children.

Treatment trial over a period of 3 months was conducted with intermittent intramuscular injections of Cortrosyn depot in fourteen children with severe and frequent asthmatic attacks. The basal plasma cortisol levels were generally high, but higher than normal in four (29%) of the patients. At a period of 24 h after the initial Cortrosyn injection was administered, plasma cortisol increases ranging between 4-52 micrograms/100 ml above the basal levels were recorded. At a period of 1 week after the end of daily injections for 1 week, increases of plasma cortisol ranging between 3-71 micrograms/100 ml above the basal levels were observed and presumed to be a reflection of an associated adrenal hypertrophy resulting from repetitive daily Cortrosyn injections. The highest increases at this stage were observed in the youngest patients with the severest asthmatic attacks, but not in their older counterparts. At the end of the trial treatment, clinical improvement was associated with lowered plasma cortisol levels compared with the elevated basal values.

Physical growth of nigerian children with bronchial asthma.

The weights and heights of 280 Nigerian children with bronchial asthma were compared with those of apparently healthy Nigerian children from a similar socio-economic background. No statistically significant differences were found between the asthmatics and their healthy counterparts. Although children with severe asthma were, on average, lighter in weight and shorter in stature than those with mild or moderate disease, weights and heights within the asthmatic group were more dependent upon the social class of the family and, to a lesser extent, the duration of asthma. It is concluded that asthma per se, is not a usual cause of severe growth retardation in childhood.

Enteric fever in childhood.

A detailed analysis of 117 cases of enteric fever in Nigerian children shows that fever, abdominal pain, vomiting and diarrhoea were the main presenting features. Disorders of sensorium occurred in 50%. Associated conditions and bizarre manifestations often delayed the diagnosis and this, coupled with complications such as intestinal haemorrhage and perforation, adversely affected the mortality which was 32% in this study.