Abstract

Objective: to determine the prevalence of measles at Brazzaville University Hospital and identify associated factors. Patients and method: Prospective descriptive and analytical study of measles cases recorded in the infectious diseases department of Brazzaville University Hospital during the period from July¹ to December 31, 2022. Results: A total of 65 cases of measles were recorded (5.6% of admissions) in children aged on average 31.3 ±33.5 (3-168) months, male (n= 39; 60%), attending primary school (n=9; 13.8%), living in town (n=58; 89.2%), with absent vaccination status (n=45; 69.2%). The median weight was 3kg, and the mean age at food diversification was 4.4±1.3(1-6) months. The children were the^2nd siblings (n=19; 29.2%), and there was a notion of contage (n=41; 63.1%). The mothers were 29.6±7.1 (18-44) years old on average, housewives (n=21; 32.3%) and secondary school students (n=38; 58.5%). The parents were living common-law (n=60;92.3%), had a low socio-economic status (n=58;89.2%) and had 6 children (n=6;9.2%). Fever and rash were the main reasons for consultation in 73.8% respectively. Crepitus rales were present (n=33;50.8%), as was a morbiliform rash (n=61; 93.8%). Chest radiography revealed an interstitial syndrome (n=13; 73.5%). GERH was positive (n=22; 33.8%). Average hospital stay was 6.5±2.7 (1-15) days. Progression under treatment was favorable in 63 cases (96.9%). Respiratory distress was the main complication (n=2; 100%). Level of education was associated with death (p=0.001).Conclusion: The high prevalence of measles is associated with unvaccinated children living in parents' disadvantaged socio-professional circumstances. The only effective measure to break the epidemic is to vaccinate the population concerned correctly.

1. Introduction

Measles is a febrile eruptive disease with epidemic potential that continues to pose a real public health problem in the Congo, due to low vaccination coverage among the population concerned ¹. The World Health Organization has set the goal of eliminating the disease by 2030. In the Congo, the weaknesses of the Expanded Program on Immunization (EPI) in terms of vaccination strategies and catch-ups mean that measles cases are reported throughout the year.

The general aim of this study is to determine the prevalence of measles in the infectious diseases department of the Brazzaville University Hospital, and to identify the factors associated with the disease. The specific objective is to describe the epidemiological characteristics of affected children and their parents.

2. Patients and Method

This was a prospective descriptive and analytical study of measles cases recorded in the infectious diseases department of Brazzaville University Hospital between July ¹ and December 31, 2022. All febrile children with a morbilliform rash up to date or not according to the EPI calendar were included. Qualitative variables were expressed as percentages and quantitative variables as mean and standard deviation. Tests were used according to their applicability. For all tests, the significance threshold was set at 0.05.

3. Results

The prevalence of measles was 5.6%. The average age of the children was 31.3 ±33.5 (3-168) months. The age group between 1 and 5 years was the most represented (Table 1).

(Figure 1). Patients were male (n= 39; 60%) and female (n=26; 40%), attended primary school (n=9; 13.8%) and lived in the city (n=58; 89.2%). Vaccination status was absent (n=45; 69.2%) or doubtful (n=6; 9.2%) (Figure 2). Low birth weight was found in 7 cases (10.8%). The median weight was 3kg, and the average age of food diversification was 4.4± 1.3(1-6) months. Children were ranked^1st (n=14; 21.5%) and^2nd among siblings (n=19; 29.2%). There was a notion of contage (n=41; 63.1%). Mothers were 29.6±7.1 (18-44) years old on average, housewives (n=21; 32.3%) and attended secondary school (n=38; 58.5%) or primary school (n=21; 32.3%). The average age of the fathers was 36.43 ± 8.9 (23-74) years. The parents were living common-law (n=60; 92.3%), had a low socio-economic level (n=58;89.2%) and had 6 children (n=6;9.2%). Fever and rash were the main reasons for consultation in 73.8% respectively. Crepitus rales (n=33; 50.8%) and morbilliform rash (n=61; 93.8%) were also present.

Dehydration was present in 8 cases (12.3%) and malnutrition (n=19; 29.2%). Chest radiography was abnormal (n=17; 26.2%), with interstitial syndrome (n=13; 73.5%). GERH was positive (n=22; 33.8%). Amoxicillin was used in 47 cases (74.6%) for a mean duration of 5.5 days. The average hospital stay was 6.5±2.7 (1-15) days. Progression under symptomatic treatment was favorable in 63 cases (96.9%). Death occurred in 2 patients (3.1%). Respiratory distress was the main cause of death, and educational level was associated with death (p=0.001). (Table 1).

4. Discussion

The present study only took into account children who had consulted the CHUB, mainly the infectious diseases department. However, during epidemic periods, cases may be under-reported if active surveillance is not effective. This may give rise to a selection bias. However, the results obtained suggest that the country is in the midst of a measles epidemic, and that the virus continues to circulate in Brazzaville.

The prevalence of measles is high compared to that previously reported in the same department, i.e. 3.6%, and males are still the most affected ². This prevalence indicates that children in Brazzaville have low vaccination coverage, and that the virus continues to circulate within the community, mainly among children. More than half of all measles patients (89.2%) lived in urban areas. In Africa, measles is permanently endemic in urban areas. However, there is an epidemic upsurge in the dry season, as the virus rapidly loses its virulence in a humid atmosphere ³. The average age of dietary diversification was 4 months. Urban measles occurs early, and the average age of affected children is lower the more promiscuous they are and the more unfavorable their social conditions, as reported in the literature ⁴. In 69% of cases, the children had not been vaccinated against measles. Despite the availability of effective, well-tolerated vaccines, administered free of charge in most tropical countries with the support of technical and financial partners such as GAVI, immunization programs do not always easily achieve the expected performance in terms of vaccine coverage. This observation is similar to that made by the World Health Organization ⁵. The lack of vaccination among children could be explained by the young age and low socio-economic level of the parents, particularly the mothers, who in the majority of cases were housewives with an average age of 29. It would seem necessary to organize educational sessions to make women of childbearing age aware of the importance of vaccination. The clinical signs found in the patients were classic and similar to those reported in the literature. Fever and rash were the main reasons for consultation, with 73.8% of patients reporting a rash. The period of invasion begins with a rise in temperature to 39-40°C and a change in the child's character, who stops playing and refuses to eat ⁶. Measles pneumonitis was found in 73.5% of cases, and manifested on the frontal chest X-ray in 26.2% of cases. These are bronchopulmonary complications that aggravate 16 to 77% of hospitalized measles cases in tropical zones, and may be viral, due to the morbid virus, or to viral or bacterial superinfection ⁷. The measles-malaria association found in the present study is not new, as it has already been reported in the same department in previous studies by Ossibi Ibara and colleagues, and in the sub-region ^{2, 8}. Most measles complications are due to bacterial superinfection, mainly pneumococcus, Haemophilus influenzae and staphylococcus aureus. Throughout the world, the clinical picture is highly varied: bronchitis and bronchopneumonia have become rare in Europe, but are still frequent and often severe in tropical areas such as the Congo.

All cases of measles were isolated and systematically disinfected nose, mouth and eyes, as reported in the literature (9). All patients received loading doses of vitamin A to reduce the risk of measles complications and mortality, as recommended in tropical settings ^{6, 10}. WHO recommends two doses at 24-hour intervals of 200,000 U from 1 to 2 years, 100,000 U between 6 months and 1 year, and 500,000 U before 6 months ¹⁰. Amoxicillin was used in 48% of patients, for a mean duration of 5.5 days. Given the frequency of superinfections, “prophylactic” antibiotic therapy was generally proposed in cases of measles, but its value is debated. The average length of hospital stay for measles patients appears to be short and similar to that found in Mauritania, in contrast to other African series ^{6, 11}. The lower frequency of complications observed in the present study largely justifies the short hospital stay among patients. In the vast majority of cases, the outcome was favorable, with a case-fatality rate of 3% due to respiratory distress and low parental education. In Abidjan, in a study of measles morbidity and mortality in hospitals, Tanon reported a case-fatality rate of 12%, and the severity factors were the eruptive phase (RR=0.56), age <1 year (RR=1.06) and the existence of complications (RR=6.11). In Mauritania, lack of vaccination (p=0.02), undernutrition (p=0.006) and seizures (p=0.05) were directly associated with death in significant proportions ⁶.

5. Conclusion

Despite the availability of a safe, effective and free vaccine under the Expanded Program on Immunization, measles continues to pose a real public health problem in the Republic of Congo, with high morbidity and mortality. Women of childbearing age remain under-informed about vaccination. There is an urgent need to reinforce preventive measures by raising awareness among the Congolese population, in order to eliminate measles in the country.

Key words: Measles, epidemic, prevalence, CHU, Brazzaville

Conflict of interest: the authors stress that they have no conflict of interest in connection with the present study.

References