The COVID-19 Prevalence among Children: Hypotheses for Low Infection Rate and Few Severe Forms among This Age Group in Sub-Saharan Africa.

Despite some cases of severe or critical manifestations of the coronavirus disease 2019 (COVID-19) described among children, the prevalence of this infection in the pediatric population is quite low worldwide, particularly in sub-Saharan Africa. Current data suggest indeed that, independent of the population considered overall, severe and critical cases of COVID-19 are rare among children. This observation prompted us to discuss the possible hypotheses which could explain the low prevalence of COVID-19 among children; amongst others, we discuss (1) immunomodulation by the Bacillus Calmette-Guerin vaccine or by some parasitic infections such as malaria, schistosomiasis, and helminthiasis and (2) cross immunization with other coronaviruses commonly found in the sub-Saharan African setting.

Knowledge on Irradiation, Medical Imaging Prescriptions, and Clinical Imaging Referral Guidelines among Physicians in a Sub-Saharan African Country (Cameroon).

BACKGROUND: Clinical imaging guidelines (CIGs) are suitable tools to enhance justification of imaging procedures. OBJECTIVE: To assess physicians' knowledge on irradiation, their self-perception of imaging prescriptions, and the use of CIGs. MATERIALS AND METHODS: A questionnaire of 21 items was self-administered between July and August 2016 to 155 referring physicians working in seven university-affiliated hospitals in Yaoundé and Douala (Cameroon). This pretested questionnaire based on imaging referral practices, the use and the need of CIGs, knowledge on radiation doses of 11 specific radiologic procedures, and knowledge of injurious effects of radiation was completed in the presence of the investigator. Scores were allocated for each question. RESULTS: 155 questionnaires were completed out of 180 administered (86.1%). Participants were 90 (58%) females, 63 (40.64%) specialists, 53 (34.20%) residents/interns, and 39 (25.16%) general practitioners. The average professional experience was 7.4 years (1-25 years). The mean knowledge score was 11.5/59 with no influence of sex, years of experience, and professional category. CIGs users' score was better than nonusers (means 14.2 versus 10.6; p < 0.01). 80% of physicians (124/155) underrated radiation doses of routine imaging exams. Seventy-eight (50.3%) participants have knowledge on CIGs and half of them made use of them. "Impact on diagnosis" was the highest justification criteria follow by "impact on treatment decision." Unjustified requests were mainly for "patient expectation or will" or for "research motivations." 96% of interviewees believed that making available national CIGs will improve justification. CONCLUSION: Most physicians did not have appropriate awareness about radiation doses for routine imaging procedures. A small number of physicians have knowledge on CIGs but they believe that making available CIGs will improve justification of imaging procedures. Continuous trainings on radiation protection and implementation of national CIGs are therefore recommended.

Ultrasonographic prevalence and characteristics of non-palpable thyroid incidentalomas in a hospital-based population in a sub-Saharan country.

BACKGROUND: Thyroid incidentalomas (TI) are highly prevalent asymptomatic thyroid nodules with ultrasound as the best imaging modality for their detection and characterization. Although they are mostly benign, potential for malignancy is up to 10-15%. In sub-Saharan Africa little data exists on the prevalence and risk categorization of TI. The aim of this study was to determine the prevalence and ultrasound characteristics of non-palpable thyroid incidentalomas among adults in sub-Saharan setting. METHODS: A cross sectional study was carried out between March and August 2015, at two university teaching hospitals. Sampling was consecutive and included all adults aged ≥ 16 years, presenting for any ultrasound other than for the thyroid, with no history or clinical signs of thyroid disease, and no palpable thyroid lesion. Ultrasound was done using 4 to 11 MHz linear probes. Subjects with diffuse thyroid abnormalities were excluded. Variables studied were age, gender, thyroid volume, ultrasound characteristics of thyroid nodules, TIRADS scores. Differences were considered statistically significant for p-value < 0.05. RESULTS: The prevalence of TI was 28.3% (126 persons with TI /446 examined). This prevalence was 46.2% in population ≥ 61-year-old; 6.3% in population ≤ 20-year-old; 33.3% for females and 18.4% for males (p < 0.001). Of the 241 TI found, 49.4% were cysts, 33.6% solid, 17.0% mixed; 37.8% <5 mm and 22% >10 mm. Solid TI were mainly hyperechoic (42.0%), 3/81 were markedly hypoechoic. Sixty-nine out of 126 persons with TI (54.8%) had at least two nodules. Solitary nodules were predominant in the age group ≤20 years. Of 241 TI, 129 (53.5%) were classified TIRADS 2, 81 (33.6%) TIRADS 3, 25 (10.4%) TIRADS 4A, 6 (2.5%) TIRADS 4B, and none TIRADS 5. Characteristics associated with increased risk of malignancy where mostly founded on solid nodules (p < 0.000) and nodules larger than 15 mm (p < 0.001). CONCLUSION: Thyroid incidentalomas were very frequent with a prevalence of 28.3% and potential risk of malignancy in 12.9%. Prevalence had a tendency to increase with age and in female. Cystic nodules were the most prevalent. Potential for malignancy would be increased for larger and solid nodules.

Epidemio-clinical and CT-scan profile of adult headache disorders in a sub-Saharan Africa country

Objective: Given the little availability of MRI in sub-Saharan Africa, we carried out this study focusing on CT-scan in adult headache disorder, in order to determine epidemiological and clinical profile of adult patients undergoing CT-scan for headache disorder, and the organic pathologies discovered in sub-Saharan Africa.Method: We carried out a multicentric prospective cross-sectional study in medical imaging departments of Yaounde Central Hospital and Douala Laquintinie Hospital, which are two teaching hospitals in Cameroon. We consecutively and non-exhaustively included all consenting patients aged eighteen years or above, referred to radiology department to undergo a head CT-scan as aetiological workup of headache disorder, from either traumatic or non-traumatic mechanism. Patients with a Glasgow coma scale less than thirteen were excluded. We interviewed eligible patients, and performed a neurological examination and a complete physical examination before they underwent head CT-scan. The scanning was performed using a brand HITACHI ECLOS 16 slices CT-scan, in helical mode with or without contrast enhancement according to the clinical context. The reading was done by experimented radiologists

Prevalence des anomalies transitionnelles lombosacrees dans une population de sujets camerounais souffrant de lombalgies chroniques

INTRODUCTION :Les vertebres transitionnelles lombosacrees (VTLS) et le spina bifida occulta (SBO) peuvent entrainer des lombalgies en particulier chez des sujets jeunes. Du fait de leur origine genetique; leur distribution pourrait varier en fonction des races ; pourtant leur prevalence demeure largement inconnue en Afrique. OBJECTIFS : Determiner la prevalence des VTLS et du SBO chez des noirs africains souffrant de lombalgie chronique. PATIENTS ET MeTHODES 575 radiographies du rachis lombaire (incidences de face et de profil) de patients noirs africains souffrant de lombalgie chronique ont ete revues a la recherche de VTLS de SBO. Les VTLS ont ete classees selon le systeme de Castellvi. Les proportions d'anomalies par sexe ont ete comparees par le test de Fisher. ReSULTATS L'age median des sujets etait de 44 ans [15 a 80 ans] et le sex ratio femme/homme de 1.03. La prevalence globale des VTLS et du SBO etait de 13;6 et 2;1 respectivement. Les VTLS etaient plus frequentes dans la population masculine avec une predominance du type IIa. La frequence du SBO n'etait pas influencee par le sexe. CONCLUSION :La prevalence de VTLS et de SBO chez le sujet noir africain souffrant de lombalgies est similaire a celles retrouvees dans les series caucasiennes et asiatiques

Pertinence des indications d'examens d'imagerie medicale a Yaounde

OBJECTIF. evaluer la pertinence des indications d'examens d'imagerie medicale par rapport au referentiel 'Guide du bon usage des examens d'imagerie medicale' (GBU) de la Societe Francaise de Radiologie (SFR). MeTHODOLOGIE. etude transversale descriptive portant sur l'analyse des renseignements cliniques de 262 demandes d'examens d'imagerie medicale a Yaounde (Cameroun). Les renseignements cliniques etaient categorises (symptome; syndrome; diagnostic; finalite; antecedents; aucun) puis confrontes a la mention d'indication et aux grades de recommandation du GBU de la SFR. La compatibilite entre examen demande; renseignements cliniques et qualite du demandeur etait evaluee de meme que le niveau d'irradiation. ReSULTATS. Quarante cinq (17;2) demandes n'avaient aucune indication. Le symptome etait l'indication la plus frequente (30;8). 76;3 des demandes n'avaient aucune question de recherche (finalite). La mention d'indication etait influencee par le type d'information clinique (p0.0001) avec la plus forte proportion d'examen 'indique' (80;7) lorsque la finalite de l'examen etait precisee. Dans 23 des cas l'indication fournie permettait de juger l'examen demande non-conforme. Dans 59;5 l'examen demande etait 'indique' quelque soit le niveau d'irradiation. 31 examens sans indications etaient irradiants dont 7 de niveau II et 5 de niveau III. Dans 19 cas (7;3) le demandeur n'avait pas qualite pour demander l'examen. La compatibilite examen demande - qualite du demandeur etait plus faible en TDM. CONCLUSION. Il existe une proportion importante de demandes sans indication ou sans finalite de l'examen. Pres d'un quart d'indications sont non-conformes et les symptomes constituent les indications les plus frequentes. Un systeme d'information hospitaliere avec les renseignements cliniques et la finalite de l'examen en 'cases obligatoires' contribuerait a ameliorer la prescription des examens d'imagerie