COVID-19 New Cases and Environmental Factors During Wet and Dry Seasons in West and Southern Africa.

Sub-Saharan Africa has been the last continent to experience a significant number of cases in the novel Coronavirus (COVID-19). Studies suggest that air pollution is related to COVID-19 mortality; poor air quality has been linked to cardiovascular, cerebrovascular, and respiratory diseases, which are considered co-morbidities linked to COVID-19 deaths. We examine potential connections between country-wide COVID-19 cases and environmental conditions in Senegal, Cabo Verde, Nigeria, Cote D'Ivorie, and Angola. We analyze PM2.5 concentrations, temperatures from cost-effective in situ measurements, aerosol optical depth (AOD), and fire count and NO2 column values from space-borne platforms from 1 January 2020 through 31 March 2021. Our results show that the first COVID-19 wave in West Africa began during the wet season of 2020, followed by a second during the dry season of 2020. In Angola, the first wave starts during the biomass burning season but does not peak until November of 2020. Overall PM2.5 concentrations are the highest in Ibadan, Nigeria, and coincided with the second wave of COVID-19 in late 2021 and early 2022. The COVID-19 waves in Cabo Verde are not in phase with those in Senegal, Nigeria, and Cote, lagging by several months in general. Overall, the highest correlations occurred between weekly new COVID-19 cases meteorological and air quality variables occurred in the dry season.

[Undifferentiated Carcinoma of the Nasopharynx in Dakar, an Area Supposed to be Non-Endemic: about 13 Cases]. / Carcinomes indifférenciés du nasopharynx à Dakar, une zone supposée non endémique : à propos de 13 cas.

Undifferentiated carcinoma of the nasopharynx (UCNT) has variable incidence throughout the world. Senegal is supposed to be a non-endemic zone. There is a constant connection with the Epstein-Barr virus. In this work, the authors study and discuss the pathological aspects of undifferentiated carcinoma of the nasopharynx in 13 cases. They also seek to make the link between this cancer and the presence of an Epstein-Barr virus infection in these patients. This is a retrospective series of cases involving patients with UCNT, diagnosed on histological basis in Dakar and confirmed by immunohistochemistry. An EBV search was performed on these cases through in situ hybridization by the EBER probe. 15 cases diagnosed on histological basis were able to benefit from immunohistochemistry, and 13 cases were confirmed, ie 87%. The mean age was 28.37 years with extremes of 5 and 56 years. The male sex predominated, with a sex ratio of 8/3. The macroscopic lesions were of ulcerous-budding type for cases revealed by a mass of the cavum. The histological aspect resulted in a proliferation of atypical undifferentiated cells, with large, clear, strongly nucleated nuclei, with eosinophilic cytoplasm, scarcely abundant. The stroma was of the lymphoid type. In situ hybridization with the EBER probe showed moderate or intense diffuse scarring of the tumor cells for 10 cases, ie 77%. The number of cases noted in our study taking into account the period of 10 years considered, is indicative of the rare nature of this type of cancer in Dakar. While globally, Epstein-Barr Virus is consistently associated with UCNT, for some of our cases we have not been able to highlight EBV, suggesting the possible involvement of other risk factors, such as HPV.

Les auteurs étudient et discutent les aspects anatomopathologiques du carcinome indifférencié du nasopharynx (UCNT) au Sénégal à propos de 13 cas. Ils recherchent par ailleurs à faire le lien entre ce cancer et la présence d'une infection par le virus d'Epstein-Barr (EBV) chez ces patients. Il s'agit d'une série rétrospective de patients porteurs d'UCNT, diagnostiqués sur base histologique à Dakar sur 10 ans, et confirmés par l'immunohistochimie. Une recherche d'EBV a été effectuée sur ces cas en hybridation in situ par la sonde EBER. Quinze cas diagnostiqués sur base histologique ont pu bénéficier de l'immunohistochimie et 13 cas ont été confirmés, soit 87 %. L'âge moyen était de 28,37 ans avec des extrêmes de 5 et 56 ans. Le sexe masculin prédominait, avec un sex-ratio de 8/3. Les lésions macroscopiques étaient de type ulcéro-bourgeonnant pour les cas se révélant par une masse du cavum. L'aspect histologique se traduisait par une prolifération de cellules indifférenciées atypiques, aux noyaux volumineux, clairs, fortement nucléolés, aux cytoplasmes éosinophiles, peu abondants. Le stroma était de type lymphoïde. L'hybridation in situ avec la sonde EBER montrait un marquage diffus modéré ou intense des cellules tumorales pour 10 cas, soit 77 %. Le nombre de cas notés dans notre étude, tenant compte de la période de 10 ans considérée, est révélateur du caractère rare de ce type de cancer à Dakar. Si à l'échelle mondiale, le virus d'Epstein-Barr est constamment associé à l'UCNT, pour certains de nos cas nous n'avons pas pu mettre en évidence EBV, suggérant l'implication possible d'autres facteurs de risque, tel que le papillomavirus humain (HPV).

Situation de la chimioresistance du paludisme dans les Etats membres de l'OCCGE de 1991 a 1994

La chimioresistance du paludisme depuis son apparition dans les pays de l'OCCGE vers la fin des annees 1980 fait l'objet d'une surveillance organisee en reseau sous la coordination du CRCP (Centre de Reference de la Chimioresistance du Paludisme). La situation de la chimioresistance du paludisme dans ces pays de 1991 a 1994 a ete dressee a la suite des ateliers de 1993 et 1995