Quality Control of Microscopic Diagnosis of Malaria in Healthcare Facilities and Submicroscopic Infections in Mossendjo, the Department of Niari, the Republic of the Congo

The control and management of malaria are linked to the quality of diagnosis. We sought to estimate the performance of routine microscopy for malaria diagnosis and assess the prevalence of submicroscopic Plasmodium (P.) falciparum infection among febrile patients in two healthcare facilities in Mossendjo, the Republic of the Congo. A cross-sectional study was conducted between January and December 2022. A total of 650 and 234 patients with signs of uncomplicated malaria were enrolled at the Centre de Sante Intégré (CSIMSJ) and Hôpital de Base (HBMSJ), respectively. Two thick blood smears were performed for each patient, one analyzed by routine microscopists and the other by an expert. The msp-1 and msp-2 genes were genotyped to detect submicroscopic P. falciparum infection. At the CSIMSJ, the sensitivity was 49.5% and the specificity was 88.6%. The positive and negative predictive values were 77.7% and 68.7%, respectively. At the HBMSJ, the sensitivity was 32.9% and the specificity was 79.4%. The positive and negative predictive values were 44.8% and 69.5%, respectively. P. falciparum was the only species detected by routine microscopists, while experts identified some cases with P. malariae and P. ovale. The proportion of submicroscopic infections was 35.75%. Children under 5 years old had higher rates of parasitemia. However, submicroscopic infections were more pronounced in the adult group. The performance of routine malaria microscopists at Mossendjo was inaccurate at both sites. With the large proportion of submicroscopic infection, malaria management at Mossendjo requires the improvement of microscopists’ skills and the concomitant use of RDTs

Prevalence of post-pandemic SARS-CoV-2 in patients with respiratory syndrome in Brazzaville, Republic of the Congo

International audienceThe first confirmed case of COVID-19 was detected in the Republic of the Congo in March 2020. Several control measures were implemented during the pandemic period. As a result, the number of reported cases decreased significantly, leading to the gradual lifting of barrier measures and the declaration of the end of the outbreak on 14 October 2022. The present study aimed to determine the post-pandemic prevalence of SARS-CoV-2 in the referral hospitals of Talangaï (HRT) and Makélékélé (HRM) in Brazzaville between October 2022 and April 2023. Nasopharyngeal samples collected from patients with respiratory syndrome were analyzed via qRT‒PCR to detect SARS-CoV-2. An overall prevalence of 5% of SARS-CoV-2 infection was found, with monthly fluctuations in cases during the study period, likely reflecting the endemic nature of the infection. The monthly proportion of SARS-CoV-2 infection cases did not correlate with the number of patients with respiratory syndrome-related symptoms. Although the post-pandemic prevalence of SARS-CoV-2 has remained low, laboratory confirmation of COVID-19, which accounts for both clinical suspicion and detection of SARS-CoV-2, using at least one rapid diagnostic test (RDT) is needed to improve case-by-case management in health centers