Epidemiology of severe acute respiratory infections from hospital-based surveillance in Madagascar, November 2010 to July 2013

Norosoa Harline Razanajatovo (1) , Julia Guillebaud (1) , Aina Harimanana (2) , Soatiana Rajatonirina (2) , Elisoa Hariniana Ratsima (2) , Zo Zafitsara Andrianirina (3) , Hervé Rakotoariniaina (3) , Todisoa Andriatahina (4) , Arnaud Orelle (1) , Rila Ratovoson (2) , Judickaelle Irinantenaina (2) , Dina Arinalina Rakotonanahary (1) , Lovasoa Ramparany (5) , Frédérique Randrianirina (5) , Vincent Richard (2) , Jean-Michel Heraud (1)

1 IPM - Unité de Virologie [Antananarivo, Madagascar]
2 IPM - Unité d'Epidémiologie [Antananarivo, Madagascar]
3 CENHOSOA - Centre Hospitalier de Soavinandriana
4 CHD 2 - Centre Hospitalier de District 2, Moramanga
5 IPM - Centre de Biologie Clinique [Antananarivo]

BACKGROUND: Few comprehensive data exist regarding the epidemiology of severe acute respiratory infections (SARI) in low income countries. This study aimed at identifying etiologies and describing clinical features of SARI-associated hospitalization in Madagascar. METHODS: It is a prospective surveillance of SARI in 2 hospitals for 3 years. Nasopharyngeal swabs, sputum, and blood were collected from SARI patients enrolled and tested for viruses and bacteria. Epidemiological and clinical information were obtained from case report forms. RESULTS: Overall, 876 patients were enrolled in the study, of which 83.1% (728/876) were tested positive for at least one pathogen. Viral and bacterial infections occurred in 76.1% (667/876) and 35.8% (314/876) of tested samples, respectively. Among all detected viruses, respiratory syncytial virus (RSV) was the most common (37.7%; 348/924) followed by influenza virus A (FLUA, 18.4%; 170/924), rhinovirus (RV, 13.5%; 125/924), and adenovirus (ADV, 8.3%; 77/924). Among bacteria, Streptococcus pneumoniae (S. pneumoniae, 50.3%, 189/370) was the most detected followed by Haemophilus influenzae type b (Hib, 21.4%; 79/370), and Klebsiella (4.6%; 17/370). Other Streptococcus species were found in 8.1% (30/370) of samples. Compared to patients aged less than 5 years, older age groups were significantly less infected with RSV. On the other hand, patients aged more than 64 years (OR = 3.66) were at higher risk to be infected with FLUA, while those aged 15-29 years (OR = 3.22) and 30-64 years (OR = 2.39) were more likely to be infected with FLUB (influenza virus B). CONCLUSION: The frequency of influenza viruses detected among SARI patients aged 65 years and more highlights the need for health authorities to develop strategies to reduce morbidity amongst at-risk population through vaccine recommendation. Amongst young children, the demonstrated burden of RSV should guide clinicians for a better case management of children. These findings reveal the need to develop point-of-care tests to avoid overuse of antibiotics and to promote vaccine that could reduce drastically the RSV hospitalizations.

Domaines: Santé publique et épidémiologie

Norosoa Harline Razanajatovo, Julia Guillebaud, Aina Harimanana, Soatiana Rajatonirina, Elisoa Hariniana Ratsima, et al.. Epidemiology of severe acute respiratory infections from hospital-based surveillance in Madagascar, November 2010 to July 2013. PLoS ONE, 2018, 13 (11), pp.e0205124. ⟨10.1371/journal.pone.0205124⟩. ⟨pasteur-01967350⟩