Viral and Atypical Bacterial Etiology of Acute Respiratory Infections in Children under 5 Years Old Living in a Rural Tropical Area of Madagascar

Abstract

BackgroundIn Madagascar, very little is known about the etiology and prevalence of acute respiratory infections (ARIs) in a rural tropical area. Recent data are needed to determine the viral and atypical bacterial etiologies in children with defined clinical manifestations of ARIs.MethodsDuring one year, we conducted a prospective study on ARIs in children between 2 to 59 months in the community hospital of Ampasimanjeva, located in the south-east of Madagascar. Respiratory samples were analyzed by multiplex real-time RT-PCR, including 18 viruses and 2 atypical bacteria. The various episodes of ARI were grouped into four clinical manifestations with well-documented diagnosis: “Community Acquired Pneumonia”(CAP, group I), “Other acute lower respiratory infections (Other ALRIs, group II)”, “Upper respiratory tract infections with cough (URTIs with cough, group III)”and “Upper respiratory tract infections without cough (URTIs without cough, group IV)”.Results295 children were included in the study between February 2010 and February 2011. Viruses and/or atypical bacteria respiratory pathogens were detected in 74.6% of samples, the rate of co-infection was 27.3%. Human rhinovirus (HRV; 20.5%), metapneumovirus (HMPV A/B, 13.8%), coronaviruses (HCoV, 12.5%), parainfluenza virus (HPIV, 11.8%) and respiratory syncytial virus A and B (RSV A/B, 11.8%) were the most detected. HRV was predominantly single detected (23.8%) in all the clinical groups while HMPV A/B (23.9%) was mainly related to CAP (group I), HPIV (17.3%) to the “Other ALRIs” (group II), RSV A/B (19.5%) predominated in the group “URTIs with cough” (group III) and Adenovirus (HAdV, 17.8%) was mainly detected in the “without cough” (group IV).InterpretationThis study describes for the first time the etiology of respiratory infections in febrile children under 5 years in a malaria rural area of Madagascar and highlights the role of respiratory viruses in a well clinically defined population of ARIs.

Molecular detection of respiratory pathogens among children aged younger than 5 years hospitalized with febrile acute respiratory infections: A prospective hospital‐based observational study in Niamey, Niger

“…Among the cases in which HPIV and HCoV were detected, HPIV type 3 and HCoV type OC43 were the predominant types, and this is consistent with previous studies . In this study, INFs were detected in 8.5% of the cases, which is in agreement with findings from the national influenza surveillance and other related studies in Africa among patients hospitalized with SARI .…”

“…RSV, HPIV, HRV, HAV, and INF were the most commonly detected viruses. As reported in other studies, RSV, INF, and HMPV were mostly detected as single viral infections . RSV, HRV, and HPIV were also the most predominant viruses detected in children aged younger than 5 years in a previous study conducted in Niger .…”

“…The very low detection rate of Hib (2.5%) may also be attributed to the introduction of the Hib conjugate (tetanus toxoid) vaccine in the expanded immunization program in 2008 in Niger . Uncommon respiratory bacterial pathogens including M pneumoniae and C pneumoniae were detected at a very low rate (less than 1%), and this correlates with the results reported in previous studies …”

Viruses causing severe acute respiratory infections (SARI) in children ≤5 years of age at a tertiary care hospital in Rajasthan, India

“…Influenza A (H1N1)pdm09 was the second most predominant virus detected in the present study with a positivity of 19.9 per cent during post-pandemic period. This was high when compared to other studies done in Madagascar (1.70%) and China (2.80%) during pandemic period of 2009-2010216. However, the results were similar to an Indian study done at Ballabgarh which reported a positivity of 17.3 per cent during the pandemic period17.…”

Bacterial and viral pathogen spectra of acute respiratory infections in under-5 children in hospital settings in Dhaka city

“…However, the study did not consider bacterial pathogens. On the other hand, the studies of respiratory infections among children of Zambia and Madagascar reported the detection rates of respiratory pathogens in 76.8% and 74.6% specimens, respectively, and these studies focused on the detection of both viral and atypical bacterial pathogens [20, 21]. A similar study conducted in China demonstrated 67.5% overall pathogen detection rate [22].…”