Besides polioviruses, non-polio enteroviruses (NPEVs) may also be associated with acute flaccid paralysis (AFP). Because poliomyelitis is on the verge of eradication, more attention should be paid to study NPEVs from non-polio AFP cases and their epidemic patterns. In West African countries the epidemiology of NPEVs remains largely unexplored. We investigated the genetic diversity, frequency, circulation patterns, and molecular epidemiology of NPEVs in seven West African countries by analyzing retrospectively a panel of 3195 stool samples from children with AFP collected through routine poliomyelitis surveillance activities between 2013 and 2014. VP1 sequencing and typing on 201 isolates revealed 39 NPEV types corresponding to EV-A (6.9%), EV-B (90.5%), EV-C (2%) and EV-D (0.5%) species. Echoviruses were isolated most frequently with 138 cases (68.6%), followed by coxsackievirus group B with 35 cases (17.4%). No single NPEV type was remarkably dominant. Interestingly, several rarely described types with limited detection worldwide were identified (EVA76, EVA119, EVB75, EVB77, EVB97, EVC99, CVA20, CVA21 and EVD94). This study demonstrates the extensive diversity and diverse circulation patterns of NPEVs from AFP surveillance and highlights the need to formulate effective long-term strategies to monitor NPEV circulations in West Africa.

We analyzed whole-genome sequences of 8 enterovirus A71 isolates (EV-A71). We confirm the circulation of genogroup C and the new genogroup E in West Africa. Our analysis demonstrates wide geographic circulation and describes genetic exchanges between EV-A71 and autochthonous EV-A that might contribute to the emergence of pathogenic lineages.

Following the 2014 outbreak, active surveillance of the EV-D68 has been implemented in many countries worldwide. Despite subsequent EV-D68 outbreaks (2014 and 2016) reported in many areas, EV-D68 circulation remains largely unexplored in Africa except in Senegal, where low levels of EV-D68 circulation were first noted during the 2014 outbreak. Here we investigate subsequent epidemiology of EV-D68 in Senegal from June to September 2016 by screening respiratory specimens from ILI and stool from AFP surveillance. EV-D68 was detected in 7.4% (44/596) of patients; 40 with ILI and 4 with AFP. EV-D68 detection was significantly more common in children under 5 years (56.8%, p = 0.016). All EV-D68 strains detected belonged to the newly defined subclade B3. This study provides the first evidence of EV-D68 B3 subclade circulation in Africa from patients with ILI and AFP during a 2016 outbreak in Senegal. Enhanced surveillance of EV-D68 is needed to better understand the epidemiology of EV-D68 in Africa.

Enterovirus D68 Subclade B3 in Children with Acute Flaccid Paralysis in West Africa, 2016

Different viruses have been identified as etiologic agents of respiratory tract infections, including severe cases. Among these, human rhinoviruses (HRVs) and human enteroviruses (HEVs) are recognized as leading causes. The present study describes the molecular epidemiology of HRVs and HEVs in Senegal over a 3-year surveillance period. From January 2012 to December 2014, nasopharyngeal and oropharyngeal swabs specimen were collected from patients with influenza-like illness (ILI). A real-time reverse transcription polymerase chain reaction was performed for HRV and HEV detection using the RV16 kit. Two regions were targeted for the molecular characterization of RVs: 5′ untranslated region (5′UTR) and viral protein 4/viral protein 2 (VP4/VP2) transition region. For enteroviruses (EVs) phylogeny, VP1 gene was targeted. A total of 4,194 samples were collected. Children up to 5 years accounted for 52.9%. Among them, 1,415 (33.7%) were positive for HRV, 857 (20.4%) for HEV, and 437 cases of dual infections HRV/HEV. HRVs and HEVs were identified significantly in children aged 5 years or less. Only cough and vomiting signs were observed with significant association with viral infection. Both viruses co-circulated all year long with a marked increase of activity during rainy and cold period. All HRV types circulate in Senegal. HRV-A and C groups were the most common. HEV serotyping identified coxsackie B viruses (CBV) only. VP1 region revealed different CBV (CBV1, CBV2, CBV3, CBV4, and CBV5), echoviruses, coxsackieviruses A4–like strains and a poliovirus 2. The results suggest strong year-round respiratory picornavirus activity in children up to 5 years of age. Molecular studies identified a wide variety of RVs along with diverse EVs in samples from patients with ILI.