Sabin polio virus protein 1 (VP1) evolution in patients with acute flaccid paralysis from 2010 to 2016 in Uganda.

Acute flaccid paralysis (AFP) is a rare side effect of the oral polio vaccine but can be associated with outbreaks and permanent disability in patients harboring circulating vaccine-derived polioviruses (cVDPVs). With the advancement of polio abolition in a glimpse, cVDPVs are causing outbreaks and slowing the polio eradication process. The polio virus protein 1 (VP1) contains the binding site that is key for virus transmission. Understanding the evolution of VP1 among AFP patients could yield more insight into the early events of cVDPVs. Polioviruses were identified from stool specimens of AFP patients using cell culture; and confirmed by the real time RT PCR intra-typic differentiation and vaccine-derived poliovirus assays. Seventy-nine (79) Sabin-like poliovirus 1 (SL1) and 86 Sabin-like poliovirus 3 (SL3) were sequenced. The VP1 amino acid substitutions T106A in Sabin poliovirus 1 and A54V in Sabin poliovirus 3 were common among the AFP patients as has been found in previous studies. Other substitutions that were associated with AFP were: T290A and A54T in SL1 and SL3 respectively. Nucleotide mutations that were common among the AFP patients included T402C, C670A, and T816C in SL1, and G22A, C375Y, A472R, and A694T in SL3 polioviruses. Characterizing mutations that are associated with AFP could contribute to efforts pursued to mitigate the risk of vaccine-derived polioviruses and promote development of safer vaccines.

The detection of 3 ambiguous type 2 vaccine-derived polioviruses (VDPV2s) in Uganda.

BACKGROUND: The Oral Polio Vaccine (OPV or Sabin) is genetically unstable and may mutate to form vaccine-derived polioviruses (VDPVs). METHODS: In 2014, two VDPVs type 2 were identified during routine surveillance of acute flaccid paralysis (AFP) cases. Consequently, a retrospective VDPV survey was conducted to ensure that there was no circulating VDPV in the country. All Sabin poliovirus isolates identified in Uganda 6 months before and 6 months after were re-screened; Sabin 1 and 3 polioviruses were re-screened for Sabin 2 and Sabin 2 polioviruses were re-screened for VDPVs type 2. The Poliovirus rRT-PCR ITD/VDPV 4.0 assay and sequencing were used respectively. RESULTS: The first two VDPVs type2 were identified in Eastern Uganda and the third was identified during the survey from South-western Uganda. These regions had low OPV coverage and poor AFP surveillance indicators. CONCLUSION: The retrospective VDPV survey was a useful strategy to screen for VDPVs more exhaustively. Supplementary surveillance methods need to be encouraged.

Laboratory Capacity in 2012 for Diagnosis of Epidemic Prone Diseases in the Context of Integrated Disease Surveillance and Response in the WHO African Region

This paper provides the status of laboratory capacity for diagnosis of epidemic prone diseases in the context of Integrated Disease Surveillance and Response (IDSR) in 46 countries in the WHO African Region as of end of 2012 through self-assessment questionnaires. The findings from this assessment revealed that 98 (45/46) of the countries have the capacity for isolation; identification and antimicrobial susceptibility testing of common bacterial causes of enteric diseases and meningitis in the Region. Forty three countries performed standard enzyme-linked immunosorbent assay (ELISA) for confirming suspected cases of pathogens such as Morbillivirus responsible of measles through the detection of specific immunoglobulin M (IgM) and 30 countries had at least polymerase chain reaction (PCR) capacity for detection of influenza viruses. However; the number of countries with an appropriate department of virology providing comprehensive diagnostic services is still limited especially for dangerous viral pathogens requiring high-level containment facilities. The collection and analysis of critical information on the existing diagnostic capacity were used to propose key recommendations for strengthening the laboratory confirmation of outbreaks in line with the IDSR Strategy and the International Health Regulations (IHR; 2005). The proposed key actions were focused in the following areas: high-level advocacy for country ownership; human resource development; laboratory space and equipment; quality assurance and laboratory networking