After more than 3 years without a documented cholera case, the Republic of Haiti reported its first resurgent case on 30 September 2022 (1–3). As of 18 February 2023, more than 27,000 cholera cases have been hospitalized and 594 deaths confirmed from all 10 departments (4). Here, we describe Vibrio cholerae isolates first characterized by the Laboratoire National de Santé Publique (LNSP) and include both genotypic and phenotypic antimicrobial resistance profiles. Whole-genome sequencing (WGS) analysis was compared with recently circulating cholera toxin-producing V. cholerae O1 in a maximum likelihood phylogeny.

BACKGROUND: Early detection and control of vaccine-derived poliovirus (VDPV) emergences are essential to secure the gains of polio eradication. METHODS: Serial sewage samples were collected in 4 towns of Mexico before, throughout, and after the May 2010 oral poliovirus vaccine (OPV) mass immunization campaign. Isolation and molecular analysis of polioviruses from sewage specimens monitored the duration of vaccine-related strains in the environment and emergence of vaccine-derived polioviruses in a population partially immunized with inactivated poliovirus vaccine (IPV). RESULTS: Sabin strains were identified up to 5-8 weeks after the campaign in all towns; in Aguascalientes, 1 Sabin 3 was isolated 16 weeks after the campaign, following 7 weeks with no Sabin strains detected. In Tuxtla Gutierrez, type 2 VDPV was isolated from 4 samples collected before and during the campaign, and type 1 VDPV from 1 sample collected 19 weeks afterward. During 2009-2010, coverage in 4 OPV campaigns conducted averaged only 57% and surveillance for acute flaccid paralysis (AFP) was suboptimal (AFP rate <1 per 100 000 population <15 years of age) in Tuxtla Gutierrez. CONCLUSIONS: VDPVs may emerge and spread in settings with inadequate coverage with IPV/OPV vaccination. Environmental surveillance can facilitate early detection in these settings.

While global polio eradication requires tremendous efforts in countries where wild polioviruses (WPVs) circulate, numerous outbreaks have occurred following WPV importation into previously polio-free countries. Countries that have interrupted endemic WPV transmission should continue to conduct routine risk assessments and implement mitigation activities to maintain their polio-free status as long as wild poliovirus circulates anywhere in the world. This article reviews the methods used by World Health Organization (WHO) regional offices to qualitatively assess risk of WPV outbreaks following an importation. We describe the strengths and weaknesses of various risk assessment approaches, and opportunities to harmonize approaches. These qualitative assessments broadly categorize risk as high, medium, or low using available national information related to susceptibility, the ability to rapidly detect WPV, and other population or program factors that influence transmission, which the regions characterize using polio vaccination coverage, surveillance data, and other indicators (e.g., sanitation), respectively. Data quality and adequacy represent a challenge in all regions. WHO regions differ with respect to the methods, processes, cut-off values, and weighting used, which limits comparisons of risk assessment results among regions. Ongoing evaluation of indicators within regions and further harmonization of methods between regions are needed to effectively plan risk mitigation activities in a setting of finite resources for funding and continued WPV circulation.