Proposta e análise metodológica para verificação do Padrão D-2 da Convenção BWM (IMO, 2004) referente ao V. cholerae O1 e O139: estudo de caso no porto da Cidade do Rio de Janeiro (Brasil)

Abstract

The current globalization process drives maritime movement worldwide, which currently accounts for about 90% of all trade between countries, increasing the volume of ballast water handled and consequently, the risk of bioinvasions. Among all the species present in this context, this work is focused on the toxigenic Vibrio cholerae (serogroups O1 and O139) that causes Cholera: an enteric disease characterized by a marked diarrhea that is closely related to environmental conditions, especially basic sanitation. between 2000 and 2017, about 4.7 million cases of the disease were registered (with approximately 71 thousand deaths) and 81% of them occurred in the African-Asian region. Treatment is carried out by hydration, antibiotics and in some cases vaccination. However, bacterial resistance to medication has been evidenced because of the horizontal gene transfer process. The BWM convention (IMO, 2004) in its D-2 rule (Ballast Water Performance Standard) establishes toxigenic vibrio cholerae as one of the main standardized bioindicators for the quality control of ballast water treatment systems on board. Thus, because of the inte nse maritime flow, the construction of a methodology that points out possible “target vessels” to verify the compliance of the D-2 standard is an important challenge. This work aims to elaborate, test and analyze an initial methodological proposal to prevent the introduction of toxigenic Vibrio cholerae in national waters by ballast water discharge, according to the D-2 standard of the BWM Convention (IMO, 2004) regarding to the specificity of the vessels to be sampled, taking the Port of the City of Rio de Janeiro as a case study. The methodology was based on the answers to three guiding questions: (i) whether the discharge region is vulnerable to the introduction of toxigenic Vibrio cholerae; (ii) whether any visiting vessel has the risk of introducing toxigenic vibrio by ballast water and (iii) whether the ballast of visiting vessels has toxigenic V.c. as well as the study site. The results detected by the established protocol were able to prioritize the “target ships” for inspection with a reduction of over 90% of all monitored vessels, with visits to the port of study from January 2016 to January 2018 (25 months). Every protocol used was analyzed and improvements are suggested in the conclusion of this work. The adopted protocol indicated to be very promising, with good perspectives for improvements and application in other national ports regarding the verification of compliance with the D-2 standard in the issue of toxigenic V. cholerae.