Changes in the epidemiology of pertussis, the introduction of new macrolides, the availability of new vaccines, and modifications to the vaccination schedule necessitate an update to the recommendations for managing both isolated and clustered cases of the disease. Particular attention must be paid to the diagnosis of pertussis in adults, who currently represent the primary reservoir of Bordetella pertussis. These cases of pertussis in adults present as a prolonged cough that worsens at night and are responsible for most infections in young infants. The implementation of prophylactic measures requires microbiological confirmation of the diagnosis of pertussis. For infants, culture and PCR are the gold-standard techniques, also applicable to children and adults who have been coughing for less than 20 days. Beyond that, serology (ELISA and immunoblotting) is the only usable method but is interpretable only if vaccination occurred more than one year ago. Case management measures include: systematic hospitalization of infants under three months of age, respiratory isolation, and exclusion from the community for five days following the initiation of appropriate antibiotic treatment. This treatment should prioritize "new macrolides": clarithromycin for seven days or azithromycin for five days. Within the patient’s immediate family, antibiotic prophylaxis should be prescribed for children and adolescents who are not up to date on their vaccinations, as well as for the parents of the index case and the parents of infants who are unvaccinated or inadequately vaccinated. It is also advisable to bring the vaccinations of those in the patient’s immediate family up to date. The same measures apply to clustered cases (at least two concurrent or successive cases within the same geographic area). In this situation, the public health physician from the DDASS will be notified and will participate in the investigation and classification of cases. Close contacts who are unvaccinated or under-vaccinated will undergo antibiotic prophylaxis and have their vaccinations updated. Among casual contacts, only those at risk will be given antibiotic prophylaxis. In daycare centers, antibiotic prophylaxis will be administered to all infants who have received fewer than four doses of vaccine, as well as to staff in contact with the cases. In schools, antibiotic prophylaxis will be administered to all children in the class or section who are not up to date on their vaccinations, as well as to teachers. In boarding schools and residential facilities for children with disabilities, antibiotic prophylaxis may be extended to the entire facility if the vaccination coverage rate is less than 50%. In healthcare facilities, the systematic wearing of a mask is recommended for healthcare workers who are coughing, and pertussis should be investigated in cases of coughing persisting for more than seven days. Preventive measures will be implemented in the event of confirmed pertussis.