Seroprevalence of Dengue Virus, West Nile Virus, Chikungunya Virus, and Zika Virus in International Travelers Attending a Travel and Migration Center in 2015-2017, Southern Italy.

International travelers to areas endemic for vector-borne diseases (VBDs) may be at risk of contracting and spreading these diseases. The aim of this study was to evaluate the prevalence of immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies that are specific for Dengue Virus (DV), West Nile Virus (WNV), Chikungunya Virus (CHIKV), or Zika Virus (ZV) in a cohort of international travelers. The study enrolled travelers who attended the Travel Medicine and Migration outpatient service of Local Health Unit of Bari, Italy, in March 2015-June 2017 for counseling and vaccine prophylaxis before travel. After receiving informed consent, post-travel blood samples were tested for IgM and IgG antibodies specific for DV, WNV, CHIKV, and ZV. Of the 207 travelers attending the vaccine service, 156 (75%) were enrolled. Of the 156 subjects, 23 (14.7%) had IgM and/or IgG antibodies specific for at least one VBD. Of these, 12 (52%) were asymptomatic. Nineteen (12.2% of the whole cohort), nine (5.8%), nine (5.8%), and two (1.3%) subjects had IgM and/or IgG antibodies specific for DV, WNV, CHIKV, and ZV, respectively. Ten subjects (6.4%) harbored antibodies that were specific for more than one VBD. A significant number of the international travelers were DV-positive. Our findings suggest that international travelers should undergo serological surveillance, particularly those who travel frequently and for long periods to areas that are endemic for hemorrhagic dengue. Due to a possible risk of introducing VBDs into nonendemic areas, increased awareness among physicians and travelers and appropriate laboratory detection are crucial. There are currently no licensed vaccines for these VBDs in Italy or other European countries; the main preventive measures are protection from mosquito bites and vector control.

Resurgence of Pertussis and Emergence of the Ptxp3 Toxin Promoter Allele in South Italy.

BACKGROUND: Despite universal immunization programs, pertussis remains a major public health concern. This study aimed to describe the pertussis epidemiology in the Puglia region in 2006-2015 and to identify recent polymorphisms in Bordetella pertussis virulence-associated genes. METHODS: The pertussis cases in 2006-2015 were identified from the National Hospital Discharge Database and the Information System of Infectious Diseases. Samples of pertussis cases in 2014-2016 that were confirmed by the Regional Reference Laboratory were subjected to ptxA, ptxP and prn gene sequencing and, in 10 cases, multiple-locus variable-number tandem repeat analysis. RESULTS: In Puglia in 2006-2015, the pertussis incidence rose from an average of 1.39/100,000 inhabitants in 2006-2013 to 2.56-2.54/100,000 in 2014-2015. In infants <1 year of age, the incidence rose from an average of 60.4/100,000 infants in 2006-2013 to 149.9/100,000 in 2015. Of the 661 cases recorded in 2006-2015, 80.3% required hospitalization; of these, 45.4% were <1 year of age. Of the 80 sequenced samples, the allelic profile ptxA1-ptxP3-prn2 was detected in 74. This variant was detected in both vaccinated and unvaccinated people. Six Bordetella pertussis samples were prn deficient. The multiple-locus variable-number tandem repeat analysis cases exhibited multiple-locus variable-number tandem repeat analysis-type 27. CONCLUSIONS: The pertussis incidence in Puglia has risen. The hypervirulent strain was also found in vaccinated people. This suggests bacterial adaptation to the vaccine and raises questions about acellular vaccine effectiveness. Prevention of infant pertussis cases is best achieved by immunizing the pregnant mother. Enhanced surveillance and systematic laboratory confirmation of pertussis should be improved in Italy.