- Seroprevalence and social determinants of varicella in Turkey. [Journal Article]
- EMEast Mediterr Health J 2018 Jun 10; 24(3):295-301
- CONCLUSIONS: High seroprevalance depends on natural exposure to the infectious agent itself and is not associated with social determinants. High vaccine coverage should be maintained for effective varicella control and switching to a 2-dose schedule may also be considered to reduce the number and size of outbreaks in the Turkish population.
- Overview of foot-and-mouth disease awareness among farmers and veterinarians in France. [Journal Article]
- VRVet Rec 2018 Jun 15
- Foot-and-mouth disease (FMD) is of major concern in most countries including Europe, where no outbreaks have occurred since a decade. Indeed, the risk of FMD introduction from infected countries is n...
Foot-and-mouth disease (FMD) is of major concern in most countries including Europe, where no outbreaks have occurred since a decade. Indeed, the risk of FMD introduction from infected countries is not negligible and the awareness of field stakeholders (farmers, veterinarians) is essential to ensure an effective detection of the viral circulation. The French veterinary services launched in 2015 a survey to estimate the awareness of farmers and veterinarians and their knowledge about epidemiological and regulatory aspects of FMD. Official health visits were used to collect information from cattle farmers and veterinarians through two separate questionnaires. The results show that not all cattle farmers were aware of the risk of FMD reintroduction in France and of its routes of infection and speed of dissemination. As for the veterinarians, their promptness to report a suspicion was dependent on the occurrence of FMD cases in European countries. These results highlight key aspectsregarding FMD epidemiology which should be regularly reminded to the field stakeholders in FMD-free countries to increase their awareness and thus ensure an effective early detection in case of FMD introduction.
- Did Zika Virus Mutate to Cause Severe Outbreaks? [Review]
- TMTrends Microbiol 2018 Jun 11
- Zika virus (ZIKV) has challenged the assumed knowledge regarding the pathobiology of flaviviruses. Despite causing sporadic and mild disease in the 50 years since its discovery, Zika virus has now ca...
Zika virus (ZIKV) has challenged the assumed knowledge regarding the pathobiology of flaviviruses. Despite causing sporadic and mild disease in the 50 years since its discovery, Zika virus has now caused multiple outbreaks in dozens of countries worldwide. Moreover, the disease severity in recent outbreaks, with neurological disease in adult and devastating congenital malformations in fetuses, was not previously seen. One hypothesis is that the virus has acquired mutations that have increased its virulence. Indeed, mutations in other arboviruses, such as West Nile virus (WNV), chikungunya virus (CHIKV), and Venezuelan equine encephalitis virus (VEEV), have enhanced outbreaks. This possibility, as well as alternative hypotheses, are explored here.
- Presence and Persistence of Salmonella in Water: The Impact on Microbial Quality of Water and Food Safety. [Review]
- FPFront Public Health 2018; 6:159
- Salmonella ranks high among the pathogens causing foodborne disease outbreaks. According to the Centers for Disease Control and Prevention, Salmonella contributed to about 53.4% of all foodborne dise...
Salmonella ranks high among the pathogens causing foodborne disease outbreaks. According to the Centers for Disease Control and Prevention, Salmonella contributed to about 53.4% of all foodborne disease outbreaks from 2006 to 2017, and approximately 32.7% of these foodborne Salmonella outbreaks were associated with consumption of produce. Trace-back investigations have suggested that irrigation water may be a source of Salmonella contamination of produce and a vehicle for transmission. Presence and persistence of Salmonella have been reported in surface waters such as rivers, lakes, and ponds, while ground water in general offers better microbial quality for irrigation. To date, culture methods are still the gold standard for detection, isolation and identification of Salmonella in foods and water. In addition to culture, other methods for the detection of Salmonella in water include most probable number, immunoassay, and PCR. The U.S. Food and Drug Administration (FDA) issued the Produce Safety Rule (PSR) in January 2013 based on the Food Safety Modernization Act (FSMA), which calls for more efforts toward enhancing and improving approaches for the prevention of foodborne outbreaks. In the PSR, agricultural water is defined as water used for in a way that is intended to, or likely to, contact covered produce, such as spray, wash, or irrigation. In summary, Salmonella is frequently present in surface water, an important source of water for irrigation. An increasing evidence indicates irrigation water as a source (or a vehicle) for transmission of Salmonella. This pathogen can survive in aquatic environments by a number of mechanisms, including entry into the viable but nonculturable (VBNC) state and/or residing within free-living protozoa. As such, assurance of microbial quality of irrigation water is critical to curtail the produce-related foodborne outbreaks and thus enhance the food safety. In this review, we will discuss the presence and persistence of Salmonella in water and the mechanisms Salmonella uses to persist in the aquatic environment, particularly irrigation water, to better understand the impact on the microbial quality of water and food safety due to the presence of Salmonella in the water environment.
- The containment of potential outbreaks triggered by imported Chikungunya cases in Italy: a cost utility epidemiological assessment of vector control measures. [Journal Article]
- SRSci Rep 2018 Jun 13; 8(1):9034
- The arrival of infected travelers from endemic regions can trigger sustained autochthonous transmission of mosquito-borne pathogens in Europe. In 2007 a Chikungunya outbreak was observed in central I...
The arrival of infected travelers from endemic regions can trigger sustained autochthonous transmission of mosquito-borne pathogens in Europe. In 2007 a Chikungunya outbreak was observed in central Italy, mostly affecting two villages characterised by a high density of Aedes albopictus. The outbreak was mitigated through intervention strategies reducing the mosquito abundance. Ten years later, in 2017, sustained Chikungunya transmission was documented in both central and southern Italy. The proposed analysis identifies suitable reactive measures for the containment and mitigation of future epidemics by combining epidemiological modeling with a health economic approach, considering different arrival times of imported infections and possible delays in the notification of cases. Obtained estimates suggest that, if the first notification will occur in the middle of the mosquito breeding season, the combination of larvicides, adulticides and breeding sites removal represents the optimal strategy. In particular, we found that interventions implemented in 2007 were cost-effective, with about 3200 prevented cases, 1450 DALYs averted and €13.5 M saved. Moreover, larvicides are proven to be more cost beneficial in early summer and warmer seasons, while adulticides should be preferred in autumn and colder seasons. Our results provide useful indications supporting urgent decision-making of public health authorities in response to emerging mosquito-borne epidemics.
- A live vaccine rapidly protects against cholera in an infant rabbit model. [Journal Article]
- STSci Transl Med 2018 Jun 13; 10(445)
- Outbreaks of cholera, a rapidly fatal diarrheal disease, often spread explosively. The efficacy of reactive vaccination campaigns-deploying Vibrio cholerae vaccines during epidemics-is partially limi...
Outbreaks of cholera, a rapidly fatal diarrheal disease, often spread explosively. The efficacy of reactive vaccination campaigns-deploying Vibrio cholerae vaccines during epidemics-is partially limited by the time required for vaccine recipients to develop adaptive immunity. We created HaitiV, a live attenuated cholera vaccine candidate, by deleting diarrheagenic factors from a recent clinical isolate of V. cholerae and incorporating safeguards against vaccine reversion. We demonstrate that administration of HaitiV 24 hours before lethal challenge with wild-type V. cholerae reduced intestinal colonization by the wild-type strain, slowed disease progression, and reduced mortality in an infant rabbit model of cholera. HaitiV-mediated protection required viable vaccine, and rapid protection kinetics are not consistent with development of adaptive immunity. These features suggest that HaitiV mediates probiotic-like protection from cholera, a mechanism that is not known to be elicited by traditional vaccines. Mathematical modeling indicates that an intervention that works at the speed of HaitiV-mediated protection could improve the public health impact of reactive vaccination.
- Probiotic strains detect and suppress cholera in mice. [Journal Article]
- STSci Transl Med 2018 Jun 13; 10(445)
- Microbiota-modulating interventions are an emerging strategy to promote gastrointestinal homeostasis. Yet, their use in the detection, prevention, and treatment of acute infections remains underexplo...
Microbiota-modulating interventions are an emerging strategy to promote gastrointestinal homeostasis. Yet, their use in the detection, prevention, and treatment of acute infections remains underexplored. We report the basis of a probiotic-based strategy to promote colonization resistance and point-of-need diagnosis of cholera, an acute diarrheal disease caused by the pathogen Vibrio cholerae Oral administration of Lactococcus lactis, a common dietary fermentative bacterium, reduced intestinal V. cholerae burden and improved survival in infected infant mice through the production of lactic acid. Furthermore, we engineered an L. lactis strain that specifically detects quorum-sensing signals of V. cholerae in the gut and triggers expression of an enzymatic reporter that is readily detected in fecal samples. We postulate that preventive dietary interventions with fermented foods containing natural and engineered L. lactis strains may hinder cholera progression and improve disease surveillance in populations at risk of cholera outbreaks.
- A serological survey of anthrax in domestic dogs in Zimbabwe: a potential tool for anthrax surveillance. [Journal Article]
- EIEpidemiol Infect 2018 Jun 14; :1-7
- Anthrax is an important disease caused by the bacterium Bacillus anthracis affecting both domestic and wild animals at the wildlife/livestock interface, defined here as a physical space in which wild...
Anthrax is an important disease caused by the bacterium Bacillus anthracis affecting both domestic and wild animals at the wildlife/livestock interface, defined here as a physical space in which wild and domestic species overlap in range and potentially interact. In endemic regions, sporadic anthrax outbreaks occur, causing significant deaths of both wildlife and livestock and sporadically, humans. However, it may also occur as isolated outbreaks with a few animals affected. Such isolated anthrax outbreaks maybe missed. High seroprevalence among carnivores suggests either regular non-fatal exposure to the pathogen circulating in a given environment, or contact with missed cases through consumption of anthrax carcases. To investigate the relevance of this potential indicator, a cross-sectional study was conducted to determine anthrax seroprevalence in domestic dogs (Canis lupus familiaris) from selected interface and non-interface areas of Zimbabwe with known history of anthrax outbreaks. Based on past anthrax outbreaks in the respective areas, the sites were further classified as high or low risk areas for anthrax outbreaks. Sera were collected from domestic dogs (n = 186) and tested for antibodies against B. anthracis protective antigens (PA) using an ELISA test. The overall seroprevalence was 51.6% (96/186; 95% CI 44.2-59.0). Sites from the non-interface areas recorded a significantly (P < 0.001) higher (72.1%) anthrax seroprevalence compared with those from the wildlife -livestock interface (41.5%). The results demonstrated a strong association (χ2 = 14.3; OR = 3.2, 1.6 < OR < 6.2, P < 0.001) between anthrax seropositivity and interface type. Low-risk sites (42.5%) had a significantly (P = 0.044) lower seroprevalence compared with high-risk sites (58.5%) but still demonstrated high seroprevalence for areas where anthrax was last reported more than 20 years back. Dogs from Tsholotsho South were more than 90-times (OR = 96.5, 13.5 < OR < 690.8) more likely to be seropositive compared with those from Hwange. The study demonstrated the potential to use domestic dogs as indicators of anthrax in the study areas to survey anthrax circulation in supposed low-risk areas and calls for a redefinition of both low and high risk areas for anthrax in Zimbabwe based on an improved surveillance.
- Utility of state-level influenza disease burden and severity estimates to investigate an apparent increase in reported severe cases of influenza A(H1N1) pdm09 - Arizona, 2015-2016. [Journal Article]
- EIEpidemiol Infect 2018 Jun 14; :1-7
- The Arizona Department of Health Services identified unusually high levels of influenza activity and severe complications during the 2015-2016 influenza season leading to concerns about potential inc...
The Arizona Department of Health Services identified unusually high levels of influenza activity and severe complications during the 2015-2016 influenza season leading to concerns about potential increased disease severity compared with prior seasons. We estimated state-level burden and severity to compare across three seasons using multiple data sources for community-level illness, hospitalisation and death. Severity ratios were calculated as the number of hospitalisations or deaths per community case. Community influenza-like illness rates, hospitalisation rates and mortality rates in 2015-2016 were higher than the previous two seasons. However, ratios of severe disease to community illness were similar. Arizona experienced overall increased disease burden in 2015-2016, but not increased severity compared with prior seasons. Timely estimates of state-specific burden and severity are potentially feasible and may provide important information during seemingly unusual influenza seasons or pandemic situations.
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- Ilheus and Saint Louis encephalitis viruses elicit cross-protection against a lethal Rocio virus challenge in mice. [Journal Article]
- PlosPLoS One 2018; 13(6):e0199071
- Rocio virus (ROCV) was the causative agent of an unprecedented outbreak of encephalitis during the 1970s in the Vale do Ribeira, Sao Paulo State, in the Southeast region of Brazil. Surprisingly, no f...
Rocio virus (ROCV) was the causative agent of an unprecedented outbreak of encephalitis during the 1970s in the Vale do Ribeira, Sao Paulo State, in the Southeast region of Brazil. Surprisingly, no further cases of ROCV infection were identified after this outbreak; however, serological surveys have suggested the circulation of ROCV among humans and animals in different regions of Brazil. Cross-protective immunity among flaviviruses is well documented; consequently, immunity induced by infections with other flaviviruses endemic to Brazil could potentially be responsible for the lack of ROCV infections. Herein, we evaluated the cross-protection mediated by other flaviviruses against ROCV infection using an experimental C57BL/6 mouse model. Cross-protection against ROCV infection was observed when animals had prior exposure to Ilheus virus or Saint Louis encephalitis virus, suggesting that cross-reactive anti-flavivirus antibodies may limit ROCV disease outbreaks.