Surveillance study of vector species on board passenger ships, Risk factors related to infestations

<p>Abstract</p> <p>Background</p> <p>Passenger ships provide conditions suitable for the survival and growth of pest populations. Arthropods and rodents can gain access directly from the ships' open spaces, can be carried in shiploads, or can be found on humans or animals as ectoparasites. Vectors on board ships may contaminate stored foods, transmit illness on board, or, introduce diseases in new areas. Pest species, ship areas facilitating infestations, and different risk factors related to infestations were identified in 21 ferries.</p> <p>Methods</p> <p>486 traps for insects and rodents were placed in 21 ferries. Archives of Public Health Authorities were reviewed to identify complaints regarding the presence of pest species on board ferries from 1994 to 2004. A detail questionnaire was used to collect data on ship characteristics and pest control practices.</p> <p>Results</p> <p>Eighteen ferries were infested with flies (85.7%), 11 with cockroaches (52.3%), three with bedbugs, and one with fleas. Other species had been found on board were ants, spiders, butterflies, beetles, and a lizard. A total of 431 <it>Blattella germanica </it>species were captured in 28 (9.96%) traps, and 84.2% of them were nymphs. One ship was highly infested. Cockroach infestation was negatively associated with ferries in which Hazard Analysis Critical Control Point system was applied to ensure food safety on board (Relative Risk, RR = 0.23, <it>p </it>= 0.03), and positively associated with ferries in which cockroaches were observed by crew (RR = 4.09, <it>p </it>= 0.007), no cockroach monitoring log was kept (RR = 5.00, <it>p </it>= 0.02), and pesticide sprays for domestic use were applied by crew (RR = 4.00, <it>p </it>= 0.05). Cockroach infested ships had higher age (<it>p </it>= 0.03). Neither rats nor mice were found on any ship, but three ferries had been infested with a rodent in the past.</p> <p>Conclusion</p> <p>Integrated pest control programs should include continuing monitoring for a variety of pest species in different ship locations; pest control measures should be more persistent in older ships. HACCP system aids in the prevention of cockroach infestations on board.</p

Legionella species colonization of water distribution systems, pools and air conditioning systems in cruise ships and ferries

Background: Legionnaires' disease continues to be a public health concern in passenger ships. This study was scheduled in order to investigate Legionella spp. colonization of water distribution systems (WDS), recreational pools, and air-conditioning systems on board ferries and cruise ships in an attempt to identify risk factors for Legionella spp. colonization associated with ship water systems and water characteristics. Methods: Water systems of 21 ferries and 10 cruise ships including WDS, air conditioning systems and pools were investigated for the presence of Legionella spp. Results: The 133 samples collected from the 10 cruise ships WDS, air conditioning systems and pools were negative for Legionella spp. Of the 21 ferries WDS examined, 14 (66.7%) were legionellae-positive. A total of 276 samples were collected from WDS and air conditioning systems. Legionella spp. was isolated from 37.8% of the hot water samples and 17.5% of the cold water samples. Of the total 96 positive isolates, 87 (90.6%) were L. pneumophila. Legionella spp. colonization was positively associated with ship age. The temperature of the hot water samples was negatively associated with colonization of L. pneumophila serogroup (sg) 1 and that of L. pneumophila sg 2 to 14. Increases in pH >= 7.8 and total plate count >= 400 CFU/L, correlated positively with the counts of L. pneumophila sg 2 to 14 and Legionella spp. respectively. Free chlorine of >= 0.2 mg/L inhibited colonization of Legionella spp. Conclusion: WDS of ferries can be heavily colonized by Legionella spp. and may present a risk of Legionnaires' disease for passengers and crew members. Guidelines and advising of Legionnaires' disease prevention regarding ferries are needed, in particular for operators and crew members

State of the art: public health and passenger ships

Background. The purpose of this report is to describe issues relevant to public health and to review all passenger ship associated diseases and outbreaks. Moreover, legislation and practices on sanitation and diseases surveillance related to ships internationally were also reviewed. Some relevant historical information about infections on merchant ships is provided as well. Material and methods. The methods used to develop the state-of-the-art report included a scientific literature review and an extensive and thorough search of the websites of organisations and government departments. A considerable effort was made to capitalise on previous experience in the field. In particular, for the literature review, a total of 158 scientific articles were used including 91 full papers and 67 abstracts, 7 guidelines published by the WHO, and 13 guideline documents published by other organisations. Moreover, 5 international conventions relevant to passenger ships were identified. Results. At the international level, public health issues related to ships are regulated by the revised International Health Regulations (2005). Other conventions of the International Maritime Organization regulate safety on board ships and waste and ballast water management, while conventions of the International Labour Organization regulates issues related to working conditions on board ships. Guidelines for preventing and controlling public health threats on board ships can be found in seven Guidelines published by the World Health Organization, including the WHO Guide to Ship Sanitation, which provides a framework for policy making and local decision making. The literature review results revealed that the infections/outbreaks that occur on passenger ships include Norovirus, Legionella spp., Salmonella spp., E. coli, Vibrio spp., and influenza A and B virus. The modes of transmission include person to person, waterborne, foodborne, airborne, and vectorborne, and shore excursions are responsible for some outbreaks. Conclusions. The industry (especially the ferry industry) and sanitary organisations can enhance collaboration in order to implement integrated hygiene programmes and prevent the occurrence of communicable diseases aboard passenger ships

Occupational health legislation and practices related to seafarers on passenger ships focused on communicable diseases: results from a European cross-sectional study (EU SHIPSAN PROJECT)

<p>Abstract</p> <p>Background</p> <p>Seafarers play an important role in the transmission of communicable diseases. The aim of the present study is to draw information and identify possible gaps on occupational health practices related to seafarers sailing on ships within the European Union Member States (EU MS) with focus on communicable diseases.</p> <p>Methods</p> <p>A structured questionnaire was sent to competent authorities from 21 EU MS. The questionnaire included questions about occupational health policies, medical certification of seafarers, communicable diseases reporting and relevant legislation. Descriptive analysis of the data was conducted by the use of Epi Info software: EU MS were categorized in four priority groups (A, B, C, D) based on: number of passenger ships visits, volume of passengers, and number of ports in each country. Moreover, EU MS were categorized to old and new, based on the date of entry in the EU.</p> <p>Results</p> <p>All 21 countries with relevant competent authorities responded to the questionnaire. The existence of specific national legislation/regulation/guidelines related to vaccination of seafarers was reported by three out of the 21 (14%) responding authorities. Surveillance data of communicable diseases related to seafarers are collected and analyzed by 4 (19%) authorities. Five out of 21 of the responding countries (24%) reported that tuberculin test result is required for the issuance of seafarer's medical certificate while a great variety of medical examination is required for the issuance of this certificate among countries.</p> <p>Gaps on occupational health services focused on communicable diseases related to maritime occupation have been reported by 33% of the responding countries.</p> <p>Responding authorities from Group A and B had the highest percentage of reported gaps followed by groups C and D. Old MS reported a higher frequency regarding gaps on occupational health services in comparison to new MS.</p> <p>Conclusion</p> <p>Our results revealed heterogeneity regarding occupational health of maritime employees in EU MS. This work provides some evidence that further work at international and European level could be considered, in order to explore the potential for harmonized initiatives regarding occupational health of seafarers.</p

Surveillance and control of communicable diseases related to passenger ships in Europe

This study was conducted within the European SHIPSAN (ship sanitation) project and aims at exploring the legislative framework and current practices related to surveillance of communicable diseases and response aboard passenger ships in Europe. A detailed questionnaire was disseminated and completed by 59 competent authorities in 27 European countries. The majority of competent authorities used national legislation without special provisions for passenger ships. Only 20% had specific provisions for ships regarding quarantine, while a smaller proportion of new Member States (MS) have specific legislation in comparison with old MS (p = 0.01). The Maritime Declaration of Health (MDH) was the main reporting tool used. About 30.5% of the competent authorities declared that they require submission of MDH by all arriving ships, but 28.8% only from affected areas, and 11.9% never require MDH. A total of 45 outbreaks or incidents (36 gastrointestinal, 1 incident of legionellosis, 3 respiratory, and 1 influenza-like illness outbreak, occupational tuberculosis, varicella, scabies, and meningitis) were reported to EU competent authorities during 2006. About 75% of the responders stated that there are gaps in the surveillance and control of communicable diseases. A diversity of approaches in EU countries, and gaps regarding surveillance and response and training needs of personnel were identified. (Int Marit Health 2011; 62, 2: 138&#8211;147

Hygiene inspections on passenger ships in Europe - an overview

<p>Abstract</p> <p>Background</p> <p>Hygiene inspections on passenger ships are important for the prevention of communicable diseases. The European Union (EU) countries conduct hygiene inspections on passenger ships in order to ensure that appropriate measures have been taken to eliminate potential sources of contamination which could lead to the spread of communicable diseases. This study was implemented within the framework of the EU SHIPSAN project and it investigates the legislation applied and practices of hygiene inspections of passenger ships in the EU Member States (MS) and European Free Trade Association countries.</p> <p>Methods</p> <p>Two questionnaires were composed and disseminated to 28 countries. A total of 92 questionnaires were completed by competent authorities responsible for hygiene inspections (n = 48) and the creation of legislation (n = 44); response rates were 96%, and 75.9%, respectively.</p> <p>Results</p> <p>Out of the 48 responding authorities responsible for hygiene inspections, a routine programme was used by 19 (39.6%) of these to conduct inspections of ships on national voyages and by 26 (54.2%) for ships on international voyages. Standardised inspection forms are used by 59.1% of the authorities. A scoring inspection system is applied by five (11.6%) of the 43 responding authorities. Environmental sampling is conducted by 84.1% of the authorities (37 out of 44). The inspection results are collected and analysed by 54.5% (24 out of 44) of the authorities, while 9 authorities (20.5%) declared that they publish the results. Inspections are conducted during outbreak investigations by 75% and 70.8% of the authorities, on ships on national and international voyages, respectively. A total of 31 (64.6%) and 39 (81.3%) authorities conducted inspections during complaint investigations on ships on international and on national voyages, respectively. Port-to-port communication between the national port authorities was reported by 35.4% (17 out of 48) of the responding authorities and 20.8% (10 out of 48) of the port authorities of other countries.</p> <p>Conclusion</p> <p>This study revealed a diversity of approaches and practices in the conduct of inspections, differences in the qualifications/knowledge/experience of inspectors, the legislation applied during inspections, and the lack of communication and training among many EU countries. An integrated European inspection programme involving competent expert inspectors in each EU Member States and special training for ship hygiene delivered to crew members and inspectors would help to minimize the risk of communicable diseases. Common inspection tools at a European level for hygiene inspection practices and port-to-port communication are needed.</p

Does tourism affect the long term course of COVID-19 pandemic in a country of destination? Evidence from a popular Greek island in 2020 where control measures were implemented

Greece opened its points of entry on July 1, 2020, with specific guidelines for travellers arriving by sea, air or land. The aim of this article is to examine the effect of tourism on the long term course of the Coronavirus Disease 2019 (COVID-19) pandemic during the pre-vaccination era (June to December 2020) on the popular Greek island of Crete. To achieve this, a cross-sectional serosurvey, repeated at monthly intervals, was conducted to compare the seroprevalence in Crete with seroprevalence in the mainland of Greece. Crete welcomed nearly 2,000,000 travellers during the 2020 summer season. Left-over serum samples were collected and obtained from public and private laboratories located in Greece, including the island of Crete. These samples were tested for the presence of anti-SARS-CoV-2 IgG antibodies. A total of 55,938 samples were collected, 3,785 of which originated from Crete. In Crete, the seroprevalence ranged between 0% (June 2020) and 2.58% (December 2020), while the corresponding seroprevalence in Greece was 0.19% and 10.75%, respectively. We identified 4.16 times lower seropositivity in Crete (2.58%) in comparison with the mainland of Greece (10.75%) during December 2020. Moreover, the monthly infection fatality rate (IFR) in Crete was calculated at 0.09%, compared with 0.21% in mainland Greece for December 2020. The island of Crete presented more than four times lower seroprevalence than the mainland of Greece, despite being a highly attractive tourist destination. This evidence supports the idea that tourism may not have affected the long term course of the COVID-19 pandemic in Greece. However, due to contradicting results from previous studies, further investigation is needed

A Systematic Review for Vaccine-Preventable Diseases on Ships: Evidence for Cross-Border Transmission and for Pre-Employment Immunization Need

A literature review was conducted to identify evidence of cases and outbreaks of vaccine-preventable diseases (VPDs) that have been reported from on board ships and the methods applied on board for prevention and control, worldwide, in 1990 to April 2019. Moreover, evidence from seroprevalence studies for the same diseases were also included. The literature review was conducted according to Preferred Reporting Items for Systematic reviews (PRISMA) guidelines. A total of 1795 cases (115 outbreaks, 7 case reports) were identified, the majority were among crew (1466/1795, 81.7%) and were varicella cases (1497, 83.4%). The origin of crew cases was from sub-tropical countries in many reports. Measles (40 cases, 69% among crew), rubella (47, 88.7%), herpes zoster (9, 69.2%) and varicella cases (1316, 87.9%) were more frequent among crew. Mumps cases were equal among passengers and crew (22/22). Hepatitis A (73/92, 70.3%), meningococcal meningitis (16/29, 44.8%), and pertussis (9/9) were more frequent among passengers. Two outbreaks resulted in 262 secondary measles cases on land. Review results were used to draft a new chapter for prevention and control of VPDs in the European Manual for Hygiene Standards and Communicable Disease Surveillance on Passenger Ships. Despite past and current evidence for cross-border VPD transmission and maritime occupational risks, documented pre-employment examination of immune status, vaccination of seafarers, and travel advice to passengers are not yet regulated.Peer Reviewe

Effects of Selection to Diflubenzuron and Bacillus thuringiensis Var. Israelensis on the Overwintering Successes of Aedes albopictus (Diptera: Culicidae)

Aedes albopictus is an invasive mosquito species responsible for local transmission of chikungunya and dengue viruses in Europe. In the absence of available treatments, insecticides-based control remains one of the most important viable strategies to prevent emerging problems. Diflubenzuron (DFB) and Bacillus thuringiensis var. israelensis (Bti) are among the most commonly used larvicides for Ae. albopictus control with consequent concerns for the potential development of resistance. Studies on the resistance emergence in Ae. albopictus and its persistence in the wild to both DFB and Bti are essential for the efficient and sustainable planning of the control programmes. In this context, larvae from a recently laboratory established population were subjected to increasing selective pressure for nine successive generations using both DFB and Bti. The resistance levels and the overwintering success of the selected populations relative to control (colonies that received no selection) were determined. Results revealed an 8.5- and 1.6-fold increase on the resistance levels following selection with DFB and Bti, respectively. The selection process to both larvicides had no apparent impacts on the overwintering capability relative to control, suggesting the successful persistence of the selected individuals in the wild on an annual base

Knowledge, Attitudes, and Practices about the Prevention of Mosquito Bites and Zika Virus Disease in Pregnant Women in Greece

A survey among 573 pregnant women in Greece was conducted through self-completion of a questionnaire in July 2016. Traveling abroad the last six months was declared by 10.5% and 13.0% of pregnant women and their male sex partners, respectively, while 77.4% (441/570) had heard about Zika virus disease (ZVD). A lack of knowledge about sexual transmission of ZVD was identified in 63.3% of pregnant women, and 24.1% of responders did not know the risks to the fetus and baby. Approximately 73% of responders believed that the mosquito bites can affect their fetus and baby and 18% did not take measures to prevent mosquito bites routinely. Multivariable logistic regression models showed that traveling abroad the last six months by pregnant women correlated with correctly answering the question about the transmission of ZVD through bites of infected mosquitoes (Odds Ratio, OR = 10.47, 95% CI = 1.11–98.41). Traveling abroad with a male sex partner over the last six months correlated (OR = 2.05, 95% CI = 0.99–4.23) with responding correctly to the four key questions about the transmission of ZVD through mosquito bites, the risk of microcephaly, and the risks of traveling to the affected countries. A score of ≥5 for the nine responses given to questions of knowledge and attitudes was associated with a Bachelor of Science degree (OR = 1.54, 95% CI = 1.09–2.18), antenatal care at a public hospital (OR = 2.26, 95% CI = 1.28–3.98), being a civil servant as occupation (OR = 1.96, 95% CI = 1.10–3.48), and having gotten information about ZVD from the public health sector (OR = 2.04, 95% CI = 1.05–3.98). In conclusion, we found considerable knowledge gaps related to ZVD among Greek pregnant women. These study results are useful in targeting pregnant women for the prevention of potential Zika virus infections