Occupational health risks due to shipboard cockroaches

Reported Cases and Diagnostics of Occupational Insect Allergy: A Systematic Review

A significant part of adult-onset asthma is caused by occupational exposure to both high- and low-molecular-mass agents. Insects are occasionally described to cause occupational allergy in professions including anglers and fishers, laboratory workers, employees of aquaculture companies, farmers, bakers, sericulture workers and pet shop workers. Occupational insect allergies are often respiratory, causing asthma or rhinoconjunctivitis, but can be cutaneous as well. The European Union recently approved three insect species for human consumption, enabling an industry to develop where more employees could be exposed to insect products. This review overviews knowledge on occupational insect allergy risks and the tools used to diagnose employees. Despite the limited availability of commercial occupational insect allergy diagnostics, 60.9% of 164 included reports used skin prick tests and 63.4% of reports used specific IgE tests. In 21.9% of reports, a more elaborate diagnosis of occupational asthma was made by specific inhalation challenges or peak expiratory flow measurements at the workplace. In some work environments, 57% of employees were sensitized, and no less than 60% of employees reported work-related symptoms. Further development and optimization of specific diagnostics, together with strong primary prevention, may be vital to the health conditions of workers in the developing insect industry.

Effectiveness of Ethyl Formate as a Fumigant of Blattella germanica and Periplaneta americana (Blattodea: Ectobiidae, Blattidae) in Cross-Border Trade Transportation

Simple Summary

Fumigation is one effective cockroach control method. Ethyl formate (EF) has recently been employed as a grain fumigant and has been evaluated as relatively safer than other fumigants. In this experiment, the effects of an ethyl formate fumigant on two species of cockroaches were investigated. Cockroach nymphs and adults had 100% mortality, but the effect on egg hatching inhibition was weak. Therefore, ethyl formate could be used as a fumigant if the control period and its usage should be adjusted considering the developmental stage of the cockroach.

Abstract

Cockroaches cause problems as pests not only locally in residential areas but also internationally, as they can disperse across borders in transport vessels. We investigated the effects of the ethyl formate (EF) fumigant on all developmental stages of Blattella germanica and Periplaneta americana. For B. germanica eggs, the hatching inhibition rate increased directly proportionately with the increasing treatment concentration of EF, but the 100% control was not observed. P. americana eggs did not show any fumigation effect, even after exposure to 60 mg/L of fumigant in a 12 L desiccator. Adults and nymphs of the two species showed various fumigation effects dependent on the concentration in the 12 L desiccator. When EF was applied at the lethal concentration for 99% mortality (LCT₉₉) values of 35 mg/L for 4 h (78.5 mg·h/L) and 60 mg/L for 2 h (70.8 mg·h/L), respectively, adults and nymphs of both species had 100% mortality in a 0.65 m³ fumigation chamber with a 20% loading ratio. However, no significant difference from the control was observed in the egg stage of either species of cockroach. The results of this experiment indicate that EF can be used as a fumigant for cross-border transport vessels if the control period occurs during the cockroach developmental stage and continuous refumigation is performed.

Surveillance of hospital contacts among Danish seafarers and fishermen with focus on skin and infectious diseases-a population-based cohort study

Objectives: A systematic overview of time trends in hospital contacts among Danish seafarers and fishermen by job title and analyses on skin and infectious diseases. Methods: Occupational cohorts with hospital contacts 1994–1998 and 1999–2003. Standardized hospital contact ratios (SHCR) were estimated using national rates and ranked by SHCR size. Results: For non-officers in 1994–1998, infectious diseases had the highest SHCR, followed by neoplastic and endocrinal diseases; in 1999–2003 skin diseases were followed by endocrinal and gastrointestinal diseases. For fishermen in 1994–1998, nervous system, gastrointestinal, and skin diseases had the highest SHCRs; in 1999–2003 it was nervous system, skin, and lymphohematopoietic diseases. As for skin diseases, male fishermen and non-officer seamen generally had increased SHCRs, but engine room personnel specifically had a low SHCR for eczema (eight cases). Fishermen had high SHCRs for tuberculosis in both time periods (six and nine cases, respectively). Non-officer seamen on cargo ships had increased SHCRs for HIV in both time periods and for hepatitis in 1994–1999. Extending the follow-up until 2000 or 2005 showed similar results. Conclusions: Surveillance of seamen’s health gives useful information. The elevated SHCR for HIV infection among non-officers has not declined despite preventive information campaigns. Tuberculosis among fishermen may be due to infection on shore. Skin diseases had very high SHCRs, not due to cutaneous oil exposure.

[Public health pests. Arthropods and rodents as causative disease agents as well as reservoirs and vectors of pathogens]

Globally, infectious diseases pose the most important cause of death. Among known human pathogenic diseases, approximately 50 % are zoonoses. When considering emerging infectious diseases separately 73 % currently belong to the group of zoonoses. In Central Europe, hard ticks show by far the biggest potential as vectors of agents of human disease. Lyme borreliosis, showing an estimated annual incidence between 60,000 and 214,000 cases is by far the most frequent tick-borne disease in Germany. Continually, formerly unknown disease agents could be discovered in endemic vector species. Additionally, introduction of new arthropod vectors and/or agents of disease occur constantly. Recently, five mosquito species of the genus Aedes have been newly introduced to Europe where they are currently spreading in different regions. Uncommon autochthonous transmission of dengue and chikungunya fever viruses in Southern Europe could be directly linked to these vector species and of these Ae. albopictus and Ae. japonicus are currently reported to occur in Germany. The German Protection against Infection Act only covers the control of public health pests which are either active hematophagous vectors or mechanical transmitters of agents of diseases. Use of officially recommended biocidal products aiming to interrupt transmission cycles of vector-borne diseases, is confined to infested buildings only, including sewage systems in the case of Norway rat control. Outdoor vectors, such as hard ticks and mosquitoes, are currently not taken into consideration. Additionally, adjustments of national public health regulations, detailed arthropod vector and rodent reservoir mapping, including surveillance of vector-borne disease agents, are necessary in order to mitigate future disease risks.

Estimating the risk of communicable diseases aboard cargo ships

BACKGROUND

International travel and trade are known to be associated with the risk of spreading communicable diseases across borders. No international surveillance system for infectious diseases on ships exists. Outbreak reports and systematic studies mainly focus on disease activity on cruise ships. The study aims to assess the relevance of communicable disease occurrence on cargo ships.

METHODS

Retrospective analysis of all documented entries to 49 medical log books from seagoing cargo ships under German flag between 2000 and 2008. Incidence rates were calculated per 100 person-years at sea. Case series of acute respiratory illness, influenza-like illness, and infectious gastrointestinal illness affecting more than two persons within 1 successive week were classified as an outbreak. Attack rates were calculated based on number of entries to the medical log book in comparison to the average shipboard population during outbreak periods.

RESULTS

During more than 1.5 million person-days of observation, 21% of the visits to the ship's infirmary were due to presumably communicable diseases (45.8 consultations per 100 person-years). As many as 33.9 patients per 100 person-years sought medical attention for acute respiratory symptoms. Of the 68 outbreaks that met predefined criteria, 66 were caused by acute respiratory illness with a subset of 12 outbreaks caused by influenza-like illness. Attack rates ranged between 3 and 10 affected seafarers per ship (12.5&-41.6% of the crew). Two outbreaks of gastrointestinal illness were detected.

DISCUSSION

Respiratory illness is the most common cause of presumably communicable diseases aboard cargo ships and may cause outbreaks of considerable morbidity. Although the validity of the data is limited due to the use of nonprofessional diagnoses, missing or illegible entries, and restriction of the study population to German ships, the results provide guidance to ship owners and to Port Health Authorities to allocate resources and build capacities under International Health Regulations 2005.