Survey of rabies vaccination status of Queensland veterinarians and veterinary students

BACKGROUND

To determine the rabies vaccination status of Queensland veterinarians and veterinary students and their perception of zoonotic risk from Australian bat lyssavirus (ABLV).

DESIGN

Cross-sectional questionnaire surveys.

METHODS

Questionnaires were sent by post in 2011 to veterinary surgeons registered in Queensland, to final-year veterinary students at James Cook University via SurveyMonkey® in 2013 and to final-year veterinary students at James Cook University and University of Queensland via SurveyMonkey® in 2014.

RESULTS

The response rate for registered veterinarians was 33.5% and for veterinary students 33.3% and 30% in 2013 and 2014, respectively. Of the 466 registered veterinary surgeons, 147 (31.5%) had been vaccinated, with 72 (15.5%) currently vaccinated. For veterinary students the rabies vaccination rate was 20.0% (4/20) and 13.0% (6/46) in the 2013 and 2014 surveys, respectively. More than 95% of veterinary students had received the mandatory Q fever vaccine. Both veterinarians and students regarded bats and horses as high-risk species for zoonoses.

CONCLUSIONS

Queensland veterinarians and veterinary students have low levels of protection against ABLV. Although incidents of ABLV spilling over from a bat to a domestic mammal are likely to remain rare, they pose a significant human health and occupational risk given the outcome of infection in humans is high consequence. Principals of veterinary practices and veterinary authorities in Australia should implement a policy of rabies vaccination for clinical staff and veterinary students.

More bark than bite: Comparative studies are needed to determine the importance of canine zoonoses in Aboriginal communities. A critical review of published research

The objective of this review was to identify and critique over forty years of peer‐reviewed literature concerned with the transmission of canine zoonoses to Aboriginal people and determine the zoonotic organisms documented in dogs in Australian Aboriginal communities. A systematic literature search of public health, medical and veterinary databases identified 19 articles suitable for critical appraisal. Thirteen articles documented the occurrence of recognized zoonotic organisms in dogs in Aboriginal communities, including Toxocara canis, Dirofilaria immitis, Streptococcus dysgalactiae, Rickettsia felis, Sarcoptes scabiei and Giardia. Currently, there is definitive evidence indicating that dogs act as a reservoir for human scabies in Aboriginal communities. However, there is a need for large‐scale, high‐quality, comparative studies of dogs and humans from the same household to assess the occurrence and importance of transmission of S. scabiei and other diseases between dogs and humans. These studies should use current genetic and molecular techniques along with traditional techniques to identify and type organisms in order to better understand their epidemiology. This review has revealed that there is a lack of high‐quality comparative studies to determine whether dogs are contributing to human disease by transmitting zoonoses. Our recommendations differ significantly from current public health policy and may have substantial implications for human and dog health.

Adenomatous hyperplasia of the mucous glands in captive Archey's frogs (Leiopelma archeyi)

AIMS

To describe the gross and light microscopic characteristics of skin lesions observed on the ventral skin of captive Archey's frogs (Leiopelma archeyi) between 2000 and 2012, and to investigate their occurrence, possible aetiology and association with survival.

METHODS

Postmortem skin samples were obtained for histological evaluation from 37 frogs, with and without skin lesions, that died while in captivity at Auckland Zoo between 2000 and 2012. Four frogs with skin lesions were biopsied under general anaesthesia and samples used for both light and transmission electron microscopy. The records of 94 frogs held at the University of Otago and Auckland Zoo between 2000-2012 were reviewed, which included some frogs recently collected from the wild. Information about the occurrence of skin lesions, and mortality associated with skin lesions was collated.

RESULTS

Grossly the skin lesions varied in appearance; most were circular, pale grey papules, which measured from <0.5-1.5 mm in diameter with no umbilication. The overlying epidermis was not fragile and there was no associated inflammation. Contents often appeared clear or semi-transparent. Lesions were located predominantly on ventral surfaces including trunk, thighs, lower legs and forearms, and gular region, but not on digits. The number ranged from single to multiple, often confluent lesions covering the entire ventral surface of the frog. Histologically the lesions consisted of enlarged proliferating mucous glands that expanded the dermis and elevated the epidermis. They were semi-organised, solid or occasionally cavitated acinar structures with central lumina which sometimes contained mucus. Nuclei showed moderate anisokaryosis and mitotic figures were uncommon. Transmission electron microscopy did not show any infectious agents. Between 2000 and 2012, skin lesions were recorded in 35/94 (37%) frogs. The size and location of skin lesions varied over time, with some resolving and sometimes reappearing. Skin lesions were not associated with an increased risk of death.

CONCLUSIONS

The skin lesions had the gross and microscopic characteristics of adenomatous hyperplasia of the dermal mucous glands.

CLINICAL RELEVANCE

The aetiology of this adenomatous hyperplasia is unknown, but factors associated with the captive environment are the most likely cause. This is the first description of adenomatous hyperplasia of the cutaneous mucous glands in amphibians.

The application of One Health concept to an outdoor problem-based learning activity for veterinary students

Background:

The One Health (OH) approach, which seeks to bring together human and animal health, is particularly suited to the effective management of zoonotic diseases across both sectors. To overcome professional silos, OH needs to be taught at the undergraduate level. Here, we describe a problem-based learning activity using the OH approach that was conducted outdoors for 3^rd-year veterinary students in Malaysia.

Materials and Methods:

A total of 118 students, divided into two groups, completed the activity which spanned 1½ days at a deer park adjacent to a wilderness area. Students were asked to evaluate the activity using an online survey that had quantitative and qualitative components.

Results:

Response rate was 69.5%. The activity was rated excellent by 69.5% and good by 30.4%. Levels of satisfaction were high on a range of criteria. 97.5% of students intended to take action in their studies as a result of what they had learned.

Conclusions:

Delivery of an outdoor problem-based learning activity using OH approach was very successful in terms of participation, knowledge delivery and understanding, and the willingness of students to integrate OH into their future practice. For the improvement of future programs, the involvement of other disciplines (such as Medical, Biology, Biotechnology, Biomedical, and Public Health) is being considered.

Response of Australian veterinarians to the announcement of a Hendra virus vaccine becoming available

DESIGN

A cross-sectional study of private veterinarians providing equine services in Queensland.

RESULTS

The study revealed that a majority of veterinarians would support the introduction of a Hendra virus (HeV) vaccine. Moreover, almost half of the respondents intended to make vaccination a prerequisite to horse patient presentation. However, participants also responded that a vaccine would not reduce the risk sufficiently to cease or downgrade their HeV management plan and infection control measures.

CONCLUSION

When devising promoting and marketing campaigns, government agencies and manufacturers should consider private veterinarians' intentions as a significant driver for the uptake of the HeV vaccine.

TB questions, East Kwaio answers: community-based participatory research in a remote area of Solomon Islands

INTRODUCTION

East Kwaio is a remote region on the island of Malaita, Solomon Islands. Atoifi Adventist Hospital (the Hospital) is the only hospital and tuberculosis (TB) services provider in the region. If people come to the Hospital with TB, they are usually admitted for the two-month intensive phase of treatment as there are no community-based TB services. Most people walk or travel by canoe to the Hospital as there are no roads. East Kwaio is known to have high rates of TB; however, it has a low case detection rate and low treatment completion. The aims of this study were to explore why people with TB, especially from the mountain areas, present to the Hospital so late in their illness or do not present at all. The study was part of a larger project to strengthen the research capacity of local health workers and community leaders, supported by visiting researchers from Australia.

METHODS

Semi-structured interviews with TB patients, a focus group of key informants and direct interaction with a community with a history of TB were used to explore reasons why people present to the Hospital late in their TB illness.

RESULTS

Four interviews and a focus group of 12 key informants were conducted and a mountain hamlet with a history of TB was visited. The results represent the data from the interviews and the focus group. The time delay in presenting to the Hospital from when participants first became unwell ranged between two and three years. In the mountain hamlet, two additional people with probable TB were seen who had not presented to the Hospital during illnesses of five and nine months. Reasons for delays included: seeking care from traditional healers; the challenge of accessing health services due to distance, cost and cultural issues different from the Hospital's worldview; social isolation when in hospital; and being old so not having long to live. Delays in diagnosis of people with TB will increase the risk of transmission to family and through hamlets and villages. This study has led to plans being developed to build a more culturally appropriate TB ward and community treatment program.

CONCLUSIONS

The study has identified TB questions that need East Kwaio answers. It has shown that a small project can inform the development of important changes to TB services, such as the redevelopment and relocation of the TB ward. To enable TB control, the local health services need to develop an understanding of, and appropriately engage with, traditional beliefs that influence how people interact with Hospital TB treatment and management. This is the case even if the beliefs are based on a worldview different than that of the health service providers. Ongoing operational research is required into TB diagnosis and treatment services and the many factors that contribute to the high TB burden in this remote area.

Measuring the sustainability of a community safety promotion network: working from the inside out

Mackay Whitsunday Safe Communities (MWSC) was developed using a capacity building model that consciously attempted to design sustainability into the network. Our aim was to quantify the flow of resources used by MWSC to implement and sustain its injury control activities. Resource exchange among network members was quantified and analysed using social network analysis. In 2004, MWSC accessed an estimated 6.5 full-time staff equivalents and $0.9 million. However, these resources were largely accessed externally. The linking relationships that connected MWSC to its external support network, more than half of which were maintained by six broker network facilitators, were the critical social asset used to access resources and sustain network productivity. The sustainability of this network and arguably similar safety promotion networks is vulnerable to the changing priorities of external sponsoring agents and highly dependent on its leaders who facilitated access to the resources it required to remain productive.

Splenogonadal fusion and sex reversal

Splenogonadal fusion is a rare congenital malformation where an abnormal union occurs between the spleen and gonad or mesonephric derivatives. Although it occurs in females it is much less prevalent than in males (male:female ratio, 16:1), but this may partly be because of the inaccessibility of the female gonads leading to under-diagnosis. To our knowledge this is the first case of splenogonadal fusion associated with sex reversal reported in the literature.

Blood, guts and knife cuts: reducing the risk of swine brucellosis in feral pig hunters in north-west New South Wales, Australia

INTRODUCTION

Humans who have close contact with livestock, wild or feral animals can risk acquiring zoonotic infections such as brucellosis, Q fever, and leptospirosis. Human infection with Brucella suis (swine brucellosis) usually follows occupational or recreational exposure to infected animals. Worldwide, many cases of human infection follow contact with infected feral pigs. In Australia there is a growing market for the export of 'wild boar' and a considerable number of people are involved in feral pig hunting. However, feral pig hunters are often hard to reach with health strategies. According to Australian authorities the most important means of preventing disease in humans includes covering cuts; wearing gloves; washing hands; and avoiding blood when coming into contact with feral pigs. There has not been an evaluation of the acceptability of these recommended risk-reduction strategies in the settings where feral pig hunting and evisceration occurs.

METHODS

Semi-structured interviews and small focus groups were conducted with feral pig hunters in north-west New South Wales (NSW), Australia, to explore their hunting experiences and views on the brucellosis prevention strategies. Interview and focus group notes were thematically analysed.

RESULTS

There was a range of experiences of feral pig hunting, from a very professional approach to a purely recreational approach. The main domains that emerged from participants' experiences during their most recent feral pig hunting activity and their reflections on current swine brucellosis risk reduction strategies were: 'you've gotta be tough to be a feral pig hunter'; 'most of the suggested strategies won't work as they are'; 'reducing risk in the scrub'; and 'how to let pig hunters know'. The recreational nature and prevailing macho perspective of participants demand a pragmatic approach to risk reduction if it is going to prove acceptable to feral pig hunters. The 'you've gotta be tough to be a feral pig hunter' context of the activity and the reality that many feral pig hunters participate with little preparation and a 'just keep going' approach, may counteract currently recommended risk-reduction strategies. The alternate strategies that emerged from the interviews need to be tested in the real activity, especially evisceration 'in the scrub' (at the site of slaughter). But the following ideas were grounded in the participants' experiences: take more time and watch your hands when making cuts; have good lighting; take care when cutting near a sow's uterus; use latex gloves to cover cuts on hands.

CONCLUSIONS

Swine brucellosis is a zoonosis of concern for feral pig hunters in many parts of Australia, including north-west NSW. Many of the current strategies to reduce the risk of brucellosis did not appear appropriate or acceptable to the feral pig hunters interviewed. More acceptable strategies when eviscerating, such as taking more time, watching hands when cutting, ensuring good lighting, being careful in the vicinity of the uterus and using a latex glove to cover cuts and abrasions on hands need to be field tested. Further development of the food safety regulations is required to also support zoonosis risk reduction strategies.

Minimising exposure of amphibians to pathogens during field studies

Many of the recent global amphibian mass mortalities, declines and extinctions have been attributed to the emerging infectious disease chytridiomycosis. There have been mass mortalities due to ranaviral disease but no major declines or extinctions. Controlling the transmission and spread of disease is of utmost importance, especially where there is the potential for human involvement. We have reviewed current hygiene guidelines for working with wild frogs, identified potential flaws and recommended those most suitable and effective for the field environment. Our within-site hygiene measures aim to reduce the risk of transmission among individuals. These measures encompass the capture, handling and holding of amphibians, skin disinfection before and after invasive procedures, marking frogs, sealing open wounds and treatment of accessory equipment. Our between-site hygiene measures aim to mitigate the risk of pathogen spread among populations. We have designed a risk calculator to help simplify and standardise the decision-making process for determining the level of risk and appropriate risk mitigation strategies to reduce the risk of increasing pathogen spread above background levels. Calculation of an overall risk score for pathogen spread takes into account the prior activity of field workers, the proposed activity, remoteness of the site, presence of known pathogens and the consequences of increased pathogen spread for amphibians in a given area.

The latest endangered species in Australia: a tobacco-smoking veterinarian

The results of a tobacco smoking survey conducted among veterinarians in Queensland, Australia, during 2007 are presented. Of the 567 participants only 3% reported being current smokers, 24% were ex-smokers and 73% had never smoked. The prevalence of smoking was similar among males and females, and the highest smoking rate was reported among veterinarians aged 31-40 years. However, the rate of never-smokers was strongly and negatively correlated with age, and the proportion of ex-smokers increased with age. Encouragingly, the results from this study suggest that tobacco use has all but disappeared from the Australian veterinary profession in recent years.

Pathology of cutaneous trombidiosis caused by larval trombiculid mites in a wild Lesueur's tree frog (Litoria wilcoxii)

Cutaneous trombidiosis caused by larvae of trombiculid mites (Vercammenia gloriosa and V. zweifelorum) in the skin of a wild tree frog, Litoria wilcoxii, in northern Queensland, Australia manifested as small, domed vesicular lesions on the dorsal and lateral surfaces posterior to the eyes. The lesions contained small, orange trombiculid mites, with a surrounding minimal inflammatory reaction. The general health and behaviour of the frog appeared unaffected. Provisional diagnosis of cutaneous trombidiosis can be made from its distinctive clinical appearance and confirmed by biopsy with direct microscopic examination of mites. This case report represents a new host record.

Musculoskeletal disorders and psychosocial risk factors among veterinarians in Queensland, Australia

OBJECTIVE

Although musculoskeletal disorders (MSD) represent one of the most important occupational health issues in contemporary society, few studies have specifically investigated this problem among veterinarians.

DESIGN

An anonymous questionnaire survey mailed to all veterinarians registered with the Veterinary Surgeons Board of Queensland during 2006.

RESULTS

Almost two-thirds of respondents (63%) had experienced MSD of the lower back, 57% had experienced neck-related MSD, 52% had experienced shoulder-related MSD and 34% had experienced MSD of the upper back during the previous 12 months. MSD was statistically correlated with a range of psychosocial factors, including stress associated with career structure, time pressures, client's attitude, lack of recognition by the public, lack of recognition by colleagues, lack of understanding from family or partners and work stress because of insufficient holidays each year.

CONCLUSION

Overall, this study has demonstrated significant correlations between MSD and psychosocial risk factors among a large cohort of veterinarians, apparently for the first time in the published literature. The results also suggest that personal and workplace issues may contribute more to the development of MSD among veterinarians than many of the previously recognised ergonomic risk factors.

In vitro efficacy of over-the-counter botanical pediculicides against the head louse Pediculus humanus var capitis based on a stringent standard for mortality assessment

Infestation of the head louse Pediculus humanus var capitis DeGeer (Phthiraptera: Pediculidae) is an important public health problem in Australia, with up to a third of children infested in some primary schools. Insecticide resistance and inadequate attention to the application instructions of topical pediculicides are common reasons for treatment failure. This study evaluated six popular Australian over-the-counter products against head lice, primarily comprised of different botanical extracts, and compared them with permethrin 1% (Quellada) and a non-treatment control in order to assess their in vitro efficacy. We also assessed commonly used criteria for evaluating pediculicide efficacy in vitro. All tested products failed to demonstrate high levels of efficacy with the exception of Tea Tree Gel((R)), which outperformed 1% permethrin. Permethrin had a high level of efficacy, but using stringent criteria 18% of lice were not dead at 3 h, indicating some resistance to Quellada. Commonly used less stringent criteria were shown to overestimate mortality of head lice as a result of the protective phenomenon of stasis or sham death observed in exposed lice that may recover after some time. Using two different levels of stringency resulted in different rankings of efficacy for most products, with the exception of the first ranked product, Tea Tree Gel. Rankings of efficacy also varied over time, even within the different assessment criteria. Government regulatory agencies should require standard in vitro tests using stringent mortality criteria, with an observation period of >or= 6 h, to determine the efficacy of new pediculicides, and only products that cause a minimum mortality rate (e.g. 80%) in head lice collected from the target population should be licensed for sale.

High in vitro efficacy of Nyda L, a pediculicide containing dimeticone

BACKGROUND

The therapy of pediculosis remains a common problem in clinical practice. As resistance to commonly used chemical pediculicides is constantly increasing, there is a need for new effective compounds.

STUDY DESIGN

The efficacy of Nyda L, a new pediculicide containing a high concentration of dimeticone, was assessed in an in vitro trial and compared with three reference products (Hedrin containing 4% dimeticone, Lyclear containing 1% permethrin, and Prioderm containing 1% malathion) and a negative control group. Head lice were collected from heavily infested patients in a resource-poor community in Northeast Brazil, where no resistance against pediculicides has been reported thus far. In each of the five groups, 50 adult fully vital lice were tested. We used a dip test (immersing head lice in the undiluted products for 3 min, washing off products after 20 min). Using predefined criteria for mortality, the lice were monitored at different points in time, for a period of 24 h.

RESULTS

Nyda L and Prioderm killed all head lice already after 5 min. The efficacy of Nyda L was better than of Lyclear. Lice treated with Hedrin resurrected after several hours and did not show a significantly higher mortality compared with the control group after 24 h.

CONCLUSION

Nyda L can be regarded as a very efficacious pediculicidal compound, killing all lice in vitro within 5 min.

Toxic effects of mebendazole at high dose on the haematology of red-legged pademelons (Thylogale stigmatica)

OBJECTIVE

To investigate the effects of mebendazole at high dose on the haematology of macropods. Experimental.

PROCEDURE

Five red-legged pademelons (Thylogale stigmatica) were dosed orally with mebendazole at 50 mg/kg/d for 5 to 6 days. Two control pademelons were dosed with water. Regular blood samples were taken for haematology over 20 days.

RESULTS

All four treated pademelons sampled at 5 days developed severe leucopenia and neutropenia, moderate lymphopenia, thrombocytopenia, eosinopenia and monocytopenia, as well as bone marrow aplasia within 5 to 11 days after the first mebendazole dose. Four pademelons died unexpectedly or became ill and were euthanased 5 to 11 days after the first dose while the other animal recovered after 5 days of illness. Necropsy revealed systemic infection with opportunistic enteric bacteria, non-suppurative inflammation in tissues, haemorrhage and ulceration of the gastrointestinal tract.

CONCLUSIONS

Red-legged pademelons rapidly develop bone-marrow aplasia and subsequent septicaemia after administration of high doses of mebendazole. Mebendazole at high doses should not be used for macropods.

What parents in Australia know and do about head lice

INTRODUCTION

Although parents in developed market economies regard head lice infections (pediculosis) as a significant problem, health departments generally rate pediculosis as a low priority health issue, encouraging parents to manage and control it. But how well equipped and willing are parents to manage the infections? There do not appear to be any studies in the literature addressing these issues. This article presents the results of a survey conducted in Australia that aimed to answer these questions.

METHODS

A cross-sectional survey of parents of primary school aged children in Victoria (Vic) and north Queensland (NQ) was conducted using a self-administered questionnaire. The study investigated the knowledge, attitudes and practices of parents regarding head lice infections.

RESULTS

Only 7.1% of 1338 who completed the questionnaire answered all 10 knowledge questions correctly and more than one-third failed to answer half correctly. There was a weak negative correlation between parents' knowledge and the prevalence of active pediculosis in the school. Almost all parents wanted the responsibility for treating pediculosis and more than three-quarters saw it as a health concern. A higher proportion of parents in NQ used preventative strategies (67% vs 41%). Most parents spent less than AU$50 per year on treatments. Alarmingly, however, the proportion of children missing school as a result of pediculosis was 24.4% and 30.3% in Vic and NQ, respectively. In Vic there was a positive correlation (r = 0.39) between missing school in the previous 12 months and prevalence of pediculosis in the school.

CONCLUSIONS

This appears to be the most comprehensive study of parental knowledge, beliefs, and practices regarding head lice infections. Although parents wanted responsibility for the management of pediculosis, deficiencies in their knowledge indicate they may be inadequately equipped to do so. Given the high proportion of children in both states who have missed school as a result of head lice, it is recommended that health departments in Australia should work to ensure that consistent and accurate messages about pediculosis are disseminated, and that relevant legislation is amended to prevent children being excluded from school.

Additional disinfectants effective against the amphibian chytrid fungus Batrachochytrium dendrobatidis

Chytridiomycosis, a disease contributing to amphibian declines worldwide, is caused by the fungus Batrachochytrium dendrobatidis. Identifying efficient and practical disinfectants effective against B. dendrobatidis is important to reduce the spread of the disease both in the wild and captivity. Previous studies identified a range of suitable disinfectant strategies. We evaluated the suitability of 3 additional disinfectants: two of these (TriGene Virucidal Disinfectant Cleaner and F10 Super Concentrate Disinfectant) are mixtures of chemicals and one (Betadine Antiseptic Liquid) contains a single active ingredient, povidone iodine. The disinfectants were tested using a range of concentrations for 1,5 and 10 min to determine their ability to kill B. dendrobatidis in vitro. The measure of effectiveness was 100% kill of zoosporangia grown in multiwell plates. All disinfectants had a 100% efficacy at concentrations recommended by the manufacturers. The lowest concentrations capable of 100% kill after exposure for 1 min were 0.1 ml l(-1) for TriGene, 0.33 ml l(-1) for F10 and 100 ml l(-1) for Betadine. TriGene is the most effective disinfectant yet to be found, and both TriGene and F10 are more effective than various disinfectants tested in previous studies. TriGene and F10 are considered suitable for use in the field, as only small amounts of concentrate are needed.

The argument for integrating vector control with multiple drug administration campaigns to ensure elimination of lymphatic filariasis

BACKGROUND

There is a danger that mass drug administration campaigns may fail to maintain adequate treatment coverage to achieve lymphatic filariasis elimination. Hence, additional measures to suppress transmission might be needed to ensure the success of the Global Program for the Elimination of Lymphatic Filariasis.

DISCUSSION

Vector control successfully eliminated lymphatic filariasis when implemented alone or with mass drug administration. Challenges to lymphatic filariasis elimination include uncertainty of the exact level and duration of microfilarial suppression required for elimination, the mobility of infected individuals, consistent non-participation of some infected individuals with mass drug administration, the possible development of anti-filarial drug resistance and treatment strategies in areas co-endemic with loasis. Integration of vector control with mass drug administration can address some of these challenges. The potential benefits of vector control would include: (1) the ability to suppress filariasis transmission without the need to identify all individual 'foci of infection'; (2) minimizing the risk of reestablishment of transmission from imported microfilaria positive individuals; and (3) decreasing the risk of dengue or malaria transmission where, respectively, Aedes or Anopheles are lymphatic filariasis vectors.

SUMMARY

With adequate sustained treatment coverage, mass drug administration should meet the criteria for elimination of lymphatic filariasis. However, it may be difficult to sustain sufficiently high mass drug administration coverage to achieve lymphatic filariasis elimination in some areas, particularly, where Aedes species are the vectors. Since vector control was effective in controlling and even eliminating lymphatic filariasis transmission, integration of vector control with mass drug administration will ensure the sustainability of transmission suppression and thereby better ensure the success of national filariasis elimination programs. Although trials of some vector control interventions are needed, proven vector control strategies are ready for immediate integration with mass drug administration for many important vectors. Vector control is the only presently available additional lymphatic filariasis control measure with the potential for immediate implementation.

Decline in the prevalence of chytridiomycosis in frog populations in North Queensland, Australia

In the early 1990s stream-associated amphibian populations in tropical upland North Queensland experienced severe declines resulting in extinction of three species, local elimination of four species, marked reductions in one species and apparently no declines in other species, Chytridiomycosis, a disease due to the amphibian chytrid fungus, Batrachochylrium dendrobatidis, was the likely cause of this epidemic. We conducted a monitoring study for chytridiomycosis in four species of frogs in North Queensland from October 1998 to October 2002 by collecting specimens in the field and using histology of removed digits to diagnose chytridiomycosis. Chytridiomycosis was diagnosed in 112 (7,1%) of the 1 578 specimens and prevalence was significantly associated with season and altitude, with higher prevalences in winter and above 300 metres altitude. A multivariate model adjusting for potential confounding effects arising from the sampling process demonstrated a significant decline in the time trend of prevalence of chytridiomycosis. The study supports the hypothesis that B. dendrobatidis becomes endemic after the initial epidemic wave. Since the surviving species of stream-associated frog, Litoria genimaculata, has increased to pre-decline numbers, the decline in prevalence of chytridiomycosis is evidence of a changed pathogen-host relationship. The reasons for this change are speculative but could be due to an increase in innate host resistance in response to selection pressure by B. dendrobatidis or to lower rainfall associated with an EI Nino effect. These findings justify management strategies that assist susceptible amphibian species to survive an initial epidemic wave of chytridiomycosis.

Head lice prevalence in primary schools in Victoria, Australia

OBJECTIVES

To determine the prevalence of and assess risk factors associated with head lice infections (pediculosis) in children from government primary schools in Victoria, Australia.

METHODS

Between May and October 2001, children were selected by clustered random sampling of schools and classes, then examined for head lice using hair conditioner and a fine-toothed head lice comb. There were 1838 children screened from 16 primary schools. Risk factors evaluated included metropolitan or rural residence, school class, gender and hair length.

RESULTS

Thirteen percent of children (239/1838) had an active infection (95% CI, 10.9-15.1) and 3.3% (61/1838) had an inactive infection (95% CI, 2.0-4.6). Prevalence of active pediculosis varied between schools from 0 to 28%. Our screening identified no more than one case per class in the majority of classes screened (58.5%). Females were 2.2 times more likely to have active infection than males (95% CI [1.7,2.9]) and there was no significant difference for the other risk factors investigated.

CONCLUSIONS

Our study demonstrated the prevalence of head lice varied across Victoria and showed that risk factors commonly attributed to head lice infections did not hold true. Our findings support the premise that traditional ad hoc mass school-based screening may not be the best use of resources when controlling head lice. We suggest a more pragmatic community-based approach.

Adaptive immunity in melioidosis: a possible role for T cells in determining outcome of infection with Burkholderia pseudomallei

Melioidosis is a potentially fatal disease caused by the bacterium Burkholderia pseudomallei. Individuals with subclinical melioidosis have no apparent clinical signs or symptoms, and are identified only by positive serology. The present study is the first to investigate cell-mediated immune (CMI) responses following in vitro stimulation with B. pseudomallei antigens in peripheral blood mononuclear cells (PBMC), collected under field conditions in Papua New Guinea (PNG) from individuals with exposure to B. pseudomallei (n = 13). While five had a clinical history of melioidosis (C(+)), the remaining individuals (n = 8) were seropositive, yet healthy with no clinical history of melioidosis (S(+)/C(-)). Proliferation and IFN-gamma production were significantly greater in lymphocyte cultures from S(+)/C(-) individuals compared to C(+) individuals (P < 0.001 and P < 0.05, respectively). These findings demonstrate that compared to C(+) patients, individuals with subclinical melioidosis have a stronger CMI response to B. pseudomallei antigens in vitro. Such a response may be essential for protection against disease progression.

Strongyloides serology--useful for diagnosis and management of strongyloidiasis in rural Indigenous populations, but important gaps in knowledge remain

General practitioners who care for Aboriginal patients in rural and remote communities from tropical Australia must be aware of strongyloidiasis. The prevalence of this parasitic infection is high and occasional cases can have a fatal outcome. Other groups in Australia at high risk of strongyloidiasis are immigrants from endemic countries, particularly from Southeast Asia, and military personnel who have served overseas in endemic areas. Elimination programs for enteric parasites in rural Australian Indigenous communities are so important that a nationally coordinated approach has been advocated. Wisely used, cost-effective diagnostic tests are a critical component of an elimination program. Strongyloidiasis must be confirmed by laboratory diagnosis and the strongyloides ELISA, although not ideal, is a useful test that can be used to diagnose strongyloidiasis and to monitor cure. In this article the value of the current strongyloides ELISA is discussed and a cost-benefit analysis is conducted using direct costs only. In a typical rural Aboriginal community in tropical Australia with prevalence of strongyloidiasis at 20% each true positive case detected by the strongyloides ELISA is estimated to cost approximately AU590 dollars to diagnose and manage until cure, proven by negative serology.

Effect of season and temperature on mortality in amphibians due to chytridiomycosis

OBJECTIVE

To investigate the distribution and incidence of chytridiomycosis in eastern Australian frogs and to examine the effects of temperature on this disease.

DESIGN

A pathological survey and a transmission experiment were conducted.

PROCEDURE

Diagnostic pathology examinations were performed on free-living and captive, ill and dead amphibians collected opportunistically from eastern Australia between October 1993 and December 2000. We conducted a transmission experiment in the laboratory to investigate the effects of temperature: eight great barred frogs (Mixophyes fasciolatus) exposed to zoospores of Batrachochytrium dendrobatidis and six unexposed frogs were housed individually in each of three rooms held at 17 degrees C, 23 degrees C and 27 degrees C.

RESULTS

Chytridiomycosis was the cause of death or morbidity for 133 (55.2%) of 241 free-living amphibians and for 66 (58.4%) of 113 captive amphibians. This disease occurred in 34 amphibian species, was widespread around the eastern seaboard of Australia and affected amphibians in a variety of habitats at high and low altitudes on or between the Great Dividing Range and the coast. The incidence of chytridiomycosis was higher in winter, with 53% of wild frogs from Queensland and New South Wales dying in July and August. Other diseases were much less common and were detected mostly in spring and summer. In experimental infections, lower temperatures enhanced the pathogenicity of B. dendrobatidis in M. fasciolatus. All 16 frogs exposed to B. dendrobatidis at 17 degrees C and 23 degrees C died, whereas 4 of 8 frogs exposed at 27 degrees C survived. However, the time until death for the frogs that died at 27 degrees C was shorter than at the lower temperatures. Infections in survivors were eliminated by 98 days.

CONCLUSION

Chytridiomycosis is a major cause of mortality in free-living and captive amphibians in Australia and mortality rate increases at lower temperatures.

A squamous cell carcinoma and an adenocarcinoma in Australian treefrogs

We describe the pathology in a captive adult White lipped treefrog (Litoria infrafrenata) with a squamous cell carcinoma of the skin and a free-living adult Common green treefrog (L. caerulea) with an adenocarcinoma of the skin. Although many amphibian neoplasms have been reported world wide, none had been described in Australian species.

Strongyloidiasis: an issue in Aboriginal communities

Strongyloidiasis, a disease caused by the parasitic gut nematode (roundworm), Strongyloides stercoralis, has the highest prevalence in the world in rural and remote Aboriginal communities of northern Australia. With prevalences greater than 25%, these communities have rates of strongyloidiasis higher those in the worst affected developing countries where surveys have been recently conducted. Available data indisputably support that strongyloidiasis is more prevalent in rural and remote Aboriginal communities than in the mainstream Australian community. However control of strongyloidiasis has not been given a high priority by government health departments, with the result that Aboriginal people in remote and rural communities in Northern Australia are still suffering from a preventable and treatable disease. This article suggests that the only way to address the strongyloidiasis problem in Indigenous communities is to have strongyloidiasis recognised and addressed at the national level. One component of this must be making health departments responsible for establishing appropriate systems of effective treatment for and monitoring of patients with strongyloidiasis.

Leprosy in Mpumalanga Province, South Africa--eliminated or hidden?

In South Africa, leprosy has been a notifiable condition since 1921. Although the WHO elimination target of less than one case per 10,000 population has been achieved at country level, the distribution of leprosy in the country is distinctly heterogeneous, with a prominent 'leprosy belt' of greater prevalence stretching across Mpumalanga Province into northern Kwa-Zulu Natal. The highest prevalence in this 'belt' has historically been in Ermelo District. Recent trends of few newly detected leprosy patients in this district raised concerns that health system changes may have resulted in failure to detect leprosy cases. Thus a large-scale community awareness campaign was conducted followed by an intensively advertised screening programme of 3-month duration at schools and central gathering points in villages and farms from 1 June to 31 August 2000. One thousand one hundred and seventy-seven people presented for clinical screening at designated points, while 790 scholars were screened at schools and an additional 1433 people were screened at their homes by the field team. Forty-four people with skin or nervous system lesions compatible with leprosy were referred for specialized assessment and biopsy where indicated. Four new leprosy patients were diagnosed, including an elderly lady with pronounced disability. Two of these patients had prior contact with the health service due to dermatological manifestations of leprosy without diagnosis being made. All patients provided a history of close prolonged contact with known leprosy patients. Ongoing intense tracing and follow-up of close contacts of proven leprosy cases may be a more efficient method of detecting leprosy cases in areas with relatively stable populations that have accomplished 'leprosy elimination', than resource intensive community surveys.

Rabies post-exposure management in South Africa: a telephonic survey used as a rapid tool for operational research

Rabies is an important disease in rural South Africa, and vaccine and immunoglobulin are provided, at the State's expense, to humans following suspected exposure to rabies virus by bite, scratch or mucosal splash. Health facilities where post-exposure treatment is available are listed, with contact telephone numbers, in national rabies guidelines. To verify the accuracy of this recently updated information, members of the national Rabies Advisory Group were tasked to complete a rapid survey. A simple standardized telephone interview technique was used. This revealed startling deficiencies in the availability of vaccine and immunoglobulin at the indicated sites and led to decisive corrective action. This 'quick and dirty' survey technique provided valuable information for improving an important public health programme, and should be considered when auditing other health programmes, particularly where a means for validating responses is readily available.

A case of pubic lice resistant to pyrethrins

BACKGROUND

Effective therapeutic protocols for the treatment of pubic lice include application of approved insecticidal products to all body and scalp hair, retreatment at seven days, and use of mechanical removal of lice and eggs.

OBJECTIVE

We report here infection with pubic lice in a 43 year old male in Australia which failed to be eradicated by adequate therapy with a pyrethrin and piperonyl butoxide product.

DISCUSSION

Pubic lice collected from the case survived after exposure to the same product in vitro. The infestation was cured by use of 5% permethrin. This appears to be the first report of Pthirus pubis resistant to insecticides, in this case pyrethrins and their synergist, piperonyl butoxide.

Salmonelliasis in wildlife from Queensland

During a 20 yr period (1978 to 1998), 233 isolates of Salmonella spp. were cultured from 179 wildlife animals (representing 25 species), 32 crocodile (Crocodylus porosus) eggs and six crocodile nesting sites, and represented 59 different serotypes. Salmonella serotype Virchow, the major serotype infecting humans in north Queensland, (Australia) was common in macropodids, but was not found in reptiles and was isolated only once from cane toads (Bufo marinus). Investigations of human cases of salmonellosis should include simultaneous studies on wild and domestic animals in contact with the case.

The use of hospital-based nurses for the surveillance of potential disease outbreaks

OBJECTIVE

To study a novel surveillance system introduced in Mpumalanga Province, a rural area in the north-east of South Africa, in an attempt to address deficiencies in the system of notification for infectious conditions that have the potential for causing outbreaks.

METHODS

Hospital-based infection control nurses in all of Mpumalanga's 32 public and private hospitals were trained to recognize, report, and respond to nine clinical syndromes that require immediate action. Sustainability of the system was assured through a schedule of regular training and networking, and by providing feedback to the nurses. The system was evaluated by formal review of hospital records, evidence of the effective containment of a cholera outbreak, and assessment of the speed and appropriateness of responses to other syndromes.

FINDINGS

Rapid detection, reporting and response to six imported cholera cases resulted in effective containment, with only 19 proven secondary cholera cases, during the two-year review period. No secondary cases followed detection and prompt response to 14 patients with meningococcal disease. By the end of the first year of implementation, all facilities were providing weekly zero-reports on the nine syndromes before the designated time. Formal hospital record review for cases of acute flaccid paralysis endorsed the value of the system.

CONCLUSION

The primary goal of an outbreak surveillance system is to ensure timely recognition of syndromes requiring an immediate response. Infection control nurses in Mpumalanga hospitals have excelled in timely weekly zero-reporting, participation at monthly training and feedback sessions, detection of priority clinical syndromes, and prompt appropriate response. This review provides support for the role of hospital-based nurses as valuable sentinel surveillance agents providing timely data for action.

Prevalence of filarial antigenaemia in Papua Nnew Guinea: results of surveys by the School of Public Health and Tropical Medicine, James Cook University, Townsville, Australia

During the period from 1991 to 1997 the School of Public Health and Tropical Medicine, James Cook University carried out filariasis surveys in several parts of Papua New Guinea using the newly introduced Onchocerca gibsoni monoclonal (Og4C3) and immunochromatographic test (ICT) antibody-based assays for filarial antigen and, in some cases, a Knott's test for microfilariae. The average prevalence of filarial antigenaemia and microfilaraemia was 56% and 35% respectively confirming earlier survey results that filariasis is hyperendemic in many parts of the country. The antigen tests detected 25% more cases than the Knott's test and the simplicity of the ICT and its capacity to produce almost instant results make it an ideal tool for surveys.