Genetic diversity of Koala retrovirus env gene subtypes: insights into northern and southern koala populations.

Koala retrovirus (KoRV) is a recently endogenized retrovirus associated with neoplasia and immunosuppression in koala populations. The virus is known to display sequence variability and to be present at varying prevalence in different populations, with animals in southern Australia displaying lower prevalence and viral loads than northern animals. This study used a PCR and next-generation sequencing strategy to examine the diversity of the KoRV env gene in both proviral DNA and viral RNA forms in two distinct populations representative of the 'northern' and 'southern' koala genotypes. The current study demonstrated that the full range of KoRV subtypes is present across both populations, and in both healthy and sick animals. KoRV-A was the predominant proviral subtype in both populations, but there was marked diversity of DNA and RNA subtypes within individuals. Many of the northern animals displayed a higher RNA viral diversity than evident in their proviral DNA, indicating relatively higher replication efficiency of non-KoRV-A subtypes. The southern animals displayed a lower absolute copy number of KoRV than the northern animals as reported previously and a higher preponderance of KoRV-A in individual animals. These discrepancies in viral replication and diversity remain unexplained but may indicate relative protection of the southern population from KoRV replication due to either viral or host factors and may represent an important protective effect for the host in KoRV's ongoing entry into the koala genome.

Health Risks and Adverse Reactions to Functional Foods.

Functional foods have become increasingly popular with consumers anxious to mitigate the effects of an unhealthy lifestyle or aging. In spite of attractive health claims, these products do not have legal or regulatory status in most countries and are regulated through their health claims. Regulation of functional foods by health claims does not address health risks and adverse effects of these products. In this essay regulatory aspects of functional foods are reviewed along with adverse effects published in the peer-reviewed literature. We detail why the lack of an internationally accepted definition of functional foods places consumers at risk of adverse outcomes. Our review will assist regulatory agencies, manufacturers and consumer groups to assess the benefits and reduce the risks associated with these products.

Postharvest treatment of fresh fruit from California with methyl bromide for control of light brown apple moth (Lepidoptera: Tortricidae).

Methyl bromide (MB) chamber fumigations were evaluated for postharvest control of light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), in fresh fruit destined for export from California. To simulate external feeding, larvae were contained in gas-permeable cages and distributed throughout loads of peaches, plums, nectarines (all Prunus spp.), apples (Malus spp.), raspberries (Rubus spp.), or grapes (Vitis spp.). Varying the applied MB dose and the differential sorption of MB by the loads resulted in a range of exposures, expressed as concentration x time cross products (CTs) that were verified by gas-chromatographic quantification of MB in chamber headspace over the course of each fumigation. CTs > or = 60 and > or = 72 mg liter(-1) h at 10.0 +/- 0.5 and 15.6 +/- 0.5 degrees C (x +/- s, average +/- SD), respectively, yielded complete mortality of approximately 6,200 larvae at each temperature. These confirmatory fumigations corroborate E. postvittana mortality data for the first time in relation to measured MB exposures and collectively comprise the largest number of larval specimens tested to date. In addition, akinetic model of MB sorption was developed for the quarantine fumigation of fresh fruit based on the measurement of exposures and how they varied across the fumigation trials. The model describes how to manipulate the applied MB dose, the load factor, and the load geometry for different types of packaged fresh fruit so that the resultant exposure is adequate for insect control.

Novel insights into viral infection and oncogenesis from koala retrovirus (KoRV) infection of HEK293T cells.

Koala retrovirus is thought to be an underlying cause of high levels of neoplasia and immunosuppression in koalas. While epidemiology studies suggest a strong link between KoRV and disease it has been difficult to prove causality because of the complex nature of the virus, which exists in both endogenous and exogenous forms. It has been difficult to identify koalas completely free of KoRV, and infection studies in koalas or koala cells are fraught with ethical and technical difficulties, respectively. This study uses KoRV infection of the susceptible human cell line HEK293T and RNAseq to demonstrate gene networks differentially regulated upon KoRV infection. Many of the pathways identified are those associated with viral infection, such as cytokine receptor interactions and interferon signalling pathways, as well as viral oncogenesis pathways. This study provides strong evidence that KoRV does indeed behave similarly to infectious retroviruses in stimulating antiviral and oncogenic cellular responses. In addition, it provides novel insights into KoRV oncogenesis with the identification of a group of histone family genes that are part of several oncogenic pathways as upregulated in KoRV infection.

Koala retrovirus viral load and disease burden in distinct northern and southern koala populations.

Koala retrovirus (KoRV) displays features of both an endogenous and exogenous virus and is linked to neoplasia and immunosuppression in koalas. This study explores the apparent differences in the nature and impact of KoRV infection between geographically and genetically separated "northern" and "southern" koala populations, by investigating the disease status, completeness of the KoRV genome and the proviral (DNA) and viral (RNA) loads of 71 northern and 97 southern koalas. All northern animals were positive for all KoRV genes (gag, pro-pol and env) in both DNA and RNA forms, whereas many southern animals were missing one or more KoRV genes. There was a significant relationship between the completeness of the KoRV genome and clinical status in this population. The proviral and viral loads of the northern population were significantly higher than those of the southern population (P < 0.0001), and many provirus-positive southern animals failed to express any detectable KoRV RNA. Across both populations there was a positive association between proviral load and neoplasia (P = 0.009). Potential reasons for the differences in the nature of KoRV infection between the two populations are discussed.

Panel: rights of people in prison to HIV prevention, treatment and care.

This article contains summaries of the five presentations made during this panel. Ralf Jürgens provides an overview of the issue of needle exchange programs in prisons, and reviews the international experience with such programs. Sandra Ka Hon Chu advances the legal and human rights arguments for establishing needle exchanges in Canadian prisons. Giselle Dias describes the inter-sectoral strategy for HIV/AIDS is prisons being developed by the Prisoners HIV/AIDS Support Action Network (PASAN). Finally, two former prisons turned activists, James Motherall and Greg Simmons, provide their personal perspectives on prevention and treatment behind bars.

Chlamydia pecorum prevalence in South Australian koala (Phascolarctos cinereus) populations: Identification and modelling of a population free from infection.

Chlamydia pecorum is an established and prevalent infection that produces severe clinical disease in many koala populations, contributing to dramatic population declines. In wild South Australian koala populations, C. pecorum occurrence and distribution is unknown. Here, C. pecorum-specific real-time quantitative PCR (qPCR) was applied to ocular and urogenital swabs from targeted surveys of wild koalas from the mainland Mount Lofty Ranges (MLR) (n = 75) and Kangaroo Island (KI) (n = 170) populations. Historical data from 13,081 KI koalas (1997-2018) provided additional evidence for assessing the absence of C. pecorum infection. In the MLR population, 46.7% (CI: 35.1-58.6%) of koalas were C. pecorum positive by qPCR but only 4% had grade 3 clinical disease. MLR koala fertility was significantly reduced by C. pecorum infection; all reproductively active females (n = 16) were C. pecorum negative, whereas 85.2% of inactive females (n = 23) were positive (P < 0.001). KI koalas were C. pecorum negative and the population was demonstrated to be free of C. pecorum infection with 95% confidence. C. pecorum is a real threat for the sustainability of the koala and KI is possibly the last isolated, large C. pecorum-free population remaining in Australia. These koalas could provide a safeguard against this serious disease threat to an iconic Australian species.

Prevalence and clinical significance of koala retrovirus in two South Australian koala (Phascolarctos cinereus) populations.

PURPOSE: Koala retrovirus (KoRV-A) is 100  % prevalent in northern Australian (Queensland and New South Wales) koala populations, where KoRV-B has been associated with Chlamydia pecorum disease and the development of lymphosarcoma. In southern populations (Victoria and South Australia), KoRV-A is less prevalent and KoRV-B has not been detected in Victoria, while the current prevalence in South Australian populations is unknown but is thought to be low. This study aimed to determine (i) the prevalence of KoRV in the two largest South Australian koala populations [Kangaroo Island (KI) and Mount Lofty Ranges (MLR)], (ii) KoRV subtype and (iii) if an association between KoRV and C. pecorum exists. METHODOLOGY: Wild koalas were sampled in KI ( n =170) between 2014 and 2017 and in MLR ( n =75) in 2016. Clinical examinations were performed, with blood collected for KoRV detection and typing by PCR. RESULTS: KoRV prevalence was 42.4  % [72/170, 95 % confidence interval (CI): 34.9-49.8  %] in KI and 65.3  % (49/75, 95 % CI: 54.6-76.1  %) in MLR. Only KoRV-A, and not KoRV-B, was detected in both populations. In MLR, there was no statistical association between KoRV and C. pecorum infection (P =0.740), or KoRV and C. pecorum disease status ( P=0.274), although KoRV-infected koalas were more likely to present with overt C. pecorum disease than subclinical infection (odds ratio: 3.15, 95 % CI: 0.91-5.39). CONCLUSION: KoRV-A is a prevalent pathogen in wild South Australian koala populations. Future studies should continue to investigate KoRV and C. pecorum associations, as the relationship is likely to be complex and to differ between the northern and southern populations.

Case-case analysis of enteric diseases with routine surveillance data: Potential use and example results.

BACKGROUND: Case-control studies and outbreak investigations are the major epidemiological tools for providing detailed information on enteric disease sources and risk factors, but these investigations can be constrained by cost and logistics. METHODS: We explored the advantages and disadvantages of comparing risk factors for enteric diseases using the case-case method. The main issues are illustrated with an analysis of routine notification data on enteric diseases for 2006 collected by New Zealand's national surveillance system. RESULTS: Our analyses of aggregated New Zealand surveillance data found that the associations (crude odds ratios) for risk factors of enteric disease were fairly consistent with findings from local case-control studies and outbreak investigations, adding support for the use of the case-case analytical approach. Despite various inherent limitations, such an approach has the potential to contribute to the monitoring of risk factor trends for enteric diseases. Nevertheless, using the case-case method for analysis of routine surveillance data may need to be accompanied by: (i) reduction of potential selection and information biases by improving the quality of the surveillance data; and (ii) reduction of confounding by conducting more sophisticated analyses based on individual-level data. CONCLUSION: Case-case analyses of enteric diseases using routine surveillance data might be a useful low-cost means to study trends in enteric disease sources and inform control measures. If used, it should probably supplement rather than replace outbreak investigations and case-control studies. Furthermore, it could be enhanced by utilising high quality individual-level data provided by nationally-representative sentinel sites for enteric disease surveillance.

A Legionnaires' disease outbreak: a water blaster and roof-collected rainwater systems.

In February 2006, an outbreak of Legionnaires' disease (LD) was identified in Beachlands, a small, isolated east Auckland suburb. It was investigated through case finding, a case-control study, sampling potential sources of infection and by molecular typing (using sequence-based typing (SBT) of all Legionella pneumophila serogroup 1 (Lp1) isolates). Lp1 was isolated from the respiratory tract of one case, the roof-collected rainwater systems of five households (three associated with cases) and from a water blaster at a nearby marina. All isolates were indistinguishable, exhibiting the same SBT allele pattern. Three LD cases lived within 500m of the water blaster (the fourth case within 1250m) and downwind in prevailing conditions. Another domestic roof-collected rainwater supply contaminated by Lp1 (identical SBT pattern) was incidentally identified in another suburb 4km east of Beachlands. This is the first outbreak of LD linked to roof-collected rainwater supplies and the first isolation of Legionella from these systems in New Zealand. Aerosols containing Legionella discharged to air by the marina water blaster may have infected some cases directly or may have seeded roof-collected rainwater systems. Some cases may have been exposed by contaminated bathroom showers. Roof-collected rainwater systems need appropriate design, careful cleaning and the maintenance of hot water temperatures at a minimum of 60 degrees C to reduce the chances of Legionella multiplying. Further research into the ecology of Legionella in roof-collected rain water systems is indicated.

Latex glove use by food handlers: the case for nonlatex gloves.

There is increasing concern that continued exposure to latex products can predispose individuals, particularly those who are atopic (allergy prone), to latex allergy. Latex allergy as a serious hazard has been well documented in the health care industry. There are also well-documented cases of food handlers who have had allergic reactions after the use of latex gloves. The contamination of food with latex proteins by food handlers using latex gloves can also result in potentially severe allergic reactions in latex-allergic consumers. We review latex allergy and present the case for avoiding latex glove use by food handlers in the food and hospitality industries. Adopting the use of nonlatex gloves has benefits for workers, consumers, and the food industry.

The obesity epidemic: is glycemic index the key to unlocking a hidden addiction?

High body mass index (BMI) is an important cause of a range of diseases and is estimated to be the seventh leading cause of death globally. In this paper we discuss evidence that food consumption shows similarities to features of other addictive behaviours, such as automaticity and loss of control. Glycemic index is hypothesised to be the element of food that predicts its addictive potential. Although we do not have substantive evidence of a withdrawal syndrome from high glycemic food abstinence, anecdotal reports exist. Empirical scientific and clinical studies support an addictive component of eating behaviour, with similar neurotransmitters and neural pathways triggered by food consumption, as with other drugs of addiction. The public health implications of such a theory are discussed, with reference to tobacco control. Subtle changes in the preparation and manufacturing of commonly consumed food items, reducing glycemic index through regulatory channels, may break such a cycle of addiction and draw large public health benefits.

Gastroenteritis outbreak caused by waterborne norovirus at a New Zealand ski resort.

In July 2006, public health services investigated an outbreak of acute gastroenteritis among staff and visitors of a popular ski resort in southern New Zealand. The source of the outbreak was a drinking water supply contaminated by human sewage. The virological component of the investigation played a major role in confirming the source of the outbreak. Drinking water, source stream water, and 31 fecal specimens from gastroenteritis outbreak cases were analyzed for the presence of norovirus (NoV). Water samples were concentrated by ultrafiltration, and real-time reverse transcription-PCR (RT-PCR) was used for rapid detection of NoV from both water and fecal samples. The implicated NoV strain was further characterized by DNA sequencing. NoV genogroup GI/5 was identified in water samples and linked case fecal specimens, providing clear evidence of the predominant pathogen and route of exposure. A retrospective cohort study demonstrated that staff who consumed drinking water from the resort supply were twice as likely to have gastroenteritis than those who did not. This is the first time that an outbreak of gastroenteritis in New Zealand has been conclusively linked to NoV detected in a community water supply. To our knowledge, this is the first report of the use of ultrafiltration combined with quantitative real-time RT-PCR and DNA sequencing for investigation of a waterborne NoV outbreak.

Acute gastroenteritis associated with seafood privately imported from the Pacific Islands.

AIMS: To investigate a potential link between consumption of food privately imported from the Pacific Islands and presentation with acute gastroenteritis to Middlemore Hospital Emergency Department. METHODS: This was a three month prospective observational case study that included patients aged greater than fifteen years presenting with acute gastroenteritis and a history of food privately imported from the Pacific Islands. Data included case demographics, symptoms, island of food origin and food type. Stool and blood samples were collected and analysed. RESULTS: Of 358 patients who presented to Middlemore Emergency Department during the study period with gastroenteritis, 34 (9.4%) had a history of consumption of food privately imported from the Pacific Islands. The seafood came from Tonga (23 cases), Samoa (10 cases) or Niue (1 case). The implicated seafood was shellfish (28 cases), jellyfish (2 cases), fish intestine (2 cases), seaweed or seaslug (1 case each). Fourteen patients (41%) provided stool samples; all were culture positive for Vibrio parahaemolyticus (VPH). CONCLUSIONS: This case series confirms a link between acute VPH gastroenteritis and consumption of seafood privately imported from the Pacific Islands. A number of public health initiatives to reduce the burden of VPH gastroenteritis among Auckland's Pacific Islanders have commenced. The Ministries of Health, Agriculture and Forestry are considering tighter controls or banning food privately imported from the Pacific Islands.

Geographically separate outbreaks of shigellosis in Auckland, New Zealand, linked by molecular subtyping to cases returning from Samoa.

AIM: To investigate simultaneous outbreaks of Shigella sonnei gastroenteritis occurring in February 2001 at a health camp for socially deprived children and an elderly care facility. METHODS: Those with symptoms were interviewed using a standardised questionnaire. Cases were defined as having at least three loose stools over a 24 hour period and stool samples requested. A case-control study investigating routes of transmission was performed at the health camp. Environmental investigations of food safety and hygiene were conducted at each facility. RESULTS: At the camp, 15 (37%) students and 15 (28%) staff met case criteria. Contact with human faeces (OR 4.0; 95% confidence interval 1.0-16.3; p = 0.05) and, for staff, eating camp food (OR 6.9; 1.0-5.0; p = 0.06) were shown to be independent risk factors for illness. At the elderly care facility, four (19%) residents and four (25%) staff met case criteria. Molecular subtyping confirmed that the outbreaks were related to each other and to other cases in travellers returning from Samoa to Auckland and other New Zealand cities over a four month period. CONCLUSION: Molecular subtyping is of considerable use in communicable disease investigation, providing strong evidence for links between outbreaks. With expanded technological capability, New Zealand could perform routine molecular subtyping of selected organisms to improve the detection and the investigation of regional and inter-regional outbreaks of infection.

Could laboratory-based notification improve the control of foodborne illness in New Zealand?

AIMS: To estimate the completeness and timeliness of notifications of seven potentially foodborne diseases in Auckland. METHODS: The diseases audited were shigellosis, salmonellosis, campylobacteriosis, yersiniosis, listeriosis, hepatitis A and verocytotoxigenic (VTEC) E. coli infections. Hospital and community laboratory-confirmed cases for the calendar year 2000 were audited against those notified to the Auckland Regional Public Health Service. Cases were matched on disease, name, date of birth, gender and National Health Index number. RESULTS: There were 3182 laboratory-confirmed cases of the seven diseases identified of which 77% had been notified to the Auckland Regional Public Health Service. The proportion of laboratory-confirmed cases notified ranged from a 65% for hepatitis A to 100% for VTEC infection. The median delay between laboratory confirmation and practitioner notification was two days. Notification of all laboratory-confirmed cases would have resulted in an estimated 145 additional investigations in the year 2000. CONCLUSION: A change to laboratory-based notification could improve public health investigation and control of foodborne disease in New Zealand.

Discovery of a novel retrovirus sequence in an Australian native rodent (Melomys burtoni): a putative link between gibbon ape leukemia virus and koala retrovirus.

Gibbon ape leukaemia virus (GALV) and koala retrovirus (KoRV) share a remarkably close sequence identity despite the fact that they occur in distantly related mammals on different continents. It has previously been suggested that infection of their respective hosts may have occurred as a result of a species jump from another, as yet unidentified vertebrate host. To investigate possible sources of these retroviruses in the Australian context, DNA samples were obtained from 42 vertebrate species and screened using PCR in order to detect proviral sequences closely related to KoRV and GALV. Four proviral partial sequences totalling 2880 bases which share a strong similarity with KoRV and GALV were detected in DNA from a native Australian rodent, the grassland melomys, Melomys burtoni. We have designated this novel gammaretrovirus Melomys burtoni retrovirus (MbRV). The concatenated nucleotide sequence of MbRV shares 93% identity with the corresponding sequence from GALV-SEATO and 83% identity with KoRV. The geographic ranges of the grassland melomys and of the koala partially overlap. Thus a species jump by MbRV from melomys to koalas is conceivable. However the genus Melomys does not occur in mainland South East Asia and so it appears most likely that another as yet unidentified host was the source of GALV.

The changing epidemiology of food allergy--implications for New Zealand.

Food allergy (FA) is recognised as an important public health problem in developed countries. Recent studies suggest a significant proportion of the general population has a definable FA. The methods used to study FA influence published estimates of incidence and prevalence. In particular, studies relying on self-assessment are likely to overestimate the condition compared to studies using a comprehensive approach including symptoms, allergy testing, rigorously conducted laboratory tests, and food challenges. Currently there are no reliable data on the prevalence of FA in New Zealand. This has had several adverse consequences including the lack of public hospital services for patients with severe allergies. In this article we summarise the epidemiological data on FA and discuss the implications for New Zealand.