Absence of high priority critically important antimicrobial resistance in Salmonella sp. isolated from Australian commercial egg layer environments.

The development of antimicrobial resistance in foodborne pathogens is a growing public health concern. This study was undertaken to determine the antimicrobial susceptibility of Salmonella enterica subspecies enterica isolated from the Australian commercial egg layer industry. S. enterica subspecies enterica (n=307) isolated from Australian commercial layer flock environments (2015-2018) were obtained from reference, research and State Government laboratories from six Australian states. All Salmonella isolates were serotyped. Antimicrobial susceptibility testing (AST) for 16 antimicrobial agents was performed by broth microdilution. Antimicrobial resistance genes and sequence types (STs) were identified in significant isolates by whole genome sequencing (WGS). Three main serotypes were detected, S. Typhimurium (n=61, 19.9%), S. Senftenburg (n=45, 14.7%) and S. Agona (n=37, 12.1%). AST showed 293/307 (95.4%) isolates were susceptible to all tested antimicrobial agents and all isolates were susceptible to amoxicillin-clavulanate, azithromycin, ceftiofur, ceftriaxone, ciprofloxacin, colistin, florfenicol, gentamicin, kanamycin and trimethoprim-sulfamethoxazole. Low levels of non-susceptibility were observed to streptomycin (2.3%, n=7), sulfisoxazole (2.0%, n=6), chloramphenicol (1.3%, n=4) and tetracycline (1.0%, n=3). Very low levels of non-susceptibility were observed to ampicillin (2/307; 0.7%) and cefoxitin (2/307; 0.7%). Two isolates (S. Havana and S. Montevideo), exhibited multidrug-resistant phenotypes to streptomycin, sulfisoxazole and tetracycline and possessed corresponding antimicrobial resistance genes (aadA4, aac(6')-Iaa, sul1, tetB). One S. Typhimurium isolate was resistant to ampicillin and tetracycline, and possessed both tetA and blaTEM-1B. WGS also identified these isolates as belonging to ST4 (S. Montevideo), ST578 (S. Havana) and ST19 (S. Typhimurium). The absence of resistance to highest priority critically important antimicrobials as well as the extremely low level of AMR generally among Australian commercial egg layer Salmonella isolates likely reflect Australia's conservative antimicrobial registration policy in food-producing animals and low rates of antimicrobial use within the industry.

Differences in the occurrence and epidemiology of cryptosporidiosis in Aboriginal and non-Aboriginal people in Western Australia (2002-2012).

Cryptosporidiosis is a diarrhoeal illness caused by the protozoan parasite Cryptosporidium. In Australia, very little is known about the epidemiology of cryptosporidiosis in Aboriginal peoples. The present study analysed long-term cryptosporidiosis patterns across Western Australia (WA) (2001-2012), combined with genotyping and subtyping data at the 18S and glycoprotein 60 (gp60) loci respectively. Comparison of cryptosporidiosis notifications between Aboriginal and non-Aboriginal people in WA, revealed that notification rates among Aboriginal people were up to 50 times higher compared to non-Aboriginal people, highlighting the burden of the disease in this population. More than 90% of notifications were in Aboriginal children aged 00-04years, who had a notification rate 20.5 times higher than non-Aboriginal children in the same age group. Cryptosporidium hominis was the predominant species infecting both Aboriginal and non-Aboriginal people. However, Aboriginal people were mainly infected with the C. hominis IdA15G1 subtype, whereas non-Aboriginal people were predominantly infected with the IbA10G2 subtype. To control cryptosporidiosis in Aboriginal populations in Australia, effective health interventions/promotions need to be a priority for public health research and action.

Human cryptosporidiosis diagnosed in Western Australia: a mixed infection with Cryptosporidium meleagridis, the Cryptosporidium mink genotype, and an unknown Cryptosporidium species.

This report describes a case of cryptosporidiosis from an immunocompetent patient from Perth, Western Australia, suffering from diarrhea and a spectrum of other symptoms. Molecular identification revealed that this patient was infected with three Cryptosporidium species-Cryptosporidium meleagridis, the Cryptosporidium mink genotype, and an unknown Cryptosporidium species.

Improvement in antenatal testing for sexually transmissible infections and blood-borne viruses in Western Australian hospitals, 2007 to 2010.

OBJECTIVE: Antenatal testing for specified sexually transmissible infections (STIs) and blood-borne viruses (BBVs) is recommended by the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG). In 2007, the Department of Health, Western Australia (DoHWA) issued an operational directive (OD) recommending universal testing for chlamydia and additional testing for women in the STI endemic regions of Western Australia (WA). To assess adherence to these guidelines, seven WA public hospitals were audited. DESIGN AND SETTING: Demographic details and testing information of the last 200 women who gave birth immediately before 30 June 2007 (baseline audit) and 30 June 2010 (follow-up audit) were obtained from each hospital's antenatal records. RESULTS: Data from 2718 women who delivered at ≥36 weeks' gestation were analysed (baselinen=1353; follow-upn=1365). Testing at the first antenatal visit in accordance with the guidelines improved over time (RANZCOG: 68-74%; χ(2)-test = 13.96, d.f.=1, P<0.001; DoHWA OD: 12-40%; χ(2)-test = 279.71, d.f.=1, P<0.001). Retesting at 28-36 weeks' gestation in the STI endemic regions improved for chlamydia (3-10%; χ(2)-test = 17.40, d.f.=1, P<0.001) and gonorrhoea (3-7%; χ(2)-test=6.62, d.f.=1, P<0.05), but not for syphilis or HIV. Chlamydia prevalence was 3% and 8% among nonAboriginal and Aboriginal women, respectively. CONCLUSION: The proportion of women delivering in WA public hospitals who had antenatal STI and BBV tests improved after publication and promotion of the OD.

Epidemiology of Shiga toxin producing Escherichia coli in Australia, 2000-2010.

BACKGROUND: Shiga toxin-producing Escherichia coli (STEC) are an important cause of gastroenteritis in Australia and worldwide and can also result in serious sequelae such as haemolytic uraemic syndrome (HUS). In this paper we describe the epidemiology of STEC in Australia using the latest available data. METHODS: National and state notifications data, as well as data on serotypes, hospitalizations, mortality and outbreaks were examined. RESULTS: For the 11 year period 2000 to 2010, the overall annual Australian rate of all notified STEC illness was 0.4 cases per 100,000 per year. In total, there were 822 STEC infections notified in Australia over this period, with a low of 1 notification in the Australian Capital Territory (corresponding to a rate of 0.03 cases per 100,000/year) and a high of 413 notifications in South Australia (corresponding to a rate of 2.4 cases per 100,000/year), the state with the most comprehensive surveillance for STEC infection in the country. Nationally, 71.2% (504/708) of STEC infections underwent serotype testing between 2001 and 2009, and of these, 58.0% (225/388) were found to be O157 strains, with O111 (13.7%) and O26 (11.1%) strains also commonly associated with STEC infections. The notification rate for STEC O157 infections Australia wide between 2001-2009 was 0.12 cases per 100,000 per year. Over the same 9 year period there were 11 outbreaks caused by STEC, with these outbreaks generally being small in size and caused by a variety of serogroups. The overall annual rate of notified HUS in Australia between 2000 and 2010 was 0.07 cases per 100,000 per year. Both STEC infections and HUS cases showed a similar seasonal distribution, with a larger proportion of reported cases occurring in the summer months of December to February. CONCLUSIONS: STEC infections in Australia have remained fairly steady over the past 11 years. Overall, the incidence and burden of disease due to STEC and HUS in Australia appears comparable or lower than similar developed countries.

Food- and waterborne disease outbreaks in Australian long-term care facilities, 2001-2008.

Abstract Food- or waterborne diseases in long-term care facilities (LTCF) can result in serious outcomes, including deaths, and they are potentially preventable. We analyzed data collected by OzFoodNet on food- and waterborne disease outbreaks occurring in LTCF in Australia from 2001 to 2008. We compared outbreaks by the number of persons affected, etiology, and implicated vehicle. During 8 years of surveillance, 5.9% (55/936) of all food- and waterborne outbreaks in Australia occurred in LTCF. These LTCF outbreaks affected a total of 909 people, with 66 hospitalized and 23 deaths. The annual incidence of food- or waterborne outbreaks was 1.9 (95% confidence intervals 1.0-3.7) per 1000 facilities. Salmonella caused 17 outbreaks, Clostridium perfringens 14 outbreaks, Campylobacter 8 outbreaks, and norovirus 1 outbreak. Residents were at higher risk of death during outbreaks of salmonellosis than for all other outbreaks combined (relative risk 7.8, 95% confidence intervals 1.8-33.8). Of 15 outbreaks of unknown etiology, 11 were suspected to be due to C. perfringens intoxication. Food vehicles were only identified in 27% (14/52) of outbreaks, with six outbreak investigations implicating pureed foods. Dishes containing raw eggs were implicated as the cause of four outbreaks. Three outbreaks of suspected waterborne disease were attributed to rainwater collected from facility roofs. To prevent disease outbreaks, facilities need to improve handling of pureed foods, avoid feeding residents raw or undercooked eggs, and ensure that rainwater tanks have a scheduled maintenance and disinfection program.

Economic costs of Shiga toxin-producing Escherichia coli infection in Australia.

Shiga toxin-producing Escherichia coli (STEC) infections are an important cause of foodborne disease in Australia. Three percent to 7% of sporadic patients develop hemolytic uremic syndrome (HUS) and 40% of patients with HUS develop chronic complications. To examine costs associated with illness, we interviewed patients notified to the South Australian Department of Health with a structured questionnaire regarding severity of illness, medical treatment, time lost from work, hospitalization, and other costs. In 2003-2006, we interviewed 46 patients of STEC infection, 2 of whom developed HUS. The median duration of illness was 7 days (range 3-31 days) and 41% (19/46) of patients were admitted to hospital. The estimated total cost for the 46 STEC cases in South Australia was AUD$144,087, equating to a mean cost of AUD$3132 per case. We estimate that the annual total costs of STEC infection in South Australia and Australia are AUD$200,283 and AUD$2,633,181, respectively. We used linear regression to identify that STEC infection costs increase by AUD$608 per day regardless of severity, and that more severe illness is strong predictor of cost. This is the first Australian study to examine costs of STEC infection and highlights the significant impact of this illness.

Serogroup-specific risk factors for Shiga toxin-producing Escherichia coli infection in Australia.

BACKGROUND: Shiga toxin-producing Escherichia coli (STEC) is an important cause of foodborne illness. In Australia, risk factors for STEC infection have not been examined at a national level. METHODS: We conducted a case-control study in 6 Australian jurisdictions from 2003 through 2007. A case patient was defined as a person from whom STEC was isolated or toxin production genes were detected in stool. Case patients were recruited from notifiable disease registers, and 3 control subjects frequency matched by age were selected from databases of controls. Using structured questionnaires, interviewers collected data on clinical illness, foods consumed, and exposures to potential environmental sources. RESULTS: We recruited 43 case patients infected with STEC serogroup O157, 71 case patients infected with non-O157 serogroups, and 304 control subjects. One patient infected with serogroup O157 and 7 infected with non-O157 serogroups developed hemolytic uremic syndrome. Compared with control subjects, case patients infected with STEC O157 were more likely to eat hamburgers, visit restaurants, have previously used antibiotics, or have family occupational exposure to red meat. Case patients infected with non-O157 STEC were more likely to eat sliced chicken meat or corned beef from a delicatessen, camp in the bush, eat catered meals, or have family occupational exposure to animals. Negative associations were observed for certain foods, particularly homegrown vegetables, fruits, or herbs. CONCLUSION: This study of risk factors for STEC infection by serogroup highlights risks associated with eating hamburgers and occupational handling of raw meat. To prevent infection, hamburgers must be cooked thoroughly, and people handling raw meat or who have close contact with animals must ensure adequate hygiene.

An increase in overseas acquired HIV infections among heterosexual people in Western Australia.

BACKGROUND: There has been a recent increase in the number of heterosexually acquired HIV infections among non-Aboriginal people in Western Australia (WA), which has not been reported in other Australian jurisdictions. This report describes the epidemiological features of this increase. METHODS: A descriptive analysis was conducted of newly diagnosed HIV infections among non-Aboriginal WA residents notified to the Department of Health from 2002 to 2006. Analysis outcomes included demographics, exposure categories, and place of HIV acquisition. RESULTS: From 2002 to 2006, 258 new HIV diagnoses were notified among non-Aboriginal WA residents. Over this period, the number of notifications increased from 41 cases in 2002 (2.2 cases/100 000 population) to 66 cases in 2006 (3.4 cases/100 000 population). Overall, 107 (42%) of the cases were heterosexually acquired, and the annual number increased threefold from 2002 to 2006 (12 to 36 cases, respectively). Of these cases, 64 (60%) were male and 43 (40%) were female. The majority (89%) of male cases acquired HIV overseas, mostly in countries other than their region of birth; South-east Asia was the most common place of acquisition reported. Over half (56%) of the female cases acquired HIV overseas, mainly in their region of birth (83%), and sub-Saharan Africa was the most common place of acquisition. CONCLUSION: There has been a recent increase in heterosexually acquired HIV infections among male and female WA residents, many of whom reported acquiring HIV overseas. Safe sex campaigns in WA should continue to reinforce safe sex messages among people travelling overseas.

Multi-drug resistant Salmonella Java infections acquired from tropical fish aquariums, Australia, 2003-04.

Antibiotic resistant Salmonella infections are rare in Australia. We investigated an increase in multidrug resistant Salmonella Paratyphi B biovar Java (S. Java) infections in Australia during 2003-04. Eighty-two per cent (18/22) of S. Java cases enrolled into the study reported that they had been in contact with aquariums housing fish during their incubation period. Seventy-two per cent (13/18) of cases were infected with strains that were resistant to ApSmTcCmSuSp (ampicillin, streptomycin, tetracycline, chloramphenicol, sulfonamides, spectinomycin). Case households commonly reported high risk behaviours, such as cleaning aquaria in sinks. Sixty-one per cent (11/18) of cases reported that fish in their aquarium had been sick or died in the week prior to their illness, and S. Java was isolated from the water or gravel of 5 cases. These antibiotic strains are being spread internationally and may become endemic in countries importing tropical fish or result in transfer of resistance to other more common Salmonella serotypes.

An outbreak of Salmonella Typhimurium phage type 64 gastroenteritis linked to catered luncheons in Adelaide, South Australia, June 2005.

Salmonella sp. are important causes of foodborne illness, with restaurants and catered functions being commonly reported settings for outbreaks. In June 2005 an investigation commenced following reports of gastrointestinal illness in attendees at luncheons catered by an Adelaide café, as well as persons eating at the café itself. The investigation sought to determine the existence of an outbreak, identify a source and method of transmission and implement public health measures to prevent further cases. Lists of luncheon attendees were obtained from function organisers. A retrospective cohort study was commenced using a structured questionnaire developed from the café's menu listings. A suspected case was defined as a person developing two or more gastrointestinal symptoms after attending a luncheon catered by the café. A case series investigation was used for café diners. Of the 102 respondents, 61 (60%) met the case definition with 32 subsequently confirmed as Salmonella Typhimurium phage type 64 (STM 64) infections. Of the 61 cases, 59 (96%) reported eating a bread roll. STM 64 was detected in raw defrosted chicken recovered from the café's kitchen. This suggested cross-contamination from the chicken to one or more ingredients common to the bread rolls was the route of infection. To prevent further cases, perishable goods were discarded, the café was closed, the premises cleaned, then restrictions were placed on the types of foods served. This investigation's findings highlight the importance of safe food handling and hand hygiene in commercial food preparation.

A multi-jurisdiction outbreak of Salmonella Typhimurium phage type 135 associated with purchasing chicken meat from a supermarket chain.

A multi-jurisdiction case control study was conducted after an increase of Salmonella Typhimurium phage type 135 notifications (a local designated subgroup) was observed throughout Australia. Hypothesis generating interviews conducted in three jurisdictions identified consumption of chicken, eggs, beef and bagged carrots as common among cases and that a high proportion of cases (> 80%) reported purchasing their groceries from a particular supermarket chain (Supermarket A). We conducted a case control study to test whether S. Typhimurium 135 infections were associated with these food items and the purchasing of these products from Supermarket A. The study comprised 61 cases and 173 controls. Cases were younger than controls (p = 0.003) and their distribution by jurisdiction was also significantly different (p < 0.001). In multivariate analysis, cases had significantly higher odds of having eaten chicken purchased from Supermarket A (OR = 3.2, 95% CI 1.2,9.0) or having eaten chicken from a fast food outlet (OR = 2.8, 95% CI 1.0,7.7) compared to controls. Two positive S. Typhimurium 135 results were obtained through a chicken sampling survey conducted at four Supermarket A stores in Victoria. The results of this study were presented to industry and retail representatives, which facilitated better communication between these groups.

Ribotyping of Salmonella enterica serovar Typhi isolates from Papua New Guinea over the period 1977 to 1996.

The prevalence of typhoid in the Papua New Guinea (PNG) highlands region increased rapidly in the mid-1980s, and now remains endemic. In this study ribotyping has been used to examine the number and types of Salmonella enterica serovar Typhi strains present during the 1977-1996 period. The ribotyping banding pattern results were based on Cla I and Eco RV digests. The 57 PNG isolates were divided into 11 different ribotypes. Comparison of ribotypes using coefficient of similarity values revealed a diverse group of ribotypes. Several strains appear to be endemic in PNG For instance, ribotypes 1, 2 and 3 were most commonly found among PNG isolates and isolates with these ribotypes have been cultured over a period of at least 11 years (1985-1996). Ribotype 3 was also observed in isolates from Malaysia and Thailand. Also found in PNG were ribotypes 4, 5, 6, 7, 8, 9, 16 and 17. The ribotyping suggests that serovar Typhi strains present in PNG include unique strains of serovar Typhi and also strains that are common to other countries.

Surveillance of Shiga toxigenic Escherichia coli in Australia.

All Australian States and Territories have low rates (< or = 0.32 cases per 100,000 population) of notification for Shiga toxin-producing Escherichia coli (STEC), except for South Australia where the rates are ten-fold higher at 2.58 cases per 100,000 population. To explore possible reasons for the variation in rates we surveyed public health reference laboratories to determine the methods used and number of specimens tested for these organisms. Only five of eight jurisdictions routinely conducted testing for STEC, and polymerase chain based tests were most common. Culture was also common and in one jurisdiction that tests specimens with culture, approximately 1.2 per cent of specimens were positive. The notification rates for different jurisdictions reflected the number of specimens tested, with jurisdiction testing < or = 500 specimens having rates < or = 0.32 cases per 100,000 population. The use of culture as a test method may also influence notification rates. Public health agencies must consider the number of specimens tested in interpreting surveillance data.

Laboratory surveillance of Shiga toxin producing Escherichia coli in South Australia and the Hunter Health Area, New South Wales, Australia.

To estimate the prevalence of Shiga toxin producing Escherichia coli in Australia, bloody stool samples from two Australian locations were screened for the presence of Shiga toxin genes, stx1 and stx2. Four of 126 (3.2%) and 139 of 5,829 (2.4%) patients from the two locations had a positive polymerase chain reaction for Shiga toxin genes.

Maternal immunization with pneumococcal polysaccharide vaccine in the highlands of Papua New Guinea.

In Tari, Southern Highlands Province (SHP), Papua New Guinea (PNG), pneumococcal polysaccharide (Pnc PS) vaccine was offered to women at 28-38 weeks gestation. Blood samples were collected for measurement of pneumococcal antibody titres prior to immunization, from mother and cord at delivery and from their children at ages 1-3 and 4-6 months; samples were also collected in a subset of children before and 1 month after Pnc PS vaccine was given at age 8-9 months. Serum was collected from unimmunized women and their children at delivery and from children of unimmunized women at the same ages in infancy. There were no differences in neonatal or post-neonatal mortality rates or congenital abnormalities in the children of 235 immunized and 202 unimmunized women. There was a significant increase in antibody titres to pneumococcal serotypes 5, 14 and 23F in immunized women but not for serotype 7F. Geometric mean titres (GMTs) of antibodies for serotypes 5 and 23F were significantly higher in children of immunized women than in the unimmunized group up to age 2 months and for serotype 14 significantly higher to age 4 months. Maternal immunization did not significantly affect the children's capacity to make antibody responses to immunization with Pnc PS vaccine in infancy. The findings of this study and those in several other developing countries provide support for the concept of Pnc PS maternal immunization and justify the planning of large-scale efficacy trials.