A Positive Association Between Cryptosporidiosis Notifications and Ambient Temperature, Victoria, Australia, 2001-2009

Increased temperatures provide optimal conditions for pathogen survival, virulence and replication as well as increased opportunities for human-pathogen interaction. This paper examined the relationship between notifications of cryptosporidiosis and temperature in metropolitan and rural areas of Victoria, Australia between 2001-2009. A negative binomial regression model was used to analyse monthly average maximum and minimum temperatures, rainfall and the monthly count of cryptosporidiosis notifications. In the metropolitan area, a 1°C increase in monthly average minimum temperature of the current month was associated with a 22% increase in cryptosporidiosis notifications (IRR 1.22; 95% CI 1.13 – 1.31). In the rural area, a 1°C increase in monthly average minimum temperature, lagged by 3 months, was associated with a 9% decrease in cryptosporidiosis notifications (IRR 0.91; 95% CI 0.86 – 0.97). Rainfall was not associated with notifications in either area. These relationships should be considered when planning public health response to ecological risks as well as when developing policies involving climate change. Rising ambient temperature may be an early warning signal for intensifying prevention efforts, including appropriate education for pool users about cryptosporidiosis infection and management, which might become more important as temperatures are projected to increase as a result of climate change

The Epidemiology of Cryptosporidiosis in Victoria, 2001-2009

Cryptosporidiosis is a protozoan parasitic infection that most commonly presents as gastroenteritis and less commonly infects the respiratory and biliary tracts. Enteric symptoms usually include diarrhoea, bloating, cramping, abdominal pain, vomiting and fever. The disease is usually mild and self-limiting but in immunocompromised individuals is prolonged and can lead to death. The infective dose in humans is low and the incubation period ranges from one to 12 days, with an average of seven days. The infectious period lasts from the onset of symptoms, as the oocysts are excreted in the stool, until several weeks after symptoms resolve. The oocysts are widespread and may remain infective outside the body for two to six months, particularly if the environment is moist. They are highly resistant to standard levels of chemical disinfection of water such as chlorine. Outbreaks have been reported in day care centres, and been associated with drinking water, recreational water (waterslides, swimming pools and lakes) and consumption of contaminated beverages. In Australia, increases in notifications tend to occur in the warmer months and over irregular cycles, with more than 3000 cases notified in Australia in 2002, 2005 and 2006. Cryptosporidiosis became notifiable in both Australia and Victoria in 2001, with more than 15,000 cases notified between 2002 and 2009. The aim of this study was to describe the epidemiology of notified cases of cryptosporidiosis in Victoria for the period 2001 to 2009 in terms of age, sex, location and season

The spread of influenza A(H1N1)pdm09 in Victorian school children in 2009:iImplications for revised pandemic planning

Background Victoria was the first state in Australia to experience community transmission of influenza A(H1N1)pdm09. We undertook a descriptive epidemiological analysis of the first 1,000 notified cases to describe the epidemic associated with school children and explore implications for school closure and antiviral distribution policy in revised pandemic plans. Methods Records of the first 1,000 laboratory-confirmed cases of influenza A(H1N1)pdm09 notified to the Victorian Government Department of Health between 20 May and 5 June 2009 were extracted from the state’s notifiable infectious diseases database. Descriptive analyses were conducted on case demographics, symptoms, case treatment, prophylaxis of contacts and distribution of cases in schools. Results Two-thirds of the first 1,000 cases were school-aged (5–17 years) with cases in 203 schools, particularly along the north and western peripheries of the metropolitan area. Cases in one school accounted for nearly 8% of all cases but the school was not closed until nine days after symptom onset of the first identified case. Amongst all cases, cough (85%) was the most commonly reported symptom followed by fever (68%) although this was significantly higher in primary school children (76%). The risk of hospitalisation was 2%. The median time between illness onset and notification of laboratory confirmation was four days, with only 10% of cases notified within two days of onset and thus eligible for oseltamivir treatment. Nearly 6,000 contacts were followed up for prophylaxis. Conclusions With a generally mild clinical course and widespread transmission before its detection, limited and short-term school closures appeared to have minimal impact on influenza A(H1N1)pdm09 transmission. Antiviral treatment could rarely be delivered to cases within 48 hours of symptom onset. These scenarios and lessons learned from them need to be incorporated into revisions of pandemic plans

Bridging of Neisseria gonorrhoeae lineages across sexual networks in the HIV pre-exposure prophylaxis era

Whole genome sequencing (WGS) has been used to investigate transmission of Neisseria gonorrhoeae, but to date, most studies have not combined genomic data with detailed information on sexual behaviour to define the extent of transmission across population risk groups (bridging). Here, through combined epidemiological and genomic analysis of 2,186N. gonorrhoeae isolates from Australia, we show widespread transmission of N. gonorrhoeae within and between population groups. We describe distinct transmission clusters associated with men who have sex with men (MSM) and heterosexuals, and men who have sex with men and women (MSMW) are identified as a possible bridging population between these groups. Further, the study identifies transmission of N. gonorrhoeae between HIV-positive and HIV-negative individuals receiving pre-exposure prophylaxis (PrEP). Our data highlight several groups that can be targeted for interventions aimed at improving gonorrhoea control, including returning travellers, sex workers, and PrEP users.D.A.W. (GNT1123854), E.P.F.C. (GNT1091226), and J.C.K. (GNT1142613) are supported by Early Career Fellowships from the National Health and Medical Research Council (NHMRC) of Australia. B.P.H. is supported by a Practitioner Fellowship from the NHMRC (GNT1105905). D.J.I. is supported by the European Union’s Horizon 2020 research and innovation programme under grant agreement 643476. Work in this study was supported by a Project Grant from the NHMRC (GNT1147735) and a Partnership grant from the NHMRC (GNT1149991). MDU PHL is funded by the Victorian Department of Health and Human Services

Intrahousehold Transmission of Pandemic (H1N1) 2009 Virus, Victoria, Australia

TOC Summary: Antiviral prophylaxis for quarantined contacts reduces secondary transmission

The spread of influenza A(H1N1)pdm09 in Victorian school children in 2009: implications for revised pandemic planning

Background: Victoria was the first state in Australia to experience community transmission of influenza A(H1N1)pdm09. We undertook a descriptive epidemiological analysis of the first 1,000 notified cases to describe the epidemic associated with school children and explore implications for school closure and antiviral distribution policy in revised pandemic plans.\ud \ud Methods: Records of the first 1,000 laboratory-confirmed cases of influenza A(H1N1)pdm09 notified to the Victorian Government Department of Health between 20 May and 5 June 2009 were extracted from the state's notifiable infectious diseases database. Descriptive analyses were conducted on case demographics, symptoms, case treatment, prophylaxis of contacts and distribution of cases in schools.\ud \ud Results: Two-thirds of the first 1,000 cases were school-aged (5–17 years) with cases in 203 schools, particularly along the north and western peripheries of the metropolitan area. Cases in one school accounted for nearly 8% of all cases but the school was not closed until nine days after symptom onset of the first identified case. Amongst all cases, cough (85%) was the most commonly reported symptom followed by fever (68%) although this was significantly higher in primary school children (76%). The risk of hospitalisation was 2%. The median time between illness onset and notification of laboratory confirmation was four days, with only 10% of cases notified within two days of onset and thus eligible for oseltamivir treatment. Nearly 6,000 contacts were followed up for prophylaxis.\ud \ud Conclusions: With a generally mild clinical course and widespread transmission before its detection, limited and short-term school closures appeared to have minimal impact on influenza A(H1N1)pdm09 transmission. Antiviral treatment could rarely be delivered to cases within 48 hours of symptom onset. These scenarios and lessons learned from them need to be incorporated into revisions of pandemic plans

Bridging of Neisseria gonorrhoeae lineages across sexual networks in the HIV pre-exposure prophylaxis era

Whole genome sequencing (WGS) has been used to investigate transmission of Neisseria gonorrhoeae, but to date, most studies have not combined genomic data with detailed information on sexual behaviour to define the extent of transmission across population risk groups (bridging). Here, through combined epidemiological and genomic analysis of 2,186N. gonorrhoeae isolates from Australia, we show widespread transmission of N. gonorrhoeae within and between population groups. We describe distinct transmission clusters associated with men who have sex with men (MSM) and heterosexuals, and men who have sex with men and women (MSMW) are identified as a possible bridging population between these groups. Further, the study identifies transmission of N. gonorrhoeae between HIV-positive and HIV-negative individuals receiving pre-exposure prophylaxis (PrEP). Our data highlight several groups that can be targeted for interventions aimed at improving gonorrhoea control, including returning travellers, sex workers, and PrEP users

Confirmed influenza A(H1N1)pdm09 cases aged 5–17 years by school and date of onset, Victoria, 2009.

<p>Confirmed influenza A(H1N1)pdm09 cases aged 5–17 years by school and date of onset, Victoria, 2009.</p

Confirmed influenza A(H1N1)pdm09 cases at School A by date of onset and age group, Victoria, 2009.

<p>Confirmed influenza A(H1N1)pdm09 cases at School A by date of onset and age group, Victoria, 2009.</p

Reported symptoms for 520 of first 1,000 confirmed influenza A(H1N1)pdm09 cases with data by age group and order of case notification, Victoria, 2009.

<p>Reported symptoms for 520 of first 1,000 confirmed influenza A(H1N1)pdm09 cases with data by age group and order of case notification, Victoria, 2009.</p