Open Access Highly Accessed Study protocol

The role of micro-organisms (Staphylococcus aureus and Candida albicans) in the pathogenesis of breast pain and infection in lactating women: study protocol

Lisa H Amir1*, Meabh Cullinane1, Suzanne M Garland234, Sepehr N Tabrizi234, Susan M Donath45, Catherine M Bennett6, Amanda R Cooklin7, Jane RW Fisher89 and Matthew S Payne12

Author Affiliations

1 Mother & Child Health Research, La Trobe University, Melbourne, VIC 3000, Australia

2 Women's Centre for Infectious Diseases, Bio 21 Institute, Parkville, VIC 3052, Australia

3 University of Melbourne Department of Obstetrics and Gynaecology, The Royal Women's Hospital, Parkville, VIC 3052, Australia

4 Murdoch Childrens Research Institute, The Royal Children's Hospital, Parkville, VIC 3052, Australia

5 University of Melbourne Department of Paediatrics, The Royal Children's Hospital, Parkville, VIC 3052, Australia

6 Deakin Population Health, Deakin University, Burwood, VIC 3125, Australia

7 Parenting Research Centre, East Melbourne, VIC 3002, Australia

8 Jean Hailes Research Unit, Monash University, Clayton, VIC 3168, Australia

9 Centre for Women's Health, Gender and Society, University of Melbourne, Carlton, VIC 3053, Australia

For all author emails, please log on.

BMC Pregnancy and Childbirth 2011, 11:54  doi:10.1186/1471-2393-11-54

Published: 22 July 2011



The CASTLE (Candida and Staphylococcus Transmission: Longitudinal Evaluation) study will investigate the micro-organisms involved in the development of mastitis and "breast thrush" among breastfeeding women. To date, the organism(s) associated with the development of breast thrush have not been identified. The CASTLE study will also investigate the impact of physical health problems and breastfeeding problems on maternal psychological health in the early postpartum period.


The CASTLE study is a longitudinal descriptive study designed to investigate the role of Staphylococcus spp (species) and Candida spp in breast pain and infection among lactating women, and to describe the transmission dynamics of S. aureus and Candida spp between mother and infant. The relationship between breastfeeding and postpartum health problems as well as maternal psychological well-being is also being investigated. A prospective cohort of four hundred nulliparous women who are at least thirty six weeks gestation pregnant are being recruited from two hospitals in Melbourne, Australia (November 2009 to June 2011). At recruitment, nasal, nipple (both breasts) and vaginal swabs are taken and participants complete a questionnaire asking about previous known staphylococcal and candidal infections. Following the birth, participants are followed-up six times: in hospital and then at home weekly until four weeks postpartum. Participants complete a questionnaire at each time points to collect information about breastfeeding problems and postpartum health problems. Nasal and nipple swabs and breast milk samples are collected from the mother. Oral and nasal swabs are collected from the baby. A telephone interview is conducted at eight weeks postpartum to collect information about postpartum health problems and breastfeeding problems, such as mastitis and nipple and breast pain.


This study is the first longitudinal study of the role of both staphylococcal and candidal colonisation in breast infections and will help to resolve the current controversy about which is the primary organism in the condition known as breast thrush. This study will also document transmission dynamics of S. aureus and Candida spp between mother and infant. In addition, CASTLE will investigate the impact of common maternal physical health symptoms and the effect of breastfeeding problems on maternal psychological well-being.