Strict hand washing is essential in avoiding person-to-person transmission of giardiasis. Giardia cysts can be eliminated by heating water to at least 70ºC for 10 minutes. Iodine disinfection carried out for at least 8 hours is more effective than chlorine-based treatment. High-quality water-filtration units may be effective for the removal of Giardia cysts.[48]Ongerth JE, Johnson RL, Macdonald SC, et al. Backcountry water treatment to prevent giardiasis. Am J Public Health. 1989 Dec;79(12):1633-7.
http://ajph.aphapublications.org/doi/pdf/10.2105/AJPH.79.12.1633
http://www.ncbi.nlm.nih.gov/pubmed/2817191?tool=bestpractice.com
[49]Centers for Disease Control and Prevention. CDC Yellow Book 2024: traveler's health. Section 2: preparing international travelers - water disinfection. May 2023 [internet publication].
https://wwwnc.cdc.gov/travel/yellowbook/2024/preparing/water-disinfection
Hygiene in children is equally important, including care with nappy disposal. In day-care centres, treatment of symptomatic children can prevent the spread of giardiasis. Breast milk contains detectable titres of secretory immunoglobulin A, which is protective for nursing infants and is particularly important in low- and middle-income countries.[50]Mahmud MA, Chappell CL, Hossain MM, et al. Impact of breast-feeding on Giardia lamblia infections in Bilbeis, Egypt. Am J Trop Med Hyg. 2001 Sep;65(3):257-60.
http://www.ncbi.nlm.nih.gov/pubmed/11561714?tool=bestpractice.com
[51]Klotz C, Aebischer T. The immunological enigma of human giardiasis. Curr Trop Med Rep. 2015 Jul;2(3):119-27.
https://link.springer.com/article/10.1007/s40475-015-0050-2#article-info
Evidence exists that interventions to improve human excreta disposal are effective in preventing diarrhoeal disease.[52]Clasen TF, Bostoen K, Schmidt WP, et al. Interventions to improve disposal of human excreta for preventing diarrhoea. Cochrane Database Syst Rev. 2010 Jun 16;(6):CD007180.
https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD007180.pub2/full
http://www.ncbi.nlm.nih.gov/pubmed/20556776?tool=bestpractice.com
There is insufficient evidence for the efficacy of commercial probiotics for the treatment and prevention of diarrhoea, including giardiasis-associated diarrhoea.[53]Schnadower D, Tarr PI, Casper TC, et al. Lactobacillus rhamnosus GG versus placebo for acute gastroenteritis in children. N Engl J Med. 2018 Nov 22;379(21):2002-2014.
https://www.doi.org/10.1056/NEJMoa1802598
http://www.ncbi.nlm.nih.gov/pubmed/30462938?tool=bestpractice.com
[54]Freedman SB, Williamson-Urquhart S, Farion KJ, et al. Multicenter trial of a combination probiotic for children with gastroenteritis. N Engl J Med. 2018 Nov 22;379(21):2015-2026.
https://www.doi.org/10.1056/NEJMoa1802597
http://www.ncbi.nlm.nih.gov/pubmed/30462939?tool=bestpractice.com
Guidelines for the prevention of giardiasis in children with HIV advise that practicing good hygiene, avoiding contact with water and food that may be contaminated, and initiating combination antiretroviral therapy may prevent severe enteric giardiasis.[55]National Institutes of Health, Centers for Disease Control and Prevention, HIV Medicine Association, and Infectious Diseases Society of America. Panel on Guidelines for the Prevention and Treatment of Opportunistic Infections in Children with and Exposed to HIV. Guidelines for the prevention and treatment of opportunistic infections in children with and exposed to HIV: giardiasis. 2019 [internet publication].
https://clinicalinfo.hiv.gov/en/guidelines/hiv-clinical-guidelines-pediatric-opportunistic-infections/giardiasis?view=full