Shared sanitation included any type of facilities intended for the containment of human faeces and
used by more than one household, but excluded public facilities. Health outcomes included diarrhoea, helminth infections,
enteric fevers, other faecal-oral diseases, trachoma and adverse maternal or birth outcomes. Studies were included
regardless of design, location, language or publication status. Studies were assessed for methodological quality using the
STROBE guidelines. Twenty-two studies conducted in 21 countries met the inclusion criteria. Studies show a pattern of
increased risk of adverse health outcomes associated with shared sanitation compared to individual household latrines. A
meta-analysis of 12 studies reporting on diarrhoea found increased odds of disease associated with reliance on shared
sanitation