 However, in areas where these infections are common, there is strong evidence that mass deworming campaigns do not have a positive effect on children's average nutritional status, levels of blood haemoglobin, cognitive abilities, performance at school or survival.To achieve health gains in the longer term, improvements in sanitation and hygiene behaviours are also required, together with deworming treatments.Coinfection is a major concern with neglected tropical diseases, making NTDs more damaging than their mortality rates might portray.