This does not prevent JWs who work in the hospital (billing, records, nursing, etc.) from telling local elders about any patients taking blood, having STDs, having drug addictions, or getting abortions. (Not uncommon).
That's pretty shocking. Here in the UK, that would be a serious breach of professional standards and your employment contract, and constitute a sackable offence (and possibly even leave you open to criminal proceedings).
NHS confidentiality policy says it's even forbidden to use internal systems to browse your own medical records or those of your family if you are an employee:
4.5 Abuse of Privilege
It is strictly forbidden for employees to knowingly browse, search for or look at any personal or confidential information about themselves without a legitimate purpose, unless through established self-service mechanisms where such access is permitted (e.g. viewing your ESR record). Under no circumstances should employees access records about their own family, friends or other persons without a legitimate purpose.
Action of this kind will be viewed as a breach of confidentiality and may be an offence under the Data Protection Act 2018.
When dealing with person-identifiable or confidential information of any nature, staff must be aware of their personal responsibility, contractual obligations and undertake to abide by the policies and procedures of NHS England and NHS Improvement.