Dr. Naseh Nawabi, MD

“When one parent has sickle cell trait and the other parent has sickle cell trait or another hemoglobin trait (such as hemoglobin C or beta-thalassemia), there is a one-in-four chance that their baby will be born with sickle cell disease.”

The literature started it causes injury to the kidneys “ GLOMERULAR DISEASE

COVID-19 associated glomerular disease — Glomerular lesions were reported in a minority of patients with COVID-19, with collapsing focal segmental glomerulosclerosis (FSGS), also called COVID-associated nephropathy (COVAN), being the most common. Such patients present with nephrotic-range proteinuria and acute kidney injury (AKI) ”

Because you don’t have antibodies to A or B blood types

There are two types, forensic and medical. The forensics are performed by pathologists or residents/fellows in coroners' offices, and medical autopsies are mostly done by the pathologist/residents/fellows in the hospitals.

A blood work can show infection, but there would fever and other constitutional symptoms and swelling and pain, etc.

The best course would be to test the child for blood work.

Call them to see what is their procedure.

It is a inherited autosomal dominant disease. It has may presentations: I have copied the information in more details from UpToDate “ One of the most common inherited disorders of connective tissue, Marfan syndrome (MFS, MIM #154700) is a predominantly autosomal dominant condition with a reported incidence of 1 in 3000 to 5000 individuals [1,2]. There is a broad range of clinical severity associated with MFS and related disorders, ranging from isolated features of MFS to neonatal presentation of severe and rapidly progressive disease involving multiple organ systems [3]. Although many clinicians view the disorder in terms of classic ocular, cardiovascular, and musculoskeletal abnormalities (picture 1), manifestations also include involvement of the lung, skin, and central nervous system.

The genetics, pathogenesis, clinical manifestations, and diagnosis of MFS and related disorders will be reviewed here. The management of patients with MFS and related disorders and issues related to pregnancy are discussed separately. (See "Management of Marfan syndrome and related disorders" and "Pregnancy and Marfan syndrome".)” please refer to this information and the source is UpToDate

The best thing would be to do a full blood work with blood smear and if there is any family history of blood disorder to see a hematologist.

These the laundry list of things can go wrong with blood transfusion: TYPES OF ACUTE TRANSFUSION REACTIONS
Potentially life-threatening reactions
Transfusion-associated circulatory overload (TACO)
Transfusion-related acute lung injury (TRALI)
Acute hemolytic transfusion reaction (AHTR)
Transfusion-associated sepsis
Anaphylactic transfusion reaction
Non-life-threatening reactions
Urticarial transfusion reaction (UTR)
Febrile non-hemolytic transfusion reaction (FNHTR)
Primary hypotensive reactions. For further details please consult UpToDate literature

The blood can be taken from any where that is visible or not

The best thing would be to call the blood bank of the hospital to see what procedure they have implemented at the time of COVID-19 pandemic.

The literature has the following:
“Geriatric Patients: High-Risk Medication:
Beers Criteria: Aspirin, when used chronically at doses more than 325 mg, is identified in the Beers Criteria as a potentially inappropriate medication to be avoided in patients 65 years and older (unless alternative agents ineffective and patient can receive concomitant gastroprotective agent) due to increased risk of GI bleeding and peptic ulcer disease in older adults in high risk category (eg, older than 75 years of age or receiving concomitant oral/parenteral corticosteroids, anticoagulants, or antiplatelet agents). In addition, when aspirin is used for the primary prevention of cardiovascular disease and colorectal cancer, it should be used with caution in older adults ≥70 years of age due to increased risk for major bleeding and inconclusive evidence for the benefits of use as primary prevention in older adults with cardiovascular risk factors (Beers Criteria [AGS 2019]).”

You have to do an autopsy to determine the cause of death.

The urine needs to be cultured for pathogen and drug sensitivity then the correct antibiotic would be prescribed.

Escherichia coli is the most common cause of UTI in children. A variety of host factors influence the predisposition for UTIs in children. These include female sex, genetic factors, urinary tract anomalies, bladder and bowel dysfunction, vesicoureteral reflux (VUR), and bladder catheterization in addition to those mentioned above for febrile young children (e.g., lack of circumcision, temperature >39°C [102.2°F]).