A figure of about 1 in 65,000 live births has been reported for Australia.Due to the particular genetic nature of SCID, a higher prevalence may be found in certain regions and associated cultures where higher rates of consanguineous mating occur. A Moroccan study reported that consanguineous parenting was observed in 75% of the families of Moroccan SCID patients.Recent studies indicate that one in every 2,500 children in the Navajo population inherit severe combined immunodeficiency. This condition is a significant cause of illness and death among Navajo children. Ongoing research reveals a similar genetic pattern among the related Apache people. SCID in animals
SCID mice were and still are used in disease, vaccine, and transplant research; especially as animal models for testing the safety of new vaccines or therapeutic agents in people with weakened immune system. Recessive gene with clinical signs similar to the human condition, also affects the Arabian horse. In horses, the condition remains a fatal disease, as the animal inevitably succumbs to an opportunistic infection within the first four to six months of life. However, carriers, who themselves are not affected by the disease, can be detected with a DNA test. Thus careful breeding practices can avoid the risk of an affected foal being produced.Another animal with well-characterized SCID pathology is the dog.
A biopsy of the retina and choroid layer may be performed. In affected liver, biopsy shows focal areas of necrosis and sinusoidal widening. H&E staining show extracellular frothy pink material. Typical cysts with a solid dark dot can be seen using a Grocott silver stain. Differential diagnosis
Pneumocystosis may appear similar to pulmonary embolism or adult respiratory distress syndrome. Other infections can present similarly such as tuberculosis, Legionella, and severe flu. Prevention
There is no vaccine that prevents pneumocystosis. Trimethoprim/sulfamethoxazole (co-trimoxazole) might be prescribed for people at high risk. Treatment
Treatment is usually with co-trimoxazole. Other options include pentamidine, dapsone and atovaquone. Outcomes
It is fatal in 10-20% of people with HIV/AIDS. Pneumocystosis in people without HIV/AIDS is frequently diagnosed late and the death rate is therefore higher; 30-50%. Epidemiology
The exact number of people in the world affected is not known. Pneumocystosis affects lungs in around 97% of cases and is often fatal without treatment. History
The first cases of pneumocystosis affecting lungs were described in premature infants in Europe following the Second World War. It was then known as plasma cellular interstitial pneumonitis of the newborn.Pneumocystis jirovecii (previously called Pneumocystis carinii) is named for Otto Jírovec, who first described it in 1952. == References ==