Epidemiology
Anophthalmia has been reported to be present in 3 out of every 100,000 births. Many instances of anophthalmia also occur with microphthalmia. A recent study in the UK indicated that anophthalmia and microphthalmia had a combined average of 1 in every 10,000 births. The annual rate of occurrence of anophthalmia/microphthalmia in the United States is about 780 children born/year. The most extensive epidemiological survey on this congenital malformation has been carried out by Dharmasena et al. and using English National Hospital Episode Statistics, they calculated the annual incidence of anophthalmia, microphthalmia and congenital malformations of orbit/lacrimal apparatus from 1999 to 2011. According to this study the incidence of congenital anophthalmia ranged from 2.4 (95% CI 1.3 to 4.0) per 100 000 infants in 1999 to 0.4 (0 to 1.3) in 2011. Parents that already have a child who suffers from anophthalmia has a 1 in 8 chance of having another child with anophthalmia. Approximately 2/3 of all cases of anophthalmia are determined to be of genetic basis. Anophthalmia is one of the leading causes of congenital blindness and accounts for 3-11% of blindness in children. Anophthalmia and microphthalmia together make up 1.7-1.8% of reconstructive surgical cases in laboratory of plastic surgery and ocular prostheses.
People infected with TB bacilli will not necessarily become sick with the disease. The immune system "walls off" the TB bacilli which, protected by a thick waxy coat, can lie dormant for years.The spread of TB bacteria depends on factors such as the number and concentration of infectious people in any one place together with the presence of people with a higher risk of being infected (such as those with HIV/AIDS). The risk of becoming infected increases with the longer the time that a previously uninfected person spends in the same room as the infectious case. The risk of spread increases where there is a high concentration of TB bacteria, such as can occur in closed environments like overcrowded houses, hospitals or prisons. The risk will be further increased if ventilation is poor. The risk of spread will be reduced and eventually eliminated if infectious patients receive proper treatment. Diagnosis
Successful diagnosis of XDR-TB depends on the patients access to quality health-care services. If TB bacteria are found in the sputum, the diagnosis of TB can be made in a day or two, but this finding will not be able to distinguish between drug-susceptible and drug-resistant TB. To evaluate drug susceptibility, the bacteria need to be cultivated and tested in a suitable laboratory. Final diagnosis in this way for TB, and especially for XDR-TB, may take from 6 to 16 weeks.The original method used to test for MDR-TB and XDR-TB was the Drug Susceptibility Testing (DST).