Excerpt from Conjunctivitis, Neonatal

Synonyms, Key Words, and Related Terms: ophthalmia neonatorum, neonatal conjunctivitis, infectious conjunctivitis, conjunctiva

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Background: By definition, neonatal conjunctivitis presents during the first month of life and may be aseptic or septic. Aseptic neonatal conjunctivitis most often is a chemical conjunctivitis that is induced by silver nitrate solution, which is used for prophylaxis of infectious conjunctivitis. Chemical conjunctivitis is not as common anymore because of the use of erythromycin ointment in place of silver nitrate solution for the prophylaxis of infectious conjunctivitis. Bacterial, chlamydial, and viral infections are major causes of septic neonatal conjunctivitis, chlamydia being the most common infectious agent. Infants may acquire these infective agents as they pass through the birth canal during the birth process.

Pathophysiology: The conjunctiva (a thin translucent mucous membrane) can be divided into palpebral, bulbar, and fornical, based on the location. The conjunctiva contains nonkeratinizing, squamous epithelium and a thin, richly vascularized substantia propria (containing lymphatic vessels and cells, such as lymphocytes, plasma cells, mast cells, and macrophages). The conjunctiva also has accessory lacrimal glands and goblet cells.

The pathology of neonatal conjunctivitis is influenced by the anatomy of the conjunctival tissues in the newborn. The inflammation of conjunctiva may cause blood vessel dilation, chemosis, and excessive secretion. This reaction tends to be more serious due to the following: lack of immunity, absence of lymphoid tissue in the conjunctiva, and absence of tears at birth.

Frequency:

In the US: The incidence of infectious neonatal conjunctivitis ranges from 1-2%, depending on the socioeconomic character of the area.
The epidemiology of neonatal conjunctivitis has changed since silver nitrate solution was introduced to prevent gonococcal ophthalmia.
Chlamydia has been reported as the most common infectious agent that causes ophthalmia neonatorum in the United States (incidence is 6.2 per 1000 live births).
In contrast, the incidence of gonococcal ophthalmia neonatorum has been reduced dramatically, from 100 per 1000 live births to 3 per 1000 live births.

Internationally: As in the United States, incidence of ophthalmia neonatorum in many other countries also decreased after silver nitrate solution was used.
In Europe, incidence fell from 10% of births to less than 1%.
The incidence was less than 7 per 1000 live births in 1943 in England.
A higher incidence of ophthalmia neonatorum exists in developing countries. In a Nairobi hospital, the incidences of gonococcal and chlamydial conjunctivitis were 40 per 1000 and 80 per 1000 (per live newborn), respectively. More than 50% of newborns in Nairobi had concurrent gonococcal conjunctivitis. Prophylaxis was not administered at birth in this area. The prevalence of gonorrhea also was high among antenatal attenders in African countries, ranging from 4-15%.

Mortality/Morbidity: Mortality is due to systemic involvement. No published information is available on mortality.

Antibiotics have significantly altered the prognosis of neonatal conjunctivitis, especially with Neisseria gonorrhoeae infection. A previous study showed that from 1906-1911, 24% of children who were admitted to American schools for the blind had a visual disability that resulted from ophthalmia neonatorum. In contrast, only 0.3% of these children were blind secondary to gonococcal conjunctivitis from 1958-1959.

Race: No published information is available on racial differences.

Sex: No published information is available on sex differences.

Age: This condition presents during the first month of life.