Why Newborn Eye Infections Differ Around the World, and Which Babies Are More Likely to Get Them

What three hospital studies from Singapore (Farooqui et al. 2025), Jabalpur, India (Pandey et al. 2026) and Ankara, Türkiye (Atar et al. 2026) tell families about the germs, the risk factors and the debate over eye drops at birth

A red, sticky eye in the first weeks of life

Newborn conjunctivitis, an eye infection or irritation in a baby's first four weeks, is still common around the world, but the germs behind it differ from place to place. Three recent hospital studies from Singapore, India and Türkiye show what causes it today and which babies are more likely to be affected, helping doctors test and treat promptly and informing the debate about routine eye drops at birth.

Many parents notice a baby's eye looking red, puffy or crusted with discharge during the first days or weeks at home. Doctors call an eye infection or inflammation in the first 28 days of life ophthalmia neonatorum, or neonatal conjunctivitis ("pink eye" in a newborn). Most cases are mild and clear with treatment, but a small number are caused by germs passed from mother to baby during birth that can also affect other parts of the body, so it helps to know what to look for.

Three hospitals, three pieces of the puzzle

The three studies looked back at hospital records, each in a very different place. At KK Women's and Children's Hospital in Singapore, a large children's hospital with a specialist eye clinic, Farooqui and colleagues reviewed ten years of babies (797 in all) seen for suspected conjunctivitis, to find out which germs were responsible and which signs point to one germ in particular, chlamydia ^[1]. At Sukh Sagar Medical College, a private teaching hospital in Jabalpur, in the state of Madhya Pradesh in central India, Pandey and colleagues checked the records of 2,450 babies over two years to count how many developed conjunctivitis and what their births had in common ^[2]. At Ankara Bilkent City Hospital, a large city hospital in Türkiye where every newborn receives antiseptic eye drops called povidone-iodine, Atar and colleagues compared 203 babies who developed conjunctivitis with 355 who did not ^[3].

Think of the studies as three photographs of the same landscape taken from different hills. One shows which germs are present, one shows who is affected where good pregnancy and birth care is harder to reach, and one shows which babies are still affected when everyone receives the same preventive drops. None of them tested whether the eye drops themselves work. For a wider view, a large 2025 review that pooled 25 earlier studies found that about 2 in every 100 newborns worldwide develop the condition, with rates far higher in low-income countries (about 7 in 100) than in high-income countries (just over 1 in 100) ^[4].

How eye drops at birth became routine, and why some countries are rethinking them

More than a century ago, gonorrhoea caught during birth caused serious eye infections that could threaten a baby's sight. In the late 1800s about 10 in every 100 newborns developed this eye infection; after a doctor named Credé began putting silver nitrate drops into every newborn's eyes, that fell to fewer than 1 in 100, figures the Singapore team quote from the US Preventive Services Task Force, an American expert panel ^[1][5]. Eye drops or ointment at birth became routine, and in some places a legal requirement, and the panel still recommended them for every baby in 2019 ^[5].

Over time, however, gonorrhoea eye infections became rare in countries such as the United States, and another germ, chlamydia, became more important. Without testing and treatment in pregnancy, up to 6 in 10 babies of mothers with chlamydia pick up the germ, about 3 in 10 develop conjunctivitis and about 15 in 100 develop pneumonia, a lung infection ^[6]. Researchers also began comparing different drops: a carefully run trial of 3,117 babies in a hospital in Kenya found fewer eye infections with povidone-iodine than with silver nitrate or with the antibiotic erythromycin ^[7]. A 2020 Cochrane review, which gathers all the trials on a question, found that drops reduce eye infections overall but gave little certainty about protection against gonorrhoea or chlamydia specifically, and no trial measured blindness ^[8].

That uncertainty has led some experts to rethink the routine. In 2015 the Canadian Paediatric Society advised doctors to push for ending compulsory eye drops and to focus instead on testing and treating mothers during pregnancy, pointing out that the drops do not prevent chlamydia ^[9]. A study from Ontario, Canada, estimated that 500,000 babies would need the drops to prevent a single case of blindness ^[10]. An Italian survey found that fewer than 1 in 100 babies who received drops were given a medicine the World Health Organization recommends ^[11], and a 2026 analysis of policy in the United States argued that giving every baby the antibiotic erythromycin at birth exposes babies to antibiotics for little benefit ^[12]. To decide wisely, doctors need up-to-date information about which germs cause newborn eye infections today and which babies get them. That is where the three new studies come in.

What the Singapore study found about chlamydia

In Singapore, chlamydia was the most common single cause, found in 140 of the 797 babies, roughly 1 in 6 ^[1]. Gonorrhoea, once the main worry, was found in only 6 babies, fewer than 1 in 100. A common skin germ, Staphylococcus aureus (often shortened to "staph"), came second. Among babies who already had conjunctivitis, the team also identified clues that made chlamydia the more likely cause: blood-tinged discharge, a swollen eyelid, a red eye, only one eye affected, and being born vaginally rather than by caesarean section.

One finding matters a great deal. The standard quick test on an eye swab, called a Gram stain, picked up chlamydia in only 4 of the 140 babies who had it ^[1]. Chlamydia rarely shows up on that test, so it needs a special test of its own, such as a genetic test called PCR (polymerase chain reaction), which the Singapore hospital switched to during the study. Like a smoke alarm tuned to one kind of fire, the usual test can stay silent when a different kind is burning.

What the Jabalpur study found about germs and the circumstances of birth

In Jabalpur, 74 of 2,450 babies developed conjunctivitis, about 3 in every 100 ^[2]. Reassuringly, none lost their sight or had serious complications. Here staph was the most common germ, causing about 3 in 10 cases, while chlamydia caused fewer than 1 in 10. Babies were more likely to be affected if the waters broke more than 18 hours before birth, if they were born at home or on the way to hospital, if the mother had fewer than three pregnancy check-ups or an infection of the birth canal, or if the baby needed a breathing tube or a feeding tube. These were simple one-at-a-time comparisons that do not untangle factors that often go together, so they show which babies deserve closer watching rather than proving what causes infection.

What the Ankara study found when every baby received the same drops

In Ankara, all babies received povidone-iodine drops, so the researchers could look at other factors ^[3]. After accounting for several factors at once, babies were more likely to develop conjunctivitis if their mothers were older, had diabetes, or had a higher level of an inflammation marker in the blood called C-reactive protein at delivery, and if the baby was a boy. Most cases began between the fifth and fourteenth day of life. The authors suggest that a mother's overall health may influence how susceptible her baby's eyes are, but a study of this kind cannot prove cause and effect.

Seeing the three studies side by side

Putting the studies together helps explain an apparent contradiction. In Singapore, vaginal birth made chlamydia more likely among babies who already had conjunctivitis, because chlamydia is passed on in the birth canal ^[1]. Yet in Jabalpur and Ankara, the way a baby was born was not clearly linked to conjunctivitis overall ^[2][3]. One possible explanation is that the germs differ: chlamydia comes from the birth canal, whereas staph and similar germs can be picked up after birth, from skin, hands or hospital equipment. The main germ in one country is not necessarily the main germ in another, which is why local information matters so much.

What families can watch for, and when to call

Most newborn eye problems are mild, and a little watery stickiness in the first day or two can simply be irritation from the drops. Contact your baby's doctor or nurse promptly if you notice thick yellow or green discharge, blood-tinged discharge, a swollen eyelid or redness that is getting worse, or if eye symptoms come with a baby who seems unwell, is breathing fast or is feeding poorly. Tell the doctor how your baby was born and whether you had infection tests during pregnancy. If the doctor suggests testing for chlamydia, it is a routine and sensible step, not a judgement. Because chlamydia can also affect a baby's lungs ^[6], doctors treat it as more than just an eye problem, and parents may be offered testing and treatment too. Attending pregnancy check-ups, including infection tests, remains one of the best ways to protect a baby's eyes ^[9].

What researchers are working on next

All three studies looked back at existing records from a single hospital. The next step is to follow babies forward in time across many hospitals, using the same definitions and modern genetic tests that can also detect viruses ^[2][3]. Researchers also want fair comparisons of different prevention approaches, such as eye drops for every baby versus testing and treating mothers in pregnancy, that measure what matters most to families, including eyesight ^[8][12].

The bottom line

Newborn eye infections are still common, but the culprit depends on where a baby is born: chlamydia in Singapore, staph in central India, and in Türkiye a pattern linked to the mother's health even when all babies received protective drops ^[1][2][3]. For families, the practical messages are simple: attend pregnancy check-ups, keep an eye on your baby's eyes in the first weeks, and call early if something looks wrong. With prompt care, most babies recover fully.

References

1. Farooqui SZ, Khan S, Biswas S. Predictors of Chlamydia trachomatis conjunctivitis in neonates: a 10-year retrospective study. BMC Ophthalmol. 2025;25(1):554. doi:10.1186/s12886-025-04395-z ↩
2. Pandey P, Soni S, Pal V. Prevalence, risk factors, and microbial spectrum of ophthalmia neonatorum: a cross-sectional study from Central India. Cureus. 2026;18(5):e109481. doi:10.7759/cureus.109481 ↩
3. Atar MB, Hançerlioğulları N, Özdemir Ö, Tokmak A. Birth and neonatal risk factors associated with neonatal conjunctivitis: a retrospective case–control study. BMC Pediatr. 2026;26(1):823. doi:10.1186/s12887-026-07202-w ↩
4. Asiamah R, Owusu G, Amoako PT, et al. Epidemiology of ophthalmia neonatorum: a systematic review and meta-analysis. BMC Pediatr. 2025;25(1):31. doi:10.1186/s12887-024-05382-x ↩
5. US Preventive Services Task Force; Curry SJ, Krist AH, Owens DK, et al. Ocular prophylaxis for gonococcal ophthalmia neonatorum: US Preventive Services Task Force reaffirmation recommendation statement. JAMA. 2019;321(4):394-398. doi:10.1001/jama.2018.21367 ↩
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7. Isenberg SJ, Apt L, Wood M. A controlled trial of povidone-iodine as prophylaxis against ophthalmia neonatorum. N Engl J Med. 1995;332(9):562-566. doi:10.1056/NEJM199503023320903 ↩
8. Kapoor VS, Evans JR, Vedula SS. Interventions for preventing ophthalmia neonatorum. Cochrane Database Syst Rev. 2020;9(9):CD001862. doi:10.1002/14651858.CD001862.pub4 ↩
9. Moore DL, MacDonald NE; Canadian Paediatric Society, Infectious Diseases and Immunization Committee. Preventing ophthalmia neonatorum. Can J Infect Dis Med Microbiol. 2015;26(3):122-125. doi:10.1155/2015/720726 ↩
10. Rowlands Snyder EC, McGregor E, Coyle D. Universal ophthalmia neonatorum prophylaxis in Ontario: a cost-effectiveness analysis. CMAJ Open. 2023;11(1):E33-E39. doi:10.9778/cmajo.20210226 ↩
11. Mondì V, Tzialla C, Aversa S, et al. Antibiotic prophylaxis for ophthalmia neonatorum in Italy: results from a national survey and the Italian intersociety new position statements. Ital J Pediatr. 2023;49(1):117. doi:10.1186/s13052-023-01507-7 ↩
12. Piccolo L, Sligar K, Kuster A. Reevaluating neonatal erythromycin prophylaxis policy amid advances in sexually transmitted infection screening, antenatal treatment, and antibiotic stewardship. J Obstet Gynecol Neonatal Nurs. 2026;55(3):323-330. doi:10.1016/j.jogn.2025.11.003 ↩