What is the global prevalence of congenital infections such as Cytomegalovirus (CMV), Toxoplasmosis, Congenital Syphilis, Herpes Simplex Virus (HSV), Rubella, and Zika virus?

Global Prevalence of Congenital Infections

The global prevalence of congenital infections varies substantially by pathogen, with CMV being the most common at 0.2-2.2% of live births, followed by toxoplasmosis at approximately 1.9 per 10,000 live births globally, while congenital syphilis, HSV, rubella, and Zika show significant geographic variation based on maternal seroprevalence and public health interventions. 1, 2

Cytomegalovirus (CMV)

CMV is the most common congenital infection worldwide, occurring in 0.2-2.2% of all live births in developed countries, with even higher rates in developing nations. 1, 3

• In the United States specifically, CMV affects approximately 1% of all live births, representing the leading cause of congenital viral infection. 3
• A Brazilian study of a low-income population documented a prevalence of 1.19% (25/2100 newborns), confirming rates consistent with other resource-limited settings. 4
• Transmission rates differ dramatically based on maternal infection status: 30-40% with primary maternal infection during pregnancy versus only 0.15-1.0% with recurrent maternal infection. 1

Toxoplasmosis

The global burden of congenital toxoplasmosis is estimated at 190,100 cases annually worldwide (95% CI: 179,300-206,300). 2

• In France, with its national antepartum screening program, the prevalence is 3.3 per 10,000 live births, with symptomatic congenital toxoplasmosis at 0.34 per 10,000 live births. 2
• European rates vary substantially by country: 0.7 per 10,000 in Sweden, 0.8 per 10,000 in the United Kingdom, 1 per 10,000 in Austria, 1.6 per 10,000 in Denmark, 5 per 10,000 in Switzerland, 11 per 10,000 in Poland, and 13 per 10,000 in Germany. 2
• In the United States, maternal seroprevalence among women of childbearing age (15-44 years) has declined from 15% in 1988-1994 to 11% in 1999-2004 to 9.1% in 2009-2010, indicating decreasing population susceptibility. 2
• The severity of congenital toxoplasmosis in Brazil is notably high and may be associated with genetic characteristics of T. gondii isolates prevalent in that region. 5

Congenital Syphilis

No specific global prevalence data for congenital syphilis is provided in the available evidence.

• The evidence mentions syphilis only in the context of genital/reproductive infections associated with periconceptional exposure, without providing discrete prevalence figures. 2

Herpes Simplex Virus (HSV)

Neonatal herpes infection is rare globally, though HSV type-2 has a high maternal seroprevalence with over 491 million (13%) individuals aged 15-49 infected worldwide. 2

• Despite high maternal seroprevalence, the actual rate of congenital/neonatal transmission resulting in symptomatic disease is much lower than the maternal infection rate. 2
• The evidence does not provide specific global prevalence rates for congenital HSV infection, only noting it is "rare" despite widespread maternal infection. 2

Rubella

Congenital rubella syndrome has been eliminated in the Americas through immunization programs, though global data on current prevalence is not provided in the available evidence. 6

• Historical cohort studies from the United States (1959-1966) measured rubella antibodies in over 55,000 pregnancies but found no significant association with specific outcomes in that context. 2

Zika Virus

Specific global prevalence rates for congenital Zika syndrome are not established in the available evidence, as the epidemic emerged only in 2015 in South America. 2

• ZIKV has spread to over 60 countries and territories, including Puerto Rico, with local mosquito-borne transmission reported in Florida and Texas. 2
• The evidence notes that transplacental infection occurs with high efficiency in non-human primate models, though severe congenital malformation is a relatively less common phenotype in humans. 2
• Congenital Zika syndrome is characterized by severe microcephaly, brain abnormalities, eye anomalies, and congenital contractures, though some affected infants may have normal head circumference at birth. 2, 7

Critical Caveats

• Surveillance limitations: Most countries lack mandatory reporting systems for congenital infections, leading to significant underestimation of true prevalence. 2
• Geographic variation: Prevalence rates differ dramatically based on maternal seroprevalence, public health interventions (screening programs, vaccination), and socioeconomic factors. 2
• Asymptomatic infections: Many congenital infections are asymptomatic at birth but may develop late sequelae, particularly hearing loss and neurodevelopmental disabilities, making true disease burden difficult to quantify. 1, 4, 8