Since the Zika virus outbreak in Brazil began in May 2015, the prevalence of suspected microcephaly has increased from a historical .5 cases/10,000 live births to an estimated prevalence of 9.97 cases/10,000 live births, representing a twenty-fold increase in cases of microcephaly (Schuler-Faccini et al., 2015; Ventura, Maia, Bravo-Filho, Gois, Belfort, 2016).
Children with microcephaly are at high risk for developmental delays and disabilities. This is a two-part blog post, in which we will discuss the virus, its consequences, and the service needs of children with microcephaly. In Part 1, we will outline the current situation in Brazil, and discuss the virus, microcephaly, and the developmental characteristics of children with microcephaly. Part 2 will focus on the early intervention needs of children with microcephaly and describe the response to these needs by the government of Brazil and the international community.
Zika virus was first identified in Uganda in 1947, but the first major recorded outbreak of the disease was in the Federated States of Micronesia. Later outbreaks were recorded in Southeast Asia and the Western pacific, but the 2015 outbreak in Brazil is the first known outbreak in the Americas. It was estimated that there were between 440,000 and 1,300,000 cases of Zika in Brazil in 2015 (Hennessey, 2016).
The virus is characterized by fever, a rash, and conjunctivitis, although many people who are infected remain asymptomatic. Hospitalization is rarely required, and symptoms are usually mild, remaining for several days to a week (CDC, 2016).
The possible association between Zika virus and microcephaly is one of the most severe potential consequences of the virus, and the increase in microcephaly in Zika-affected areas led Brazil’s Ministry of Health (MoH) to declare a state of national emergency (Oliviera Melo et al., 2016).
Microcephaly is most commonly a result of abnormal brain development in utero or in early infancy. While causation of microcephaly in infants can not always be determined, some common causes of microcephaly are chromosomal syndromes, neurometabolic syndromes, pregnant mother’s exposure to alcohol, certain drugs, or toxic chemicals, and diseases during pregnancy such as rubella, toxoplasmosis, and cytomegalovirus (CDC, 2016).
Microcephaly is usually diagnosed by a measurement of infant head circumference. The cutoff for diagnosis is usually a measurement of head circumference that is 2 or more standard deviations below the mean for sex and gestational age at birth (Schuler-Faccini et al., 2015). Diagnosis is often followed with a CT or MRI scan to determine the structure of the infant’s brain, and evaluate any possible health risks associated with its abnormal development (CDC, 2016).
Children with microcephaly are at risk for health consequences ranging from mild to life threatening. Seizures, developmental delays, intellectual disabilities, movement and balance, vision, and hearing problems are all linked with microcephaly. Children with microcephaly often benefit from early intervention services such as speech, occupational, and physical therapies in order to maximize their abilities (CDC, 2016). Medications for seizures and neuromuscular symptoms are sometimes advised for children with microcephaly, and genetic counseling is used to help families determine the risk of microcephaly for subsequent children (NINDS, 2015).
Zika and Microcephaly in Brazil
Although the role of Zika virus in causing microcephaly has not been determined, recent research indicates a correlation. Vertical transmission of Zika from mother to child in utero was suggested when it was determined that the amniotic fluid samples of two pregnant women were positive for Zika RNA while the mothers’ urine and serum samples were negative for the virus (European Centre for Disease, 2015). A Brazilian MoH taskforce investigation found that all mothers in their study sample (n=35) had either lived in or visited Zika affected areas during pregnancy, and 74% reported a febrile rash during pregnancy. Further studies, however, are needed to determine causal association between Zika virus infection and microcephaly in infants (Schuler-Faccini et al., 2016).
Historical tracking and diagnosis of microcephaly in Brazil has created limitations for determining a causal relationship. The historical birth prevalence of microcephaly is lower in Brazil than expected (0.5 cases/10,000 live births as opposed to 1-2 cases/10,000 live births), implying a generally low diagnosis rate for microcephaly. This historical under-discovery could have increased case reporting for microcephaly, over-representing the increase in microcephaly during the Zika outbreak. Reported histories of nonspecific rash illness during pregnancy for mothers of children with microcephaly is also subject to recall bias and cannot confirm a definitive association between the virus and outcome (Schuler-Faccini et al., 2016).
The sharp increase in microcephaly during the Zika outbreak falls outside the range for simple diagnosis errors, however, and a rapid risk assessment determined that a causal association between microcephaly in newborns and Zika virus infection during pregnancy is plausible (European Centre for Disease, 2015). The World Health Organization (WHO) also issued an epidemiological alert about the association of Zika virus and congenital malformations or neurological syndromes (WHO PAHO, 2015).
Developmental Needs for Children with Microcephaly and their Families
Regardless of the possible association with Zika virus, such a large increase in the prevalence of microcephaly has implications for early developmental intervention resources in Brazil.
While some children with microcephaly have mild developmental delays, most children are at high risk for displaying severe developmental delays. Common characteristics of children with microcephaly include delayed speech, neuromotor dysfunction, balance difficulties, and seizures. Early intervention services to promote the child’s development and support the family is required as well as medical treatment for seizure control (Microcephaly, 2014). Specialized services such as physical therapy and child neurology may be available in some of the bigger cities within Brazil, but families from more rural areas of the country often have to travel 10 to 12 hours to reach specialized facilities. Additionally, existing facilities will soon face a quickly rising patient population that they may not be prepared to serve (Sifferlin, 2016).
The recent Zika virus outbreak in Brazil with its association to infants born with microcephaly and concomitant developmental issues leads us to ask if Brazil and the global community are prepared to provide the services needed by the child now and in the future. This increase in children with developmental needs will affect the already overburdened social, educational, and health care systems in Brazil.
In Part 2 we will address the early intervention and development needs of children with microcephaly and examine the capacity of the Brazilian government to handle these emerging development needs.
- Centers for Disease Control. (2016, February 5). Zika Virus. Retrieved from Centers for Disease Control and Prevention website: http://www.cdc.gov/zika/index.html
- Centers for Disease Control (2016). Facts about Microcephaly [Fact sheet]. Retrieved from Centers for Disease Control and Prevention website: http://www.cdc.gov/ncbddd/birthdefects/microcephaly.html
- European Centre for Disease Control and Prevention. (2015, December). Zika virus epidemic in the Americas: potential association with microcephaly and Guillain- Barre syndrome. Stockholm.
- Hennessey, M. (2016). Zika virus spreads to new areas—region of the Americas, May 2015–January 2016. MMWR. Morbidity and Mortality Weekly Report, 65.
- Microcephaly. (2014, June 26). Retrieved from Raising Children Network website:http://raisingchildren.net.au/articles/microcephaly.html
- National Institute of Neurological Disorders and Stroke (2015). Microcephaly Information. Retrieved from National Institute of Neurological Disorders and Stroke. website: http://www.ninds.nih.gov/disorders/microcephaly/microcephaly.htm
- Oliveira Melo, A. S., Malinger, G., Ximenes, R., Szejnfeld, P. O., Alves Sampaio, S., & Bispo de Filippis, A. M. (2016). Zika virus intrauterine infection causes fetal brain abnormality and microcephaly: tip of the iceberg?. Ultrasound in Obstetrics & Gynecology, 47(1), 6-7.
- Schuler-Faccini, L., Ribiero E.M., Feitosa I.M., Horovitz, D.G., Cavalcanti, D.P., Pessoa, A., …Sanseverino, M.T. (2016). Possible Association Between Zika Virus Infection and Microcephaly—Brazil, 2015. MMWR. Morbidity and Mortality Weekly Report, 65.
- Sifferlin, A. (2016, February 1). See Inside a Rehab Center for Babies with Likely Zika-Related Birth Defects. Time. Retrieved from http://time.com/4202473/microcephaly-birth-defect-zika/
- Ventura, C. V., Maia, M., Bravo-Filho, V., Góis, A. L., & Belfort, R. (2016). Zika virus in Brazil and macular atrophy in a child with microcephaly. The Lancet, 387(10015), 228.
- WHO PAHO. (2015, December). Neurological syndrome, congenital malformations, and Zika virus infection. Implications for public health in the Americas.
Eleanor Birch and Jamie King (Georgetown University ’17)