Prevalence and clinical profile of microcephaly in South America pre-Zika, 2005-14: prevalence and case-control study

Ieda Orioli, Helen Dolk, Jorge Lopez-Camelo, Daniel Mattos, Fernando Poletta, Maria Dutra, Flavia Carvalho, Eduardo Castilla

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Objective To describe the prevalence and clinical spectrum of microcephaly in South America for the period 2005-14, before the start of the Zika epidemic in 2015, as a baseline for future surveillance as the Zika epidemic spreads and as other infectious causes may emerge in future.Design Prevalence and case-control study.Data sources ECLAMC (Latin American Collaborative Study of Congenital Malformations) database derived from 107 hospitals in 10 South American countries, 2005 to 2014. Data on microcephaly cases, four non-malformed controls per case, and all hospital births (all births for hospital based prevalence, resident within municipality for population based prevalence). For 2010-14, head circumference data were available and compared with Intergrowth charts.Results 552 microcephaly cases were registered, giving a hospital based prevalence of 4.4 (95% confidence interval 4.1 to 4.9) per 10 000 births and a population based prevalence of 3.0 (2.7 to 3.4) per 10 000. Prevalence varied significantly between countries and between regions and hospitals within countries. Thirty two per cent (n=175) of cases were prenatally diagnosed; 29% (n=159) were perinatal deaths. Twenty three per cent (n=128) were associated with a diagnosed genetic syndrome, 34% (n=189) polymalformed without a syndrome diagnosis, 12% (n=65) with associated neural malformations, and 26% (n=145) microcephaly only. In addition, 3.8% (n=21) had a STORCH (syphilis, toxoplasmosis, other including HIV, rubella, cytomegalovirus, and herpes simplex) infection diagnosis and 2.0% (n=11) had consanguineous parents. Head circumference measurements available for 184/235 cases in 2010-14 showed 45% (n=82) more than 3 SD below the mean, 24% (n=44) between 3 SD and 2 SD below the mean, and 32% (n=58) larger than −2 SD.Conclusion Extrapolated to the nearly 7 million annual births in South America, an estimated 2000-2500 microcephaly cases were diagnosed among births each year before the Zika epidemic began in 2015. Clinicians are using more than simple metrics to make microcephaly diagnoses. Endemic infections are important enduring causes of microcephaly.
LanguageEnglish
JournalBMJ
Volume359
Issue numberj5018
Early online date21 Nov 2017
DOIs
Publication statusE-pub ahead of print - 21 Nov 2017

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Microcephaly
South America
Case-Control Studies
Parturition
Head
Herpes Simplex
Rubella
Information Storage and Retrieval
Toxoplasmosis
Syphilis
Infection
Cytomegalovirus
Population
HIV
Databases
Confidence Intervals

Keywords

  • microcephaly in South America pre-Zika

Cite this

Orioli, Ieda ; Dolk, Helen ; Lopez-Camelo, Jorge ; Mattos, Daniel ; Poletta, Fernando ; Dutra, Maria ; Carvalho, Flavia ; Castilla, Eduardo. / Prevalence and clinical profile of microcephaly in South America pre-Zika, 2005-14: prevalence and case-control study. In: BMJ. 2017 ; Vol. 359, No. j5018.
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title = "Prevalence and clinical profile of microcephaly in South America pre-Zika, 2005-14: prevalence and case-control study",
abstract = "Objective To describe the prevalence and clinical spectrum of microcephaly in South America for the period 2005-14, before the start of the Zika epidemic in 2015, as a baseline for future surveillance as the Zika epidemic spreads and as other infectious causes may emerge in future.Design Prevalence and case-control study.Data sources ECLAMC (Latin American Collaborative Study of Congenital Malformations) database derived from 107 hospitals in 10 South American countries, 2005 to 2014. Data on microcephaly cases, four non-malformed controls per case, and all hospital births (all births for hospital based prevalence, resident within municipality for population based prevalence). For 2010-14, head circumference data were available and compared with Intergrowth charts.Results 552 microcephaly cases were registered, giving a hospital based prevalence of 4.4 (95{\%} confidence interval 4.1 to 4.9) per 10 000 births and a population based prevalence of 3.0 (2.7 to 3.4) per 10 000. Prevalence varied significantly between countries and between regions and hospitals within countries. Thirty two per cent (n=175) of cases were prenatally diagnosed; 29{\%} (n=159) were perinatal deaths. Twenty three per cent (n=128) were associated with a diagnosed genetic syndrome, 34{\%} (n=189) polymalformed without a syndrome diagnosis, 12{\%} (n=65) with associated neural malformations, and 26{\%} (n=145) microcephaly only. In addition, 3.8{\%} (n=21) had a STORCH (syphilis, toxoplasmosis, other including HIV, rubella, cytomegalovirus, and herpes simplex) infection diagnosis and 2.0{\%} (n=11) had consanguineous parents. Head circumference measurements available for 184/235 cases in 2010-14 showed 45{\%} (n=82) more than 3 SD below the mean, 24{\%} (n=44) between 3 SD and 2 SD below the mean, and 32{\%} (n=58) larger than −2 SD.Conclusion Extrapolated to the nearly 7 million annual births in South America, an estimated 2000-2500 microcephaly cases were diagnosed among births each year before the Zika epidemic began in 2015. Clinicians are using more than simple metrics to make microcephaly diagnoses. Endemic infections are important enduring causes of microcephaly.",
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Orioli, I, Dolk, H, Lopez-Camelo, J, Mattos, D, Poletta, F, Dutra, M, Carvalho, F & Castilla, E 2017, 'Prevalence and clinical profile of microcephaly in South America pre-Zika, 2005-14: prevalence and case-control study', BMJ, vol. 359, no. j5018. https://doi.org/10.1136/bmj.j5018

Prevalence and clinical profile of microcephaly in South America pre-Zika, 2005-14: prevalence and case-control study. / Orioli, Ieda; Dolk, Helen; Lopez-Camelo, Jorge; Mattos, Daniel; Poletta, Fernando; Dutra, Maria; Carvalho, Flavia; Castilla, Eduardo.

In: BMJ, Vol. 359, No. j5018, 21.11.2017.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Prevalence and clinical profile of microcephaly in South America pre-Zika, 2005-14: prevalence and case-control study

AU - Orioli, Ieda

AU - Dolk, Helen

AU - Lopez-Camelo, Jorge

AU - Mattos, Daniel

AU - Poletta, Fernando

AU - Dutra, Maria

AU - Carvalho, Flavia

AU - Castilla, Eduardo

PY - 2017/11/21

Y1 - 2017/11/21

N2 - Objective To describe the prevalence and clinical spectrum of microcephaly in South America for the period 2005-14, before the start of the Zika epidemic in 2015, as a baseline for future surveillance as the Zika epidemic spreads and as other infectious causes may emerge in future.Design Prevalence and case-control study.Data sources ECLAMC (Latin American Collaborative Study of Congenital Malformations) database derived from 107 hospitals in 10 South American countries, 2005 to 2014. Data on microcephaly cases, four non-malformed controls per case, and all hospital births (all births for hospital based prevalence, resident within municipality for population based prevalence). For 2010-14, head circumference data were available and compared with Intergrowth charts.Results 552 microcephaly cases were registered, giving a hospital based prevalence of 4.4 (95% confidence interval 4.1 to 4.9) per 10 000 births and a population based prevalence of 3.0 (2.7 to 3.4) per 10 000. Prevalence varied significantly between countries and between regions and hospitals within countries. Thirty two per cent (n=175) of cases were prenatally diagnosed; 29% (n=159) were perinatal deaths. Twenty three per cent (n=128) were associated with a diagnosed genetic syndrome, 34% (n=189) polymalformed without a syndrome diagnosis, 12% (n=65) with associated neural malformations, and 26% (n=145) microcephaly only. In addition, 3.8% (n=21) had a STORCH (syphilis, toxoplasmosis, other including HIV, rubella, cytomegalovirus, and herpes simplex) infection diagnosis and 2.0% (n=11) had consanguineous parents. Head circumference measurements available for 184/235 cases in 2010-14 showed 45% (n=82) more than 3 SD below the mean, 24% (n=44) between 3 SD and 2 SD below the mean, and 32% (n=58) larger than −2 SD.Conclusion Extrapolated to the nearly 7 million annual births in South America, an estimated 2000-2500 microcephaly cases were diagnosed among births each year before the Zika epidemic began in 2015. Clinicians are using more than simple metrics to make microcephaly diagnoses. Endemic infections are important enduring causes of microcephaly.

AB - Objective To describe the prevalence and clinical spectrum of microcephaly in South America for the period 2005-14, before the start of the Zika epidemic in 2015, as a baseline for future surveillance as the Zika epidemic spreads and as other infectious causes may emerge in future.Design Prevalence and case-control study.Data sources ECLAMC (Latin American Collaborative Study of Congenital Malformations) database derived from 107 hospitals in 10 South American countries, 2005 to 2014. Data on microcephaly cases, four non-malformed controls per case, and all hospital births (all births for hospital based prevalence, resident within municipality for population based prevalence). For 2010-14, head circumference data were available and compared with Intergrowth charts.Results 552 microcephaly cases were registered, giving a hospital based prevalence of 4.4 (95% confidence interval 4.1 to 4.9) per 10 000 births and a population based prevalence of 3.0 (2.7 to 3.4) per 10 000. Prevalence varied significantly between countries and between regions and hospitals within countries. Thirty two per cent (n=175) of cases were prenatally diagnosed; 29% (n=159) were perinatal deaths. Twenty three per cent (n=128) were associated with a diagnosed genetic syndrome, 34% (n=189) polymalformed without a syndrome diagnosis, 12% (n=65) with associated neural malformations, and 26% (n=145) microcephaly only. In addition, 3.8% (n=21) had a STORCH (syphilis, toxoplasmosis, other including HIV, rubella, cytomegalovirus, and herpes simplex) infection diagnosis and 2.0% (n=11) had consanguineous parents. Head circumference measurements available for 184/235 cases in 2010-14 showed 45% (n=82) more than 3 SD below the mean, 24% (n=44) between 3 SD and 2 SD below the mean, and 32% (n=58) larger than −2 SD.Conclusion Extrapolated to the nearly 7 million annual births in South America, an estimated 2000-2500 microcephaly cases were diagnosed among births each year before the Zika epidemic began in 2015. Clinicians are using more than simple metrics to make microcephaly diagnoses. Endemic infections are important enduring causes of microcephaly.

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DO - 10.1136/bmj.j5018

M3 - Article

VL - 359

JO - BMJ

T2 - BMJ

JF - BMJ

SN - 0959-8138

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ER -