SEROLOGIC SCREENING FOR CYTOMEGALOVIRUS, RUBELLA VIRUS, HERPESSIMPLEX VIRUS, HEPATITIS B VIRUS, AND Z-DXOl?~snIlA GONDII IN TWO URBAN POPULATIONS OF PREGNANT WOMEN IN CHILE1 Pablo Vzlzl;2 Jorge Toves-Pereyra, 3 Sergio Stagno, 4 Francisco Gonzhfez,’ Enrique Donoso, G Chades A. Allford, 7 Zimara Hirsch, 8 and Luk Rodtiguezg I NTRODUCTION these agents represent naturally acquired infections. There are only a few reports Although the prevalence of concerning the epidemiology of congeni- congenital and perinatal infections is tal and perinatal infections in Chile (l- high, however, it is.unclear whether their $&In general, these reports show that incidence during the childbearing years the prevalences of infection with most of (and hence their potential to cause fetal the causative agents are high and that disease) is different from that observed in most infections are acquired at an early communities such as those in developed age. Since vaccinations against cytomeg- countries where lower prevalences are the alovirus (CMV), herpes simplex virus rule. Therefore, in order to help assess (HSV), and Toxopl’asma gondii have not the importance of CMV, HSV, rubella, yet been introduced, high prevalences of HBV, and ToxopLasmagondii as causesof z 2 < ’ This article is also being published in Spanish in the 4 Department of Pediatrics, University of Alabama. Bir- 2 BoLefin de /a Oficina Sanitankz Panameticana, 99(5), mingham. Alabama, United States. % 1985. The work reported here was supported by Grant s Division of Obstetrics and Gynecology, Dr. Sotero de1 x ‘4 LHZ503Q from the Pan American Health Organita- Rio Hospital, Puente Alto, Chile. u 6 Department of Obstetrics and Gynecology. School of tion and the Kellogg Foundation, by Grant HD-10699 2 from the U.S. National Institute of Child Health and Medicine, Catholic University, Santiago, Chile. Human Development, by the Pontifical Catholic LJni- ’ Department of Pediatrics, University of Alabama. 2 versity of Chile, and by the Southeastern Metropolitan 8 Department OfPediatrics, School of Medicine, Catholic Health Service of Santiago, Chile. University, Santiago, Chile. 2 a Department of Pediatrics, School of Medicine, Catholic ” Central Laboratory, School of Medicine, Catholic Uni- n, University, Santiago, Chile. versity. Santiago, Chile. ’ Department ofpediatrics, School of Medicine, Catholic University, Santiago, Chile. 53 perinatal infections, we determined the counted for approximately 5% of all rate of susceptibility to these infections pregnancies seen at area public health during pregnancy among women of both clinics in one year. low and middle socioeconomic status in The 372 middle-income Santiago, Chile. The report presented women in the study population were en- here indicates the prevalences of these in- rolled at the obstetrics clinic of the Hos- fections early in gestation and compares pital of the Catholic University of Chile the results with other results obtained ( Universidad Catdica de Ck’e). All of from the same population and from these women were white, their mean age other populations in other countries. was 27.2 years, and their mean gesta- tional age at enrollment was 14 weeks. This population accounted for nearly 20% of all pregnant women seen at the M A’I’ERIALS obstetric clinic in one year. AND METHODS Serum samples obtained at enrollment from all of the subjects were The study population con- stored at - 20°C until tested by one of sisted of 833 pregnant women residing in us (P.V.) at the virology laboratory at the Santiago, Chile, who were enrolled in University of Alabama in Birmingham. the study between January and March of IgG-class antibodies against CMV, HSV I 1983, at their first or second prenatal and HSV II, rubella virus, hepatitis B vi- clinic visit. The age distribution of the rus, and Toxoplasma go&ii were assessed study population, by income group, is using commercially available enzyme- shown in Table 1. linked immunosorbent assay(ELISA) kits. The 461 low-income women That is, serum samples were assayed on in this population, all white, were drawn microtiter plates in accordance with the from three different public health clinics method recommended by the manufac- operated for beneficiaries of the National turer of the “Cytomegalisa,” “Herpe- Health Service in the southeast area of l&a,” “Rubelisa,” and “Toxoelisa” kits Santiago; their mean age was 24.5 years (M.A. Bioproducts, Wakersville, Mary- and their mean gestational age at enroll- land, USA). The anti-HBc antibodies ment was 18 weeks. This population ac- were also determined by a commercially available ELISA (Corzyme, Abbott Labo- ratories). The samples that were positive for anti-HBc were subsequently tested b TABLE1. Distributionof the study population,by income for surface antigen (HBsAg) and HBe an- and age groups. 3 tigen (HBeAg) by another ELISA (aus- zime II, Abbott HBe, Abbott Laborato- 4 Middle-income Low-income z. ries). All these assaysare routinely done group group % Age group in our laboratory. .g (in years) No. % No. % 9, %4 16-20<15 -28 - 7.5 12221 26.54.6 s 21-2526-30 132118 35.531.7 11996 25.820.8 a, 31-35 61 16.4 68 14.7 136 33 8.9 35 7.6 54 Total 372 100 461 100 In each run we included ap- cal comparisons were analyzed by the propriate positive and negative controls. Chi square test. Because the Herpelisa kit used to test an- tibodies to HSV I and II had not been li- censed by the U.S. Food and Drug Ad- ministration, we felt it was necessary to RESULTS verify that test’s specificity. Dr. A. Nah- Among pregnant women mias of Emory University in Atlanta, from the lower of the two socioeconomic Georgia, generously provided us with 30 groups, the rate of seropositivity was serum specimens known to contain ei- 96.5% for CMV, 97.2% for HSV, 94.8% ther type I or type II antibodies (deter- for rubella, 68.2 % for Toxoplasma gon- mined. by testing them against specific dii, and 1.4% for HBV, These rates dif- HSV I and II glycoproteins). We found fered significantly from somewhat lower that specimens containing HSV I anti- rates found for the group of women with bodies had a high rate of cross-reactivity intermediate socioeconomic status in the with the HSV type II antigen used in the casesof Ch4V,HSV, and ToxopZasmagon- Herpelisa test. (HSV type II antibodies dii (Table 2). did not cross-react with HSV type I anti- gen.) Because of this cross-reactivity, we have reported our results without distin- guishing between types I and II. Statisti- TABLE2. Resultsobtained from ELISAtesting of sera tom two differ- ent populations of pregnant women in Chile for exposure to five agents causing congenital and perinafal disease (cnw=cytomega- lovirus; HSV= herpL!Ssimplex virus; and HBV= hepatitis B virus). No. of pregnant women in group Socioeconomic background of No. No. % Agent populationgroup tested positive positive CMV Low 456b 440 963 t Middle 370b 321 86.8a Rubella Low 461 437 94.8 virus t Middle 372 351 94.4 HSV . Low 458b 445 97.2a i Middle 37P 326 87.ga Toxoplasma Low 449b 306 68.2a gondii I Middle 370b 179 48.4a HEV Low 513c 7 1.4 L Middle 358 5 1.4 a The difference between the results for the two scciceconomic groups is statistically significant (p< 0.001). b Seven of the study subjects were not tested far CMV,four were nol tested for HN, and 14 were not tested for Toxp/asma goncb. c In addition to sera from study subjects. sera from 52 other low-income women were tested for HENThe serum samples tested were obtainedfrom pregnantwomen coming to the three participating clmics during the study period. Within the middle-class pop- TABLE 3. Indicated prevalencesof three HBV markers, ulation group, none of five samples test- (anti-HE& HBsAg, and HBeAg)among the 871 pregnant ing positively for anti-HBc were positive women participating in the study. for HBsAg or HBeAg. However, of seven No. of Positivesera samples testing positively for anti-HBc in subjects the lower-class population group, one Marker tested No. % was positive for HBsAg and two were Anti-HBc 871 12a 1.4 positive for both HBsAg and HBeAg. HBsAg 871 0.34 The rate of HBsAg carriers among the to- HBeAg 871 0.22 tal population studied thus appeared to a FM of these subjects came from the mlddle-class group and seven be 0.34 % (Table 3). came from the lower-class group. The age distributions of sero- b The sera posfilve for HBsAg and HEeAg came from among the 12 test- ing positively for antr-HBc Only these 12 sera were tested for HEsAg and negative women within both popula- HE&g. tions for CMV, HSV, rubella, and Toxo- @sma gondii are shown in Figure 1. As LEGEND A. Cytomegalovirus 8. Herpes simplex virus * P< 0.025 30 30 ** P< 0.010 9 *** P<O.O50 ‘... I Cl5 16-20 21-25 26.30 31-35 236 <I5 16-20 21-25 26-30 31-35 236 Age (years) Age (years) 70 D. Toxoplasma gondii C. Rubella virus 60 ,,/ ,m -/I , I I I I I <,5 16-20 21-25 26-30 31-35 a36 $15 16-20 21.25 26-30 31-35 236 Age (years) Age (years) FIGURE1. Percentagesof the two Santiagostudy populatfonsresponding negativelyto ELISA serologictesting for IgG antibodiesto cytomegalovirus,herpes simplex virus, rubella virus, and Toxoplasmago&i, by age group. may been seen, the number of women positive rates (97.5% and 87.5 %, re- susceptible to CMV, HSV, and Toxop~usma spectively). These rates are similar to gondii declined notably with advancing those reported from communities in Ja- age. pan (7)) Guatemala (8), Barbados (9), Saint Lucia (1 Q), and Tanzania (11) , and higher than those reported from the United States (I, 15, and 18) and Great D ISCUSSION Britain (12).