924
CHILDREN ADMITTED FOR INFECTIOUS CAUSES*/TOTAL
unlikely explanation. Hence, higher mortality in mixedfamilies is probably related to the higher risk of getting infected from someone of the opposite sex. These observations from western Kenya indicate that the increased mortality associated with cross-sex transmssion is not restricted to West Africa. 1-3
seems an sex
Department of Epidemiology, Statens Seruminstitut, 2300 Copenhagen S, Denmark
PETER AABY
International Child Health Unit, Uppsala University, Uppsala, Sweden
BO BURSTRÖM
Kenya EPI, Ministry of Health, Nairobi, Kenya
DOMINIC M. MUTIE
Aaby P, Bukh J, Lisse IM, Smits AJ. Cross-sex transmission of infection and increased mortality due to measles Rev Infect Dis 1986; 8: 138-43. 2. Aaby P, Lamb WH. Sex and transmission of measles in a Gambian village. J Infect 1991; 22: 287-92. 3. Pison G, Aaby P, Knudsen K. Increased nsk of measles mortality for children with a sibling of the opposite sex among the Fula Bande and Niokholonko, Senegal. BMJ 1992; 304: 284-87 4. Burström B, Aaby P, Mutie DM, Kimani G, Bjerregaard P. Severe measles outbreak in Western Kenya. East Afr Med J (in press). 5. Rothman KJ. Modem epidemiology. Boston: Little, Brown, 1986. 6. Aaby P, Leeuwenburg J. Sex and patterns of transmission of measles infection: a reanalysis of data from the Machakos area, Kenya. Ann Trop Pediatr 1991; 11: 1.
397-402.
Mortality and morbidity after high titre measles vaccine in Mexico SIR,-Differences in long-term mortality have been reported between children who received high titre measles vaccines at less than 9 months and those who received standard titre vaccine at older ages."We studied morbidity and mortality in children in a 1987 randomised trial of different titre Edmonston-Zagreb (EZ) and Schwarz measles vaccines in Mexico City to compare the serological response to the two strains at different titres in infants aged 6 and 9 months.’ In 1989, around 20 months after vaccination (median age 26 months), parents/carers were recontacted for a study of antibody persistence. 1007 (73%) children were located and rebled. During second follow-up in 1992, we tried to obtain information on all 1380 children. Home visitors were blind to the study group of the child and collected information on general health and socioeconomic status. If a child had died, a study doctor determined the cause and information was abstracted from the death certificate. Date, cause, and length of any hospital admission (we tried to locate the record), visits to a doctor during the previous 3 months, and diarrhoea during the previous 2 weeks were noted. Because of differences in mortality by gender,3analyses were stratified by gender. Differences were tested by the two-tailed Fisher’s exact test; the Mantel-Haenszel y2 was used to test for trend. We obtained information on 1029 (75%) of the original study children (including some who had not been recontacted in 1989). There were no significant differences in follow-up by vaccine group or gender. The median age was 59 months (range 57-61). Socioeconomic status did not vary by vaccine group. The combined follow-ups in 1989 and 1992 provided information on the vital status of 90% of study children at (median) 26 months of age. 3 deaths were detected. 2 boys died from motor-vehicle accidents (standard titre: 1 EZ at 9 months,1 Schwarz at 6 months), and 1 boy died at 16 months from pneumonia (standard titre EZ at 9 months). Mortality at 26 months was 0-08% and at 59 months, 0-3%, which is less than that expected (annual mortality, age 1-4 in Mexico City, 0-08%). 72 children had been admitted at least once (12 twice or more). The infectious disease reasons are shown in the table; 20 children were admitted for an operation. Compared with the standard titre Schwarz group at 9 months, none of the groups had increased risk of admission due to infectious disease, overall or when stratified by gender. There was a non-significant trend within the groups that received Schwarz vaccine at 6 months of age for those who received high titre to have more admissions because of infectious disease. 30% of children had consulted a doctor in the 3 months before interview, mostly because of respiratory infections. Only 4% of
*Pneumon!a (23), diarrhoea (11 hepatitis (1 meningitis (1 encephalitis (1),), urinary tract infection (2). tPlaque-formlng units, measured at Food and Drug Adminstration, j:EZ vaccine produced by Institute of Virology, Mexico City §EZ vaccine produced by Institute of Immunology, Zagreb
child
m
USA
each group admitted twice because of infectious disease
children had had diarrhoea in the 2 weeks before interview. Compared with the standard dose Schwarz group at 9 months, none of the groups had increased visits for disease or episodes of diarrhoea, overall or when stratified by gender. Thus we found no differences in mortality by vaccine group or gender. Also we did not find any significant increase in morbidity in children who received the high titre vaccines at 6 months compared with those who received standard titre vaccines at 9 months. Our study had low power to detect differences because of the small number of children in each of the original groups and the low mortality in the study population. Another limitation of the study was incomplete follow-up at 59 months, although the status of 90% of the children was known at 26 months. Our study population differed from others in which differences in mortality have been found.l,2 Health-care services were more available, and socioeconomic status and educational levels of the mothers were higher. Infectious disease mortality was substantially lower and some infectious diseases that were common in African countries, such as malaria, were absent. Although deaths among those lost to follow-up cannot be excluded, the lack of increase in morbidity or mortality among those receiving high titre vaccines suggests that the differences in mortality detected in some studies may not be generalisable to all populations, and/or that there may be some interaction between the effects of vaccination and other environmental factors. Funded under USAID/PHS BST-5947-P-HI-4265.
Participating Agency Service Agreement
JOSE LUIS DIAZ-ORTEGA Ministry of Health, Mexico
MAGDALENA LUNA-ABASCAL JOSE LUIS VALDESPINO JAIME SEPULVEDA
Division of Immunization, National Center for Prevention Services, Centers for Disease Control, Atlanta, Georgia 30333, USA
LAURI E. MARKOWITZ ELIZABETH R. ZELL
1 Garenne
M, Leroy O, Beau JP, Sene I Child mortality after high-titre measles prospective study in Senegal Lancet 1991; ii: 903-07.
vaccines
Immunization. Safety and efficacy of high titre measles Wkly Epid Rec 1991, 66: 249-51 3. Aaby P, Burstrom B, Mutie DM. Measles mortality m same-sex and mixed-sex siblings in western Kenya Lancet 1992, 340: 923-24. 4 Markowitz LE, Sepulveda J, Diaz-Ortega JL, et al Immunization of six month old infants with different doses of Edmonston-Zagreb measles vaccine N Engl JMed 1990, 322: 580-87
2
Expanded Programme vaccine at
on
6 months of age
CORRECTION Antibiotic resistance in pneumococcal meningitis -In this letter by Dr M. 1. Issack and colleagues (Aug 15, p 438) an important sentence was omitted: "... no zone around a lug oxacillin disc. Intravenous cefotaxime every 8 h was substituted for benzylpenicillin A CT scan ..."
Dr M. I. Issack and colleagues (Aug 15, p438) an tmportant this letterby
CHILDREN ADMITTED FOR INFECTIOUS CAUSES*/TOTAL
unlikely explanation. Hence, higher mortality in mixedfamilies is probably related to the higher risk of getting infected from someone of the opposite sex. These observations from western Kenya indicate that the increased mortality associated with cross-sex transmssion is not restricted to West Africa. 1-3
seems an sex
Department of Epidemiology, Statens Seruminstitut, 2300 Copenhagen S, Denmark
PETER AABY
International Child Health Unit, Uppsala University, Uppsala, Sweden
BO BURSTRÖM
Kenya EPI, Ministry of Health, Nairobi, Kenya
DOMINIC M. MUTIE
Aaby P, Bukh J, Lisse IM, Smits AJ. Cross-sex transmission of infection and increased mortality due to measles Rev Infect Dis 1986; 8: 138-43. 2. Aaby P, Lamb WH. Sex and transmission of measles in a Gambian village. J Infect 1991; 22: 287-92. 3. Pison G, Aaby P, Knudsen K. Increased nsk of measles mortality for children with a sibling of the opposite sex among the Fula Bande and Niokholonko, Senegal. BMJ 1992; 304: 284-87 4. Burström B, Aaby P, Mutie DM, Kimani G, Bjerregaard P. Severe measles outbreak in Western Kenya. East Afr Med J (in press). 5. Rothman KJ. Modem epidemiology. Boston: Little, Brown, 1986. 6. Aaby P, Leeuwenburg J. Sex and patterns of transmission of measles infection: a reanalysis of data from the Machakos area, Kenya. Ann Trop Pediatr 1991; 11: 1.
397-402.
Mortality and morbidity after high titre measles vaccine in Mexico SIR,-Differences in long-term mortality have been reported between children who received high titre measles vaccines at less than 9 months and those who received standard titre vaccine at older ages."We studied morbidity and mortality in children in a 1987 randomised trial of different titre Edmonston-Zagreb (EZ) and Schwarz measles vaccines in Mexico City to compare the serological response to the two strains at different titres in infants aged 6 and 9 months.’ In 1989, around 20 months after vaccination (median age 26 months), parents/carers were recontacted for a study of antibody persistence. 1007 (73%) children were located and rebled. During second follow-up in 1992, we tried to obtain information on all 1380 children. Home visitors were blind to the study group of the child and collected information on general health and socioeconomic status. If a child had died, a study doctor determined the cause and information was abstracted from the death certificate. Date, cause, and length of any hospital admission (we tried to locate the record), visits to a doctor during the previous 3 months, and diarrhoea during the previous 2 weeks were noted. Because of differences in mortality by gender,3analyses were stratified by gender. Differences were tested by the two-tailed Fisher’s exact test; the Mantel-Haenszel y2 was used to test for trend. We obtained information on 1029 (75%) of the original study children (including some who had not been recontacted in 1989). There were no significant differences in follow-up by vaccine group or gender. The median age was 59 months (range 57-61). Socioeconomic status did not vary by vaccine group. The combined follow-ups in 1989 and 1992 provided information on the vital status of 90% of study children at (median) 26 months of age. 3 deaths were detected. 2 boys died from motor-vehicle accidents (standard titre: 1 EZ at 9 months,1 Schwarz at 6 months), and 1 boy died at 16 months from pneumonia (standard titre EZ at 9 months). Mortality at 26 months was 0-08% and at 59 months, 0-3%, which is less than that expected (annual mortality, age 1-4 in Mexico City, 0-08%). 72 children had been admitted at least once (12 twice or more). The infectious disease reasons are shown in the table; 20 children were admitted for an operation. Compared with the standard titre Schwarz group at 9 months, none of the groups had increased risk of admission due to infectious disease, overall or when stratified by gender. There was a non-significant trend within the groups that received Schwarz vaccine at 6 months of age for those who received high titre to have more admissions because of infectious disease. 30% of children had consulted a doctor in the 3 months before interview, mostly because of respiratory infections. Only 4% of
*Pneumon!a (23), diarrhoea (11 hepatitis (1 meningitis (1 encephalitis (1),), urinary tract infection (2). tPlaque-formlng units, measured at Food and Drug Adminstration, j:EZ vaccine produced by Institute of Virology, Mexico City §EZ vaccine produced by Institute of Immunology, Zagreb
child
m
USA
each group admitted twice because of infectious disease
children had had diarrhoea in the 2 weeks before interview. Compared with the standard dose Schwarz group at 9 months, none of the groups had increased visits for disease or episodes of diarrhoea, overall or when stratified by gender. Thus we found no differences in mortality by vaccine group or gender. Also we did not find any significant increase in morbidity in children who received the high titre vaccines at 6 months compared with those who received standard titre vaccines at 9 months. Our study had low power to detect differences because of the small number of children in each of the original groups and the low mortality in the study population. Another limitation of the study was incomplete follow-up at 59 months, although the status of 90% of the children was known at 26 months. Our study population differed from others in which differences in mortality have been found.l,2 Health-care services were more available, and socioeconomic status and educational levels of the mothers were higher. Infectious disease mortality was substantially lower and some infectious diseases that were common in African countries, such as malaria, were absent. Although deaths among those lost to follow-up cannot be excluded, the lack of increase in morbidity or mortality among those receiving high titre vaccines suggests that the differences in mortality detected in some studies may not be generalisable to all populations, and/or that there may be some interaction between the effects of vaccination and other environmental factors. Funded under USAID/PHS BST-5947-P-HI-4265.
Participating Agency Service Agreement
JOSE LUIS DIAZ-ORTEGA Ministry of Health, Mexico
MAGDALENA LUNA-ABASCAL JOSE LUIS VALDESPINO JAIME SEPULVEDA
Division of Immunization, National Center for Prevention Services, Centers for Disease Control, Atlanta, Georgia 30333, USA
LAURI E. MARKOWITZ ELIZABETH R. ZELL
1 Garenne
M, Leroy O, Beau JP, Sene I Child mortality after high-titre measles prospective study in Senegal Lancet 1991; ii: 903-07.
vaccines
Immunization. Safety and efficacy of high titre measles Wkly Epid Rec 1991, 66: 249-51 3. Aaby P, Burstrom B, Mutie DM. Measles mortality m same-sex and mixed-sex siblings in western Kenya Lancet 1992, 340: 923-24. 4 Markowitz LE, Sepulveda J, Diaz-Ortega JL, et al Immunization of six month old infants with different doses of Edmonston-Zagreb measles vaccine N Engl JMed 1990, 322: 580-87
2
Expanded Programme vaccine at
on
6 months of age
CORRECTION Antibiotic resistance in pneumococcal meningitis -In this letter by Dr M. 1. Issack and colleagues (Aug 15, p 438) an important sentence was omitted: "... no zone around a lug oxacillin disc. Intravenous cefotaxime every 8 h was substituted for benzylpenicillin A CT scan ..."
Dr M. I. Issack and colleagues (Aug 15, p438) an tmportant this letterby
