Global vaccine action plan lessons learned I: Recommendations for the next decade.

The Global Vaccine Action Plan 2011-2020 (GVAP) was developed to realize the ambitions of the Decade of Vaccines - that all individuals and communities enjoy lives free from vaccine-preventable diseases. It included a comprehensive monitoring and evaluation/accountability framework to assess progress towards global targets with recommendations for corrective actions. While many of the GVAP targets are very unlikely to be met by the end of 2020, substantial progress has nevertheless been made, establishing a strong foundation for a successor global immunization strategy, the Immunization Agenda 2030 (IA2030). The Strategic Advisory Group of Experts on immunization has made a series of recommendations to ensure that the lessons learned from GVAP inform the development and implementation of IA2030.

Meningococcal serogroup C serum and salivary antibody responses to meningococcal quadrivalent conjugate vaccine in Saudi Arabian adolescents previously vaccinated with bivalent and quadrivalent meningococcal polysaccharide vaccine.

Following repeated polysaccharide vaccination, reduced immune responses have been reported, but there are limited data on the mucosal response of meningococcal polysaccharide vaccine (PSV) or meningococcal conjugate vaccination. Saudi Arabian adolescents (aged 16-19 years) who had previously been vaccinated with ≥1 dose of bivalent meningococcal polysaccharide vaccine and 1 dose of quadrivalent meningococcal polysaccharide (MPSV4) were enrolled in a controlled, randomised, and modified observer-blind study (collectively termed the PSV-exposed group). The PSV-exposed group was randomised to receive either quadrivalent meningococcal conjugate vaccine (MCV4) (PSV-exposed/MCV4 group) or MPSV4 (PSV-exposed/MPSV4 group), and a PSV-naïve group received MCV4. Serum and saliva samples were collected pre-vaccination and 28 days post-vaccination. Serum serogroup-specific A, C, W and Y IgG were quantified as were salivary serogroup-specific C IgG and IgA together with total salivary IgG and IgA. For each serogroup, the post-vaccination serum geometric mean concentrations (GMCs) were significantly higher in the PSV-naïve and the PSV-exposed/MCV4 group than in the PSV-exposed/PSV4 group. For serogroup C, serum serogroup-specific IgG for the PSV-naïve group was significantly higher than both the PSV exposed groups. Higher levels of salivary serogroup C-specific IgG were found in the PSV-naïve group than those who had received two doses of polysaccharide but no significant differences were noted with regards to serogroup-specific IgA.

Safety and immunogenicity of a meningococcal quadrivalent conjugate vaccine in five- to eight-year-old Saudi Arabian children previously vaccinated with two doses of a meningococcal quadrivalent polysaccharide vaccine.

Saudi Arabian children respond poorly to 2 doses of meningococcal quadrivalent polysaccharide vaccine (MPSV4) when given before 2 years of age. This study examined whether such children were able to respond to 1 dose of quadrivalent meningococcal diphtheria toxoid conjugate vaccine (MCV4) when they were older. Saudi Arabian children 5 to 8 years of age who had previously been vaccinated with 2 doses of MPSV4 when they were under 2 years of age (termed the prior-MPSV4 group) were enrolled in a controlled, open-label, multicenter study. In the prior-MPSV4 group, children (n = 153) received 1 dose of MCV4, as did a group of age-matched meningococcal vaccine-naïve children (n = 85). Blood samples collected prevaccination and 28 days postvaccination were measured for serogroup-specific serum bactericidal antibody (SBA) levels in the presence of baby rabbit complement (rSBA) and for IgG antibody levels. Vaccine tolerability and safety were also evaluated. For all of the measured serogroups (A, C, Y, and W-135), the meningococcal vaccine-naïve participants achieved higher postvaccination rSBA geometric mean titers (GMTs) than did those in the prior-MPSV4 group. This was statistically significant for serogroup C (512 versus 167). Percentages of participants with postvaccination titers of ≥8 and with ≥4-fold increases in prevaccination to postvaccination titers appeared to be quite similar in the 2 groups. No worrisome safety signals were detected. MCV4 induced robust immune responses and was well tolerated in Saudi Arabian children who previously received 2 doses of MPSV4 as well as in those who were previously meningococcal vaccine naïve.

Immunogenicity and safety of a meningococcal quadrivalent conjugate vaccine in Saudi Arabian adolescents previously vaccinated with one dose of bivalent and quadrivalent meningococcal polysaccharide vaccines: a phase III, controlled, randomized, and modified blind-observer study.

Reduced immune responses to repeated polysaccharide vaccination have been previously reported, but there are limited immunogenicity data on the use of meningococcal polysaccharide vaccine (PSV) followed by meningococcal conjugate vaccine. Saudi Arabian adolescents (aged 16 to 19 years) who had previously been vaccinated with ≥1 dose of bivalent meningococcal polysaccharide vaccine and 1 dose of quadrivalent meningococcal polysaccharide (MPSV4) were enrolled in a controlled, randomized, and modified observer-blind study (collectively termed the PSV-exposed group). The PSV-exposed group was randomized to receive either quadrivalent meningococcal conjugate vaccine (MCV4) (n = 145 PSV-exposed/MCV4 group) or MPSV4 (n = 142 PSV-exposed/MPSV4 group), and a PSV-naïve group received MCV4 (n = 163). Serum samples collected prevaccination and 28 days postvaccination were measured by baby rabbit serum bactericidal antibody (rSBA) assay, and vaccine tolerability and safety were also evaluated. For each serogroup, the postvaccination geometric mean titers (GMTs) were significantly higher in the PSV-naïve group than in either group comprised of the PSV-exposed participants. The postvaccination serogroup C rSBA GMT was significantly higher in the PSV-MCV4 group than in the PSV-MPSV4 group after adjusting for prevaccination GMTs. Although not statistically significant, similar differences were observed for serogroups A, Y, and W-135. No worrisome safety signals were detected. This study demonstrated MCV4 to be safe and immunogenic in those who had previously received polysaccharide vaccination, and it suggests that conjugate vaccine can partially compensate for the hyporesponsiveness seen with repeated doses of polysaccharide vaccine.

Factors affecting child mortality in Saudi Arabia.

OBJECTIVE: To estimate levels and trends, gender differentials, effect of modes of living, regional differentials, and the effect of parental educational on infant and child mortality. METHODS: A nationwide stratified random sample was used to estimate levels, trends and differentials of infant and child mortality in Saudi Arabia. The study was executed during the period February 2006 to June 2006 and covered all the 20 health regions of Saudi Arabia. The randomly selected sample was limited to ever married Saudi women in the reproductive age group (15-49 years). RESULTS: The findings show a continuous and considerable infant and child mortality decline during the 1994-2004 period. The infant mortality rate has decline from 22 per 1,000 live births in 1994 to 17 per 1,000 live births in 2004; while the child mortality rate has declined from 34 to 22 per 1,000 live births in the same period. There is a strong relation between infant and child mortality and the mode of living and parental education. CONCLUSION: The study proves the continuous decline of infant and child mortality during the study period and affirms the effect of parental education on these indicators.

Diphtheria, pertussis, and tetanus serosurvey in Saudi children.

OBJECTIVE: To evaluate immune protection against vaccine-preventable diseases targeted by the Expanded Program of Immunization in Saudi Arabia. METHODS: The study was carried out from September 2001 to February 2002. Using multistage sampling techniques, samples were collected from 5 regions of Saudi Arabia and sent for laboratory assay from the following age groups; 50 samples at 12 months, 50 at 6 years, and 100 at 17 years. Sera were assayed for diphtheria, tetanus, and pertussis. Sero neutralization was used for anti-diphtheria antibody assay, while enzyme linked immunoassay was used for anti-tetanus, anti-filament hemoagglutination (anti-FHA), and anti-pertussis titer (anti-PT) antibody assay. RESULTS: This survey showed that 100% of children had protection levels (>/=0.01 IU/ml) against diphtheria at one year, 100% at 6 years, and 93.7% at 17 years. For tetanus, 95.9% had protection levels (>/=0.1 IU/ml) at one year, 100% at 6 years, and 98.9% at 17 years. The geometric mean titer (GMT) of anti-FHA is 22 at one year, 29 at 6 years, and 24 IU/ml at 17 years, while the GMT of anti-PT is 36 at one year, 18 at 6 years, and 11 IU/ml at 17 years. CONCLUSION: Children at one, 6, and 17 years are well protected against diphtheria, pertussis, and tetanus.

Preeclampsia, gestational hypertension and intrauterine growth restriction, related or independent conditions?

OBJECTIVE: Preeclampsia, gestational hypertension, and unexplained intrauterine growth restriction may have similar determinants and consequences. In this study, we compared determinants and perinatal outcomes associated with these obstetric conditions. STUDY DESIGN: We analyzed 39,615 pregnancies (data from the WHO Antenatal Care Trial), of which 2.2% were complicated by preeclampsia, 7.0% by gestational hypertension, and 8.1% by unexplained intrauterine growth restriction (ie, not associated with maternal smoking, maternal undernutrition, preeclampsia, gestational hypertension, or congenital malformations). We compared the risk factors associated with these groups. Fetal death, preterm delivery, and severe neonatal morbidity and mortality were the primary outcomes. Logistic regression analyses were adjusted for study site, socioeconomic status, and (if appropriate) birth weight and gestational age. RESULTS: Diabetes, renal or cardiac disease, previous preeclampsia, urinary tract infection, high maternal age, twin pregnancy, and obesity increased the risk of both hypertensive conditions. Previous large-for-age birth, reproductive tract surgery, antepartum hemorrhage and reproductive tract infection increased the risk for gestational hypertension only. Independent of maternal age, primiparity was a risk factor only for preeclampsia. Both preeclampsia and gestational hypertension were associated with increased risk for fetal death and severe neonatal morbidity and mortality. Mothers with preeclampsia compared with those with unexplained intrauterine growth restriction were more likely to have a history of diabetes, renal or cardiac disease, chronic hypertension, previous preeclampsia, body mass index more than 30 kg/cm2, urinary tract infection and extremes of maternal age. Conversely, unexplained intrauterine growth restriction was associated with higher risk of low birth weight in previous pregnancies, but not with previous preeclampsia. Both conditions increased the risk for perinatal outcomes independently but preeclampsia was associated with considerable higher risk. CONCLUSION: Preeclampsia and gestational hypertension shared many risk factors, although there are differences that need further evaluation. Both conditions significantly increased morbidity and mortality. Conversely, preeclampsia and unexplained intrauterine growth restriction, often assumed to be related to placental insufficiency, seem to be independent biologic entities.

Impact of health education on knowledge and attitudes of Saudi paramedical students toward HIV/AIDS.

OBJECTIVE: To assess the impact of health education on the knowledge and attitudes of paramedical students in Saudi Arabia toward HIV/AIDS. METHODS: We carried out an interventional study on a sample selected from students of health institutes and health colleges in Saudi Arabia during the calendar year 2002-2003. RESULTS: The intervention shows a positive effect on students' knowledge regarding means of transmission of HIV and means of protection from HIV/AIDS. Furthermore, it has a positive impact on students' attitudes toward accepting discussion of AIDS topics with others, acceptance of home care for HIV infected family member and acceptance of HIV-infected individual's right at work. Preference of confidentiality was also significantly increased after intervention. CONCLUSION: Health education intervention has a positive impact on students' knowledge and attitudes towards HIV/AIDS and we recommend a nationwide health education program on HIV/AIDS.

Measles in Saudi Arabia: from control to elimination.

This article describesthe tremendous efforts made in the field of measles immunization in Saudi Arabia in the past 20 years, from the control phase to the elimination phase. Mandatory measles vaccination with one-dose Schwartz vaccine was introduced in 1982 by a royal decree, a step aimed at increasing vaccine coverage. In 1991, a two-dose schedule was implemented using Edmonston-Zagreb measles vaccine, with a first dose at 6 months to protect children younger than 9 months and a second dose of MMR at 12 months of age to protect those who did not respond to the first dose. A marked reduction in the epidemic peak and a shift of infection to older age were noticed. But the same data showed that 50% of measles cases in the 1- to 4-year age group occurred in vaccinated children. In 1998, with the start of elimination phase, an MMR campaign was launched in two phases, targeting school children in 1998 (secondary schools) and in 2000 (primary and intermediate schools). Evaluation of the MMR campaign and surveillance data was reflected in the measles immunization policy by shifting the age of measles immunization to 12 months and to preschool using the two-dose MMR schedule.

Serosurvey of measles, mumps and rubella antibodies in Saudi children.

OBJECTIVE: A serosurvey study to evaluate the proportion of children with antibodies against diseases targeted by the Expanded Program of Immunization in the Kingdom of Saudi Arabia. METHODS: Using multistage sampling techniques, we collected samples and sent them for laboratory assay from the following age groups; 100 samples at 6 months, 12 months, 18 months, 6 years, 13 years, and 17 years. We conducted the study from September 2001 to February 2002. We assayed sera for measles, rubella, and mumps antibodies in the measles-mumps-rubella reference laboratory in Germany, using enzyme immunoassay and plaque neutralization (PN) as a backup test for equivocal and negative samples. We only carried out a backup test for measles samples. RESULTS: The age group of 6 months had the highest proportion with negative measles antibodies. After adding the backup test (PN), the proportions of children with protective measles antibody were; 64% at 6 months, 87% at 12 months, 91% at 18 months, 75% at 6 years, 96% at 13 years, and 98% at 17 years. Rubella antibody positivity rates (>7 IU) were 28% at 6 months, 49% at 12 months, 97% at 18 months, 98% at 6 years, and 100% at 13 years. While positivity rates in mumps were 14% at 6 months, 29% at 12 months, 59% at 18 months, 64% at 6 years, and 75% at 13 years. CONCLUSION: The unexpected low proportion of children with protective level at 6 years, despite being vaccinated with 2 measle doses is an important phenomenon. This reflects the interference between the first and the second measles dose. The Ministry of Health decided to conduct a catch up campaign targeting 1st through 3rd grade primary schools, who did not catch the mass campaign conducted in 2000. Also, this supports the decision taken by the ministry to change the measles immunization schedule to MMR at 12 months and a second dose at 6 years of age.

Knowledge and attitudes of paramedical students in Saudi Arabia toward HIV/AIDS.

OBJECTIVES: The present study aimed to build a baseline profile for knowledge and attitudes of Saudi paramedical students toward human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS). METHODS: The study was a cross-sectional one conducted on a sample selected from health institutes and colleges in Saudi Arabia during the calendar year 2002/2003. RESULTS: A high percentage of students correctly perceive the risk presented by HIV/AIDS. Extramarital sex and unprotected sex were the most frequently mentioned risky behaviors. Misconceptions and lack of knowledge regarding transmission of HIV/AIDS were reported. Lack of knowledge on the means of individual protection, means of protection of infants of HIV/AIDS-infected mothers and means of protection of HIV/AIDS-infected individual's wife was observed. While friends were the main source of information among male students, booklets were the main source of information among females. More than two-thirds of students were willing to be tested for HIV. We observed negative attitudes toward discussing AIDS topics with others, home-care for HIV/AIDS individuals and HIV/AIDS-infected individual's right at work. CONCLUSION: We found lack of knowledge regarding HIV/AIDS transmission and means for prevention in addition to unfavorable attitudes towards HIV/AIDS individuals. We recommend an evaluation of HIV/AIDS information in the curricula of health institutes and health colleges in addition to conduction of a nationwide health education campaign on HIV/AIDS.

HIV/AIDS epidemic features and trends in Saudi Arabia.

BACKGROUND: More than 60 million persons have been infected since AIDS was described in 1981. By the end of 2003, an estimated 40 million individuals were living with HIV globally. The surveillance of HIV/AIDS still faces challenges in Saudi Arabia. This study describes the pattern and characteristics of HIV/AIDS cases in Saudi Arabia. METHODS: This descriptive analytic study describes the reported HIV/AIDS data for all notifiable cases during the period 1984 to 2003 in the Kingdom of Saudi Arabia. Case definitions based on ELISA and Western Blot tests were used. Age, sex and regional distribution were studied in addition to survival rates. RESULTS: As of 2003, 1743 Saudi nationals and 6064 non-Saudi HIV cases were reported. Among Saudis, 872 were AIDS cases. Males accounted for 1329 HIV infections, comprising 77%, with a male-to-female ratio of about 3:1. Adults 15-49 years constituted 78% of cases, including 46% of cases infected through sexual activity, while 33% of reported HIV seropositive cases had already died. Most cases (67%) were registered in Jeddah, Riyadh and Dammam. Infection through blood transfusion declined with no reported cases since 2001. CONCLUSION: The number of reported HIV infections in KSA has increased in the last few years. Using the coverage rate estimating method, the number of Saudi HIV infections since the emergence of the epidemic was estimated to be 2640 cases as of the beginning of the year 2004. The estimated number of HIV infections is almost one and one-half times the reported number, indicating that a problem of underreporting of HIV/AIDS cases still exists.

Clinical growth charts for pre-school children.

OBJECTIVE: Growth standards are indicators for normal growth of the children and growth charts are important tools for their growth monitoring. Children from different populations are different in their growth pattern, it is important to create national standards for the growth of children in each population to develop local growth charts, and since these were not available in the Kingdom of Saudi Arabia (KSA), the aim of this study was to construct national growth standards and to develop growth charts for 0-5-years Saudi children. METHODS: A cross-sectional study following World Health Organization (WHO) criteria in determining sample size was adopted, where by 24000 children from 5 regions in the KSA were selected during the period 1992 to 1995 to be the desired sample. One hundred and two Primary Health Care centers (PHCCs) were selected randomly from the 5 regions, from where the sample was drawn, and a special questionnaire was designed. Weight, height and head circumference were measured by standard procedures. RESULTS: The total number of children examined was 23821 (11913 boys and 11908 girls). Saudi (0-5-years) boys weight and height for age measurements were significantly different from girls. The same difference was found between urban and rural boys and girls and between boys and girls from the different regions of the country (p<0.05). CONCLUSION: These national standards derived from this study were used to develop national growth charts that are currently utilized to monitor growth in all Saudi health institutes.

Changes in epidemiological pattern of Meningococcal disease in Saudi Arabia. Does it constitute a new challenge for prevention and control?

OBJECTIVE: Meningococcal meningitis epidemics, which occurred in the Kingdom of Saudi Arabia (KSA) coincided with Hajj and Umra seasons; the 2 major pilgrims to Muslims. In many countries, the disease showed major changes of its epidemiological determinants, in particular to age and prevailing serogroup. This study was conducted to determine the epidemiological trend of meningococcal meningitis disease in KSA. METHODS: All confirmed meningococcal meningitis cases reported in KSA during the period from January 1999 to December 2002 were studied retrospectively. Confirmation of cases was based on isolation of the causative organism from cerebrospinal fluid (CSF) or blood culture or detection of antigen in the CSF. Personal, clinical and laboratory results were analyzed using Epi info version 6 software. Categorical data were tested using chi2 test. RESULTS: A total of 729 cases were reported, 304 cases (42%) were among people coming from abroad for Hajj or Umra and 425 (58%) were among local population. Nearly half of the later (48%) were reported at the 2 holy areas of Makkah and Madinah, KSA. Thirty-nine percent of cases were children aged <2 years and 58% were <5 years of age. Proportion of cases affected with serogroup W135 increased over time (up to 95%) and significantly affected children aged <5 years (p<0.001). CONCLUSION: Continuous monitoring of epidemiological determinants is essential to guide vaccination policy.

Screening of pregnant Saudi women for hepatitis B surface antigen.

BACKGROUND: The high prevalence of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) in pregnant women is considered the most important factor contributing to the higher carrier rate of HBsAg in some populations, including Saudi Arabia. Universal hepatitis B vaccination in infancy was implemented in Saudi Arabia in 1990 to avoid early acquisition of infection. At the same time, another program was launched to vaccinate all school children at school entry as a second target group. The aim of this study was to evaluate the HBsAg prevalence rate in Saudi pregnant women 12 years after launching the program and to assess regional variation, if any. METHODS: In a cross-sectional study, 2664 pregnant Saudi women were recruited from the five main regions in Saudi Arabia. Blood samples were tested for HBsAg. Positive samples were tested also for HBeAg. RESULTS: Of 2664 pregnant Saudi women, 65 were positive for HBsAg (2.46%, 95% CI=2.11%-2.69%). Four were positive for HBeAg (0.15%). The HBsAg prevalence rate was higher in Gizan (4.2%) and lower in Tabuk (1.4%) (P=-0.035). Only one case was positive for HBsAg in women under the age of 20 years (1/186), a 0.5% positivity rate in this age group compared with 2.6% in the older age group (P=-0.049 for the one-sided test). A history of surgical procedures was associated with a higher (3%), but not significantly higher rate of HBsAg positivity. No significant association was found between HBsAg positivity and a history of dental procedures or blood transfusion. CONCLUSION: Although the HBsAg prevalence rate among Saudi pregnant women was lower than previously published data, the full impact of the hepatitis B vaccination program in infancy and childhood will take more years to decrease the prevalence rate in pregnant women. The MOH should continue to give the first dose of hepatitis B vaccine at birth to prevent early acquisition, but in the meantime a regional policy can be adopted to deal with the high prevalence rate of HBsAg among pregnant Saudi women.

Epidemiology of the human immunodeficiency virus in Saudi Arabia; 18-year surveillance results and prevention from an Islamic perspective.

BACKGROUND: data on HIV epidemiology and preventive measures in Islamic countries is limited. This study describes the results of 18-year of HIV surveillance in Saudi Arabia (SA) and the preventive measures implemented from an Islamic perspective. METHODS: surveillance for HIV has been underway in SA since 1984. Indications for HIV testing include clinical suspicion, screening of contacts of HIV-infected patients, and routine screening of blood and organ donors, prisoners, intravenous drug users, patients with other sexually transmitted infections, and expatriates pre-employment. This is a case series descriptive study of all confirmed HIV infections diagnosed in SA from 1984 through 2001. RESULTS: a total of 6046 HIV infections were diagnosed, of which 1285 (21.3%) cases were Saudi citizens. Over the 18-year surveillance period the number of HIV infections diagnosed annually among Saudi citizens gradually increased and, over the period 1997-2001, it reached to 84 to 142 cases per year. The number of cases per 100,000 population varied widely between regions with a maximum of 74 cases and a minimum of 2 cases. The infection was most common in the age group 20-40 years (74.6%) and predominantly affected men (71.6%). The modes of transmission among Saudi citizens and expatriates, respectively, were as follows: heterosexual contact, 487 (37.9%) and 1352 (28.4%) cases; blood transfusion, 322 (25.0%) and 186 (3.9%) cases; perinatal transmission, 83 (6.5%) and 19 (0.4%) cases; homosexual contact, 32 (2.5%) and 38 (0.8%) cases; intravenous drug use, 17 (1.3%) and 33 (0.7%) cases; bisexual contact, 10 (0.8%) and 14 (0.3%) cases; unknown, 334 (26.0%) and 3119 (65.5%) cases. The number of HIV infections transmitted by blood or blood products transfusion declined to zero by year 2001 and all such infections occurred due to transfusions administered before 1986. At HIV diagnosis, 4502/6046 (74.5%) patients had no symptoms, 787 (13.0%) patients had non-AIDS defining manifestations, and 757 (12.5%) patients had AIDS. A total of 514/1285 (40%) Saudi patients died by year 2001. CONCLUSIONS: the number of HIV cases in SA is limited with heterosexual contact being the main mode of transmission. From an Islamic perspective, preventive strategies include prevention of non-marital sex and intravenous drug use with encouragement of "safe sex" through legal marriage.

Haemophilus type B meningitis in Saudi children under 5 years old.

This study was designed to determine the magnitude of bacterial meningitis in general and Hib meningitis in particular among children below the age of 5 years. A population-based, prospective descriptive and analytical study was conducted in five regions, one each in northern, southern, eastern, western, and central parts of Saudi Arabia. Active surveillance for cases of bacterial meningitis among the study population, which comprised 171,818 children under 5 years of age, was implemented. A total of 208 cases of meningitis were identified, of which 141 (67.8 per cent) were identified with a definite causative organism. The remaining 67 cases (32 per cent) were labeled as aseptic meningitis. The overall incidence of meningitis was 60.53/10(5) in under-fives with a disease spectrum similar to that reported in studies conducted in other countries. The three leading causes of meningitis were Hib (Haemophilus influenzae type B), MCM (Neisseria menigitides) and SPN (Streptococcus pneumoniae). Hib meningitis constituted 28 per cent of cases with an incidence rate of 16.88/10(5) children. There was a marked regional variation in Hib incidence. MCM was the second leading cause (18 per cent) of meningitis with an incidence of 10.77/10(5) while SPN comprised 11 per cent of cases and its incidence was 9.69/10(5). Almost all MCM cases were related to meningitis outbreaks that occurred in Saudi Arabia during two successive Hajj seasons (2000-2001). Hib cases showed a bimodal seasonality, one peak during March-May, the other during September-November. The fact that this study is the first national base-line data on meningitis in general and Hib incidence in particular, has augmented further justification for introducing Hib vaccine within the national Expanded Program on Immunization (EPI). Based on the experience gained during this study regarding surveillance of meningitis disease, optimal methods to strengthen meningitis surveillance were identified. A model of Meningitis Diseases Surveillance was generated that can be tested and then generalized. The study has documented beyond doubt the impact of Hajj seasons on MCM disease occurrence and further justifies the rigorous control and preventive measures being taken in this aspect.

Heterogeneity of perinatal outcomes in the preterm delivery syndrome.

OBJECTIVE: Our aim was to document the differential neonatal morbidity and intrapartum and neonatal mortality of subgroups of preterm delivery. METHODS: This analysis included 38,319 singleton pregnancies, of which 3,304 (8.6%) were preterm deliveries (less than 37 completed weeks) enrolled in the World Health Organization randomized trial of a new antenatal care model. We classified them as preterm deliveries after spontaneous initiation of labor, either with or without maternal obstetric and medical complications; preterm deliveries after prelabor spontaneous rupture of amniotic membranes (PROM), either with or without obstetric and medical complications; and medically indicated preterm deliveries with maternal obstetric and medical complications. Severe neonatal morbidity and neonatal mortality were the primary outcomes. RESULTS: Fifty-six percent of all preterm deliveries were spontaneous, without maternal complications. Small for gestational age was increased only among the medically indicated preterm delivery group (22.3%). Very early preterm delivery (less than 32 weeks of gestation) was highest among PROM with complications (37%). For intrapartum fetal death and neonatal death, after adjusting by gestational age and other confounding variables, we found that the obstetric and medical complications preceding preterm delivery predicted the different risk levels. Conversely, for severe neonatal morbidity the clinical presentation, ie, PROM or medically indicated, predicted the increased risk. CONCLUSION: There are differential neonatal outcomes among preterm deliveries according to clinical presentation, pregnancy complications, gestational age at delivery, and its association with small for gestational age. This syndromic nature of the condition should be considered if preterm delivery is to be fully understood and thus reduced.