Sex ratio at birth: scenario from normal- and high-level natural radiation areas of Kerala coast in south-west India.

Newborns were monitored for congenital malformations in four government hospitals located in high-level (ambient dose >1.5 mGy/year) and normal-level (≤ 1.5 mGy/year) natural radiation areas of Kerala, India, from August 1995 to December 2012. Sex ratio at birth (SRB) among live singleton newborns and among previous children, if any, of their mothers without history of any abortion, stillbirth or twins is reported here. In the absence of environmental stress or selective abortion of females, global average of SRB is about 1050 males to 1000 females. A total of 151,478 singleton, 1031 twins, 12 triplets and 1 quadruplet deliveries were monitored during the study period. Sex ratio among live singleton newborns was 1046 males (95 % CI 1036-1057) for 1000 females (77,153 males:73,730 females) and was comparable to the global average. It was similar in high-level and normal-level radiation areas of Kerala with SRB of 1050 and 1041, respectively. It was consistently more than 1000 and had no association with background radiation levels, maternal and paternal age at birth, parental age difference, gravida status, ethnicity, consanguinity or year of birth. Analysis of SRB of the children of 139,556 women whose reproductive histories were available suggested that couples having male child were likely to opt for more children and this, together with enhanced rate of males at all birth order, was skewing the overall SRB in favour of male children. Though preference for male child was apparent, extreme steps of sex-selective abortion or infanticide were not prevalent.

Study of stillbirth and major congenital anomaly among newborns in the high-level natural radiation areas of Kerala, India.

Monitoring newborns for adverse outcomes like stillbirth and major congenital anomalies (MCA) is being carried out in government hospitals since 1995 in and around high-level natural radiation areas, a narrow strip of land on the southwest coast of Kerala, India. Natural deposits of monazite sand containing thorium and its daughter products account for elevated levels of natural radiation. Among 141,540 newborns [140,558 deliveries: 139,589 singleton, 957 twins (6.81 ‰), 11 triplets (0.078 ‰), and one quadruplet] screened, 615 (4.35 ‰) were stillbirth and MCA were seen in 1,370 (9.68 ‰) newborns. Clubfoot (404, 2.85 ‰) was the most frequent MCA followed by hypospadias (152, 2.10 ‰ among male newborns), congenital heart disease (168, 1.19 ‰), cleft lip/palate (149, 1.05 ‰), Down syndrome (104, 0.73 ‰), and neural tube defects (72, 0.51 ‰). Newborns with MCA among stillbirths were about 20-fold higher at 190.24 ‰ (117/615) compared to 8.89 ‰ (1,253/140,925) among live births (P < .001). Logistic regression was carried out to compare stillbirth, overall, and specific MCA among newborns from areas with dose levels of ≤1.5, 1.51-3.0, 3.01-6.0 and >6 mGy/year after controlling for maternal age at birth, gravida, consanguinity, ethnicity, and gender of the baby. Clubfoot showed higher prevalence of 3.26 ‰ at dose level of 1.51-3.0 mGy/year compared to 2.33 ‰ at ≤1.5 mGy/year (OR = 1.39; 95 % CI, 1.12-1.72), without indication of any clear dose-response. Prevalences of stillbirth, overall MCA, and other specific MCA were similar across different dose levels and were relatively lower than that reported elsewhere in India, probably due to better literacy, health awareness, and practices in the study population.

Genetic monitoring of the human population from high-level natural radiation areas of Kerala on the southwest coast of India. I. Prevalence of congenital malformations in newborns.

In the densely populated monazite-bearing sands of Kerala, on the southwest coast of India, natural radiation dose rates range from 1. 0 to over 35.0 mGy per year in certain well-defined high-level natural radiation areas. As a part of the program to assess the health effects of this naturally occurring high-level natural radiation on human populations, monitoring of newborns is being undertaken to determine the incidence of congenital malformations. From August 1995 to December 1998, a total of 36,805 newborns were screened, including 212 (0.58%) stillbirths. There were 36,263 singletons, 536 (1.45%) twins, and 6 born as triplets. The overall incidence of malformations was 1.46% and was dependent on maternal age. The stillborns exhibited a very high malformation rate of 20.75% compared to 1.35% among the live births. Likewise, twins also had a higher malformation rate (2.99%) compared to singletons (1.44%). About 3.5% of the newborns originated from consanguineous marriages. Consanguinity also led to a relatively higher rate of malformations (1.97%) as well as of stillbirths (1.18%). About 92% of the deliveries took place by the maternal age of 29 years and only 1.2% among women above 34 years old. The stratification of newborns with malformations, stillbirths or twinning showed no correlation with the natural radiation levels in the different areas. Thus no significant differences were observed in any of the reproductive parameters between the two population groups based on the monitoring of 26,151 newborns from high-level natural radiation and 10,654 from normal-level natural radiation (dose rate

Second-generation anti-HCV screening in a Saudi Arabian donor population.

The 2nd-generation anti-HCV test system was applied to a Saudi Arabian multi-ethnic donor population. When donors were stratified according to first-time donations versus repeat donations, the latter having been screened previously by a 1st-generation set of tests, it was found that in Saudi Arabian and Middle East nationals, the 2nd-generation tests (EIA and RIBA), identified close to double the number of anti-HCV-positive donors, compared to an earlier study using the 1st-generation tests. Part of this finding was due to a 38% higher rate of RIBA-confirmable repeat-positive EIA results. In groups of donors, previously screened by the 1st-generation system, some additional cases of anti-HCV reactivity were identified, most prominently in Middle East nationals. It is assumed that some of these represented recent seroconversions, while others were cases of serologic subtypes of HCV, not reacting in the 1st-generation tests. The current test system identifies 0.66% of Saudi-Arabian, and 2.87% of other Middle East donors as putative carriers of hepatitis C virus. The study lends support to the opinion that donors who return regularly over the years have a lower prevalence of disease markers, thereby being a safer source of blood than first-time donors.

HTLV-1 antibody testing in a Saudi Arabian blood donor population.

Human-T lymphotrophic virus Type 1 may be transmitted by cellular blood products. A low but definite risk exists that recipients of HTLV-1 infected products may develop severe even fatal disease. After one year of screening for HTLV-1 antibodies in 12,851 units of blood collected from a multinational volunteer donor population of which 42.6% were Saudi nationals, we found two units of blood which reacted repeatedly positive in the screen test. In both cases, the Western Blot confirmatory test was indeterminate in that not all bands required for a positive reaction were present. Both donors were expatriates from North America either living in an endemic area or with Caribbean ancestors. Although more than 5,000 Saudi national donors were tested and found negative for HTLV-1 antibodies, a statistical estimate of the maximal risk of finding a positive donor in this donor population subgroup is in the order of 0.055%. Based on these results it is recommended that blood banks in this region screen for HTLV-1.

Hepatitis C antibody prevalence in Saudi Arabian blood donor population.

Based on the screening of 10,646 units of blood by a recombinant hepatitis C antibody enzyme-linked immunosorbent assay (ELISA), the prevalence of hepatitis C (HCV) antibody-reactive donors was established in a Saudi Arabian donor population. The overall prevalence of HCV antibody was found to be 1.01%. By nationality, the antibody frequency was 1.00% (Saudi males), 2.30% (other Middle Easterners), 0.71% (Far East nationals), and 0.39% (Europeans/North Americans). The ELISA HCV antibody reactive units were further tested by a recombinant immunoblot assay (RIBA) in which 47.2% of the initially reactive samples were found to contain specific antibodies to two recombinant antigens. HCV antibody seroprevalence defined by reactiveness in both tests was 0.48% for the entire population, 0.33% (Saudis), 1.42% (Middle Easterners), 0.27% (Far East nationals and Europeans/North Americans). The surrogate markers alanine aminotransferase (ALT) and hepatitis B core (HBc) antibody identified 7.7 to 40% and 20 to 56.4%, respectively, of donors of different nationalities testing repeatedly reactive in the HCV ELISA. Likewise, ALT and HBc antibody identified 20 to 57.1% and 0 to 66.75%, respectively, of HCV ELISA and RIBA reactive donor samples, depending on nationality. It was concluded that the present anti-HCV testing, althought useful in screening blood for HCV carriers, must be supplemented by surrogate tests until additional specific tests are available.