Acetogenin-Based Formulated Bioinsecticides on Anastrepha fraterculus: Toxicity and Potential Use in Insecticidal Toxic Baits.

The present study evaluated the lethal toxicity and oviposition deterrence of ethanolic extracts of Annona mucosa Jacq., Annona muricata L., and Annona sylvatica A. St.-Hil on Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) compared with those of a limonoid-based bioinsecticide (Azamax™ 1.2 EC-azadiractin +3-tigloyl-azadiractol) and a synthetic spinosyn-based insecticide (Delegate™ 250 WG-spinetoram). In addition, the efficacy of the selected toxic bait formulations was evaluated by mixing them with food attractants (Anamed™, 3% Biofruit and 7% sugarcane molasses). In the topical application and ingestion bioassays (2000 mg L-1), the aqueous emulsion of the A. mucosa extract caused greater than 80% mortality of A. fraterculus adults in a similar manner to the spinosyn-based synthetic insecticide. Concentration-response curves were performed for the most promising treatments and showed an activity level dependent on the mode of contamination, exposure time, and applied concentration. In bioassays with and without choice, the A. mucosa (77%), A. muricata (51%), A. sylvatica (60%), Azamax™ (74%), and Delegate™ 250 WG (100%) significantly reduced the number of punctures and galleries in grape berries. In combination with the food attractants Anamed™, 3% Biofruit, and 7% sugarcane molasses, the emulsion of the A. mucosa extract had a residual effect similar to that of the spinetoram insecticide, with a mortality rate of over 80% of A. fraterculus adults up to 14 days after application (DAA) in the absence of rain. Thus, acetogenin-rich formulations, especially from A. mucosa seeds, are useful alternatives for the integrated management of A. fraterculus in agricultural orchards.

The relationship of interpregnancy interval to infant birthweight and length of gestation among low-risk women, Georgia.

To examine the association between interpregnancy interval and low birthweight (< 2500 g), preterm delivery (< 37 weeks' gestation), and inadequate fetal growth, we studied a population-based sample of 23,388 white and 4885 black women at low risk for adverse pregnancy outcomes who delivered their first and second infants in Georgia from 1980 to 1992. We used fetal death and livebirth certificates. The interpregnancy interval was the time from delivery to the woman's next conception. For each pregnancy outcome, we stratified by race and used logistic regression to assess the association between interpregnancy interval and outcome, while controlling for confounders. Intervals < 6 months were observed for 3.7% of white women and 7.0% of black women and intervals > or = 48 months were seen for 16.8% of white women and 24.8% of black women. Results from logistic regression showed that, for both races, interpregnancy interval was associated with low birthweight and preterm delivery. Nearly all of the increased risk occurred in intervals < 6 months or > or = 48 months. The magnitude of the increase in risk associated with these intervals ranged from modest to moderate and was similar for black and white women. Because short interpregnancy intervals are rare and are weak risk factors among low-risk women, efforts to lengthen interpregnancy intervals are unlikely to reduce substantially their rates of adverse pregnancy outcomes.

Applying the sisterhood method for estimating maternal mortality to a health facility-based sample: a comparison with results from a household-based sample.

BACKGROUND: The sisterhood method is an indirect technique used to estimate maternal mortality in developing countries, where maternal deaths are often poorly registered in official statistics. It has been used successfully in many community-based household surveys. Because such surveys can be costly, this study investigated the suitability of using data collected in outpatient health facilities. METHODS: Adults visiting any one of 91 health centres or posts in a rural region of Nicaragua were randomly sampled and interviewed by health personnel. A sample size, proportional to the population served, was assigned to each facility and 9232 adults were interviewed. Characteristics of health facility users were compared with the general population to identify factors that would allow generalization of results to other settings. RESULTS: Based on these data, the lifetime risk of maternal death was 0.0144 (1 in 69). This estimate is essentially identical to that from a household-based survey in the same region 8 months earlier, which obtained a lifetime risk of 0.0145 (1 in 69). These findings correspond to a maternal mortality ratio of 241 and 243/100000 livebirths, respectively. CONCLUSIONS: This is the first report comparing results of the sisterhood method from household and health facility-based samples. The sisterhood method provided a robust estimate of the magnitude of maternal mortality. Results from the opportunistic health facility-based sample were virtually identical to results from the household-based study. Guidelines need to be developed for applying this low-cost and efficient aproach to estimating maternal mortality in suitable opportunistic settings at subnational levels.

PIP: Researchers compared maternal mortality estimates using the sisterhood method in a household survey conducted in November 1991 and in an outpatient health facility survey conducted in July 1992. Both surveys were conducted in Region I, a predominantly rural, mountainous area in northern Nicaragua. They analyzed data from 9232 interviews with adults younger than 49. The estimated lifetime risk of maternal death and the corresponding maternal mortality ratio were essentially identical for both the household and health facility surveys (0.145 and 0.144 [i.e., 1 in 69 of reproductive age died due to pregnancy-related events] and 243 and 241/100,000 live births, respectively). The estimates were similar for both surveys, even when the results were standardized for age, residence, and socioeconomic characteristics. An important limitation to the sisterhood method of estimating maternal mortality is that it estimates maternal mortality for a period about 10-12 years before the study and therefore cannot be used to assess the immediate effect of interventions to reduce maternal mortality. Nevertheless, in areas with poor maternal mortality surveillance or where no alternative exists to collecting population-based data, the sisterhood method can reliably estimate maternal mortality. These findings suggest that health facilities-based studies using the sisterhood method is a feasible, low-cost, and efficient method to estimate maternal mortality in certain settings at subnational levels.

Estimates of net migration by age at migration from pairs of enumerations of the foreign born: United States, 1880-1930.

"This paper describes a new method for indirectly estimating age schedules of net migration. The method is illustrated with historical data for the United States. The analysis employs a recently developed technique--iterative intracohort interpolation--to estimate age schedules of net migration from pairs of enumerations of the foreign born by age. The data required for this application are enumerations of the foreign born (or more generally of those born outside the enumeration area) by age in two successive censuses, a life table presumed to reflect the mortality experience of the foreign born during the intercensal period, and, optionally, data on variations in the overall level of migration during the intercensal period. The procedure provides estimates of the average annual number of foreign born net migrants during a decade by their age at the time of entry/exit." (SUMMARY IN ITA AND FRE)

The impact of recent policy changes on fertility, abortion, and contraceptive use in Romania.

A national household survey of 4,861 women aged 15-44 on reproductive health issues was conducted in Romania in 1993. The survey provided the opportunity to study the impact of policy changes by comparing selected aspects of fertility, abortion, and contraceptive use before and after the December 1989 revolution, when the laws restricting abortion and contraceptive use were abolished. After abortion became legal, the total fertility rate dropped to below replacement level, while the induced abortion rate doubled. Contraceptive prevalence increased 20 percent, but augmentation of the use of traditional methods, rather than the change in legislation, accounted for 70 percent of the increase. Limited sex education and contraceptive information, mistrust and misinformation about modern methods, a lack of adequately trained providers, and a shortage or uneven distribution of contraceptive supplies are major reasons for the continued high rates of unintended pregnancy.

PIP: After the restrictive abortion law was abolished in 1989 during the Romanian revolution, the legal abortion rate reached almost 200/1000 women 15-44 years old, the highest in the world. A national household survey of 4861 women 15-44 years old on reproductive health issues was conducted in Romania in 1993 (RRHS). The survey provided the opportunity to study the impact of policy changes by comparing selected aspects of fertility, abortion, and contraceptive use before and after the December 1989 revolution, when the laws restricting abortion and contraceptive use were abolished. Two 36-month periods, from June 1987 to May 1990 and from June 1990 to May 1993, were analyzed to calculate age-specific fertility, induced abortion, and pregnancy rates. 12387 households were selected where 4861 women were successfully interviewed on pregnancy history and births, planning pregnancies, family planning, maternal and child health, and knowledge about reproductive health. After abortion became legal, the total fertility rate (TFR) dropped to below replacement level, while the induced abortion rate doubled. The TFR dropped from 2.3 live births per woman for 1987-90 to 1.5 for 1990-93. The total induced abortion rate doubled from 1.7 to 3.4 abortions per woman for the same periods. In the second period the pregnancy rate was also 30% higher. Almost 70% of the TFR could be attributed to women 20-29 years old in both periods. Both mistimed and unwanted pregnancies increased by 1/3 after the repeal of the restrictive abortion law. More than 95% of women who had undergone induced abortion reported their pregnancy to be unintended. Contraceptive prevalence increased 20%, but augmentation of the use of traditional methods, rather than the change in legislation, accounted for 70% of the increase. IUD use increased from 0.6% to 1.7% and condoms from 1.8% to 2.7%, while the use of oral contraceptives remained unchanged at 2.3%. 41% of all women reported contraceptive usage, while the rate for those in union was 57%. Limited sex education, mistrust about modern methods, a lack of adequately trained providers, and a shortage of contraceptives are major reasons for the continued high rates of unintended pregnancy.

Using parity-progression ratios to estimate the effect of female sterilization on fertility.

In this article, a new methodology that employs parity-progression ratios to estimate the effect of female sterilization on fertility is described, and results using data from Ecuador are compared to those obtained using a previously existing approach that classifies women by marital duration. The methods differ in how they disaggregate marital fertility and in the assumption they make about what the subsequent fertility of sterilized women would have been if they had not been sterilized. The analysis of the Ecuadoran data shows that the estimate of births averted by sterilization has diminished over time, even as sterilization prevalence has been increasing. This situation is attributed to a decline in the fertility of nonsterilized women resulting from increased use of reversible methods of contraception.

PIP: Two methods are used to show the impact on fertility of sterilization: births averted in a single five-year period before the survey and the parity progression ratio approach for 1979-84 and 1984-89 used to estimate births averted by birth order and duration since first union. The births averted analysis revealed that fertility among nonsterilized women declined from 5.93 in 1979-84 to 5.01 in 1984-89. The births averted approach showed almost no change in total births averted and a shift in the distribution of births averted by marital duration. Births averted were greater during 1984-89 among marital durations under 15 years and during 1979-84 at marital durations of 15-24 years. The actual percentage of ever married women who were sterilized increased over the decade, but the hypothetical proportions being sterilized in a given duration remained almost unchanged. This approach underestimated births averted, because it did not account for future declines in fertility among nonsterilized women. The parity progression ratio (PPR) approach indicated a nonsterilized fertility decline of 1.28 births per woman and a marital fertility decline of 1.04 births. Between the two periods, sterilization contributed to a reduction of 0.24 births. The preferred PPR approach accounted for the effects of sterilization on individual PPRs and proportions of ever-married women. This method offered consideration of increased sterilization prevalence, but declining births averted by sterilization. A comparison of both methods shows that the parity progression approach yielded higher estimates of the average number of births averted by sterilization and higher total nonsterilized marital fertility rates (total marital fertility rates in the absence of sterilization). Marital fertility rates remained similar. Data are obtained from the 1989 Ecuador Demographic and Health Survey and the World Fertility Surveys of 1979 and 1989.

Ethnicity and the use of health services in Belize.

Data from the 1991 Belize Family Health Survey show differentials in the use of maternal and child health services between ethnic groups (Creole, Mestizo, Maya/Ketchi and Garifuna). Multivariate analysis is used to explore whether such differentials can truly be attributed to ethnicity or to other characteristics that distinguish the ethnic groups. Health services considered are: family planning, place of delivery (hospital/other), postpartum and newborn check-ups after a birth, and immunisations for children. The language usually spoken in the household is found to be important for interpreting ethnic differentials. Mayan-speaking Maya/Ketchis are significantly less likely to use family planning services or to give birth in a hospital. Spanish-speakers (Mestizos and Maya/Ketchis) are less likely to use newborn and postpartum check-ups, after controlling for other characteristics. There are no ethnic differentials for immunisations. Programmatic implications of these results are discussed.

Young women's work and family formation in Sri Lanka.

"Patterns of family formation in Sri Lanka resemble those of wealthier nations, with late marriage, delayed childbearing, and moderately low fertility. This article addresses two questions: How have these family formation patterns emerged in the absence of the normally expected levels of economic development? And what activities have occupied young women in the premarital, prechildbearing period? Answers are suggested by data from three sources: the 1981 census; a set of focus-group discussions on the rights, obligations, and aspirations of young women related to marriage, work, childbearing, and child care; and a sample survey of 1,535 women of ages 15-30 in Kalutara District. The article describes the interplay of socioeconomic and familial forces that have affected the status of young Sri Lankan women."

Estimating intercensal age schedules by intracohort interpolation.

"This paper describes a procedure for estimating intercensal age schedules of rates of occurrence of demographic events (birth, death, marriage) from tabulations at two points in time of a status of the population (average children ever born, persons surviving, proportion ever married) classified by age." The procedure is called iterative intracohort interpolation. The paper describes a more general version than that originally developed by Ansley J. Coale and provides a probabilistic interpretation of the age-specific rates estimated by the procedure.