Malaria in late pregnancy in Al Hodeidah Governorate, Yemen

To investigate the consequences of maternal malaria during late pregnancy, we conducted a preliminary study in the 2 hospitals in Al Hodeidah on 276 women who had uncomplicated vaginal deliveries. Only 17 women had malaria (Plasmodium falciparum), 6 with peripheral parasitaemia and 11 with both peripheral parasitaemia and placental malaria. Coincident infection carried a 9.44 times higher risk of preterm delivery and a 12.2 times greater risk of low birth weight (< 2500 g). Anaemia was diagnosed in 46.4%, associated with malaria in 11.7% of cases. All risk factors, rural residence (OR 5.18), maternal age < 20 years (OR 4.93) and primigravidae (OR 8.29), were significantly associated with malaria infection.

The effect of dual infection with HIV and malaria on pregnancy outcome in western Kenya

OBJECTIVE

To determine the effect of dual infection with HIV and malaria on birth outcomes and maternal anaemia among women delivering at a large public hospital in Kisumu, western Kenya.

SUBJECTS AND METHODS

Data on obstetric and neonatal characteristics, maternal and placental parasitaemia, and postpartum haemoglobin levels were collected from women enrolled in a cohort study of the interaction between malaria and HIV during pregnancy.

RESULTS

Between 1996 and 1999, data were available from 2466 singleton deliveries. The maternal HIV seroprevalence was 24.3%, and at delivery 22.0% of the women had evidence of malaria. Low birthweight, preterm delivery (PTD), intrauterine growth retardation (IUGR) and maternal anaemia (haemoglobin < 8 g/dl) occurred in 4.6, 6.7, 9.8 and 13.8% of deliveries, respectively. Maternal HIV, in the absence of malaria, was associated with a 99 g (95% CI 52-145) reduction in mean birthweight among all gravidae. Malaria was associated with both IUGR and PTD, resulting in a reduction in mean birthweight of 145 g (95% CI 82-209) among HIV-seronegative and 206 g (95% CI 115-298) among HIV-seropositive primigravidae, but not among multigravidae. Both HIV and malaria were significant risk factors for postpartum maternal anaemia, and HIV-seropositive women with malaria were twice as likely to have anaemia than HIV-seronegative women with or without malaria.

CONCLUSION

Women with dual infection are at particular risk of adverse birth outcomes. In areas with a moderate or high prevalence of HIV and malaria, all pregnant women should be the focus of malaria and anaemia control efforts to improve birth outcomes.

Importance and prevention of malaria in pregnancy

Malaria in pregnancy is one of the most important preventable causes of low birthweight deliveries worldwide. It is also a major cause of severe maternal anaemia contributing to maternal mortality. It is estimated that 40% of the world's pregnant women are exposed to malaria infection during pregnancy. The clinical features of Plasmodium falciparum malaria in pregnancy depend to a large extent on the immune status of the woman, which in turn is determined by her previous exposure to malaria. In pregnant women with little or no pre-existing immunity, such as women from non-endemic areas or travellers to malarious areas, infection is associated with high risks of severe disease with maternal and perinatal mortality. Women are at particular risk of cerebral malaria, hypoglycaemia, pulmonary oedema and severe haemolytic anaemia. Fetal and perinatal loss has been documented to be as high as 60-70% in non-immune women with malaria. Adults who are long-term residents of areas of moderate or high malaria transmission, including large parts of sub-Saharan Africa, usually have a high level of immunity to malaria. Infection is frequently asymptomatic and severe disease is uncommon. During pregnancy this immunity to malaria is altered. Infection is still frequently asymptomatic, so may go unsuspected and undetected, but is associated with placental parasitization. Malaria in pregnancy is a common cause of severe maternal anaemia and low birthweight babies, these complications being more common in primigravidae than multigravidae. Preventative strategies include regular chemoprophylaxis, intermittent preventative treatment with antimalarials and insecticide-treated bednets.

Sexual intercourse association with asymptomatic bacterial vaginosis and Trichomonas vaginalis treatment in relationship to preterm birth

OBJECTIVE

The purpose of this study was to determine whether sexual intercourse was associated with the treatment efficacy or the incidence of preterm birth in two large randomized trials in which metronidazole treatment of bacterial vaginosis or Trichomonas vaginalis did not reduce preterm birth.

STUDY DESIGN

Secondary analysis of two multicenter, double-blind, placebo-controlled trials in which women with asymptomatic bacterial vaginosis on Gram stain or asymptomatic T vaginalis on culture were randomized at 16 to 23 weeks of gestation to metronidazole or placebo. In both studies, women took 2 g of metronidazole or placebo in the presence of a nurse (first dose) and were given a second dose to take 48 hours later. This regimen was repeated (third and fourth doses) at 24 to 29 weeks. At the time of the third dose, bacterial vaginosis and T vaginalis specimens were collected again. Patients who were randomly selected to receive metronidazole were analyzed for bacterial vaginosis and T vaginalis at 24 to 29 weeks and for preterm birth of <37 weeks of gestation, according to intercourse between first and second doses and between the second and third doses. Continuous variables were compared with the use of the Wilcoxon rank-sum test; categoric variables were compared with the use of the chi(2 ) test, Fisher exact test, or the Mantel-Haenzel test of trend.

RESULTS

Sexual intercourse between the first and second doses or between the second and third doses did not influence the incidence of bacterial vaginosis (18% vs 24%; relative risk, 0.7; 95% CI, 0.5-1.1; and 23% vs 20%; relative risk, 1.2; 95% CI, 0.9-1.6, respectively) or T vaginalis (4% vs 8%; relative risk, 0.5; 95% CI, 0.1-3.6; and 5% vs 10%; relative risk, 0.5; 95% CI, 0.2-1.1; respectively) at 24 to 29 weeks of gestation compared with no intercourse. In the T vaginalis trial, sexual intercourse between the first and second doses or between the second and third doses did not influence the incidence of preterm birth (13% vs 17%; relative risk, 0.8; 95% CI, 0.3-2.1; and 16% vs 17%; relative risk, 1.0; 95% CI, 0.6-1.6; respectively) compared with no intercourse. In the bacterial vaginosis trial, although sexual intercourse between the first and second doses did not influence the incidence of preterm birth (11% vs 12%; relative risk, 0.9; 95 % CI, 0.6-1.5), sexual intercourse between the second and third doses was associated with a reduction in the incidence of preterm birth (10% vs 16%; relative risk, 0.6; 95% CI, 0.4-0.9) compared with no intercourse.

CONCLUSION

Sexual intercourse was associated with neither the efficacy of metronidazole treatment of bacterial vaginosis or T vaginalis nor with the incidence of preterm birth. In the bacterial vaginosis study, intercourse between the second and third doses had a negative association with preterm birth.

Influence of placental malaria infection on foetal outcome in the Gambia: twenty years after Ian Mcgregor

Malaria infection in pregnancy has serious health consequences among mothers and offspring. The influence of placental malaria infection on foetal outcome was studied in a Gambian rural setting where few pregnant women take antimalarial chemoprophylaxis. During July-December 1997, three hundred thirteen mother-newborn pairs (singletons only) were consecutively recruited into a study of the effects of placental malaria infection on the outcome of pregnancy. Placental blood and tissue were collected at delivery. Babies were clinically assessed until discharge. The overall prevalence of placental malaria infection was 51.1% by placental histology and 37.1% by blood smear. The primigravid women were more susceptible to placental malaria than the multigravidae (65.3% vs 44.7%, p=0.01). Placental malaria was significantly associated with pre-term deliveryand intrauterine growth retardation (p<0.01), and there was a four-fold risk of delivering low-birth-weight babies if mothers had parasitized placentae [OR=4.42, 95% confidence interval (CI) 2.10-9.27]. A reduction of mean birth-weight of babies by 320 g was associated with placental malaria infection (p<0.001). Similarly, a two-fold risk of stillbirth delivery (OR=2.22, 95% CI 1.04-4.72) was observed among the infected mothers. The findings showed that there was still an overall poor foetal outcome associated with placental malaria infection. The findings of this study confirm the findings of an earlier study by McGregor in the Gambia that the low birth-weight rate is significantly higher if the placenta is parasitized. In addition, this study observed that the high stillbirth and prematurity rates were associated with placental malaria infection. The findings of the present study suggest undertaking of effective malaria-control strategies during pregnancy, such as use of insecticide-impregnated bednets, intermittent and early treatment for malaria, and antimalarial chemoprophylaxis, in the Gambia.

Metronidazole treatment of women with a positive fetal fibronectin test result

Eighty-nine women with either bacterial vaginosis, Trichomonas vaginalis, or both, who also had a positive fetal fibronectin test result were randomized to two courses of metronidazole treatment as part of a Maternal-Fetal Medicine Network Units study of the National Institute of Child Health and Human Development. In this subgroup analysis, compared with the placebo group, women who were treated with metronidazole had a nonsignificant reduction in spontaneous preterm birth from 14.6% to 8.3%.

Causes of preterm delivery and intrauterine growth retardation in a malaria endemic region of Papua New Guinea

AIM

To identify causes of preterm delivery and intrauterine growth retardation (IUGR) in a malaria endemic region of Papua New Guinea.

METHODS

Independent predictors of preterm delivery and birthweight in term infants were identified using multiple regression analysis in a prospective study of 987 singleton live births delivered in Madang Hospital.

RESULTS

Overall, Plasmodium falciparum infection of the placenta was associated with a reduction in birthweight of 130 g. Malaria was significantly more common in primigravidae than multigravidae and probably contributed to both preterm delivery and IUGR. Maternal haemoglobin concentrations were significantly lower in malaria infected than noninfected women and reduced haemoglobin was the main determinant of preterm delivery. Poorer maternal nutritional status and smoking were associated with both prematurity and IUGR. Greater antenatal clinic attendance predicted increased birthweight in term infants.

CONCLUSIONS

Protection against malaria during pregnancy, especially in primigravidae, improved nutrition in women and discouragement of smoking would probably reduce both preterm delivery and IUGR. Greater use of existing antenatal clinics might increase birthweight in term infants.

Studies on pathogenesis, tissue infection and congenital transmission in cows experimentally infected with Sarcocystis cruzi by various routes

A group of nine cows, naturally infected with Sarcocystis, were challenged with Sarcocystis cruzi: three intrarumenally with sporocysts, two intrarumenally with water (controls), two intravenously with merozoites grown in vitro and two intravenously with saline solution (controls). The animals intrarumenally challenged with sporocysts developed acute sarcocystiosis and produced stillborn calves, whereas those intravenously challenged with merozoites suffered from subclinical sarcocystiosis with premature births. No parasites were found in calves from cows challenged with sporocysts; however, a meront of Sarcocystis was found within a macrophage in the cerebrospinal fluid of a calf from a cow intravenously inoculated with merozoites of S. cruzi. This is the first time that merozoites of S. cruzi grown in vitro have been demonstrated to retain the ability to infect their natural intermediate host and complete their life cycle.