Nutritional impact of intestinal helminthiasis during the human life cycle

Poor people in developing countries endure the burden of disease caused by four common species of soil-transmitted nematode that inhabit the gastrointestinal tract. Disease accompanying these infections is manifested mainly as nutritional disturbance, with the differing infections having their deleterious effects at different phases during the human life cycle. Reduced food intake, impaired digestion, malabsorption, and poor growth rate are frequently observed in children suffering from ascariasis and trichuriasis. Poor iron status and iron deficiency anemia are the hallmarks of hookworm disease. The course and outcome of pregnancy, growth, and development during childhood and the extent of worker productivity are diminished during hookworm disease. Less is known about the impact of these infections in children under 2 years of age. The severity of disease caused by soil-transmitted nematodes has consistently been found to depend on the number of worms present per person. Cost-effective measures based on highly efficacious anthelminthic drugs are now available to reduce and control disease caused by these infections.

A theoretical analysis of the relations between the risk of congenital toxoplasmosis and the annual infection rates with a convincing argument for better public intervention

In a theoretical analysis of the present study, we quantitatively indicate a potential threat of congenital toxoplasmosis to Japanese young women by the use of a simple mathematical model or a special case of the well-known catalytic infection model. For introducing a risk function of congenital toxoplasmosis, an annual infection rate, r, was divided into r(1), the rate before age a(0 < a < 15), and r(2), the rate after age a. Presuming the values of r(1), r(2) and a on the basis of the current situation of Toxoplasma infection in Japan, simulation analyses were performed with the mathematical model. As the simulation clearly demonstrated, Japanese young women are potentially facing a threat of congenital toxoplasmosis, although the current risk of it is relatively lower. From the viewpoint of risk management, public intervention programs are required. Based on our analyses, public intervention programs can be classified into two groups: group 1 for women before age a and group 2 for those after age a, and each group is expected to give a different kind of effect to the risk of congenital toxoplasmosis. The present study implies that a certain public intervention program could augment the risk, inadvertently.

Demonstration of Trichomonas vaginalis in tracheal aspirates in infants with early respiratory failure

Trichomonas vaginalis was isolated from the tracheal aspirates of two premature newborns with early respiratory failure who were delivered vaginally by mothers with T. vaginalis infection. The babies were treated successfully with antiparasitic drugs.

[Maternal toxoplasma infection and mosaic trisomy 8 syndrome]

INTRODUCTION

Mosaic trisomy 8 syndrome shows significant phenotypic variability. High forehead, deep set eyes, wide base of the nose, upturned tip of the nose, protruding lips, prominent ears, strabism, corpus callosum agenesia, deep plantar furrow and variable degree of psychomotor retardation are present in most patients.

PATIENTS/METHODS

The authors describe a patient with severe motor and mental retardation, optic disc hypoplasia, cardiomyopathy and partial extrahepatic bile-duct atresia, who's mother was treated for toxoplasma infection in her pregnancy. Perinatal infection of the child was ruled out by the documentation of decreasing IgG values in the mother and newborn and normal IgM levels in the newborn.

RESULTS

Facial characteristics and the bilateral deep plantar furrow raised the possibility of trisomy 8 syndrome. Routine chromosomal analysis and fluorescent in situ hybridization studies revealed a normal cell line, mosaic trisomy 8 in 13% of the cells, and a pericentric marker 8 ring chromosome in 27% of the cells.

CONCLUSION

The authors suggest that the periconceptional toxoplasma infection may play a role in the occurrence of the mosaic trisomy presenting with cardiomyopathy and partial bile-duct atresia previously undescribed in this syndrome.

Malaria in pregnancy as an indirect cause of infant mortality in sub-Saharan Africa

Although randomized controlled trials of interventions to reduce malaria in pregnancy have demonstrated an increase in the birthweight of the newborn in primigravidae, the subsequent impact on infant mortality in all-parities has not been assessed. The aim of this paper was to model the possible impact of placental malarial infection on infant mortality through reduced birthweight. An extensive literature search was undertaken to define a series of parameters describing the associations between placental infection, birthweight and premature mortality in sub-Saharan Africa. It was shown that a baby is twice as likely to be born of low birthweight if the mother has an infected placenta at the time of delivery (all-parities: 23% vs 11%, primigravidae only: 32% vs 16%), and that the probability of premature mortality of African newborns in the first year of life is 3 times higher in babies of low birthweight than in those of normal birthweight (16% vs 4.6%). Assuming 25% of pregnant women in malaria-endemic areas of Africa harbour placental malarial infection, it is suggested that 5.7% of infant deaths in malarious areas could be an indirect cause of malaria in pregnancy. This would imply that, in 1997, malaria in pregnancy could have been responsible for around 3700 infant deaths under the diverse epidemiological conditions in Kenya. Placental infection with Plasmodium falciparum appears to have a more significant role in infant survival in Africa than has been previously assumed. This may explain the high reduction in infant mortality rates from interventions aimed at reducing transmission, over and above that expected from a decline in direct malaria-specific mortality alone.

Malaria in pregnancy as an indirect cause of infant mortality in sub-Saharan Africa

Although randomized controlled trials of interventions to reduce malaria in pregnancy have demonstrated an increase in the birthweight of the newborn in primigravidae, the subsequent impact on infant mortality in all-parities has not been assessed. The aim of this paper was to model the possible impact of placental malarial infection on infant mortality through reduced birthweight. An extensive literature search was undertaken to define a series of parameters describing the associations between placental infection, birthweight and premature mortality in sub-Saharan Africa. It was shown that a baby is twice as likely to be born of low birthweight if the mother has an infected placenta at the time of delivery (all-parities: 23% vs 11%, primigravidae only: 32% vs 16%), and that the probability of premature mortality of African newborns in the first year of life is 3 times higher in babies of low birthweight than in those of normal birthweight (16% vs 4.6%). Assuming 25% of pregnant women in malaria-endemic areas of Africa harbour placental malarial infection, it is suggested that 5.7% of infant deaths in malarious areas could be an indirect cause of malaria in pregnancy. This would imply that, in 1997, malaria in pregnancy could have been responsible for around 3700 infant deaths under the diverse epidemiological conditions in Kenya. Placental infection with Plasmodium falciparum appears to have a more significant role in infant survival in Africa than has been previously assumed. This may explain the high reduction in infant mortality rates from interventions aimed at reducing transmission, over and above that expected from a decline in direct malaria-specific mortality alone.

Prevalence of toxoplasma infection in Qualyobia governorate, Egypt

ELISA for toxoplasmosis was done on 152 randomly selected individuals, 31 full term parturient and 38 aborted or prematurely delivered women. Seropositivity to specific antitoxoplasma IgG antibodies was observed in 57.9%, 58.1% and 44.7% of random, full term and aborted samples respectively. Only 10.5%, 6.5% and 23.7% were found seropositive for specific antitoxoplasma IgM, respectively. The risk of feto-maternal transmission was very high (50%).

A study on Trichomoniasis vaginalis and female infertility

A total of 280 patients, 240 infertile and 40 pregnant were subjected to thorough history taking, general and local examination for exclusion of organic lesion, laboratory investigations to exclude parasitic, bacterial and fungal infections. Sterile vaginal swab from the posterior fornix was taken, and examined by wet smear preparation, Giemsa staining and cultivation on C.P.L.M. medium for trichomoniasis infection. The mean age of the infertile group was 25.75+/-3.92, and of the control group was 21.6+/-2.38 (in years). The mean duration of infertility was 2.81+/-1.51 (years). Out of 240 infertile women, 18.75% complained of discharge, 17.5% itching, 15.42% dysuria, 14.58% dyspareunia, and 10% had cervical lesion. Of the 40 controls, 5% complained of discharge, 2.5% complained of itching, dysuria, dyspareunia, but none had cervical lesion. Of the total cases (280), 36 (12.9%) had T. vaginalis. The clinical data observed were significantly higher among the infertile group than the control group. Cultures were positive in 14.58% of the infertile group and 2.5% in the control group. The difference between the 2 groups was statistically significant. No doubt, T. vaginalis plays an important role in female infertility.

Prenatal risk factors of wheezing at the age of four years in Tanzania

BACKGROUND

A study was undertaken to assess the interactions between prenatal exposures, early life infections, atopic predisposition, and allergen exposures in the development of wheezing up to the age of 4 years in a tropical region of Africa.

METHODS

The study subjects comprised children born at the district hospital in Ifakara, Tanzania during a 1 year period who were participating in a trial of iron supplementation and malaria chemoprophylaxis during the first year of life and followed for up to 4 years. From this group of subjects, 658 (79%) participated in the interview at 18 months and 528 (64%) in a second interview at 4 years. Wheezing was measured with the ISAAC questionnaire. A hospital based inpatient and outpatient surveillance system was set up to document all attendance by study children for any cause, including episodes of clinical malaria and lower respiratory tract infections. Total IgE levels and malaria parasites were measured in maternal and cord blood. Total IgE was also measured at 18 months of age. Indoor environmental levels of Der p I and Fel d I were determined using an enzyme linked immunosorbent assay at the same time as the interview at the age of 18 months.

RESULTS

The prevalence of wheezing at 4 years is common in Ifakara (14%, range 13-15%). The presence of malaria parasites in cord blood (odds ratio, OR = 6.84, 95% CI 1.84 to 24.0) and maternal asthma (OR = 8.47, 95% CI 2.72 to 26.2) were positively associated with wheezing at the age of 4 years, and cord blood total IgE was negatively associated (OR = 0.24, 95% CI 0.07 to 0.85) (all p<0.05). Parasitaemia at birth was not related to total IgE levels in cord blood (p=0.6). Clinical episodes of malaria during infancy were not associated with wheezing, and nor were levels of indoor aeroallergens.

CONCLUSION

These findings suggest that events occurring during pregnancy may play a role in the future appearance of wheezing, although the results must be interpreted with caution because of the small numbers studied.

The epidemiology and burden of Plasmodium falciparum-related anemia among pregnant women in sub-Saharan Africa

The paucity of precise information on the burden of malaria among pregnant women has hampered effective lobbying for the inclusion of preventative strategies against malaria in Safe Motherhood Initiatives. This article reviews the evidence on the coincidental risks of malaria and anemia in Africa and attempts to estimate the probable burden of malaria-related severe anemia in this susceptible group. Twenty-six studies on hemoglobin levels in all-parity pregnant women throughout this region could be matched with a malaria parasite ratio in children < 15 yr old (a measure of the intensity of transmission). In areas with no malaria, the mean hemoglobin levels were markedly higher than those found in areas with stable malaria transmission, though changes with increasing intensity of transmission were unclear. Eighteen studies from areas with stable malaria transmission in sub-Saharan Africa suggested that the median prevalence of severe anemia in all-parity pregnant women is approximately 8.2%. Assuming that 26% of these cases are due to malaria, it is suggested that as many as 400,000 pregnant women may have developed severe anemia as a result of infection with malaria in sub-Saharan Africa in 1995.

The potential utility of the Semi-Nested Multiplex PCR technique for the diagnosis and investigation of congenital malaria

We report three cases of congenital malaria involving two malarial immune mothers living in Spain. Diagnostic PCR and Genotyping PCR for merozoite surface proteins 1 and 2 were essential to show that mothers and new-borns had different Plasmodium population parasites at the moment of the delivery, and that the infection was acquired earlier in gestation by transplacental transmission. In the first case the Plasmodium species founded in both, mother and child were different. Malaria in the twins showed a mixed infection (P. falciparum plus P. malariae) while the mother presented a P. falciparum infection. These facts were confirmed studying the polymorphisms for MSP1 and MSP2. Blood samples of the newborns were analyzed an half hour after delivery excluding the possibility of re-infection by mosquito bite and indicating a vertical transmission during pregnancy.

Malaria-related anaemia

Malaria infection in humans by Plasmodium species is associated with a reduction in haemoglobin levels, frequently leading to anaemia. Plasmodium falciparum causes the most severe and profound anaemia, with a significant risk of death. This cannot be explained simply by the direct destruction of parasitized red blood cells at the time of release of merozoites, a process shared by all these species. In this review, Clara Menendez, Alan Fleming and Pedro Alonso focus on recent advances in our knowledge of the pathophysiology, epidemiology, management and prevention of anaemia from falciparum malaria.

The complexity of pregnancy anemia in Dar-es-Salaam

OBJECTIVES

To investigate the main causes of anemia in pregnancy in Dar-es-Salaam and identify appropriate investigations at all levels of care.

MATERIALS

All pregnant women booking for antenatal care at 2 clinics (n = 2,235) were screened for anemia. Investigations for etiology of anemia were done in all anemic women (Hb <10.5 g/dl) (n = 361).

METHODS

Blood cell counts, microscopy of blood films, S-ferritin, C-reactive protein, HIV, stool parasite and bone marrow analysis were performed.

RESULTS

Iron deficiency dominated in 86% and malaria in 1/3 of anemia cases. Since 42% had indication of ongoing inflammation, S-ferritin was less useful as indicator of iron deficiency but blood film microscopy identified most cases.

The impact of placental malaria on gestational age and birth weight

Maternal malaria is associated with reduced birth weight, which is thought to be effected through placental insufficiency, which leads to intrauterine growth retardation (IUGR). The impact of malaria on preterm delivery is unclear. The effects of placental malaria-related changes on birth weight and gestational age were studied in 1177 mothers (and their newborns) from Tanzania. Evidence of malaria infection was found in 75.5% of placental samples. Only massive mononuclear intervillous inflammatory infiltration (MMI) was associated with increased risk of low birth weight (odds ratio ¿OR, 4.0). Maternal parasitized red blood cells and perivillous fibrin deposition both were associated independently with increased risk of premature delivery (OR, 3.2; OR, 2.1, respectively). MMI is an important mechanism in the pathogenesis of IUGR in malaria-infected placentas. This study also shows that placental malaria causes prematurity even in high-transmission areas. The impact of maternal malaria on infant mortality may be greater than was thought previously.

Anti-merozoite surface protein-1 19-kDa IgG in mother-infant pairs naturally exposed to Plasmodium falciparum: subclass analysis with age, exposure to asexual parasitemia, and protection against malaria. V. The Asembo Bay Cohort Project

The anti-merozoite surface protein-1 19-kDa IgG (anti-MSP119KD) IgG responses of 33 parasitemic infants, aged 6-14 months, were compared with those of their mothers at the time of the infant's delivery and at the time the infants were sampled; the antimalaria protection associated with these responses was also compared. IgG1 and IgG3 were the predominant subclasses. Infants <300 days old and pregnant mothers had the lowest cytophilic-to-noncytophilic IgG ratio. By 300 days of age, the infants had IgG subclass compositions and levels similar to those of their mothers at the same date. Among infants, older infants with only 1 or 2 detected asexual parasitemias had the highest cytophilic-to-noncytophilic IgG ratio and IgG1 levels. IgG1 level was negatively correlated with protection. The findings suggest that the MSP119KD antibody response develops with age, not with multiple experiences with parasitemia, and, thus, that an antimalaria vaccine strategy for pregnant mothers could delay infants' first parasitemias until they are more capable of mounting a favorable anti-MSP119KD response.

Disturbances of mouse pregnancy after injection of Ascaris homogenate during early organogenesis

Administration of the Ascaris tegumental homogenate (0.6-1.2 g of Ascaris proteins/kg/day) at a early stage of organogenesis (5-9 days of pregnancy) had a harmful effect upon the developing mouse fetuses. It has been found that injection of the homogenate did not delay or prevent implantation, but causes a high rate of intrauterine deaths. The Ascaris homogenate significantly decreased the number of live fetuses per litter, increased the frequency of litter resorption, produced a delay in bone formation and induced pathological changes of fetal organs and tissues. The congenital malformations were noted in fetuses after injection of higher doses of Ascaris homogenate (exencephaly, craniomeningocele and internal hydrocephalus). No malformations were noted in control groups and after injection of minimum dose of the homogenate. The symptoms that occurred after administration of the tegumental homogenate to pregnant mice included: decreased body weight gain (p<0.001) as compared to controls, vaginal hemorrhage, intrauterine resorption of litter and mortality. These signs suggest that the Ascaris homogenate causes maternal toxicity.