Infectious diseases
General • Marlaria • Parasites • Viruses

Parasites

1.      Liu LX, Weller PF. Strongyloidiasis and other intestinal nematode infections. Infect Dis Clin North Am 1993 Sep;7(3):655-82

2.      Kain KC, Keystone JS. Recurrent hydatid disease during pregnancy. Am J Obstet Gynecol 1988 Nov;159(5):1216-7 A Syrian woman with pulmonary and hepatic Echinococcus granulosus had symptoms of hydatid disease during each of three consecutive pregnancies. We postulate that the decrease in cellular immunity that accompanies pregnancy might allow for increased parasite growth. Obstetricians should be aware of the potential during pregnancy for rapid progression and complications of hydatid disease.

3.      Guderian RH, Lovato R, Anselmi M, Mancero T, Cooper PJ. Onchocerciasis and reproductive health in Ecuador. Trans R Soc Trop Med Hyg 1997 May-Jun;91(3):315-7.  A retrospective study was performed comparing the number of spontaneous abortions in a hyperendemic area for onchocerciasis in Ecuador before and after invermectin treatment with that of a comparable non-endemic area. The frequency of spontaneous abortions was associated with a change in the community microfilarial load, suggesting that there may be a relationship between spontaneous abortions and infection with Onchocerca volvulus. In the endemic area, a significantly greater rate of spontaneous abortions was seen in the period before ivermectin distribution compared to that after the start of ivermectin treatments every 6 months. In the non-endemic area, no change in the rate of spontaneous abortions was seen over the same time period. In addition to the well-documented improvements in skin and ocular disease, ivermectin may also improve the reproductive health of endemic populations.

4.      Alexander ND, Grenfell BT. The effect of pregnancy on Wuchereria bancrofti microfilarial load in humans. Parasitology 1999 Aug;119 ( Pt 2):151-6. As part of a drug trial against bancroftian filariasis in the East Sepik Province of Papua New Guinea we measured the pre-treatment microfilarial densities of 2219 individuals. Mean levels generally increased with age in both sexes, with a tendency to plateau at the highest ages. However, there was a reduction among women of approximately reproductive age. Allowing for the tendency for aggregation to decrease with age, this reduction was statistically significant. However, a comparison of pregnant women and controls showed no evidence that the reduction is specifically related to pregnancy. Moreover, a simple differential equation model of microfilarial acquisition and loss suggests that age-specific patterns of exposure are also unlikely to be solely responsible. Therefore, we suggest that the observed reduction in microfilarial intensity may result from hormonal changes associated with female reproduction, possibly in combination with other factors.

5.      Bialek R, Knobloch J. [Parasitic infections in pregnancy and congenital parasitoses. II. Helminth infections]. Z Geburtshilfe Neonatol 1999 May-Jun;203(3):128-33 [Article in German]. The main sequela of helminthic infections is anemia, causing increased perinatal mortality and morbidity worldwide. During pregnancy symptomatic treatment is usually sufficient to control the disease. The specific and very effective treatment with albendazole, mebendazole, ivermectin and praziquantel has embryo-, fetotoxic, mutagenic and teratogenic potential. Therefore, it should be delayed until after delivery. In some cases immediate specific therapy might be mandatory. Congenital helminthic infection in humans is a rarely described event.

6.      Soboslay PT, Geiger SM, Drabner B, Banla M, Batchassi E, Kowu LA, Stadler A, Schulz-Key H. Prenatal immune priming in onchocerciasis-onchocerca volvulus-specific cellular responsiveness and cytokine production in newborns from infected mothers. Clin Exp Immunol 1999 Jul;117(1):130-7. This study investigated the effect of maternal Onchocerca volvulus infection on humoral and cellular responsiveness in newborn children and their mothers. Onchocerca volvulus-specific IgG isotypes and IgE were significantly elevated in infected mothers and their infants. One year post partum, O. volvulus-specific IgG4 was strongly reduced in children of infected mothers, while IgG1 responses weakened only slightly. Umbilical cord mononuclear blood cells (UCBC) and peripheral blood cells (PBMC) from mothers proliferated in response to phytohaemagglutinin (PHA), concanavalin A (Con A), and the bacterial antigens streptolysin-O (SL-O) or purified protein derivative (PPD). UCBC from neonates born to O. volvulus-infected mothers responded lower (P < 0.01) to Con A (at 5 micrograms/ml), PPD (at 10 and 50 micrograms/ml) and O. volvulus-derived antigens (OvAg) (at 35 micrograms/ml), and in parallel, a diminished cellular reactivity (P < 0.01) by PBMC was observed to OvAg in mothers positive for O. volvulus. Several Th1-type (IL-2, IL-12, interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha)) and Th2-type (IL-4, IL-5, IL-10, IL-13) cytokines were secreted by UCBC and PBMC in response to OvAg, bacterial SL-O and PHA. OvAg did not stimulate IL-2 and none of the mitogens or antigens induced production of IL-4 in neonates. In response to OvAg, substantially elevated (P < 0.01) amounts of IFN-gamma were produced by UCBC from newborns of O. volvulus-infected mothers. UCBC secreted low levels of IL-5 and IL-13, while higher amounts of IL-10 were found (P < 0. 01) in newborns from onchocerciasis-free mothers. In conclusion, maternal O. volvulus-infection will sensitize in utero parasite-specific cellular immune responsiveness in neonates and activate OvAg-specific production of several Th1- and Th2-type cytokines.

7.      Nouhou H, Seve B, Idi N, Moussa F [Schistosomiasis of the female genital tract: anatomoclinical and histopathological aspects. Apropos of 26 cases]. [Article in French] Bull Soc Pathol Exot 1998;91(3):221-3. The authors report 26 cases of female genital schistosomiasis. This parasitosis is observed in women of ages ranging between 17 and 70 years (mean age = 30 years) and associated with sterility (6 cases), uterine tract cancer (1 case), tubular pregnancy (1 case), benign teratoma (1 case) and serous cystadenoma (1 case). The diagnosis is based on an histological analysis which shows several lesions with schistosomiasis (Schistosoma haematobium) eggs, confirmed by ZIEHL coloration. When coupled with infections these anatomical lesions lead to dysfunctions such as sterility and extra-uterine pregnancy through tubular dysfunction.

8.      Navitsky RC, Dreyfuss ML, Shrestha J, Khatry SK, Stoltzfus RJ, Albonico M. Ancylostoma duodenale is responsible for hookworm infections among pregnant women in the rural plains of Nepal. J Parasitol 1998 Jun;84(3):647-51. Fecal specimens from 292 pregnant women (ages 15-40 yr) and 129 infants (ages 10-20 wk) were examined for helminth eggs by the Kato-Katz method and cultured for helminth larvae identification using a modified Harada Mori method. These specimens were collected from June 1995 through July 1996 in Sarlahi District in the southern rural plains of Nepal. Among pregnant women, the prevalence of helminth infection by the Kato-Katz method was 78.8%, 56.2%, and 7.9% for hookworm, Ascaris lumbricoides, and Trichuris trichiura, respectively. Using the modified Harada-Mori method, 66.1% and 2.0% of women's fecal cultures were positive for hookworm and Strongyloides stercoralis, respectively. All of the cultured hookworm larvae were identified as Ancylostoma duodenale. Among infants, 1 specimen was positive for hookworm and 1 for A. lumbricoides using the Kato-Katz method. The modified Harada Mori method detected no larvae in specimens from infants. There was 81.8% agreement between the 2 methods for the detection of hookworm infection. Ancylostoma duodenale is endemic in this study population and highly prevalent in pregnant women.

9.      Hassan MM, Hassounah OA, Hegab M, Salah K, el-Mahrouky L, Galal N Transmission of circulating schistosomal antigens from infected mothers to their newborns. J Egypt Soc Parasitol 1997 Dec;27(3):773-80. Two previous reports have appeared in the literature regarding tansplacental transfer of Schistosoma mansoni antigens which raised the question of its reality. In a previous study the senior author, and others (1992 & 1997) detected circulating antigens of S. mansoni and S. haematobium in infected  patients, using monoclonal antibodies 128C3, with a very high sensitivity using ELISA. This work tried to answer the question of antigen transfer possibility using a high sensitive assay in 50 mothers and their newborns at birth and 1, 3, and 6 months after delivery. The assay used in the present work could detect\ circulating S. mansoni antigens in 45 infected mothers (90%) with active S. mansoni infection. A significant direct increase in mean antigen levels was found with the intensity of infection evaluated by egg counting (p < 0.01). The clinical stage of the diseased mothers was apparently unrelated to the ELISA test values as no significant relations were observed. Positive antigen levels were detected in 33 newborns (66%) of the 45 positive antigen mothers, then the percentage positivity was directly decreased with the advancement of age as only 5 infants (10%) had positive antigen levels compared to 0% at 6 months of age. A positive correlation between newborn serum antigen concentration and concentration of antigen in sera of their mothers was obtained. This work answers some of the questions concerning the ability of the used monoclonal to detect antigens in newborns and the possibility of antigen transfer through the placenta alone or incorporated in immune complexes forms. This work clarifies the time of antigen disappearance from the circulation.

10.  de Silva N, Guyatt H, Bundy D. Anthelmintics. A comparative review of their clinical pharmacology. Drugs 1997 May;53(5):769-88. Virtually all the important helminth infections in humans can be treated with one of 5 anthelmintics currently in use: albendazole, mebendazole, diethylcarbamazine, ivermectin and praziquantel. These drugs are vital not only for the treatment of individual infections, but also useful in controlling transmission of the more common infections. This article reviews briefly the pharmacology of these 5 drugs, and then discusses current issues in the use of anthelmintics in the treatment and/or control of soil-transmitted nematode infections, filariasis, onchocerciasis, schistosomiasis (and other trematode infections), neurocysticercosis and hydatidosis. Mebendazole and albendazole are most effective against intestinal nematodes, but are contraindicated during the first trimester of pregnancy. The efficacy of prolonged therapy with these 2 drugs for treatment of larval cestode infections has not yet been established. Diethylcarbamazine is widely used to treat and control lymphatic filariasis, but adverse effects related to death of microfilariae or damage to adult worms may be marked. While ivermectin has been used in the treatment of patients with onchocerciasis, it is also undergoing investigation against lymphatic filariae. Praziquantel, used to treat schistosome infections, is also effective in other trematode infections and adult cestode infections.

11.  Asrat T, Rogers N. Acute pancreatitis caused by biliary ascaris in pregnancy. J Perinatol 1995 Jul-Aug;15(4):330-2.  Ascaris lumbroicoides is the most prevalent human parasite worldwide. Although usually asymptomatic, ascaris is responsible for a variety of severe complications such as intestinal obstruction, cholangitis, or hepatitis, which are caused by worm migration. This article is the second known case report of pancreatitis caused by biliary ascaris during pregnancy. We also review the pathophysiology of this disease and review the various treatment modalities available for pregnant patients. We believe that because of the growing influx of immigrants from endemic areas into the United States, the clinician needs a basic understanding of the etiology, diagnosis, and treatment of biliary ascarasis.

12.  Hamblin J, Connor PD. Pinworms in pregnancy. J Am Board Fam Pract 1995 Jul-Aug;8(4):321-4.

13.  Okonofua FE, Ojo OS, Odunsi OA, Odesanmi WO. Ectopic pregnancy associated with tubal schistosomiasis in a Nigerian woman. Int J Gynaecol Obstet 1990 Jul;32(3):281-4. A case of ruptured tubal ectopic pregnancy is presented. On histological examination of the fallopian tube involved, ova of Schistosoma haematobium were found in the submucosal and intramural parts of the tube. The case illustrates a rare preventable cause of ectopic pregnancy in this population.

14.  Mendoza E, Jorda M, Rafel E, Simon A, Andrada E. Invasion of human embryo by Enterobius vermicularis. Arch Pathol Lab Med 1987 Aug;111(8):761-2. Two Enterobius vermicularis organisms invading a macerated embryo 2 cm in length were found in the tissue from an endometrial curettage performed for missed abortion in a pregnant woman. Ova from the helminths were recovered from the vagina and endometrium of the patient. This most unusual case provides further evidence for the invading capacity of E vermicularis.

15. Jenum PA, Stray-Pedersen B, Melby KK, Kapperud G, Whitelaw A, Eskild A, Eng J. Department of Bacteriology, National Institute of Public Health, Oslo, Norway.  Incidence of Toxoplasma gondii infection in 35,940 pregnant women in Norway and pregnancy outcome for infected women.  J Clin Microbiol. 1998 Oct;36(10):2900-6. From 1992 to 1994 a screening program for detection of specific Toxoplasma gondii antibodies involving 35,940 pregnant women was conducted in Norway. For women with serological evidence of primary T. gondii infection, amniocentesis and antiparasitic treatment were offered. The amniotic fluid was examined for T. gondii by PCR and mouse inoculation to detect fetal infection. Infants of infected mothers had clinical and serological follow-up for at least 1 year to detect congenital infection. Of the women 10.9% were infected before the onset of pregnancy. Forty-seven women (0.17% among previously noninfected women) showed evidence of primary infection during pregnancy. The highest incidence was detected (i) among foreign women (0.60%), (ii) in the capital city of Oslo (0.46%), and (iii) in the first trimester (0.29%). Congenital infection was detected in 11 infants, giving a transmission rate of 23% overall, 13% in the first trimester, 29% in the second, and 50% in the third. During the 1-year follow-up period only one infant, born to an untreated mother, was found to be clinically affected (unilateral chorioretinitis and loss of vision). At the beginning of pregnancy 0.6% of the previously uninfected women were falsely identified as positive by the Platelia Toxo-IgM test, the percentage increasing to 1.3% at the end of pregnancy. Of the women infected prior to pregnancy 6.8% had persisting specific immunoglobulin M (IgM). A positive specific-IgM result had a low predictive value for identifying primary T. gondii infection.