Infectious diseases
General • Marlaria • Parasites • Viruses
Malaria
1. Nahlen BL. Rolling Back Malaria in Pregnancy NEJM 2000;343:9
2. Matteelli A, Caligaris S, Castelli F, Carosi G. The placenta and malaria. Ann Trop Med Parasitol 1997 Oct;91(7):803-10. Placental malaria is recognized as a common complication of malaria in pregnancy in areas of stable transmission, and is particularly frequent and severe in primigravidae. Many hypotheses, based on a systemic or local failure of the immunological response to malaria, have been proposed to explain the 'preference' of the parasites for replication in the placenta. Some of the hypotheses are briefly reviewed here, with a particular focus on the discovery of an uncommon subpopulation of Plasmodium falciparum which can adhere and massively sequester in the placenta. Histologically, placental malaria is characterized by the presence of parasites and leucocytes within the intervillous spaces, pigment within macrophages, fibrin deposits and trophoblasts, proliferation of cytotrophoblastic cells and thickening of the trophoblastic basement membrane. The exact mechanisms leading to placental changes and determining the observed impairment of materno-foetal exchange are incompletely understood. Parasites are unlikely to be directly responsible for the placental pathology, but leucocytes, through the production of non-chemotactic cytokines, might be associated with the thickening of the trophoblastic basement membrane, and might cause a mechanical blockage of oxygen and nutrient transport across the placenta. There is sound epidemiological evidence that placental malaria determines low birthweight, mainly mediated by intrauterine growth retardation, and increases the risk of death and disease during the first year of life. Antimalarial chemoprophylaxis significantly reduces placental malaria and prevents the development of low birthweight. It is likely that, in areas of high endemicity, the placenta is where the drama of maternal malaria is mostly played. A deeper understanding of the mechanisms involved in this process is of key importance in the design of protective interventions which are effective and acceptable during the gestation period.
3. Lindsay S, Ansell J, Selman C. Effect of pregnancy on exposure to malaria mosquitoes. Lancet 2000;355:1972. Pregnant women attracted twice the number of Anopheles gambia complex—the predominant African malaria-carrying mosquito—than did their non-pregnant counterparts. We postulate that physiological and behavioural changes that occur during pregnancy are responsible for increased attractiveness, which could be important in intervention strategies aimed at protecting this high-risk group against malaria.
4. Ansell J, Hamilton KA, Pinder M, Walraven GE, Lindsay SW. Short-range attractiveness of pregnant women to Anopheles gambiae mosquitoes. Trans R Soc Trop Med Hyg. 2002 Mar-Apr;96(2):113-6. Malaria is a major cause of illness and an indirect cause of mortality in pregnant women. It can also cause stillbirths and low-birthweight babies. We have shown previously that pregnant women attracted twice as many Anopheles gambiae mosquitoes, the principal African malaria vector, as their non-pregnant counterparts over distances of about 15 m. In the current study (in 1998/99) we compared the short-range attractiveness of both pregnant and non-pregnant women sleeping under untreated bednets in Gambian villages. First, we measured the rate of mosquito entry under bednets and, second, we calculated the proportion of mosquitoes biting mothers under each bednet compared to their children. The feeding preference of An. gambiae collected under nets was determined by DNA fingerprinting blood samples from human subjects sleeping under each bednet and comparing these to fingerprints obtained from mosquito bloodmeals. Pregnant women were more attractive to An. gambiae mosquitoes than non-pregnant women under an untreated bednet. The number of mosquitoes entering bednets each night was 1.7-4.5 times higher in the pregnant group (P = 0.02) and pregnant women also received a higher proportion of bites under the bednets than did non-pregnant women (70% vs 52%, P = 0.001). This study clearly demonstrates that pregnant women are more exposed to malaria parasites than other women, which contributes to the greater vulnerability of pregnant women to malaria.
5. Singh N, Shukla MM, Sharma VP. Epidemiology of malaria in pregnancy in central India. Bull World Health Organ 1999;77(7):567-72. Analysis of three years of data from a malaria clinic operated by the Indian Council of Medical Research (ICMR) in the Government Medical College Hospital in Jabalpur, central India, showed a high malaria prevalence among pregnant women, which was statistically highly significant (P < 0.0001) compared with the situation among nonpregnant women. Cerebral malaria was a common complication of severe Plasmodium falciparum infection, with a high mortality during pregnancy, requiring immediate attention. The study also showed that malaria infection was more frequent in primigravidae, falling progressively with increasing parity. Mean parasite densities were significantly higher in pregnant women compared with nonpregnant women for both P. falciparum (P < 0.001; df = 137) and P. vivax (P < 0.05; df = 72) infection. Pregnant women with falciparum or vivax malaria were significantly more anaemic than noninfected pregnant women or infected nonpregnant women. The average weight of 155 neonates from infected mothers was 350 g less than that of 175 neonates from noninfected mothers. This difference in birth weight was statistically significant for both P. falciparum (P < 0.0001; df = 278) and P. vivax (P < 0.0001; df = 223) infection. Congenital malaria was not recorded. We conclude that pregnant women from this geographical area require systematic intervention owing to their high susceptibility to malaria during pregnancy and the puerperium.
6. Garner P, Gulmezoglu AM. Prevention versus treatment for malaria in pregnant women. Cochrane Database Syst Rev 2000;(2):CD000169
7. Shulman CE. Malaria in pregnancy: its relevance to safe-motherhood programmes. Ann Trop Med Parasitol 1999 Dec;93 Suppl 1:S59-66
8. Davis TM, Suputtamongkol Y, Spencer JL, Wilson SG, Mekhton S, Croft KD, White NJ Glucose turnover in pregnant women with acute malaria. Clin Sci (Colch) 1994 Jan;86(1):83-90. Hypoglycaemia is a serious complication of falciparum malaria, especially in pregnant patients. To investigate malaria-associated changes in glucose metabolism in pregnancy, steady-state [6,6-2H2] glucose turnover and clearance were measured in 10 women (eight with uncomplicated falciparum malaria and two with vivax malaria at 16-30 weeks gestation) before treatment, after intravenous quinine infusion (patients with falciparum malaria) and in convalescence. 2. Admission basal plasma glucose concentrations were higher than those in convalescence [median (range); 4.8 (3.6-7.0) versus 4.0 (3.6-4.6) mmol/l, P = 0.02], and there was a significant fall during initial quinine treatment in patients with falciparum malaria [5.0 (4.3-7.6) to 3.6 (3.2-5.4) mmol/l, P < 0.01]. Basal plasma insulin levels were comparable at presentation and follow-up (P = 0.35) and rose an average of only 2m-units/l during quinine infusion (P < 0.05). Pretreatment glucose turnover rates [3.37 (2.57-4.16) mg min-1 kg-1] were comparable with those found in a previously reported study of non-pregnant severely ill patients [3.22 (2.12-4.82) mg min-1 kg-1, n = 11] and correlated significantly with the admission parasitaemia (P < 0.025). In the eight patients with falciparum malaria, there was a significant fall in turnover during intravenous quinine infusion [3.42 (2.58-4.16) to 2.66 [1.94-3.94) mg min-1 kg-1] whereas clearance did not change significantly.(ABSTRACT TRUNCATED AT 250 WORDS)
9. Diagne N, Rogier C, Sokhna CS, et al. Increased Susceptibility to Malaria during the Early Postpartum Period NEJM 2000;343:9. Abstract Background. Pregnancy is associated with increased susceptibility to malaria. It is generally agreed that this increased risk ends with delivery, but the possible persistence of increased susceptibility during the puerperium has not been investigated. Methods. From June 1, 1990, to December 31, 1998, we monitored exposure to malaria, parasitemia, and morbidity among the residents of a village in Senegal in which the rate of transmission of malaria was high. In this population we analyzed 71 pregnancies in 38 women from the year before conception through one year after delivery. Results. Among the 38 women, there were 58 episodes of clinical Plasmodium falciparum malaria during 61,081 person-days of observation. The incidence of malaria was 20.2 episodes per 1000 person-months during the year preceding conception and 12.0 episodes per 1000 person-months during the period from 91 to 365 days after delivery. The incidence of episodes of malaria increased significantly during the second and third trimesters of pregnancy and reached a maximum of 75.1 episodes per 1000 person-months during the first 60 days after delivery. The adjusted relative risk of an episode of malaria was 4.1 (95 percent confidence interval, 1.8 to 9.5) during the first 60 days post partum, as compared with the year preceding pregnancy. The duration of fever during the episodes of malaria was longer and the prevalence and density of asymptomatic malarial parasitemia were significantly higher during pregnancy and the early postpartum period than during the other periods. Conclusions. Among women who live in areas with high rates of transmission of malaria, the susceptibility to malaria is highest during the second and third trimesters of pregnancy and the early postpartum period.
10. Boulos M, Costa JM, Tosta CE Pulmonary involvement in malaria. Rev Inst Med Trop Sao Paulo 1993 Jan-Feb;35(1):93-102
11. Tian LP, Nelson EA, Senok AC, Yu LM, Oppenheimer SJ, Li K. Red cell age and susceptibility to malaria during pregnancy. Acta Obstet Gynecol Scand 1998 Aug;77(7):717-21
12. The Working Group for Malaria Prophylaxis, Malaria prophylaxis; advice for the individual traveller. Ned Tijdschr Geneeskd 1998 Apr 18;142(16):912-4
13. Taha TE . Comparison of reported and confirmed malaria during pregnancy: findings from hospital and community studies in Sudan. East Afr Med J 1996 Sep;73(9):571-4
14. Silver HM. Malarial infection during pregnancy. Infect Dis Clin North Am 1997 Mar;11(1):99-107 This article reviews the parasitology of malaria, epidemiology in pregnancy, pathogenesis of increased susceptibility to infection in pregnancy, the effect of pregnancy on the clinical manifestations of malaria, the effect of malaria on perinatal outcomes, the safety of antimalarial agents during pregnancy, the role of chemoprophylaxis for inhabitants and travelers to endemic areas, and treatment of clinical malarial infections during pregnancy.
15. Baud M, Bauchet E, Poilane I, Levacher S, Pourriat JL. Acute respiratory distress syndrome due to falciparum malaria in a pregnant woman. Intensive Care Med 1997 Jul;23(7):787-9 UI97436328
16. Bukman A, Weinans MJ, van Loon AJ. Severe Plasmodium falciparum malaria in a non-immune pregnant woman. Int J Gynaecol Obstet 1997 Nov;59(2):143-4
17. Shulman CE. Malaria in pregnancy: its relevance to safe-motherhood programmes. Ann Trop Med Parasitol 1999 Dec;93 Suppl 1:S59-66
18. Verhoeff FH, Brabin BJ, Chimsuku L, Kazembe P, Broadhead RL. Malaria in pregnancy and its consequences for the infant in rural Malawi. Ann Trop Med Parasitol 1999 Dec;93 Suppl 1:S25-33
19. Nosten F, McGready R, Simpson JA, Thwai KL, Balkan S, Cho T, Hkirijaroen L, Looareesuwan S, White NJ. Effects of Plasmodium vivax malaria in pregnancy. Lancet 1999 Aug 14;354(9178):546-9. BACKGROUND: Plasmodium vivax is more common than P. falciparum as a cause of malaria in many parts of the tropics outside Africa. P. falciparum infection has harmful effects in pregnancy, but the effects of P. vivax have not beencharacterised. We investigated the effects of P. vivax infection during pregnancy. METHODS: Since 1986, pregnant Karen women living in camps for displaced people on the western border of Thailand have been encouraged to attend antenatal clinics. Karen women were screened for malaria and anaemia at each week of pregnancy until delivery, and pregnancy outcome recorded. We compared the effects of P. vivax infection on anaemia and pregnancy outcome with those of P. falciparum and no malaria infection in the first pregnancy recorded at the antenatal clinics. FINDINGS: There were 634 first episodes of pure P. vivax malaria in 9956 women. P. vivax malaria was more common in primigravidae than in multigravidae and was associated with mild anaemia and an increased risk of low birthweight (odds ratio 1.64 [95% CI 1.29-2.08], p<0.001). The birthweight was a mean of 107 g (95% CI 61-154) lower in women with P. vivax infection than in uninfected women. By contrast with P. falciparum malaria, the decrease in birthweight was greater in multigravidae. P. vivax malaria was not associated with miscarriage, stillbirth, or with a shortened duration of pregnancy. INTERPRETATION: P. vivax malaria during pregnancy is associated with maternal anaemia and low birthweight. The effects of P. vivax infection are less striking than those of P. falciparum infection, but antimalarial prophylaxis against P. vivax in pregnancy may be justified.
20. Alecrim WD, Espinosa FE, Alecrim MG, Plasmodium falciparum infection in the pregnant patient. Infect Dis Clin North Am 2000 Mar;14(1):83-95, viii-ix. Malaria should be considered a risk factor in women who are pregnant, principally when the infection is Plasmodium falciparum. Moreover, the risk is greater if the woman is pregnant for the first time; if she has no immunity for malaria; if the diagnosis is made late; or if P. falciparum shows resistance to antimalarial drugs. This article presents the most significant aspects of P. falciparum malaria during pregnancy, including information about treatments and prophylaxis.
21. Bruce-Chwatt LJ. Malaria and pregnancy. BMJ 1983;286:1457-8.
22. McGregor IA, Wilson ME, Billewicz WZ. Malaria infection of the placenta in The Gambia, west Africa: its incidence and relationship to stillbirth, birth weight and placental weight. Trans R Soc Trop Med Hyg 1983;77:232-44.
23. Rietveld AE. Malaria prevention for special groups : pregnant women, infants and young children. In P. Schlagenhauf Ed. Travelers’s malaria. BC Decker Inc Hamilton. 2001:303-323. ABSTRACT During pregnancy or when traveling with infants and young children, it is preferable to completely avoid travel to areas with chloroquine-resistant Plasmodium falciparum malaria. At times, however, that is not possible; in such instances, there are no totally safe and effective preventive measures, and difficult choiceshave to be made. This chapter describes why young children and pregnant travelers are at special risk of malaria and lays out the currently available options and safety aspects of chemoprophylaxis and personal protection measures for these high-risk groups. Falciparum malaria in infants, young children, and pregnant women is a medical emergency. The rapid progression of clinical symptoms carries the risk of severe disease, fetal loss, and death. Key practical points for the prevention, early diagnosis, and management of malaria in pregnant travelers and in early childhood are provided.
24. Steketee RW, Wirima JJ, Hightower AW, Slutsker L, Heymann DL, Breman JG The effect of malaria and malaria prevention in pregnancy on offspring birthweight, prematurity, and intrauterine growth retardation in rural Malawi. Am J Trop Med Hyg 1996;55(1 Suppl):33-41. While there is broad evidence for the adverse effects of Plasmodium falciparum infection in pregnancy, and the World Health Organization recommends preventive strategies, there is markedly reduced efficacy in sub-Saharan Africa of the most widely available, affordable and used antimalarial drug for chemoprophylaxis-chloroquine (CQ). During 1987-1990, we studied pregnant women in an area of high malaria endemicity in rural Malawi to compare the efficacy of CQ (the drug recommended by national policy) with mefloquine (MQ, a relatively new and highly effective antimalarial) in preventing low birth weight (LBW) due to prematurity and intrauterine growth retardation (IUGR). Among 1,766 women monitored during at least their last six weeks of pregnancy with observed ingestion of their regimen and facility delivery of a live born singleton, their babies had a mean +/- SD birth weight of 2,905 +/- 461 gm and 16.8% had LBW. In a multivariate analysis, factors significantly associated with LBW included: first birth (odds ratio [OR] = 4.27), female infant (OR = 2.92), maternal human immunodeficiency virus infection (OR = 2.66), low maternal weight (OR = 1.95), and placental blood P. falciparum infection (OR = 1.71). Factors significantly associated with IUGR-LBW included first birth, female infant, low maternal weight, and placental malaria. Factors significantly associated with preterm-LBW included maternal syphilis infection, umbilical cord blood malaria, first birth, low maternal weight, and female infant. Use of an effective antimalarial (MQ) was protective against LBW through its effect on reducing placental and umbilical cord blood malaria infection. The proportion of LBW babies born to women on MQ (12.5% [parity-adjusted for the population of delivering women]) was significantly lower than the proportion born to women on CQ (15.5%; P = 0.05). Effective prevention of malaria in pregnant women in malaria-endemic settings may reduce the likelihood of LBW by 5-14%, and may reduce the amount of preventable LBW by more than 30%. When evaluating antenatal care programs, health policy makers must consider providing an effective preventive drug (either MQ or other drugs identified in additional studies, e.g., sulfa-pyrimethamine compounds) as a means to prevent low birth weight and its consequences.
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