100 Uneke: Effects of placental malaria on perinatal outcome During pregnancy, the presence of malaria parasites is associated with a higher HIV-1 load [75], and placental HIV-1 viral load is increased in women with placental malaria, especially those with high parasite densities [74]. It can be hypothesized that increased placental HIV-1 load, due to the presence of malaria parasites, might be associated with increased excretion of HIV-1 in the genital tract, thus increasing the risk of MTCT. Ma- ternal immune responses to malaria on the one hand may stimulate HIV viral replication in the placenta, thereby increasing the local viral load. Alternatively, maternal immune re- sponses may control the severity of malarial infection and HIV replication and may either have a protective effect or increase the risk of MTCT [62,76]. It has been suggested that the direction of the effect may depend on the de- gree of HIV-related immunosuppression and, thus, the degree of placental monocyte infil- trates and proinflammatory cytokine and chemokine responses [62] and on the severity of the malaria. More studies are urgently needed to evaluate the immunological bases for the increased susceptibility of HIV-in- fected mothers to both peripheral and placen- tal malaria and for the effect of co-infection on mother-to-child transmission of HIV. CONCLUSIONS In sub-Saharan Africa, with high birth rates, a high endemicity of malaria, and alarming rates of new cases of HIV, prophy- laxis against both diseases with combination agents during pregnancy has been described as a great challenge [77]. Low adherence, poor-quality drugs, and drug resistance de- crease the effectiveness of both antiretrovi- ral and anti-malarial drugs and may further hamper treatment outcome and overall im- provement of maternal and infant health. This calls for more research on malaria and HIV infection treatment and prevention in- tervention strategies because only with suf- ficient evidence can appropriate public health policy be devised on integrating the prevention, care, treatment, and support ac- tivities for malaria and HIV among pregnant women in the sub-region. REFERENCES 1. Matteelli A, Caligaris S, Castelli F, Carosi G. The placenta and malaria. Ann Trop Med Par- asitol. 1997; 91:803-10. 2. Rogerson SJ, Hviid L, Duffy PE, Leke RF, Taylor DW. Malaria in pregnancy: pathogen- esis and immunity. Lancet Infect Dis. 2007;7:105-17. 3. Nyirjesy P, Kavasya T, Axelrod P, Fischer PR. Malaria during pregnancy: neonatal morbid- ity and mortality and the efficacy of chloro- quine chemoprophylaxis. Clin Infect Dis. 1993;16:127-132. 4. World Health Organization. Perinatal Mortal- ity: A Listing of Available Information. Ma- ternal Health and Safe Motherhood Program. Geneva: WHO/FRH/MSM/96.7;1996. 5. Remington JS, Klein JO, editors. Infectious Diseases of the Fetus and Newborn Infant. 3rd ed. Philadelphia: WB Saunders; 1995. pp. 765-68. 6. Behrman RE, Keligman R, Jenson HB. Nel- son Textbook of Pediatrics. 17th ed. Philadel- phia: WB Saunders; 2004. pp. 1140. 7. Covell G. Congenital malaria. Trop Dis Bull. 1950;47:1147-65. 8. Redd SC, Wirima JJ, Steketee RW, Breman JG, Heymann DL. Transplacental transmission of Plasmodium falciparum in rural Malawi. Am J Trop Med Hyg. 1996;55:57-60. 9. Egwunyenga OA, Ajayi JA, Duhlinska- Popova DD. Transplacental passage of Plas- modium falciparum and seroevaluation of newborns in northern Nigeria. Southeast Asian J Trop Med Public Health. 1997;28:741-5. 10. Chippaux JP, Massougbodji A, Ekoue S, Lan- masso T, Akogbeto M, Aguessy-Ahyi B. The transplacental transport of Plasmodium falci- parum in non-febrile parturient women in a holoendemic region. [Article in French]. Bull Soc Pathol Exot. 1991;84:458-464. 11. Larkin GL, Thuma PE. Congenital malaria in a hyperendemic area. Am J Trop Med Hyg. 1991;45:587-92. 12. Uneke CJ. Congenital Plasmodium falci- parum malaria in sub-Saharan Africa: a rarity or frequent occurrence? Parasitol Res. 2007; 101(4):835-42. 13. Logic DE, McGregor IA. Acute malaria in newborn infants. Br Med J. 1970;ii:404-5. 14. Fischer PR. Malaria and newborns. J Trop Pe- diatrics. 2003;49:132-4. 15. Ahmed A, Cerilli LA, Sanchez PJ. Congential malaria in a preterm neonate: case report and review of the literature. Am J Perinatol. 1998;15:19-22. 16. De Silva DHG, Mendis KN, Premaratne UN, Jayatilleke SMD, Soyza PE. Congenital malaria due to Plasmodium vivax: A case re- port from Sri Lanka. Trans R Soc Trop Med Hyg. 1982;75:33-35. 17. Miller IJ, Telford SR III. Placental malaria. N Engl J Med. 1996;335:98.