EVALUATION OF A RAPID DIAGNOSTIC TEST FOR ASSESSING THE BURDEN OF MALARIA AT DELIVERY IN INDIA NEERU SINGH,* AJAY SAXENA, S. B. AWADHIA, RITA SHRIVASTAVA, AND M. P. SINGH Malaria Research Centre, Field Station, Jabalpur, Madhya Pradesh, India; Civil Hospital Maihar, District Satna, Madhya Pradesh, India; District Hospital Mandla, Madhya Pradesh, India Abstract. All pregnant women who came for delivery at a district hospital in Mandla and a civil hospital in Maihar were screened for Plasmodium falciparum (placental parasitemia using a rapid test and microscopy and peripheral and umbilical cord parasitemia using microscopy alone). Two rapid diagnostic tests (RDTs), Paracheck Pf and ParaHITf, were used. At Mandla, the sensitivity and specificity of the Paracheck Pf for P. falciparum were 93% and 84%, respectively. The positive predictive values (PPVs) and negative predictive values (NPVs) were 50% and 99%, respec- tively. At Maihar, the sensitivity and specificity of the ParaHITf for P. falciparum were 87.5% and 97%, respectively. The PPVs and NPVs were 75.4% and 98.7%, respectively. Placental infection was significantly associated with low birth weight. The RDTs for the identification of P. falciparum were more sensitive in placental blood than the placental blood smear by microscopy. Thus, the RDTs should be useful for rapid assessment of malaria at delivery. INTRODUCTION Malaria in pregnancy is associated with adverse outcomes for mother and fetus, notably maternal anemia and low birth weight. 1,2 In many studies, the strongest association with poor outcomes are with placental parasite density, but placental parasitemia is often not associated with peripheral parasit- emia and can be diagnosed only at delivery. 3,4 The problem of malaria in pregnancy had not been studied in India, although both Plasmodium vivax and P. falciparum have been detected in peripheral blood of pregnant women. 5,6 Little is known about the occurrence of these parasites in placentas in the Indian subcontinent. 7 Measuring the burden of malaria during pregnancy usually involves determining the presence of placental malaria infec- tion through microscopic examination of placental blood films. However, placental blood films are often difficult to read because of the presence of cellular debris and a large number of white blood cells. 8 In addition, microscopic exami- nation of placental blood smears depends on good laboratory facilities and skilled technicians. The World Health Organi- zation 9 has repeatedly emphasized an urgent need for simple and cost-effective diagnostics tests for malaria to overcome the deficiencies of both light microscopy and clinical diagno- sis. The potential alternative to microscopy is the rapid diagnostic tests (RDTs) based on the detection of the P. falciparum- specific histidine-rich protein 2. 10 The RDTs do not require extensive training, good infrastructure, and or even electric- ity. 9 Two RDTs, Paracheck Pf (Orchid Biomedical Systems, Verna, Goa, India) and ParaHIT f (Span Diagnostics, Surat, India), were evaluated for rapid screening of P. falciparum malaria at delivery to determine placental infection in com- parison with microscopy of placental blood smear as a gold standard. We also looked at the association of placental P. falciparum infection and low birth weight. MATERIALS AND METHODS All pregnant women with or without clinical symptoms of malaria who came to deliver at district hospital in Mandla, India from October 2002 to January 2003 and at a civil hos- pital in Maihar (Satna district), India (Figure 1) from May to December 2004 were screened for malaria parasites. Mandla is a tribal district with a population of 1.5 million. Malaria cases are mainly due to P. vivax in the dry hot season (March– June) and P. falciparum is the dominant infection during the monsoon and post-monsoon period. 11 Chloroquine resistance in P. falciparum is common. 12 The district has had two regular rounds of spraying with a synthetic pyrethroid (deltamethrin, 20 mg/m 2 ) since 2000. Furthermore, surveillance is strength- ened by hiring workers who provide radical treatment (chloroquine and primaquine) to all fever cases without ex- amination of blood smears during monsoon and post- monsoon season, except for pregnant women who were not given primaquine. Maihar has a mixed rural, urban and tribal population (202,832). The prevalence of both P. falciparum and P. vivax was very high in adjacent villages and few deaths from malaria were recorded in 2003. 13 Maihar has not had a spraying campaign since 1997. Most women in both districts who participated in the study had a low socioeconomic status. The pregnant women and their family members were informed about the objectives of the study and the women were enrolled after informed con- sent was obtained. The study was reviewed and approved by the Ethics Committee of Regional Medical Research Center for tribals. The obstetrics and gynecology wards of the district hospital in Mandla (40 beds) and the civil hospital in Maihar (15 beds) have an antenatal clinic twice a week and an aver- age of 200–300 women attend every month. However, tech- nical expertise in diagnosing malaria at both hospitals is lim- ited. For the study, a malaria clinic was established in the gynecology wards of both hospitals by the Malaria Research Center Field Station (Indian Council of Medical Research, Jabalpur). A clinical and obstetric history was obtained for each woman by a medical officer. Other clinical parameters (weight, temperature, pulse rate, blood pressure, fundal height, fetal heart rate, and the presence of edema or anemia) were obtained by a complete physical examination. Those with fever or a history of fever at some time during pregnancy were asked about periodicity of fever and if any drugs were used. Chemoprophylaxis was not given. A finger prick sample of peripheral blood was collected from pregnant women during labor for thick and thin blood * Address correspondence to Neeru Singh, Malaria Research Centre, Field Station, Jabalpur 482003, Madhya Pradesh, India. E-mail: neeru.singh@gmail.com or oicmrc@yahoo.co.in Am. J. Trop. Med. Hyg., 73(5), 2005, pp. 855–858 Copyright © 2005 by The American Society of Tropical Medicine and Hygiene 855