Prevalence of Asymptomatic Plasmodium Infection and Associated Risk Factors among Pregnant Women in Arba Minch Zuria District, Southern Ethiopia: A Community Based Cross-Sectional Survey

Abstract

Background: Pregnant women, after frequent infections with Plasmodium spp., may develop immunity that can result in asymptomatic malaria. Though asymptomatic, the women harbor parasites that can trigger deleterious effects in maternal and child health, and can reserve gametocytes for perpetuation of transmission in an area. Therefore, this study aimed at determining the prevalence of asymptomatic malaria and related risk factors among pregnant women living in the malarious areas of Arba Minch Zuria District, Southern Ethiopia. Method: A community based cross-sectional study comprising multistage sampling was conducted from April to June 2013 on 341 pregnant women in the malarious areas of Arba Minch Zuria District, Southern Ethiopia. Socio-demographic & economic data were collected with questionnaire. Malaria parasites were detected by Giemsa-stained blood smear microscopy and SD BIOLINE Malaria Ag Pf/Pv POCT test. Packed cell volume was determined by microhematocrit centrifugation to define anemia. Data were analyzed by SPSS 16; integrating both descriptive and inferential statistics with 95% confidence interval for odds ratio calculation. Results: Of the total 341 pregnant women participated in this study, 31 women (9.1%) by microscopy with the mean parasite density of 3202.58/µl, and 33 women (9.7%) by the rapid Ag test were positive for malaria. The species diagnosed by microscopy & rapid test, respectively, were P.falciparum (38.71% & 39.4%), P.vivax (48.38% & 48.5%), and mixed Pf+Pv (12.9% & 12.1%). The sensitivity and specificity of the rapid test when compared to microscopy were 100% and 99.35%, respectively. Parasitemia was more likely to occur in primigravidae [Adjusted odds ratio (AOR)= 84.40, 95% CI: 7.30-976.53, P<0.001], secondigravida (AOR=16.34, 95% CI: 2.98-89.53, P=0.001), using insecticide treated net (ITN) sometimes (AOR=10.22, 95% CI: 1.80–57.95, P=0.009), not using ITN at all (AOR=4.61, 95% CI: 1.48- 14.41, P=0.009), age group of 31-35 years (AOR=24.74, 95% CI: 2.31-265.42, P=0.008), and age group of >35 years (AOR=69.26, 95% CI: 3.99-1200.86, P=0.00) compared to multigravida, using ITN always & young age(<21 yrs), respectively. Of the total study subjects, 118 (34.6%) were anemic. Anemia was likely higher in Plasmodium infected women (AOR=12.76, 95% CI: 2.40-67.73, P=0.003), using ITN sometimes (AOR=7.33, 95% CI:1.83- 29.42, P=0.005), not using ITN at all (AOR=2.06, 95%CI: 1.07-3.99, p-value=0.032) related to malaria negatives & using ITN always, respectively. There was a significant correlation between increasing malaria parasite load and decreasing hematocrit (r = −0.463, P = 0.009). Conclusion. The prevalence of asymptomatic malaria in this study is moderate, however it has shown significant association with anemia in pregnant women. Symptomless malaria may create problems in Ethiopia where malaria control is essentially based on the treatment of symptomatic patients & mosquito control. It is, therefore, critical to design strategies that assist to diagnose pregnant women for asymptomatic malaria through the antenatal care(ANC) service package