Plasmodium falciparum infection in pregnant women attending antenatal care in Luanda, Angola

Maternal Profiles and Pregnancy Outcomes: A Descriptive Cross-Sectional Study from Angola

OBJECTIVES

To characterize pregnant women admitted to Irene Neto Maternity Hospital, Lubango city, Huíla province, and their pregnancy outcomes.

METHODS

We conducted a descriptive cross-sectional facility-based survey between October 2016 and September 2017, involving 500 pregnant women, followed from admission in labor until the end of delivery. Mean (SD) was computed for quantitative variables, while relative and absolute frequencies were determined for categorical variables. Additionally, confidence intervals were estimated.

RESULTS

Among pregnant women 18.3% were adolescents (≤ 19 years) and 14.5% had advanced maternal age (≥ 35 years). Illiteracy was reported by 8.2%. One in three (33.6%) had a short stature (< 1.55 m). Malaria was the most frequent infection during pregnancy (16.3%). Upon admission, 18.1% were anemic (Hb < 11 g/dl) and 36.0% had hypertension (SBP ≥ 140 mmHg and/or DBP ≥ 90 mmHg), contrasting with the few cases reported of chronic hypertension and pregnancy-induced hypertension. There were 15 twin pregnancies. Cesarean section was performed in 25.2% of the women, although there was no medical indication for 23.0% of women having cesareans. Two maternal deaths occurred in our sample. Among live births from singleton pregnancies (97.1%), birth asphyxia (Apgar < 7 at 5 min) was observed in 22.7% and 10.3% had low birth weight (< 2.5 kg).

CONCLUSIONS

There are very few studies reporting pregnancy outcomes in Angola. This analysis presents data from Huíla province, the second most populous province. We identified characteristics for higher risk of adverse pregnancy outcomes: adolescence, illiteracy, and short stature. Among newborn outcomes, birth asphyxia and low birth weight demand special attention. Further research is needed to explore the non-medical indications for cesarean section and to better understand the twinning rate in Lubango.

Modelling sociodemographic factors that affect malaria prevalence in Sussundenga, Mozambique: a cross-sectional study

Background: Malaria is still one of the leading causes of mortality and morbidity in Mozambique with little progress in malaria control over the past 20 years. Sussundenga is one of most affected areas. Malaria transmission has a strong association with environmental and sociodemographic factors. The knowledge of sociodemographic factors that affects malaria, may be used to improve the strategic planning for its control. Currently such studies have not been performed in Sussundenga. Thus, the objective of this study is to model the relationship between malaria and sociodemographic factors in Sussundenga, Mozambique.

Methods: Houses in the study area were digitalized and enumerated using Google Earth Pro version 7.3. In this study 100 houses were randomly selected to conduct a community survey of Plasmodiumfalciparum parasite prevalence using rapid diagnostic test (RDT). During the survey, a questionnaire was conducted to assess the sociodemographic factors of the participants. Descriptive statistics were analyzed and backward stepwise logistic regression was performed establishing a relationship between positive cases and the factors. The analysis was carried out using SPSS version 20 package.

Results: The overall P. falciparum prevalence was 31.6%. Half of the malaria positive cases occurred in age group 5 to 14 years. Previous malaria treatment, population density and age group were significant predictors for the model. The model explained 13.5% of the variance in malaria positive cases and sensitivity of the final model was 73.3%.

Conclusion: In this area the highest burden of P. falciparum infection was among those aged 5–14 years old. Malaria infection was related to sociodemographic factors. Targeting malaria control at community level can combat the disease more effectively than waiting for cases at health centers. These finding can be used to guide more effective interventions in this region.

Effectiveness of antenatal intermittent preventive treatment for malaria with sulphadoxine-pyrimethamine on peripartum outcomes

Background

Following the World Health Organization (WHO) recommendations for 4-weekly antenatal intermittent preventive treatment of malaria in pregnancy using sulphadoxine-pyrimethamine (IPTp-SP), there is a need to evaluate the drug performance in order to determine their effectiveness as tools in malaria control policy.

Objectives

To determine prevalence of cord blood malaria, compliance gap and adverse pregnancy outcomes (anaemia, preterm delivery, spontaneous abortion, intra-uterine foetal death and low birth weight) among antenatal IPTp-SP users compared with non-users.

Methods

A cross-sectional analytical study was conducted among consenting 390 participants who were administered a questionnaire, and paired blood samples were collected from the venous blood of participants and neonatal cord immediately after delivery. The participants were categorised as IPTp-SP users and non-users. Adverse pregnancy outcomes were assessed. Neonatal birth weights were also measured within 1 h after delivery. Malaria parasitaemia and anaemia were analysed using standard parasitological and haematological methods of examination. Data were analysed using SPSS version 25 for Windows and p-value of < 0.05 considered significant.

Results

Of 390 women, 336 (86.2%) were IPTp-SP users, while 54 (13.8%) were non-users. The compliance gap was 13.8%. Malaria parasitemia in pregnant women (21.7% versus 53.7%; p < 0.001) and their babies (12.2% versus 25.4%; p = 0.002) were observed for IPTp-SP users and non-users, respectively. The prevalence of maternal anaemia was 27(8.0%) in IPTp-SP users and 5 (9.3%) in non-users (p = 0.789). Mean parasite density was reduced in IPTp-SP users than in non-users (p < 0.001). Correlation of birth weight according to their sex showed a weak correlation [correlation coefficient (r) = 0.027; p = 0.736]. Pregnant women with preterm delivery, spontaneous abortion, intra-uterine foetal death, and low birth weight were significantly lower (p < 0.001, for all) in IPTp-SP users compared with non-users.

Conclusion

Although the compliance gap was low, IPTp-SP users had significantly better pregnancy and foetal outcomes compared with non-users. Efforts should be intensified towards achieving total compliance in IPTp-SP usage by pregnant women.

Characterization of asymptomatic Plasmodium falciparum infection and its risk factors in pregnant women from the Republic of Congo

Malaria in pregnancy remains a serious public health problem in the Republic of Congo despite the implementation of intermittent preventive treatment with sulfadoxine-pyrimethamine (IPTp-SP) in 2006. The aim of this cross-sectional study was to characterize Plasmodium falciparum infections and determine possible risk factors in pregnant Congolese women attending an antenatal clinic in a periurban area of southern Brazzaville. This study was conducted from March 2012 to December 2013 in a site where several years ago, high malaria resistance to SP was reported. Pregnant women were enrolled during antenatal visits and the number of received IPTp-SP doses was recorded as well as individual sociodemographic data. Peripheral blood was collected and P. falciparum infection was checked by microscopy and by PCR targeting P. falciparum merozoite surface protein gene (msp2). Haemoglobin concentration was measured and P. falciparum positive samples were typed for msp2 allelic diversity. A total of 363 pregnant women were recruited. The prevalence of asymptomatic P. falciparum infection was 7% and 19% by microscopy and by PCR, respectively. More than one half (51.5%) of the pregnant women were anaemic. Multivariate analysis indicated that P. falciparum infection was associated with anaemia. It was also observed that women who have received IPTp-SP have significantly lower prevalence of infection. The administration of IPTp-SP did not influence the multiplicity of infection (MOI). This first study investigating asymptomatic malaria infection on pregnant women of the Republic of Congo shows that P. falciparum infections were clearly associated with maternal anaemia, and use of IPTp-SP reduced the risk of carrying asymptomatic infections.

Molecular epidemiology of drug-resistant Plasmodium falciparum in Benguela province, Angola

Background

The malaria situation has been worsening in Angola, partly due to armed conflict until the recent past and drug-resistant Plasmodium falciparum. Malaria transmission is heterogeneous within the country, and data on drug-resistant malaria in different parts of the country are incomplete. The aim of the present study was to evaluate resistance to 4-aminoquinolines and antifolate drugs in P. falciparum isolates collected in Benguela province, central Angola, using molecular markers.

Methods

Fingerprick capillary blood was collected from asymptomatic children aged less than 15 years old during a household survey in and around Balombo town in 2010–2011. Samples were screened for P. falciparum by nested PCR. Molecular markers (P. falciparum dihydrofolate reductase [pfdhfr], P. falciparum dihydropteroate synthase [pfdhps], P. falciparum chloroquine resistance transporter [pfcrt], and P. falciparum multidrug-resistance gene 1 [pfmdr1]) were sequenced to determine the key codons associated with drug resistance.

Results

A total of 60 blood samples were positive for P. falciparum. Most isolates with successful PCR amplification had mutant pfdhfr alleles, with either double mutant AICNI (69%) or triple mutant AIRNI (21%) haplotypes. A16V, S108T, and I164L substitutions were not found. Many of the isolates were carriers of either SGKAA (60%) or AGKAA (27%) pfdhps haplotype. K540E substitution was absent. There were only two pfcrt haplotypes: wild-type CVMNK (11%) and mutant CVIET (89%). Wild-type pfmdr1 NYSND haplotype was found in 19% of the isolates, whereas single mutant pfmdr1 YYSND and NFSND haplotypes occurred in 48% and 11%, respectively. Double mutant pfmdr1 haplotypes (YFSND and YYSNY) occurred rarely.

Conclusions

The results suggest that the high prevalence of mutant pfcrt CVIET haplotype is in agreement with low clinical efficacy of chloroquine observed in earlier studies and that the double pfdhfr mutant AICNI and single pfdhps mutant SGKAA are currently the predominant haplotypes associated with antifolate resistance in Benguela province. The hallmark of clinical resistance observed in East Africa, i.e. triple pfdhfr mutant haplotype (AIRNI) and double pfdhps mutant haplotype (SGEAA), was absent. These molecular findings need to be further evaluated in parallel with clinical studies, in particular with the efficacy of intermittent preventive treatment using sulphadoxine-pyrimethamine in pregnant women and artesunate-amodiaquine for uncomplicated malaria.

Prevalence and risk factors for Plasmodium falciparum malaria in pregnant women attending antenatal clinic in Bobo-Dioulasso (Burkina Faso)

Background

Malaria during pregnancy remains a serious public health problem. The aim of this study was to determine the prevalence and possible risk factors for malaria in pregnant women attending antenatal clinic at two primary health facilities in Bobo-Dioulasso.

Methods

We conducted a cross sectional study from September to December 2010 in two primary health facilities located in the periurban area of Bobo-Dioulasso. Pregnant women attending antenatal clinic (ANC) were included in the study after signing informed consent. For each participant, the social-demographic profile, malaria and obstetric histories were investigated through a questionnaire. Peripheral blood was collected and thick and thin blood smears were prepared to check Plasmodium falciparum parasitaemia. Hemoglobin concentration was measured. The associations between age, parity, gestational age, schooling, number of ANC visits, use of IPTp-SP, use of insecticide-treated nets (ITN) and anemia with the occurrence of P. falciparum malaria infection during pregnancy were analyzed through logistic regression.

Results

During the period of study, 105 (18.1%) out of 579 pregnant women were infected by P. falciparum. The hemoglobin concentration mean was 10.5 ± 1.7/dL and was significantly lower in pregnant women with malaria infection (9.8 g/dL ±1.6) than in those who had no malaria infection (10.6 g/dL ±1.7) (P < 0.001). Multivariate analysis indicated that, education (AOR 1.9, 95% CI = [1.2-3.2]), parity [primigravidae (AOR 5.0, 95% CI = [2.5-9.8]) and secundigravidae (AOR 2.1, 95% CI = [1.2-3.8])], and anaemia (AOR 2.1, 95% CI = [1.3-3.5]) were significantly associated with P. falciparum malaria infection. The use of IPTp-SP was not associated with P. falciparum malaria infection.

Conclusions

P. falciparum malaria infection is common in pregnant women attending antenatal clinic and anaemia is an important complication. The results show that the use of IPTp-SP does not reduce the risk of malaria incidence during pregnancy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-014-0631-z) contains supplementary material, which is available to authorized users.

Possible artemisinin-based combination therapy-resistant malaria in Nigeria: a report of three cases

Artemisinin-based combination therapy-resistant malaria is rare in Sub-Saharan Africa. The World Health Organization identifies monitoring and surveillance using day-3 parasitaemia post-treatment as the standard test for identifying suspected artemisinin resistance. We report three cases of early treatment failure due to possible artemisinin-based combination therapy-resistant Plasmodium falciparum malaria. All cases showed adequate clinical and parasitological responses to quinine. This study reveals a need to re-evaluate the quality and efficacy of artemisinin-based combination therapy agents in Nigeria and Sub-Saharan Africa.

Malaria in pregnancy

Pregnant women have a higher risk of malaria compared to non-pregnant women. This review provides an update on knowledge acquired since 2000 on P. falciparum and P.vivax infections in pregnancy. Maternal risk factors for malaria in pregnancy (MiP) include low maternal age, low parity, and low gestational age. The main effects of MIP include maternal anaemia, low birth weight (LBW), preterm delivery and increased infant and maternal mortality.

P. falciparum infected erythrocytes sequester in the placenta by expressing surface antigens, mainly variant surface antigen (VAR2CSA), that bind to specific receptors, mainly chondroitin sulphate A. In stable transmission settings, the higher malaria risk in primigravidae can be explained by the non-recognition of these surface antigens by the immune system. Recently, placental sequestration has been described also for P.vivax infections. The mechanism of preterm delivery and intrauterine growth retardation is not completely understood, but fever (preterm delivery), anaemia, and high cytokines levels have been implicated.

Clinical suspicion of MiP should be confirmed by parasitological diagnosis. The sensitivity of microscopy, with placenta histology as the gold standard, is 60% and 45% for peripheral and placental falciparum infections in African women, respectively. Compared to microscopy, RDTs have a lower sensitivity though when the quality of microscopy is low RDTs may be more reliable. Insecticide treated nets (ITN) and intermittent preventive treatment in pregnancy (IPTp) are recommended for the prevention of MiP in stable transmission settings. ITNs have been shown to reduce malaria infection and adverse pregnancy outcomes by 28–47%. Although resistance is a concern, SP has been shown to be equivalent to MQ and AQ for IPTp. For the treatment of uncomplicated malaria during the first trimester, quinine plus clindamycin for 7 days is the first line treatment and artesunate plus clindamycin for 7 days is indicated if this treatment fails; in the 2^nd and 3^rd trimester first line treatment is an artemisinin-based combination therapy (ACT) known to be effective in the region or artesunate and clindamycin for 7 days or quinine and clindamycin. For severe malaria, in the second and third trimester parenteral artesunate is preferred over quinine. In the first trimester, both artesunate and quinine (parenteral) may be considered as options. Nevertheless, treatment should not be delayed and should be started immediately with the most readily available drug.