Multidisciplinary biomarkers aggrieve morbidity in schistosomiasis

BACKGROUND

Biomarkers by definition are measurable molecules that mark the evidence of certain pathological processes. Collaboration of various biomarkers influences morbidity of schsitosomiasis in Egypt.

OBJECTIVES

To identify the biomarkers: CRP, IgE, hemoglobin, ferritin, vitamin D, and platelets in terms of relationship with active and chronic schistosomiasis; demographic data, and their interinfluence.

STUDY DESIGN

A cross-sectional study.

METHODS

Parasitological analysis of stool and urine samples, Indirect Hemagglutination Test, Enzyme linked Immunoassay, Hematology Analyzer, and Statistical Package SPSS (Statistical Package for the Social Sciences) version 25.

RESULTS

Out of 400 participants, 25% suffered of schistosomiasis: active S. mansoni infections in 7 cases (1.75%), S. haematobium infections in 6 cases (1.5%), and chronic schistosomiasis infections in 20 cases (5%). Creactive protein (CRP) likewise IgE levels were higher in active S. mansoni and S. haematobium infections when compared with chronic schistosomiasis. IgE levels appeared to affect infection intensity in S. haematobium. Inversely, hemoglobin (Hb) values were low in active schistosomiasis and upgraded in chronic infection (*p<0.05). Ferritin levels varied in active Schistosoma infection and normalized during chronicity. Vitamin D was reduced in active and chronic schistosomiais. Platelet counts were within normal ranges throughout the study groups. Distribution of ferritin, vit D, and platelets was statistically insignificant among Schistosoma infected population. Age affected only hemoglobin, CRP, and IgE biomarkers. CRP and IgE were in direct relationship together and inversely proportional with hemoglobin (*P <0.05).

CONCLUSION

Anemia increased proportionally with biomarkers of inflammatory stress (CRP and IgE) in early infections. Meanwhile, Hb and ferritin (iron stores) improved during chronicity. Hypovitaminosis-D associated the entire course of schistosomiasis while platelet counts were not affected.

von Willebrand factor in experimental malaria-associated acute respiratory distress syndrome

BACKGROUND

Malaria-associated acute respiratory distress syndrome (MA-ARDS) is a lethal complication of severe malaria, characterized by marked pulmonary inflammation. Patient studies have suggested a link between von Willebrand factor (VWF) and malaria severity.

OBJECTIVES

To investigate the role of VWF in the pathogenesis of experimental MA-ARDS.

METHODS

Plasmodium berghei NK65-E (PbNK65) parasites were injected in Vwf+/+ and Vwf-/- mice. Pathological parameters were assessed following infection.

RESULTS

In accordance with patients with severe malaria, plasma VWF levels were increased and ADAMTS13 activity levels were reduced in experimental MA-ARDS. ADAMTS13- and plasmin-independent reductions of high molecular weight VWF multimers were observed at the end stage of disease. Thrombocytopenia was VWF-independent because it was observed in both Vwf+/+ and Vwf-/- mice. Interestingly, Vwf-/- mice had a shorter survival time compared with Vwf+/+ controls following PbNK65 infection. Lung edema could not explain this shortened survival because alveolar protein levels in Vwf-/- mice were approximately two times lower than in Vwf+/+ controls. Parasite load, on the other hand, was significantly increased in Vwf-/- mice compared with Vwf+/+ mice in both peripheral blood and lung tissue. In addition, anemia was only observed in PbNK65-infected Vwf-/- mice. Of note, Vwf-/- mice presented with two times more reticulocytes, a preferential target of the parasites.

CONCLUSIONS

This study suggests that parasite load together with malarial anemia, rather than alveolar leakage, might contribute to shortened survival in PbNK65-infected Vwf-/- mice. VWF deficiency is associated with early reticulocytosis following PbNK65 infection, which potentially explains the increase in parasite load.

Spatio-temporal prevalence of malaria and anaemia in relation to agro-ecosystems in Mvomero district, Tanzania

BACKGROUND

Agro-ecological systems have been associated with increased malaria intensity. This study determined association between different agro-ecological systems, prevalence of malaria parasitaemia and anaemia in Mvomero district, Tanzania.

METHODS

The study was carried out in three agro-ecosystems namely, savannah, rice-irrigation, and sugarcane. Malaria and anaemia prevalence were measured in four seasons of a year. Villages were categorized according to environmental characteristics, proportion of water-shaded areas and agro-ecosystems. Mixed-effects logistic regression analysis was used to determine factors associated with malaria infection.

RESULTS

A total of 7888 individuals were involved with the overall malaria prevalence of 34.4%. Plasmodium falciparum was the dominant (99.52%) malaria species. Malaria prevalence was highest (42.9%) in children of 10-15 years of age, and significantly low during dry and hot season. Of the infected individuals, 78.1% were from rice-irrigation, 18.7% savannah and 3.2% sugarcane ecosystem. Individuals living in villages with high levels of water-shaded areas had highest malaria risk. Over three-quarters (78.9%) of the individuals slept under a mosquito net, with the highest (88.5%) coverage among individuals in sugarcane ecosystem. On average 47.1% of the children were anaemic. Anaemia was more prevalent (60.5%) among individuals in the savannah than in the rice-irrigation (48.2%) or sugarcane communities (23%). Analysis indicated that ecosystems and levels of water-shaded area were highly correlated, and altered levels of malaria infection. Gender, age, mosquito net-use, and season were other significant determinants of P. falciparum infection. Males had higher odds than females (OR = 1.16, 95% CI 1.05, 1.29). The risk for children 6-9 years and older children (10-15 years) was over 50% and 24%, respectively, higher compared to young ones (0-5 years). Use of mosquito net reduced malaria risk by 26%. The risk of infection was higher during dry and cool season (OR = 1.92, 95 %CI 1.66, 2.23) compared to other seasons. Living in villages with high level of water-shaded areas increased the chances of getting malaria up to 15 times than living in drier areas. Similarly, infection odds increased when living in savannah and rice-irrigation ecosystems than in the sugarcane ecosystem.

CONCLUSIONS

Findings show significant variations in malaria prevalence between communities living in different agro-ecosystems within the same district. Local malaria control strategies should consider these variations and liaise with agricultural experts while designing interventions to maximize effectiveness.

Adverse birth outcomes among mothers who received intermittent preventive treatment with Sulphadoxine-Pyrimethamine in the low malaria transmission region

BACKGROUND

Malaria in pregnancy increases the risk of adverse birth outcomes such as low birth weight (LBW), maternal and foetal anemia. In Tanzania, some areas have attained low malaria transmission. However, data on the burden of preterm delivery, LBW, maternal and foetal anemia following substantial reduction of malaria transmission in recent years is still scarce in these settings.

METHODS

A study involving 631 pregnant women was conducted at Mwananyamala referral hospital in Dar es Salaam from April to August, 2018. Study enrollment was done prior to delivery. Structured interview and antenatal clinic cards were used to obtain data including the use of intermittent preventive therapy in pregnancy using sulfadoxine-pyrimethamine (IPTp-SP). Infants birth weights were recorded, maternal venous and cord blood were taken for testing of malaria and determination of haemoglobin (Hb) levels. Chi-square test and regression analysis were done to identify risk factors for preterm delivery, LBW, maternal and foetal anemia.

RESULTS

The prevalence of malaria among mothers who used at least one dose of IPTp-SP was 0.6% (4/631). Fourteen mothers (2.2%) did not use IPTp-SP and had no malaria infection. The prevalence of maternal anemia, LBW, foetal anemia and preterm delivery was 40.6, 6.5, 5.9 and 9.2% respectively. Participants who were malaria positive had 11 times more risk of LBW compared to those who were negative (AOR, 11; 95%, CI 1.07-132.2; p = 0.04). The risk of delivering babies with LBW was 1.12 times high among mothers who were ≤ 36 weeks of gestation (AOR, 1.12; 95% CI, 0.06-0.25; p = < 0.001). The use of ≥3 doses of IPTp-SP was associated with 83% decrease in risk of LBW compared to those who did not use any dose of IPTp-SP (AOR, 0.17; 95% CI, 0.03-0.88; p = 0.05). Severe anaemia at delivery was associated with seven times increased risk of preterm delivery compared to non-anemic participants (AOR, 6.5; 95% CI, 1.49-28.16; p = 0.013).

CONCLUSION

Despite the reduced malaria transmission and use of IPTp-SP, prevalence of preterm delivery, maternal anemia, LBW and foetal anemia is still high in Tanzania. The recommended ≥3 doses of IPTp-SP should continue be provided even in areas with substantial reduction of malaria.

Prevalence of intestinal parasitic infection and its association with anemia among pregnant women in Wondo Genet district, Southern Ethiopia: a cross-sectional study

BACKGROUND

Previous studies reported contradicting findings about the association between intestinal parasitosis and maternal anemia. In this study we aimed to determine the prevalence of intestinal parasitic infection and its association with anemia among pregnant women in Wondo Genet district, Southern Ethiopia.

METHODS

This facility-based cross-sectional study was conducted in June and July 2018. Pregnant women (n = 352) were randomly drawn from five health centers using antenatal care follow-up lists. Trained data collectors administered the questionnaire. Capillary blood was collected and analyzed for hemoglobin using the HemoCue method. Stool sample was collected following standard procedure and analyzed for the presence and types of intestinal parasites using direct microscopy with Formalin-ether concentration technique. Association between intestinal parasitosis and anemia was measured using multivariable binary logistic regression analysis. The outputs are presented using adjusted odds ratio (AOR) with 95% confidence intervals (CI).

RESULTS

The overall prevalence of intestinal parasitic infection was 38.7% (95% CI: 33.6-43.8%). One-tenth (9.7%) of the pregnant women were infected with polyparasites. Ascaris lumbricoides was the predominant infection encountered in 24.9% of the women. The other infections identified were: hookworms (11.2%), Giardia lamblia (5.4%), Entamoeba histolytica (3.4%), Trichuris trichiura (2.9%) and Schistosoma mansoni (2.3%). The mean (± standard deviation) hemoglobin concentration was 12.3 (±1.9) g/dl and 31.5% (95% CI: 26.6-36.4%) women were anemic (hemoglobin < 11 g/dl). The prevalence of anemia among women infected with intestinal parasite (55.6%) was substantially higher than the prevalence in their counterparts (16.4%) (p <  0.001). In a multivariable model adjusted for multiple potential confounders including socio-economic status indicators, the odds of anemia were six times increased (AOR = 6.14, 95% CI: 2.04-18.45) among those affected by at least one intestinal parasite.

CONCLUSION

Strengthening the existing water, sanitation and hygiene programs and routine deworming of pregnant mothers may help to reduce the burden of both intestinal parasitic infection and anemia in pregnant women.

Association between Insulin-Like Growth Factor-I Levels and the Disease Progression and Anemia in Visceral Leishmaniasis

We analyzed the association between insulin-like growth factor-I (IGF-I) and the pathogenesis of anemia during active visceral leishmaniasis (VL). Serum levels of IGF-I, IGF-binding protein 3 (IGFBP3), and cytokines were measured in samples from individuals with active VL and cured VL, asymptomatic Leishmania-infected, and noninfected individuals. Then, we extended our analysis to VL dogs to evaluate hematimetric parameters, bone marrow alterations, and cytokine and IGF-I expression. We identified a positive correlation between lower IGF-I and IGFBP3 levels in active VL patients and lower hemoglobin levels. In infected dogs, there was a positive correlation between lower IGF-I expression in the bone marrow and lower peripheral blood hematocrit and hemoglobin levels. There was no correlation between decreased IGF-I level/expression and any measured cytokine serum levels in either host. The data suggest that low IGF-I expression is associated with pathogenesis of anemia in active VL, primarily in severe cases, by mechanisms other than alterations in cytokine production.

Prevalence and clinical outcomes of Plasmodium falciparum and intestinal parasitic infections among children in Kiryandongo refugee camp, mid-Western Uganda: a cross sectional study

BACKGROUND

The prevalence of Plasmodium falciparum and Intestinal Parasitic Infections (IPIs) - with the corresponding pathogenesis among children remain uncertain. This study aimed at determining the prevalence and the outcomes (including anaemia) of the respective infections and co-infections. Anaemia is a condition in which the number of red blood cells transporting oxygen to the various body parts is not sufficient to meet the needs of the body.

METHODS

This was a cross sectional study conducted among 476-refugee camp school children. Kato-Katz technique was used to screen stool samples for intestinal parasites. Microscopy was used for malaria testing while the portable Haemoglobin (Hb) calorimeter was used to measure haemoglobin concentration.

RESULTS

The overall prevalence of the mixed infections was 63.03%. Plasmodium falciparum was most prevalent of the single infections 262(55.04%) followed by Taenia spp. 14 (2.9%), Schistosoma mansoni 12(2.5%), Giardia lamblia 7 (2.9%), Trichuris trichiura 2(0.4%), Hookworm 2(0.4%) and Strongyloides stercoralis 1(0.2%). The odds of developing simple or uncomplicated malaria infection or anaemia was 14 times higher in individuals with dual co-infection with Plasmodium falciparum + Taenia sp. compared to single parasitic infection (Odds = 14.13, P = 0.019). Co-infection with Plasmodium falciparum + Taenia spp, was a strong predictor of Malaria and anaemia.

CONCLUSION

This study shows that Plasmodium falciparum and Taenia spp. co-infections is a stronger predictor of malaria and anaemia. The prevalence of malaria and anaemia remains higher than the other regions in Uganda outside restricted settlements. The findings of this study underline the need for pragmatic intervention programmes to reduce burden of the co-infections in the study area and similar settlements.

Hymenolepis nana-An Emerging Intestinal Parasite Associated with Anemia in School Children from the Bolivian Chaco

Tropical anemia can have multiple causes, whether socioeconomic, dietary, or infectious. In the Bolivian Chaco, soil-transmitted helminthiases (STH), malaria, and Chagas disease are potential infectious causes of anemia among school-aged children (SAC). Following years of preventive chemotherapy with mebendazole, the prevalence of STH among SAC living in that area is now negligible, whereas protozoan infections are still highly prevalent (81%); Hymenolepis nana is the most frequent intestinal helminth (∼13%). We present results of hemoglobin (Hb) assessment and the association between parasitic infections and Hb levels of that SAC population. Overall, 511 SAC (girls:boys ratio 1:1, mean age 9.4 years [95% confidence interval {CI}: 9.3-9.5]) had Hb levels measured by using a point of care testing (HemoCue® Hb 301 System; HemoCue, Angelhome, Sweden). The prevalence of anemia was 23% (117/511), with mean and median Hb level = 12.2 g/dL (95% CI: 12.1-12.3; range 9.2-15.4 g/dL). By multivariate analysis, H. nana infection was associated with an increased risk of anemia (odds ratio 2.9, 95% CI: 1.5-5.7, P = 0.002). Two samples (0.5%) were positive for Trypanosoma cruzi and none for Plasmodium spp. by polymerase chain reaction of the 439 children tested. Anemia is still a concern among SAC living in the Bolivian Chaco. Our findings call for a greater attention to fecal-oral emerging pathogens, such as H. nana, and highlight the importance of water, sanitation, and hygiene improvements for disadvantaged population such as those living in the Bolivian Chaco.

Anaemia and malaria

Malaria is a major cause of anaemia in tropical areas. Malaria infection causes haemolysis of infected and uninfected erythrocytes and bone marrow dyserythropoiesis which compromises rapid recovery from anaemia. In areas of high malaria transmission malaria nearly all infants and young children, and many older children and adults have a reduced haemoglobin concentration as a result. In these areas severe life-threatening malarial anaemia requiring blood transfusion in young children is a major cause of hospital admission, particularly during the rainy season months when malaria transmission is highest. In severe malaria, the mortality rises steeply below an admission haemoglobin of 3 g/dL, but it also increases with higher haemoglobin concentrations approaching the normal range. In the management of severe malaria transfusion thresholds remain uncertain. Prevention of malaria by vector control, deployment of insecticide-treated bed nets, prompt and accurate diagnosis of illness and appropriate use of effective anti-malarial drugs substantially reduces the burden of anaemia in tropical countries.

Systemic oxidative stress in Suffolk and Santa Ines sheep experimentally infected with Haemonchus contortus

The mechanisms responsible for the imbalance between oxidants and antioxidants in sheep infected with Haemonchus contortus are not well established. This study aimed to prove the hypothesis that oxidative stress occurring during infection by H. contortus varies according to breed, and that the parasite burden correlates with hypoalbuminaemia and anaemia. Thus, after deworming and confirming the absence of infection, two different sheep breeds, Suffolk (n = 15) and Santa Ines (n = 22), were orally inoculated with a single dose of 5,000 L3 of H. contortus. The egg counts per gram of faeces (EPG), packed cell volume (PCV) and concentrations of several plasma markers of oxidative stress (lipid peroxidation, albumin, uric acid, total bilirubin, total antioxidant capacity [TAC], total oxidant concentration [TOC] and the oxidative stress index [OSI]) were quantified before (control group) and during the experimental infection (28, 34 and 42 days post-inoculation). In both breeds, TOC increased at 28 days and TAC increased at 42 days. In Suffolk sheep, there was a positive correlation of EPG with oxidant components (28 days) and a negative correlation of EPG with PCV (42 days). In Santa Ines sheep, there was a positive correlation of EPG with bilirubin (r = 0.492; p = 0.020). H. contortus infection caused oxidative stress, which varied according to the breed. Parasite burden was not associated with hypoalbuminaemia, whereas there was a negative correlation with PCV. This research provides the first evidence that the antioxidant status contributes more to the resilience to H. contortus in Santa Ines sheep compared to Suffolk sheep.

Gametocyte Development and Carriage in Ghanaian Individuals with Uncomplicated Plasmodium falciparum Malaria

Plasmodium falciparum gametocytes develop over 9-12 days while sequestered in deep tissues. On emergence into the bloodstream, they circulate for varied amounts of time during which certain host factors might influence their further development. We aimed to evaluate the potential association of patient clinical parameters with gametocyte development and carriage via in vivo methods. Seventy-two patients were enrolled from three hospitals in the Volta region of Ghana in 2016. Clinical parameters were documented for all patients, and gametocyte prevalence by microscopy was estimated at 12.5%. By measuring RNA transcripts representing two distinct gametocyte developmental stages using reverse transcriptase quantitative polymerase chain reaction (RT-qPCR), we obtained a more precise estimate of gametocyte carriage while also inferring gametocyte maturation. Fifty-three percent of the study participants harbored parasites expressing transcripts of the immature gametocyte-specific gene (PF3D7_1477700), whereas 36% harbored PF3D7_1438800 RNA-positive parasites, which is enriched in mid and mature gametocytes, suggesting the presence of more immature stages. Linear logistic regression showed that patients older than 5 years but less than 16 years were more likely to carry gametocytes expressing both PF3D7_1477700 and PF3D7_1438800 compared with younger participants, and gametocytemia was more likely in mildly anemic individuals compared with those with severe/moderate anemia. These data provide further evidence that a greater number of malaria patients harbor gametocytes than typically estimated by microscopy and suggest a possible association between age, fever, anemia, and gametocytemia.

Prevalence studies for Theileria orientalis conducted during the early stages of the 2012 New Zealand epidemic of Theileria associated bovine anaemia

Since 1982 there have been two epidemics of bovine anaemia associated with Theileria orientalis infection (TABA) in New Zealand. The latest and more serious epidemic started in 2012 and is associated with the T. orientalis (Ikeda) type. In 2013 the Ministry for Primary Industries (MPI) carried out several epidemiological investigations on the TABA epidemic, which included a series of on-farm herd prevalence studies. The aims of this paper are to present and summarise the results of these herd prevalence studies. The data were collected from March 2013 to September 2013 and comprised 26 farms. For 21/26 of these farms, a T. orientalis (Ikeda) positive index case of TABA precipitated the follow-up herd prevalence study. Each herd prevalence study involved a random sample of 10 cows for haematocrit, for piroplasm counts (number of Theileria infected RBCs per 1000 RBCs) and for PCR molecular diagnosis. Animals were diagnosed anaemic if the haematocrit ≤0.24. The results showed that for the index cases, the average haematocrit = 0.10 L/L and the average piroplasm count = 10.9 Theileria infected RBCs per 1000 RBCs, and for the herd prevalence studies the average haematocrit = 0.26 and the average piroplasm count = 6.9. The average herd prevalence of T. orientalis (Ikeda) PCR positive cattle and of anaemic cattle was 87% and 26% respectively. For dairy herds (n = 7 herds) it took, on average, 80 days for the within herd prevalence of anaemia to return to zero after the initial diagnosis. In conclusion the prevalence studies showed that infection rates and anaemia rates were already high in herds when the index case of TABA was observed. At the time, these prevalence studies significantly added to our understanding of the epidemiology of the evolving T. orientalis (Ikeda) epidemic and furthermore met the New Zealand MPI objective of being rapid and applied, fit for purpose and completed at a relatively low cost.

Severe malaria and death risk factors among children under 5 years at Jason Sendwe Hospital in Democratic Republic of Congo

INTRODUCTION

Malaria is still a major public health concern in the Democratic Republic of Congo. Its morbidity and mortality challenge the actual strategies of the fight agains malaria. This study was aimed to describe the epidemiology, the clinical caracteristics and the risk factors of death associated to severe malaria in the pediatric population under 5 years at Sendwe Hospital of Lubumbashi.

METHODS

This analytical retrospective study was conducted in Lubumbashi, in the province of Haut-Katanga. All patients under 5 years hospitalized for severe malaria were registered from January 2014 to December 2016.

RESULTS

Among the 3,092 patients hospitalised during our study period, 452 (14.6%) were admitted for severe malaria. The average age was 27.04 months, the male sex was the most affected (53.54% with the sex-ratio 1.15). The most frequent forms of gravity noticed were cerebral malaria (48.23%) and severe anemia (46.90%). Death was noted in the evolution in 28.32%. Repeated convulsion (OR = 2.27; 95% CI: 1.47-3.48), coma (OR = 3.55; 95% CI: 2.19-5.74) and severe acute malnutrition (OR = 3.32; 95% CI: 1.56-7.06) were asscociated with a high risk of death.

CONCLUSION

This research shows that severe malaria is still an important cause of morbidity and mortality among young children in Lubumbashi. Neurologic and anemic forms are the most frequent. The predictive signs of death are: repeated convulsions, coma and severe acute malnutrition.

Current prevalence of intestinal parasitic infections and their impact on hematological and nutritional status among Karen hill tribe children in Omkoi District, Chiang Mai Province, Thailand

Intestinal parasitic infection represents a substantial problem for children living in rural or limited resources areas and significantly relates to anemia and nutritional status. This study aimed to determine the current prevalence of intestinal parasitic infections among school-age children of Karen hill tribe population in Omkoi District, Chiang Mai Province, Thailand and assess the impact of intestinal parasitic infection on hematological and nutritional status in those children. A total of 375 Karen hill tribe children, 6-14 years of age, in Omkoi District were randomly selected to participate in this study. Stool samples were collected and examined for intestinal parasitic infection through formalin-ether concentration method. Blood samples were collected for hematological and iron analysis. The overall prevalence of intestinal parasitic infection was 47.7% (179/375), with single infections (29.3%) and polyparatism (18.4%). The most common pathogenic parasite was Trichuris trichiura (16.0%), followed by Ascaris lumbricoides (13%) and Giardia lamblia (3.5%). In addition, non-pathogenic amoeba, Entamoeba coli was observed with a high prevalence rate (31.2%). Anemia and eosinophilia prevalence were 6.40% (24/375) and 74.7% (280/375), respectively. Eosinophilia was significantly more prevalent in children with intestinal parasitic infection compared to uninfected children. Among 249 children, 13.7% were iron deficiency, 9.6% were thalassemia and hemoglobinophathy and 8% were G-6-PD deficiency. A high prevalence infection rate was significantly associated with eosinophilia, but independently related to anemia and iron deficiency. Intestinal parasitic infections are endemic in school-age children of Karen hill tribe population in Omkoi District. These data highlight the need for an integrated approach to control transmission of intestinal parasites and improve the health and sanitation status of Karen hill tribe children in Thailand.

Profile of red blood cell morphologies and causes of anaemia among pregnant women at first clinic visit in the mount Cameroon area: a prospective cross sectional study

OBJECTIVE

Anaemia is a serious problem in pregnancy in malaria-endemic countries. This study investigated red cell morphologies and possible causes of anaemia among pregnant women at first clinic visit. Venous blood samples from consented women were used to determine haemoglobin (Hb) levels, mean corpuscular volume (MCV) and mean corpuscular haemoglobin (MCH) using an automated haematology analyzer. Malaria parasitaemia was diagnosed by microscopy. Definitions were as follows: anaemia (Hb < 11.0 g/dl), microcytosis (MCV < 78 fl), macrocytosis (MCV > 101 fl), hypochromasia (MCH < 27 pg), microcytic hypochromia or normocytic hypochromia with anaemia [iron deficiency anaemia (IDA)], normocytic normochromia with anaemia in the absence of malaria parasitaemia (physiological anaemia of pregnancy).

RESULTS

Of the 279 pregnant women enrolled, 57% had anaemia. Malaria parasitaemia was associated with 23.3% of anaemic cases while 76.7% were non-malaria related. The distribution of red cell alterations was as follows: hypochromasia (32.6%), microcytosis (14.7%) and macrocytosis (1.1%). The co-occurrence of malaria parasitaemia, iron deficiency and anaemia was seen in 23.3% of the women, iron deficiency anaemia only occurred in 35.9% while physiological anaemia of pregnancy was 40.9%. Iron deficiency and physiological anaemia of pregnancy contribute to a greater proportion of anaemia in the study area.

Phenotypic plasticity in reproductive effort: malaria parasites respond to resource availability

The trade-off between survival and reproduction is fundamental in the life history of all sexually reproducing organisms. This includes malaria parasites, which rely on asexually replicating stages for within-host survival and on sexually reproducing stages (gametocytes) for between-host transmission. The proportion of asexual stages that form gametocytes (reproductive effort) varies during infections-i.e. is phenotypically plastic-in response to changes in a number of within-host factors, including anaemia. However, how the density and age structure of red blood cell (RBC) resources shape plasticity in reproductive effort and impacts upon parasite fitness is controversial. Here, we examine how and why the rodent malaria parasite Plasmodium chabaudi alters its reproductive effort in response to experimental perturbations of the density and age structure of RBCs. We show that all four of the genotypes studied increase reproductive effort when the proportion of RBCs that are immature is elevated during host anaemia, and that the responses of the genotypes differ. We propose that anaemia (counterintuitively) generates a resource-rich environment in which parasites can afford to allocate more energy to reproduction (i.e. transmission) and that anaemia also exposes genetic variation to selection. From an applied perspective, adaptive plasticity in parasite reproductive effort could explain the maintenance of genetic variation for virulence and why anaemia is often observed as a risk factor for transmission in human infections.

Factors associated with malaria parasitaemia among children under 5 years in Uganda: a secondary data analysis of the 2014 Malaria Indicator Survey dataset

BACKGROUND

In the midst of success with malaria reduction in Uganda, there are areas that still have high prevalence of malaria parasitaemia. This project aimed at investigating factors associated with this prevalence and its relationship with anaemia.

METHODS

This is a secondary data analysis of the 2014 Malaria Indicator Survey dataset of children under 5 years. All had a blood sample taken by finger or heel prick for determination of malaria parasitaemia and estimation of haemoglobin level for anaemia status. The main outcome was the presence of malaria parasitaemia by microscopy and independent variables included: age, gender, residence (urban vs rural), use of a long-lasting, insecticidal-treated net, indoor residual spraying (IRS) of household in the past 6 months, mother's highest education level, mother heard malaria prevention message in the past 6 months, and household wealth status.

RESULTS

The analysis included 4930 children and of these, 938 (19.04%: 95% CI 16.63-21.71) tested positive for malaria parasites. Malaria parasite prevalence significantly increased from 11.08 (95% CI 9.12-13.40) among children with no anaemia to 50.99% (95% CI 39.13-62.74) with severe anaemia (Chi-square p-value = 0.001). Additionally, prevalence significantly rose from the youngest age group (under 6 months) by 1.62 times (95% CI 1.04-2.52, p = 0.033) among the age group of 7-12 months and to four times (95% CI 2.57-6.45, p = 0.001) among those who were between 49 and 59 months. The following were associated with reduced parasitaemia: IRS use (AOR 0.23 [0.08-0.61], p = 0.004), educated mothers (primary AOR 0.75 [0.59-0.96], p = 0.023 to tertiary AOR 0.11 [0.02-0.53], 0.006), mother heard malaria message (AOR 0.78 [0.62-0.99], p = 0.037), and wealthier households (richest AOR 0.17 [0.08-0.36], p = 0.001).

CONCLUSIONS

Increasing malaria parasite prevalence among children under 5 years is still related to increasing age and severity of anaemia even in the context of decreasing malaria prevalence. Designing interventions that include the use of IRS and behaviour change communication tailored to include older children, especially in areas with high malaria prevalence, could be of added value. All this should be done in an environment that improves the socio-economic status and equity of such populations.

Hookworm infestation as a cause of melena and severe anaemia in farmer

Hookworm infections remain a major cause of morbidity in the developing world. Prevalence is highest in agricultural areas, where use of waste water for irrigation and poor hygiene increases infection rates among farmers. Infections present with gastrointestinal symptoms and chronic anaemia, and there are usually no signs of overt blood loss. The following report describes a case of melena in a middle-aged farmer, where the diagnosis of hookworm infestation was delayed due to the unusual presentation. The patient underwent multiple blood transfusions before referral to the Aga Khan University Hospital (AKUH), Karachi and was managed conservatively with mebendazole at our hospital after exclusion of other possible causes of gastrointestinal bleeding. This case highlights the importance of considering hookworm infestations as a cause of melena in the older age group, where other critical differentials such as peptic ulcer disease and occult malignancy may result in delay in initiation of treatment and a significant financial burden on the patient.

Recent uptake of intermittent preventive treatment during pregnancy with sulfadoxine-pyrimethamine is associated with increased prevalence of Pfdhfr mutations in Bobo-Dioulasso, Burkina Faso

BACKGROUND

The impact of sulfadoxine-pyrimethamine (SP) used as intermittent preventive treatment during pregnancy (IPTp-SP) on mutant parasite selection has been poorly documented in Burkina Faso. This study sought first to explore the relationship between IPTp-SP and the presence of mutant parasites. Second, to assess the relationship between the mutant parasites and adverse pregnancy outcomes.

METHODS

From September to December 2010, dried blood spots (DBS) were collected during antenatal care visits and at delivery from 109 pregnant women with microscopically confirmed falciparum malaria infection. DBS were analysed by PCR-restriction fragment length polymorphism (PCR-RFLP) for the polymorphisms at codons 51, 59, 108, and 164 of the Pfdhfr gene and codons 437 and 540 in the Pfdhps gene.

RESULTS

Both the Pfdhfr and Pfdhps genes were successfully genotyped in 92.7% (101/109) of the samples. The prevalence of Pfdhfr mutations N51I, C59R and S108N was 71.3, 42.6 and 64.4%, respectively. Overall, 80.2% (81/101) of samples carried the Pfdhps A437G mutation. None of the samples had the Pfdhfr I164L and the Pfdhps K540E mutations. The prevalence of the triple mutation N51I + C59R + S108N was 25.7% (26/101). The use of IPTp-SP was associated with a threefold increased odds of Pfdhfr C59R mutation [crude OR 3.29; 95% CI (1.44-7.50)]. Pregnant women with recent uptake of IPTp-SP were at higher odds of both the Pfdhfr C59R mutation [adjusted OR 4.26; 95% CI (1.64-11.07)] and the Pfdhfr intermediate-to-high resistance, i.e., ≥ 2 Pfdhfr mutations [adjusted OR 3.45; 95% CI (1.18-10.07)]. There was no statistically significant association between the presence of the Pfdhfr intermediate-to-high resistance and parasite densities or both maternal haemoglobin level and anaemia.

CONCLUSION

The data indicate that despite the possibility that IPTp-SP contributes to the selection of resistant parasites, it did not potentiate pregnancy-associated malaria morbidity, suggesting the continuation of SP use as IPTp in Burkina Faso.

Epidemiology of visceral leishmaniasis among children in Gadarif hospital, eastern Sudan

BACKGROUND

Since 1900s, visceral leishmaniasis (VL) has been among the most important health problems in Sudan, particularly in the endemic areas such as eastern and central regions.

METHODS

This was a cross sectional, hospital-based study conducted from 1st January 2015 to 31st December 2015 to investigate the epidemiological factors of VL in Gadarif hospital, eastern Sudan.

RESULTS

During the study period there were 47 identified children with VL among 145 suspected cases. The most common clinical presentations were fever (47, 100%), pallor (47, 100%), weight loss (40, 85.1%), splenomegaly (37, 78.7%), lymphadenopathy (33, 70.2%), vomiting (32, 68%) cough (28, 59%), loss of appetite (22, 46.8%), diarrhoea (17, 36.1%) and jaundice (5, 10.6%). With regard to the outcome after short term follow up 37 patients (78.8%) improved without complications, while 3 (6.4%, 2 (4.3%), 2 (4.3%), 1 (2.1%), 1 (2.1%) and 1 (2.1%) developed pneumonia, otitis media, septicaemia, urinary tract infection, parasitic infestation and PKDL respectively. Lower mean of haemoglobin level was observed among the VL cases in comparison with the suspected cases (in whom VL was excluded) haemoglobin level {8.9 (3.1) Vs 11 (6.3), P = 0.021}. Again more proportion of anaemic (47 (100%) Vs 14 (14.2%), P = 0.000) and severely anaemic (23 (48.9%) Vs 2 (2%), P = 0.006) patients was detected among the infected children. Using logistic regression analyses there was significant association between rural residence (CI = 1.5-24, OR = 19.1, P = 0.023), male gender (CI = 6.6-18.7, OR = 6.4, P = 0.001) and VL among children.

CONCLUSIONS

While there is an advance in prevention and management of visceral leishmaniasis our results indicate that VL is still a public health problem with its severe complications among children in eastern Sudan.

AN IMPORTED CASE OF COMPLICATED FALCIPARUM MALARIA

The paper describes a clinical case of imported severe Pfalciparum malaria in a French citizen treated at the clinic of the Research Institute of Epidemiology, Microbiology, and Infectious Disdases, Ministry of the Republic of Uzbekistan. Due to the fact that the patient with tropical malaria sought medical advice too late, the disease was complicated by grade I malaria-induced coma, acute renal failure- in an oliguric phase, severe anemia, and disseminated intravascular coagulation syndrome. Thanks to effective etiopathogenetic and pathogenetic therapy, the patient recovered and returned to his motherland.

Asymptomatic Vivax and Falciparum Parasitaemia with Helminth Co-Infection: Major Risk Factors for Anaemia in Early Life

BACKGROUND

Anaemia in children under five years old is associated with poor health, growth and developmental outcomes. In Papua, Indonesia, where the burden of anaemia in infants is high, we conducted a community survey to assess the association between Plasmodium infection, helminth carriage and the risk of anaemia.

METHODS

A cross sectional household survey was carried out between April and July 2013 in 16 villages in the District of Mimika using a multistage sampling procedure. A total of 629 children aged 1-59 months from 800 households were included in the study. Demographic, symptom and anthropometry data were recorded using a standardized questionnaire. Blood and stool samples were collected for examination.

RESULTS

Of the 533 children with blood film examination, 8.8% (47) had P. vivax parasitaemia and 3.9% (21) had P. falciparum; the majority of children with malaria were asymptomatic (94.4%, 68/72). Soil transmitted helminth (STH) infection was present in 43% (105/269) of children assessed; those with STH were at significantly greater risk of P. vivax parasitaemia compared to those without STH (OR = 3.7 [95%CI 1.5-9.2], p = 0.004). Anaemia (Hb<10 g/dl) was present in 24.5% (122/497) of children and associated with P. vivax parasitaemia (OR = 2.9 [95%CI, 1.7-4.9], p = 0.001), P. falciparum parasitaemia (OR = 4.3 [95%CI, 2.0-9.4], p<0.001), hookworm carriage (OR = 2.6 [95%CI, 1.2-5.8], p = 0.026), Plasmodium-helminth coinfection (OR 4.0 [95%CI, 1.4-11.3], p = 0.008) and severe stunting (OR = 1.9 ([95%CI, 1.1-3.3], p = 0.012).

CONCLUSIONS

Asymptomatic P. vivax and P. falciparum infections and hookworm all contribute to risk of paediatric anaemia in coendemic areas and should be targeted with prevention and treatment programs. The relationship between helminth infections and the increased risk of P. vivax parasitaemia should be explored prospectively.

Hematological Indices in Malian Children Change Significantly During a Malaria Season and with Increasing Age: Implications for Malaria Epidemiological Studies

Standard hematological indices are commonly used in malaria epidemiological studies to measure anemia prevalence and calculate blood parasite densities. In Africa, few studies have investigated how these indices change during a malaria transmission season and with increasing age. To address these knowledge gaps, we collected blood from 169 healthy Malian children aged 3-12 years before (May 2010) and after (January 2011) a transmission season. Red blood cell (RBC) count, hemoglobin (Hb) level, hematocrit (Ht), white blood cell (WBC) count, and WBC subsets were measured in paired blood samples, and the data were stratified by month (May, January) and age group (3-5, 6-8, and 9-12 years). From May to January, RBC count (4.53-4.70 × 10(6)/μL; P < 0.0001), Hb level (11.5-11.9 g/dL; P < 0.0001), and Ht (37.1-39.2%; P < 0.0001) increased, and WBC count (6.46-5.96 × 10(3)/μL; P = 0.0006) decreased. From May to January, the prevalence of WBC subsets also changed: 35-43% neutrophils, 6.5-7.6% monocytes, and 53-45% lymphocytes (P < 0.001). These seasonal changes were not associated with the number of malaria episodes experienced in the interim or the presence of RBC polymorphisms. In May, Hb (11.2, 11.4, and 11.8 g/dL; P = 0.0013) and Ht (36.5%, 36.7%, and 38.1%; P = 0.0154) increased and WBC count (8.04, 6.43, and 5.76 × 10(3)/μL; P < 0.0001) decreased with age group; similar differences were observed in January. These data suggest that season- and age-based reference values for hematological indices are needed to better estimate anemia prevalence and parasite density in malaria epidemiological studies.

Therapeutic efficacy and effects of artesunate-amodiaquine and artemether-lumefantrine on malaria-associated anaemia in Nigerian children aged two years and under

BACKGROUND

Artemisinin-based combination therapies are recommended as first-line treatments for uncomplicated falciparum malaria, but there is little evaluation of their efficacy and effects on uncomplicated malaria-associated anaemia in children aged 2 years and under.

METHODS

Parasitological efficacy and effects on malaria-associated anaemia were evaluated in 250 malarious children aged 2 years and under, and efficacy was evaluated in 603 malarious children older than two but younger than 5 years of age following treatment with artesunate-amodiaquine (AA) or artemether-lumefantrine (AL). Kinetics of the disposition of parasitaemia following treatment were evaluated using a non-compartment model. Late-appearing anaemia (LAA) was diagnosed using the following criteria: clearance of parasitaemia, fever and other symptoms occurring within 7 days of starting treatment, adequate clinical and parasitological response on days 28-42, haematocrit (HCT) ≥ 30 % at 1 and/or 2 weeks, a fall in HCT to < 30 % occurring at 3-6 weeks, absence of concomitant illness at 1-6 weeks, and absence of asexual parasitaemia detected using both microscopy and polymerase chain reaction (PCR) at 1-6 weeks.

RESULTS

Overall, in children aged 2 years and under, the PCR-corrected parasitological efficacy was 97.2 % (95 % CI 92.8-101.6), which was similar for both treatments. In children older than 2 years, parasitological efficacy was also similar for both treatments, but parasite prevalence 1 day after treatment began was significantly higher, and fever and parasite clearance times were significantly faster in the AA-treated children compared with the AL-treated children. Declines in parasitaemia were monoexponential with an estimated elimination half-time of 1 h. Elimination half-times were similar for both treatments. In children aged 2 years and under who were anaemic at presentation, the mean anaemia recovery time was 12.1 days (95 % CI 10.6-13.6, n = 127), which was similar for both treatments. Relatively asymptomatic LAA occurred in 11 children (4.4 %) aged 2 years and under, the recovery from which was uneventful.

CONCLUSION

This study showed that AA and AL are efficacious treatments for uncomplicated falciparum malaria in Nigerian children aged 2 years and under, and that AA clears parasitaemia and fever significantly faster than AL in children older than 2 years. Both treatments may cause a relatively asymptomatic LAA with uneventful recovery in a small proportion of children aged 2 years and under.

TRIALS REGISTRATION

Pan African Clinical Trial Registry PACTR201508001188143, 3 July 2015; PACTR201510001189370, 3 July 2015; PACTR201508001191898, 7 July 2015 and PACTR201508001193368, 8 July 2015  http://www.pactr.org .