Impact of Drought on the Spatial Pattern of Transmission of Sehistosoma haematobium in Coastal Kenya

We analyzed temporal changes in spatial patterns of active Schistosoma haematobium infection in different age groups and associated them with ponds infested with Bulinus snails. A major drought between 2001 and 2009 resulted in drying of ponds that were known sources of infection, and we detected very few or no snails in ponds that were infested in the past. The household-level spatial pattern of infection for children of various age groups in 2009 was contrasted with historical data from 2000. The significant local clustering of high- and low-infection levels among school-aged children that occurred in 2000 was absent in 2009. We attribute the disappearance of significant clustering around historical transmission hot spots to a decade-long drought in our study area. The implications of extreme weather and climate conditions on risk and transmission of S. haematobium and their relevance to control strategies are discussed. Copyright © 2011 by The American Society of Tropical Medicine and Hygiene

Anemia among Children Exposed to Polyparasitism in Coastal Kenya

Anemia represents a substantial problem for children living in areas with limited resources and significant parasite burden. We performed a cross-sectional study of 254 Kenyan preschool-and early school-age children in a setting endemic for multiple chronic parasitic infections to explore mechanisms of their anemia. Complete venous blood cell counts revealed a high prevalence of local childhood anemia (79%). Evaluating the potential links between low hemoglobin and socioeconomic factors, nutritional status, hemoglobinopathy, and/or parasite infection, we identified age < 9 years (odds ratio [OR]: 12.0, 95% confidence interval [CI]: 4.4, 33) and the presence of asymptomatic malaria infection (OR: 6.8, 95% CI: 2.1, 22) as the strongest independent correlates of having anemia. A total of 130/155 (84%) of anemic children with iron studies had evidence of iron-deficiency anemia (IDA), 16% had non-IDA; 50/52 of additionally tested anemic children met soluble transferrin-receptor (sTfR) criteria for combined anemia of inflammation (AI) with IDA. Children in the youngest age group had the greatest odds of iron deficiency (OR: 10.0, 95% CI: 3.9, 26). Although older children aged 9-11 years had less anemia, they had more detectable malaria, Schistosoma infection, hookworm, and proportionately more non-IDA. Anemia in this setting appears multifactorial such that chronic inflammation and iron deficiency need to be addressed together as part of integrated management of childhood anemia

Can Prenatal Malaria Exposure Produce an Immune Tolerant Phenotype?: A Prospective Birth Cohort Study in Kenya

In a prospective cohort study of newborns residing in a malaria holoendemic area of Kenya, Christopher King and colleagues find a subset of children born to malaria-infected women who acquire a tolerant phenotype, which persists into childhood and is associated with increased susceptibility to malarial infection and anemia

The Association of Parasitic Infections in Pregnancy and Maternal and Fetal Anemia: A Cohort Study in Coastal Kenya

Background: Relative contribution of these infections on anemia in pregnancy is not certain. While measures to protect pregnant women against malaria have been scaling up, interventions against helminthes have received much less attention. In this study, we determine the relative impact of helminthes and malaria on maternal anemia. Methods: A prospective observational study was conducted in coastal Kenya among a cohort of pregnant women who were recruited at their first antenatal care (ANC) visit and tested for malaria, hookworm, and other parasitic infections and anemia at enrollment. All women enrolled in the study received presumptive treatment with sulfadoxine-pyrimethamine, iron and multi-vitamins and women diagnosed with helminthic infections were treated with albendazole. Women delivering a live, term birth, were also tested for maternal anemia, fetal anemia and presence of infection at delivery. Principal Findings: Of the 706 women studied, at the first ANC visit, 27% had moderate/severe anemia and 71% of women were anemic overall. The infections with highest prevalence were hookworm (24%), urogenital schistosomiasis (17%), trichuria (10%), and malaria (9%). In adjusted and unadjusted analyses, moderate/severe anemia at first ANC visit was associated with the higher intensities of hookworm and P. falciparum microscopy-malaria infections. At delivery, 34% of women had moderate/severe anemia and 18% of infants' cord hemoglobin was consistent with fetal anemia. While none of the maternal infections were significantly associated with fetal anemia, moderate/severe maternal anemia was associated with fetal anemia. Conclusions: More than one quarter of women receiving standard ANC with IPTp for malaria had moderate/severe anemia in pregnancy and high rates of parasitic infection. Thus, addressing the role of co-infections, such as hookworm, as well as under-nutrition, and their contribution to anemia is needed

Age-Stratified Profiles of Serum IL-6, IL-10, and TNF-α Cytokines Among Kenyan Children with Schistosoma haematobium, Plasmodium falciparum, and Other Chronic Parasitic Co-Infections.

In a study of children having polyparasitic infections in a Schistosoma haematobium-endemic area, we examined the hypothesis that S. haematobium-positive children, compared with S. haematobium-negative children (anti-soluble worm antigen preparation [SWAP] negative and egg negative) have increased systemic production of pro-inflammatory cytokines (interleukin [IL]-6, tumor necrosis factor [TNF]-α) and decreased down-regulatory IL-10. A total of 804 children, 2-19 years of age, were surveyed between July and December 2009 and tested for S. haematobium, Plasmodium falciparum, filariasis, and soil-transmitted helminth infections. Plasma levels of IL-6, TNF-α, and IL-10 were compared for S. haematobium-positive and S. haematobium-negative children, adjusting for malaria, filaria, and hookworm co-infections, and for nutritional status, age group, sex, and geographic location. IL-10 was significantly elevated among children infected with S. haematobium, showing bimodal peaks in 7-8 and 13-14 years age groups. IL-10 was also higher among children who were acutely malnourished, whereas IL-10 levels were lower in the presence of S. haematobium-filaria co-infection. After adjustment for co-factors, IL-6 was significantly elevated among children of 5-6 years and among those with P. falciparum infection. Lower levels of IL-6 were found in malaria-hookworm co-infection. High levels of TNF-α were found in children aged 11-12 years regardless of infection status. In addition, village of residence was a strong predictor of IL-6 and IL-10 plasma levels. In adolescent children infected with S. haematobium, there is an associated elevation in circulating IL-10 that may reduce the risk of later morbidity. Although we did not find a direct link between S. haematobium infection and circulating pro-inflammatory IL-6 and TNF-α levels, future T-cell stimulation studies may provide more conclusive linkages between infection and cytokine responses in settings that are endemic for multiple parasites and multiple co-infections

A cohort study of Plasmodium falciparum malaria in pregnancy and associations with uteroplacental blood flow and fetal anthropometrics in Kenya

To use ultrasound to explore the impact of malaria in pregnancy on fetal growth and newborn outcomes among a cohort of women enrolled in an intermittent presumptive treatment in pregnancy (IPTp) with sulfadoxine/pyrimethamine (SP) program in coastal Kenya

Evaluation of the health-related quality of life of children in Schistosoma haematobium-endemic communities in Kenya: a cross-sectional study.

BACKGROUND: Schistosomiasis remains a global public health challenge, with 93% of the ~237 million infections occurring in sub-Saharan Africa. Though rarely fatal, its recurring nature makes it a lifetime disorder with significant chronic health burdens. Much of its negative health impact is due to non-specific conditions such as anemia, undernutrition, pain, exercise intolerance, poor school performance, and decreased work capacity. This makes it difficult to estimate the disease burden specific to schistosomiasis using the standard DALY metric. METHODOLOGY/PRINCIPAL FINDINGS: In our study, we used Pediatric Quality of Life Inventory (PedsQL), a modular instrument available for ages 2-18 years, to assess health-related quality of life (HrQoL) among children living in a Schistosoma haematobium-endemic area in coastal Kenya. The PedsQL questionnaires were administered by interview to children aged 5-18 years (and their parents) in five villages spread across three districts. HrQoL (total score) was significantly lower in villages with high prevalence of S. haematobium (-4.0%, p<0.001) and among the lower socioeconomic quartiles (-2.0%, p<0.05). A greater effect was seen in the psychosocial scales as compared to the physical function scale. In moderate prevalence villages, detection of any parasite eggs in the urine was associated with a significant 2.1% (p<0.05) reduction in total score. The PedsQL reliabilities were generally high (Cronbach alphas ≥0.70), floor effects were acceptable, and identification of children from low socioeconomic standing was valid. CONCLUSIONS/SIGNIFICANCE: We conclude that exposure to urogenital schistosomiasis is associated with a 2-4% reduction in HrQoL. Further research is warranted to determine the reproducibility and responsiveness properties of QoL testing in relation to schistosomiasis. We anticipate that a case definition based on more sensitive parasitological diagnosis among younger children will better define the immediate and long-term HrQoL impact of Schistosoma infection

Notes for genera: basal clades of Fungi (including Aphelidiomycota, Basidiobolomycota, Blastocladiomycota, Calcarisporiellomycota, Caulochytriomycota, Chytridiomycota, Entomophthoromycota, Glomeromycota, Kickxellomycota, Monoblepharomycota, Mortierellomycota, Mucoromycota, Neocallimastigomycota, Olpidiomycota, Rozellomycota and Zoopagomycota)

Compared to the higher fungi (Dikarya), taxonomic and evolutionary studies on the basal clades of fungi are fewer in number. Thus, the generic boundaries and higher ranks in the basal clades of fungi are poorly known. Recent DNA based taxonomic studies have provided reliable and accurate information. It is therefore necessary to compile all available information since basal clades genera lack updated checklists or outlines. Recently, Tedersoo et al. (MycoKeys 13:1--20, 2016) accepted Aphelidiomycota and Rozellomycota in Fungal clade. Thus, we regard both these phyla as members in Kingdom Fungi. We accept 16 phyla in basal clades viz. Aphelidiomycota, Basidiobolomycota, Blastocladiomycota, Calcarisporiellomycota, Caulochytriomycota, Chytridiomycota, Entomophthoromycota, Glomeromycota, Kickxellomycota, Monoblepharomycota, Mortierellomycota, Mucoromycota, Neocallimastigomycota, Olpidiomycota, Rozellomycota and Zoopagomycota. Thus, 611 genera in 153 families, 43 orders and 18 classes are provided with details of classification, synonyms, life modes, distribution, recent literature and genomic data. Moreover, Catenariaceae Couch is proposed to be conserved, Cladochytriales Mozl.-Standr. is emended and the family Nephridiophagaceae is introduced

Real-Time Quantitative PCR for Determining the Burden of Plasmodium falciparum Parasites during Pregnancy and Infancy

Real-time quantitative PCR (RTQ-PCR) provides a quick, accurate, and reproducible quantification of parasites. However, the value of RTQ-PCR for predicting clinical outcomes of malaria is unknown. Here, we compared RTQ-PCR to microscopy of blood smears, nested PCR (nPCR), and parasite circulating-antigen (CAg) assays for detection of Plasmodium falciparum in pregnant Kenyan women and their infants and related these findings to parity and birth weights in their newborns (n = 554). nPCR was the most sensitive assay for detection of malaria in pregnancy, followed in decreasing order of sensitivity by RTQ-PCR, CAg assays, and blood smears. RTQ-PCR detected a higher frequency of malaria infection (46%) in maternal peripheral blood in primiparous than in multiparous women (35%; P < 0.001), with a >12-fold difference in parasite burden (geometric mean = 25,870 versus 2,143 amplicons/μl blood; P < 0.0001). Similarly, the presence of placental malaria determined by RTQ-PCR was approximately twofold higher in primiparous versus multiparous women (21% versus 13%; P < 0.01). The presence and intensity of malaria infection in pregnant women estimated by RTQ-PCR strongly correlated with low-birth-weight babies, especially in those with high amplicon numbers. RTQ-PCR identified malaria-infected women, missed by blood smear, who were at risk for having underweight offspring. By contrast, malaria detected by nPCR and CAg assay showed a much weaker association with parity or low birth weight. Thus, RTQ-PCR provides an estimate of parasite burden that is more sensitive than blood smear and is predictive of clinical outcomes of malaria infection in pregnant women and newborns

Distinct Th1- and Th2-Type Prenatal Cytokine Responses to Plasmodium falciparum Erythrocyte Invasion Ligands

Prenatal immunity to Plasmodium falciparum merozoite proteins involved in erythrocyte invasion may contribute to the partial protection against malaria that is acquired during infancy in areas of stable malaria transmission. We examined newborn and maternal cytokine and antibody responses to merozoite surface protein-1 (MSP-1), ribosomal phosphoprotein P0 (PfP0), and region II of erythrocyte binding antigen-175 (EBA-175) in infant-mother pairs in Kenya. Overall, 82 of 167 (50%), 106 of 176 (60%), and 38 of 84 (45%) cord blood lymphocytes (CBL) from newborns produced one or more cytokines in response to MSP-1, PfP0, and EBA-175, respectively. Newborns of primigravid and/or malaria-infected women were more likely to have antigen-responsive CBL than were newborns of multigravid and/or uninfected women at delivery. Newborn cytokine responses did not match those of their mothers and fell into three distinct categories, Th1 (21 of 55 CBL donors produced only gamma interferon and/or interleukin 2 [IL-2]), Th2 (21 of 55 produced only IL-5 and/or IL-13), and mixed Th1/Th2 (13 of 55). Newborns produced more IL-10 than adults. High and low levels of cord blood IL-12 p70 production induced by anti-CD40 activation were associated with malaria-specific Th1 and Th2 responses, respectively. Antigen-responsive CBL in some newborns were detected only after depletion of IL-10-secreting CD8 cells with enrichment for CD4 cells. These data indicate that prenatal sensitization to blood-stage Plasmodium falciparum occurs frequently in areas where malaria is holoendemic. Modulation of this immunity, possibly by maternal parity and malaria, may affect the acquisition of protective immunity against malaria during infancy