BackgroundPyruvate kinase (PK) deficiency, causing hemolytic anemia, has been associated to malaria protection and its prevalence in sub-Saharan Africa is not known so far. This work shows the results of a study undertaken to determine PK deficiency occurrence in some sub-Saharan African countries, as well as finding a prevalent PK variant underlying this deficiency.Materials and MethodsBlood samples of individuals from four malaria endemic countries (Mozambique, Angola, Equatorial Guinea and Sao Tome and Principe) were analyzed in order to determine PK deficiency occurrence and detect any possible high frequent PK variant mutation. The association between this mutation and malaria was ascertained through association studies involving sample groups from individuals showing different malaria infection and outcome status.ResultsThe percentage of individuals showing a reduced PK activity in Maputo was 4.1% and the missense mutation G829A (Glu277Lys) in the PKLR gene (only identified in three individuals worldwide to date) was identified in a high frequency. Heterozygous carrier frequency was between 6.7% and 2.6%. A significant association was not detected between either PK reduced activity or allele 829A frequency and malaria infection and outcome, although the variant was more frequent among individuals with uncomplicated malaria.ConclusionsThis was the first study on the occurrence of PK deficiency in several areas of Africa. A common PKLR mutation G829A (Glu277Lys) was identified. A global geographical co-distribution between malaria and high frequency of PK deficiency seems to occur suggesting that malaria may be a selective force raising the frequency of this 277Lys variant.

ObjectiveTo present the pregnancy results and interim birth results of a pragmatic randomised controlled trial comparing routine iron prophylaxis with screening and treatment for anaemia during pregnancy in a setting of endemic malaria and HIV.DesignA pragmatic randomised controlled trial.SettingTwo health centres (1° de Maio and Machava) in Maputo, Mozambique, a setting of endemic malaria and high prevalence of HIV.ParticipantsPregnant women (≥18-year-olds; non-high-risk pregnancy, n=4326) attending prenatal care consultation at the two health centres were recruited to the trial.InterventionsThe women were randomly allocated to either Routine iron (n=2184; 60 mg ferrous sulfate plus 400 μg of folic acid daily throughout pregnancy) or Selective iron (n=2142; screening and treatment for anaemia and daily intake of 1 mg of folic acid).Outcome measuresThe primary outcomes were preterm delivery (delivery <37 weeks of gestation) and low birth weight (<2500 g). The secondary outcomes were symptoms suggestive of malaria and self-reported malaria during pregnancy; birth length; caesarean section; maternal and child health status after delivery.ResultsThe number of follow-up visits was similar in the two groups. Between the first and fifth visits, the two groups were similar regarding the occurrence of fever, headache, cold/chills, nausea/vomiting and body aches. There was a suggestion of increased incidence of self-reported malaria during pregnancy (OR 1.37, 95% CI 0.98 to1.92) in the Routine iron group. Birth data were available for 1109 (51%) in the Routine iron group and for 1149 (54%) in the Selective iron group. The birth outcomes were relatively similar in the two groups. However, there was a suggestion (statistically non-significant) of poorer outcomes in the Routine iron group with regard to long hospital stay after birth (relative risk (RR) 1.43, 95% CI 0.97 to 1.26; risk difference (RD) 0.02, 95% CI −0.00 to 0.03) and unavailability of delivery data (RR 1.06, 95% CI 1.00 to 1.13; RD 0.03, 95% CI −0.01 to 0.07).ConclusionsThese interim results suggest that routine iron prophylaxis during pregnancy did not confer advantage over screening and treatment for anaemia regarding maternal and child health. Complete data on birth outcomes are being collected for firmer conclusions.Trial registrationThe trial is registered at ClinicalTrials.gov, number NCT00488579 (June 2007). The first women were randomised to the trial proper April 2007–March 2008. The pilot was November 2006–March 2008. The 3-month lag was due to technical difficulties in completing trial registration.

The effects of prophylactic iron during pregnancy on maternal and child health in developing settings with endemic malaria and high prevalence of HIV remain unclear. This paper describes the rationale, implementation and success of a pragmatic randomised controlled trial comparing routine iron supplementation vs. screening and treatment for anaemia during pregnancy. The setting was two health centres in Maputo, Mozambique. Pregnant women (≥ 12-week gestation; ≥ 18 years old; and not with a high-risk pregnancy, n=4326) were recruited. The main outcomes are preterm delivery and low birthweight. The women were randomly assigned to one of two iron administration policies: a routine iron group (n=2184) received 60 mg of ferrous sulphate plus 400 μg of folic acid daily while a selective iron group (n=2142) had screening and treatment for anaemia and a daily intake of 1 mg of folic acid. The recruitment, follow-up, and collection of follow-up data were successful; both groups were similar to each other in all the trial stages. Collection of delivery data was challenging and data on about 40% of births is missing. These are currently being traced through different hospitals and health centres. The compliance of the study personnel and the women with regard to regular measurement of haemoglobin and intake of the iron and folic acid tablets was high and similar in both trial arms. Taking into account the various constraints encountered, the stages of the present trial prior to delivery were carried out well.

Objective: Assessing the level of adherence and its determinants is important in appraising the overall effectiveness of trials. The present study aimed to evaluate the extent of adherence and its determinants in a pragmatic randomized controlled trial of Fe prophylaxis during pregnancy in Maputo, Mozambique. Design: A pragmatic randomized controlled trial. Setting: Two health centres (1 o de Maio and Machava) in Maputo, Mozambique. Subjects: Pregnant women (≥12 weeks' gestation, ≥18 years old, non-high-risk pregnancy; n 4326) attending prenatal care consultations at two health centres were randomized to receive routine Fe (n 2184; 60 mg ferrous sulfate plus 400 μg folic acid daily throughout pregnancy) or selective Fe (n 2142; screening and treatment for anaemia and daily intake of 1 mg folic acid). Results: The level of adherence was 79 % for having two or more visits, 53 % for adequate prenatal care and 67 % for complete intake of Fe/folic acid tablets during the trial. The correlation between the adherence measures ranged between 0·151 and 0·739. Adherence did not differ by trial arm, but there were centre differences in adequate prenatal visits and intake of tablets. Older women (>20 years) and those with a history of abortion were more likely to achieve greater adherence, whereas an increased number of previous births decreased the likelihood of adherence. HIV positivity decreased the likelihood of adherence in one trial centre and increased it in the other. Conclusions: The variation in adherence by trial centre, women's characteristics and outcome measures suggests that adherence in trials fully depends on participants' behaviour and can be increased by paying attention to contextual factors.

ObjectiveTo compare routine versus selective (ie, screening and treatment for anaemia) prenatal iron prophylaxis in a malaria-endemic and HIV-prevalent setting, an extended analysis including previously missing data.DesignA pragmatic randomised controlled clinical trial.Setting2 health centres in Maputo, Mozambique.ParticipantsPregnant women (≥18 years old; non-high-risk pregnancy) were randomly allocated to routine iron (n=2184) and selective iron (n=2142) groups.InterventionsIn the routine group, women received 60 mg ferrous sulfate plus 400 μg folic acid daily. In the selective group, women received 1 mg of folic acid daily and haemoglobin (Hb) screening at each visit; with low Hb (cut-off 9 g/dL) treatment (120 mg+800 μg of folic acid daily) for a month.Outcome measuresPrimary outcomes: preterm birth, low birth weight; secondary outcomes: self-reported malaria, labour complications, caesarean section, perinatal death, woman's death. Nurses collected pregnancy data. Birth data were abstracted from hospital records for 52% of women and traced using various methods and linked with probabilistic matching for 24%. Women's deaths were collected from death registers.ResultsBirth data were available for 3301 (76%) of the women. Outcomes were similar in the two groups: preterm births (27.1% in the selective vs 25.3% in the routine group), low birthweight infants (11.0% vs 11.7%), perinatal deaths (2.4% vs 2.4%) and caesarean sections (4.0% vs 4.5%). Women's deaths during pregnancy or <42 days postpartum were more common in the selective group (0.8% among the two best matched women) than in the routine group (0.4%). Extra deaths could not be explained by the cause of death, Hb level or HIV status at recruitment.ConclusionsBirth outcomes were similar in the two iron groups. There might have been more women's deaths in the selective iron group, but it is unclear whether this was due to the intervention, other factors or chance finding.Trial registration numberNCT00488579.

Pyruvate kinase (PK), encoded by the PKLR gene, is a key player in glycolysis controlling the integrity of erythrocytes. Due to Plasmodium selection, mutations for PK deficiency, which leads to hemolytic anemia, are associated with resistance to malaria in sub-Saharan Africa and with susceptibility to intracellular pathogens in experimental models. In this case-control study, we enrolled 4,555 individuals and investigated whether PKLR single nucleotide polymorphisms (SNPs) putatively selected for malaria resistance are associated with susceptibility to leprosy across Brazil (Manaus–North; Salvador–Northeast; Rondonópolis–Midwest and Rio de Janeiro–Southeast) and with tuberculosis in Mozambique. Haplotype T/G/G (rs1052176/rs4971072/rs11264359) was associated with leprosy susceptibility in Rio de Janeiro (OR = 2.46, p = 0.00001) and Salvador (OR = 1.57, p = 0.04), and with tuberculosis in Mozambique (OR = 1.52, p = 0.07). This haplotype downregulates PKLR expression in nerve and skin, accordingly to GTEx, and might subtly modulate ferritin and haptoglobin levels in serum. Furthermore, we observed genetic signatures of positive selection in the HCN3 gene (xpEHH>2 –recent selection) in Europe but not in Africa, involving 6 SNPs which are PKLR/HCN3 eQTLs. However, this evidence was not corroborated by the other tests (FST, Tajima’s D and iHS). Altogether, we provide evidence that a common PKLR locus in Africans contribute to mycobacterial susceptibility in African descent populations and also highlight, for first, PKLR as a susceptibility gene for leprosy and TB.

Malaria vector surveillance provides important data to inform the effective planning of vector control interventions at a local level. The aim of this study was to determine the species diversity and abundance, biting activity, and Plasmodium infectivity of Anopheles mosquitoes from a rural village in southern Mozambique. Human landing catches were performed monthly between December 2020 and August 2021. All collected Anopheles were identified to the species level and tested for the presence of malaria parasites. Eight Anopheles species were identified among the 1802 collected anophelines. Anopheles gambiae sensu lato (s.l.) were the most abundant (51.9%) and were represented by Anopheles quadriannulatus and Anopheles arabiensis. Anopheles funestus s.l. represented 4.5%. The biting activity of An. arabiensis was more pronounced early in the evening and outdoors, whereas that of An. funestus sensu stricto (s.s.) was more intense late in the night, with no significant differences in location. One An. funestus s.s. and one An. arabiensis, both collected outdoors, were infected with Plasmodium falciparum. The overall entomologic inoculation rate was estimated at 0.015 infective bites per person per night. The significant outdoor and early evening biting activity of An. arabiensis and An. funestus found in this village may negatively impact the effectiveness of current vector control interventions. Additional vector control tools that can target these mosquitoes are needed.

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