Seroprevalence and Parasite Rates of Plasmodium malariae in a High Malaria Transmission Setting of Southern Nigeria.

Although Plasmodium falciparum continues to be the main target for malaria elimination, other Plasmodium species persist in Africa. Their clinical diagnosis is uncommon, whereas rapid diagnostic tests (RDTs), the most widely used malaria diagnostic tools, are only able to distinguish between P. falciparum and non-falciparum species, the latter as "pan-species." Blood samples from health facilities were collected in southern Nigeria (Lagos and Calabar) in 2017 (October-December) and Calabar only in 2018 (October-November), and analyzed by several methods, namely, microscopy, quantitative real-time PCR (qPCR), and peptide serology targeting candidate antigens (Plasmodium malariae apical membrane antigen, P. malariae lactose dehydrogenase, and P. malariae circumsporozoite surface protein). Both microscopy and qPCR diagnostic approaches detected comparable proportions (∼80%) of all RDT-positive samples infected with the dominant P. falciparum malaria parasite. However, higher proportions of non-falciparum species were detected by qPCR than microscopy, 10% against 3% infections for P. malariae and 3% against 0% for Plasmodium ovale, respectively. No Plasmodium vivax infection was detected. Infection rates for P. malariae varied between age-groups, with the highest rates in individuals aged > 5 years. Plasmodium malariae-specific seroprevalence rates fluctuated in those aged < 10 years but generally reached the peak around 20 years of age for all peptides. The heterogeneity and rates of these non-falciparum species call for increased specific diagnosis and targeting by elimination strategies

Malariometric indices among Nigerian children in a rural setting

Malaria contributes to high childhood morbidity and mortality in Nigeria. To determine its endemicity in a rural farming community in the south-south of Nigeria, the following malariometric indices, namely, malaria parasitaemia, spleen rates, and anaemia were evaluated in children aged 2-10 years. This was a descriptive cross-sectional survey among school-age children residing in a rubber plantation settlement. The children were selected from six primary schools using a multistaged stratified cluster sampling technique. They were all examined for pallor, enlarged spleen, or liver among other clinical parameters and had blood films for malaria parasites. Of the 461 children recruited, 329 (71.4%) had malaria parasites. The prevalence of malaria parasitaemia was slightly higher in the under fives than that of those ≥5 years, 76.2% and 70.3%, respectively. Splenic enlargement was present in 133 children (28.9%). The overall prevalence of anaemia was 35.7%. Anaemia was more common in the under-fives (48.8%) than in those ≥5 years (32.8%). The odds of anaemia in the under fives were significantly higher than the odds of those ≥5 years (OR = 1.95 [1.19-3.18]). Malaria is highly endemic in this farming community and calls for intensification of control interventions in the area with special attention to school-age children

Antioxidant supplementation for sickle cell disease.

Background Sickle cell disease (SCD) refers to a group of genetic disorders characterized by the presence of an abnormal haemoglobin molecule called haemoglobin S (HbS). When subjected to oxidative stress from low oxygen concentrations, HbS molecules form rigid polymers, giving the red cell the typical sickle shape. Antioxidants have been shown to reduce oxidative stress and improve outcomes in other diseases associated with oxidative stress. Therefore, it is important to review and synthesize the available evidence on the effect of antioxidants on the clinical outcomes of people with SCD. Objectives To assess the effectiveness and safety of antioxidant supplementation for improving health outcomes in people with SCD. Search methods We used standard, extensive Cochrane search methods. The latest search date was 15 August 2023. Selection criteria We included randomized and quasi‐randomized controlled trials comparing antioxidant supplementation to placebo, other antioxidants, or different doses of antioxidants, in people with SCD. Data collection and analysis Two authors independently extracted data, assessed the risk of bias and certainty of the evidence, and reported according to Cochrane methodological procedures. Main results The review included 1609 participants in 26 studies, with 17 comparisons. We rated 13 studies as having a high risk of bias overall, and 13 studies as having an unclear risk of bias overall due to study limitations. We used GRADE to rate the certainty of evidence. Only eight studies reported on our important outcomes at six months. Vitamin C (1400 mg) plus vitamin E (800 mg) versus placebo Based on evidence from one study in 83 participants, vitamin C (1400 mg) plus vitamin E (800 mg) may not be better than placebo at reducing the frequency of crisis (risk ratio (RR) 1.18, 95% confidence interval (CI) 0.64 to 2.18), the severity of pain (RR 1.33, 95% CI 0.40 to 4.37), or adverse effects (AE), of which the most common were headache, nausea, fatigue, diarrhoea, and epigastric pain (RR 0.56, 95% CI 0.31 to 1.00). Vitamin C plus vitamin E may increase the risk of SCD‐related complications (acute chest syndrome: RR 2.66, 95% CI 0.77 to 9.13; 1 study, 83 participants), and increase haemoglobin level (median (interquartile range) 90 (81 to 96) g/L versus 93.5 (84 to 105) g/L) (1 study, 83 participants) compared to placebo. However, the evidence for all the above effects is very uncertain. The study did not report on quality of life (QoL) of participants and their caregivers, nor on frequency of hospitalization. Zinc versus placebo Zinc may not be better than placebo at reducing the frequency of crisis at six months (rate ratio 0.62, 95% CI 0.17 to 2.29; 1 study, 36 participants; low‐certainty evidence). We are uncertain whether zinc is better than placebo at improving sickle cell‐related complications (complete healing of leg ulcers at six months: RR 2.00, 95% CI 0.60 to 6.72; 1 study, 34 participants; very low‐certainty evidence). Zinc may be better than placebo at increasing haemoglobin level (g/dL) (MD 1.26, 95% CI 0.44 to 1.26; 1 study, 36 participants; low‐certainty evidence). The study did not report on severity of pain, QoL, AE, and frequency of hospitalization. N‐acetylcysteine versus placebo N‐acetylcysteine (NAC) 1200 mg may not be better than placebo at reducing the frequency of crisis in SCD, reported as pain days (rate ratio 0.99 days, 95% CI 0.53 to 1.84; 1 study, 96 participants; low‐certainty evidence). Low‐certainty evidence from one study (96 participants) suggests NAC (1200 mg) may not be better than placebo at reducing the severity of pain (MD 0.17, 95% CI ‐0.53 to 0.87). Compared to placebo, NAC (1200 mg) may not be better at improving physical QoL (MD ‐1.80, 95% CI ‐5.01 to 1.41) and mental QoL (MD 2.00, 95% CI ‐1.45 to 5.45; very low‐certainty evidence), reducing the risk of adverse effects (gastrointestinal complaints, pruritus, or rash) (RR 0.92, 95% CI 0.75 to 1.14; low‐certainty evidence), reducing the frequency of hospitalizations (rate ratio 0.98, 95% CI 0.41 to 2.38; low‐certainty evidence), and sickle cell‐related complications (RR 5.00, 95% CI 0.25 to 101.48; very low‐certainty evidence), or increasing haemoglobin level (MD ‐0.18 g/dL, 95% CI ‐0.40 to 0.04; low‐certainty evidence). L‐arginine versus placebo L‐arginine may not be better than placebo at reducing the frequency of crisis (monthly pain) (RR 0.71, 95% CI 0.26 to 1.95; 1 study, 50 participants; low‐certainty evidence). However, L‐arginine may be better than placebo at reducing the severity of pain (MD ‐1.41, 95% CI ‐1.65 to ‐1.18; 2 studies, 125 participants; low‐certainty evidence). One participant allocated to L‐arginine developed hives during infusion of L‐arginine, another experienced acute clinical deterioration, and a participant in the placebo group had clinically relevant increases in liver function enzymes. The evidence is very uncertain whether L‐arginine is better at reducing the mean number of days in hospital compared to placebo (MD ‐0.85 days, 95% CI ‐1.87 to 0.17; 2 studies, 125 participants; very low‐certainty evidence). Also, L‐arginine may not be better than placebo at increasing haemoglobin level (MD 0.4 g/dL, 95% CI ‐0.50 to 1.3; 2 studies, 106 participants; low‐certainty evidence). No study in this comparison reported on QoL and sickle cell‐related complications. Omega‐3 versus placebo Very low‐certainty evidence shows no evidence of a difference in the risk of adverse effects of omega‐3 compared to placebo (RR 1.05, 95% CI 0.74 to 1.48; 1 study, 67 participants). Very low‐certainty evidence suggests that omega‐3 may not be better than placebo at increasing haemoglobin level (MD 0.36 g/L, 95% CI ‐0.21 to 0.93; 1 study, 67 participants). The study did not report on frequency of crisis, severity of pain, QoL, frequency of hospitalization, and sickle cell‐related complications. Authors' conclusions There was inconsistent evidence on all outcomes to draw conclusions on the beneficial and harmful effects of antioxidants. However, L‐arginine may be better than placebo at reducing the severity of pain at six months, and zinc may be better than placebo at increasing haemoglobin level. We are uncertain whether other antioxidants are beneficial for SCD. Larger studies conducted on each comparison would reduce the current uncertainties

Congenital Malaria in Calabar, Nigeria: The Molecular Perspective

Polymerase chain reaction (PCR) has been shown to be more sensitive in detecting low-level parasitemia than conventional blood film microscopy. We estimated the prevalence of congenital malaria using nested PCR amplification of the small subunit 18S RNA gene to detect low-level parasitemia and identify Plasmodium species in 204 mother–neonate pairs. Cord-blood parasitemia was detected in four babies by PCR, giving a prevalence of 2.0%. The newborns of primidgravidae were more susceptible to congenital malaria than those of multigravidae (P < 0.0001). There was a strong correlation between placental malaria and congenital malaria (odds ratio = 10.1, 95% confidence interval = 1.3–76.1, P = 0.0487). We conclude that the prevalence of congenital malaria in Calabar detected by PCR is lower than has been reported in this environment through microscopy