Malarial Infection and Curable Sexually Transmitted and Reproductive Tract Infections Among Pregnant Women in a Rural District of Zambia.

Malarial infection and curable sexually transmitted and reproductive tract infections (STIs/RTIs) are important causes of adverse birth outcomes. Reducing the burden of these infections in pregnancy requires interventions that can be easily integrated into the antenatal care (ANC) package. However, efforts to integrate the control of malarial infection and curable STIs/RTIs in pregnancy have been hampered by a lack of evidence related to their coinfection. Thus, we investigated the prevalence of coinfection among pregnant women of rural Zambia. A prospective cohort study was conducted in Nchelenge District, Zambia, involving 1,086 first ANC attendees. We screened participants for peripheral malarial infection and curable STIs/RTIs (syphilis, Chlamydia, gonorrhea, trichomoniasis, and bacterial vaginosis), and collected relevant sociodemographic data at booking. Factors associated with malarial and STI/RTI coinfection were explored using univariate and multivariate regression models. Among participants with complete results (N = 1,071), 38.7% (95% confidence interval [CI] = 35.7-41.6) were coinfected with malaria parasites and at least one STI/RTI; 18.9% (95% CI = 16.5-21.2) were infected with malaria parasites only; 26.0% (95% CI = 23.5-28.8) were infected with at least one STI/RTI but no malaria parasites, and 16.4% (95% CI = 14.1-18.6) had no infection. Human immunodeficiency virus (HIV)-infected women had a higher risk of being coinfected than HIV-uninfected women (odds ratio [OR] = 3.59 [95% CI = 1.73-7.48], P < 0.001). The prevalence of malarial and STI/RTI coinfection was high in this population. An integrated approach to control malarial infection and STIs/RTIs is needed to reduce this dual burden in pregnancy

Combining malaria vaccination with chemoprevention: a promising new approach to malaria control.

Malaria control has stalled in a number of African countries and novel approaches to malaria control are needed for these areas. The encouraging results of a recent trial conducted in young children in Burkina Faso and Mali in which a combination of the RTS,S/AS01E malaria vaccine and seasonal malaria chemoprevention led to a substantial reduction in clinical cases of malaria, severe malaria, and malaria deaths compared with the administration of either intervention given alone suggests that there may be other epidemiological/clinical situations in which a combination of malaria vaccination and chemoprevention could be beneficial. Some of these potential opportunities are considered in this paper. These include combining vaccination with intermittent preventive treatment of malaria in infants, with intermittent preventive treatment of malaria in pregnancy (through vaccination of women of child-bearing age before or during pregnancy), or with post-discharge malaria chemoprevention in the management of children recently admitted to hospital with severe anaemia. Other potential uses of the combination are prevention of malaria in children at particular risk from the adverse effects of clinical malaria, such as those with sickle cell disease, and during the final stages of a malaria elimination programme when vaccination could be combined with repeated rounds of mass drug administration. The combination of a pre-erythrocytic stage malaria vaccine with an effective chemopreventive regimen could make a valuable contribution to malaria control and elimination in a variety of clinical or epidemiological situations, and the potential of this approach to malaria control needs to be explored

Safety and efficacy of dihydroartemisinin-piperaquine versus artemether-lumefantrine in the treatment of uncomplicated Plasmodium falciparum malaria in Zambian children

<p>Abstract</p> <p>Background</p> <p>Malaria in Zambia remains a public health and developmental challenge, affecting mostly children under five and pregnant women. In 2002, the first-line treatment for uncomplicated malaria was changed to artemether-lumefantrine (AL) that has proved to be highly efficacious against multidrug resistant <it>Plasmodium falciparum</it>.</p> <p>Objective</p> <p>The study objective was to determine whether dihydroartemisinin-piperaquine (DHA/PQP) had similar efficacy, safety and tolerability as AL for the treatment of children with uncomplicated <it>P. falciparum </it>malaria in Ndola, Zambia.</p> <p>Methods</p> <p>Between 2005 and 2006, 304 children (6-59 months old) with uncomplicated <it>P. falciparum </it>were enrolled, randomized to AL (101) or DHA/PQP (203) and followed up for 42 days. Outcome of treatment was defined according to the standard WHO classification, i.e. early treatment failure (ETF), late clinical failure (LCF, late parasitological failure (LPF) and adequate clinical and parasitological response (ACPR). Recurrent infections were genotyped to distinguish between recrudescence and new infection.</p> <p>Results</p> <p>No ETF was observed. At day 28, PCR-uncorrected ACPR was 92% in the DHA/PQP and 74% in the AL arm (OR: 4.05; 95%CI: 1.89-8.74; p < 0.001). Most failure were new infections and PCR-corrected ACPR was similar in the two study arms (OR: 0.69; 95%CI: 0.22-2.26; p = 0.33). Similar results were observed for day 42, i.e. higher PCR-uncorrected ACPR for DHA/PQP, mainly due to the difference observed up to day 28, while the PCR-corrected ACPR was similar: DHA/PQP: 93% (179/192), AL: 93% (84/90), (OR: 0.92; 95%CI: 0.30-2.64; p = 0.85). Except for cough, more frequent in the DHA/PQP arm (p = 0.04), there were no differences between treatment arms in the occurrence of adverse events. Two serious adverse events were probably associated to AL treatment.</p> <p>Conclusion</p> <p>DHA/PQP was as efficacious, safe and well tolerated in treatment of uncomplicated malaria as AL, though in the latter group more new infections during the follow up were observed. DHA/PQP seems a potential candidate to be used as an alternative first-line or rescue treatment in Zambia.</p> <p>Trial Registration</p> <p><a href="http://www.controlled-trials.com/ISRCTN16263443">ISRCTN16263443</a>, at <url>http://www.controlled-trials.com/isrctn</url></p

Gradual emergence followed by exponential spread of the SARS-CoV-2 Omicron variant in Africa.

The geographic and evolutionary origins of the SARS-CoV-2 Omicron variant (BA.1), which was first detected mid-November 2021 in Southern Africa, remain unknown. We tested 13,097 COVID-19 patients sampled between mid-2021 to early 2022 from 22 African countries for BA.1 by real-time RT-PCR. By November-December 2021, BA.1 had replaced the Delta variant in all African sub-regions following a South-North gradient, with a peak Rt of 4.1. Polymerase chain reaction and near-full genome sequencing data revealed genetically diverse Omicron ancestors already existed across Africa by August 2021. Mutations, altering viral tropism, replication and immune escape, gradually accumulated in the spike gene. Omicron ancestors were therefore present in several African countries months before Omicron dominated transmission. These data also indicate that travel bans are ineffective in the face of undetected and widespread infection

Retraction.

This is a retraction of 'Gradual emergence followed by exponential spread of the SARS-CoV-2 Omicron variant in Africa' 10.1126/science.add873

Predictive Malaria Risk and Uncertainty Mapping in Nchelenge District, Zambia: Evidence of Widespread, Persistent Risk and Implications for Targeted Interventions

Abstract. Malaria risk maps may be used to guide policy decisions on whether vector control interventions should be targeted and, if so, where. Active surveillance for malaria was conducted through household surveys in Nchelenge District, Zambia from April 2012 through December 2014. Households were enumerated based on satellite imagery and randomly selected for study enrollment. At each visit, participants were administered a questionnaire and a malaria rapid diagnostic test (RDT). Logistic regression models were used to construct spatial prediction risk maps and maps of risk uncertainty. A total of 461 households were visited, comprising 1,725 participants, of whom 48% were RDT positive. Several environmental features were associated with increased household malaria risk in a multivariable logistic regression model adjusting for seasonal variation. The model was validated using both internal and external evaluation measures to generate and assess root mean square error, as well as sensitivity and specificity for predicted risk. The final, validated model was used to predict and map malaria risk including a measure of risk uncertainty. Malaria risk in a high, perennial transmission setting is widespread but heterogeneous at a local scale, with seasonal variation. Targeting malaria control interventions may not be appropriate in this epidemiological setting

Individual and Household Level Risk Factors Associated with Malaria in Nchelenge District, a Region with Perennial Transmission: A Serial Cross-Sectional Study from 2012 to 2015.

BACKGROUND:The scale-up of malaria control interventions has resulted in substantial declines in transmission in some but not all regions of sub-Saharan Africa. Understanding factors associated with persistent malaria transmission despite control efforts may guide targeted interventions to high-risk areas and populations. METHODS:Household malaria surveys were conducted in Nchelenge District, Luapula Province, in northern Zambia. Structures that appeared to be households were enumerated from a high-resolution satellite image and randomly sampled for enrollment. Households were enrolled into cross-sectional (single visit) or longitudinal (visits every other month) cohorts but analyses were restricted to cross-sectional visits and the first visit to longitudinal households. During study visits, a questionnaire was administered to adults and caretakers of children and a blood sample was collected for a malaria rapid diagnostic test (RDT) from all household residents. Characteristics associated with RDT positivity were analyzed using multi-level models. RESULTS:A total of 2,486 individuals residing within 742 households were enrolled between April 2012 and July 2015. Over this period, 51% of participants were RDT positive. Forty-three percent of all RDT positive individuals were between the ages of 5 and 17 years although this age group comprised only 30% of study participants. In a multivariable model, the odds being RDT positive were highest in 5-17 year olds and did not vary by season. Children 5-17 years of age had 8.83 higher odds of being RDT positive compared with those >18 years of age (95% CI: 6.13, 12.71); there was an interaction between age and report of symptoms, with an almost 50% increased odds of report of symptoms with decreasing age category (OR = 1.49; 95% CI 1.11, 2.00). CONCLUSIONS:Children and adolescents between the ages of 5 and 17 were at the highest risk of malaria infection throughout the year. School-based programs may be effective at targeting this high-risk group

Percent of enrolled participants who were RDT positive per month in Nchelenge District, Zambia from April 2012 to July 2015.

<p>Percent of enrolled participants who were RDT positive per month in Nchelenge District, Zambia from April 2012 to July 2015.</p