Antenatal care (ANC) is a key strategy to improve maternal and infant health. However, survey data from sub-Saharan Africa indicate that women often only initiate ANC after the first trimester and do ...not achieve the recommended number of ANC visits. Drawing on qualitative data, this article comparatively explores the factors that influence ANC attendance across four sub-Saharan African sites in three countries (Ghana, Kenya and Malawi) with varying levels of ANC attendance.
Data were collected as part of a programme of qualitative research investigating the social and cultural context of malaria in pregnancy. A range of methods was employed interviews, focus groups with diverse respondents and observations in local communities and health facilities.
Across the sites, women attended ANC at least once. However, their descriptions of ANC were often vague. General ideas about pregnancy care - checking the foetus' position or monitoring its progress - motivated women to attend ANC; as did, especially in Kenya, obtaining the ANC card to avoid reprimands from health workers. Women's timing of ANC initiation was influenced by reproductive concerns and pregnancy uncertainties, particularly during the first trimester, and how ANC services responded to this uncertainty; age, parity and the associated implications for pregnancy disclosure; interactions with healthcare workers, particularly messages about timing of ANC; and the cost of ANC, including charges levied for ANC procedures - in spite of policies of free ANC - combined with ideas about the compulsory nature of follow-up appointments.
In these socially and culturally diverse sites, the findings suggest that 'supply' side factors have an important influence on ANC attendance: the design of ANC and particularly how ANC deals with the needs and concerns of women during the first trimester has implications for timing of initiation.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In 2021, nearly half of the world's population lived at risk from malaria, with over 600 000 deaths annually, of which over 95% occur in the WHO African region and 80% of these in children younger ...than 5 years.1 WHO recommends several preventive and curative interventions that, when used together, can greatly reduce malaria illness and death, including effective vector control, chemoprevention, and prompt diagnosis and treatment, and since October, 2021 malaria vaccines, the first of which is RTS,S/AS01.2 Malaria, specifically Plasmodium falciparum, is the first human parasite for which vaccination has proved possible. R21/Matrix-M is formulated with a saponin-based adjuvant, Matrix-M, which is distinct from the AS01 adjuvant of RTS,S. In the phase 3 trial4 of R21/Matrix-M reported in The Lancet, 5477 children aged 5–36 months in five sites in four sub-Saharan African countries were to be screened; 4878 children received the first dose of vaccine and 3103 children in the R21/Matrix-M group and 1541 children in the control group were included in the modified per-protocol analysis (2412 51·9% were male and 2232 48·1% were female; mean age 19 SD 9·0 months). The malaria vaccine community also has the benefit of a strategic framework in the form of the malaria vaccine technology roadmap, and agreement on the priority use cases, and preferred product characteristics for these use cases.10 WHO prioritises the use of malaria vaccines in moderate-to-high transmission settings because this is where the impact will be greatest.2 In these areas, it will be important to ensure that the malaria vaccines are integrated into the existing package of WHO-recommended high-impact measures for malaria control.
Summary Background The RTS,S/AS01 malaria vaccine targets the circumsporozoite protein, inducing antibodies associated with the prevention of Plasmodium falciparum infection. We assessed the ...association between anti-circumsporozoite antibody titres and the magnitude and duration of vaccine efficacy using data from a phase 3 trial done between 2009 and 2014. Methods Using data from 8922 African children aged 5–17 months and 6537 African infants aged 6–12 weeks at first vaccination, we analysed the determinants of immunogenicity after RTS,S/AS01 vaccination with or without a booster dose. We assessed the association between the incidence of clinical malaria and anti-circumsporozoite antibody titres using a model of anti-circumsporozoite antibody dynamics and the natural acquisition of protective immunity over time. Findings RTS,S/AS01-induced anti-circumsporozoite antibody titres were greater in children aged 5–17 months than in those aged 6–12 weeks. Pre-vaccination anti-circumsporozoite titres were associated with lower immunogenicity in children aged 6–12 weeks and higher immunogenicity in those aged 5–17 months. The immunogenicity of the booster dose was strongly associated with immunogenicity after primary vaccination. Anti-circumsporozoite titres wane according to a biphasic exponential distribution. In participants aged 5–17 months, the half-life of the short-lived component of the antibody response was 45 days (95% credible interval 42–48) and that of the long-lived component was 591 days (557–632). After primary vaccination 12% (11–13) of the response was estimated to be long-lived, rising to 30% (28–32%) after a booster dose. An anti-circumsporozoite antibody titre of 121 EU/mL (98–153) was estimated to prevent 50% of infections. Waning anti-circumsporozoite antibody titres predict the duration of efficacy against clinical malaria across different age categories and transmission intensities, and efficacy wanes more rapidly at higher transmission intensity. Interpretation Anti-circumsporozoite antibody titres are a surrogate of protection for the magnitude and duration of RTS,S/AS01 efficacy, with or without a booster dose, providing a valuable surrogate of effectiveness for new RTS,S formulations in the age groups considered. Funding UK Medical Research Council.
High coverage of insecticide-treated bed nets in Asembo and low coverage in Seme, two adjacent communities in western Nyanza Province, Kenya; followed by expanded coverage of bed nets in Seme, as the ...Kenya national malaria programme rolled out; provided a natural experiment for quantification of changes in relative abundance of two primary malaria vectors in this holoendemic region. Both belong to the Anopheles gambiae sensu lato (s.l.) species complex, namely A. gambiae sensu stricto (s.s.) and Anopheles arabiensis. Historically, the former species was proportionately dominant in indoor resting collections of females.
Data of the relative abundance of adult A. gambiae s.s. and A. arabiensis sampled from inside houses were obtained from the literature from 1970 to 2002 for sites west of Kisumu, Kenya, to the region of Asembo ca. 50 km from the city. A sampling transect was established from Asembo (where bed net use was high due to presence of a managed bed net distribution programme) eastward to Seme, where no bed net programme was in place. Adults of A. gambiae s.l. were sampled from inside houses along the transect from 2003 to 2009, as were larvae from nearby aquatic habitats, providing data over a nearly 40 year period of the relative abundance of the two species. Relative proportions of A. gambiae s.s. and A. arabiensis were determined for each stage by identifying species by the polymerase chain reaction method. Household bed net ownership was measured with surveys during mosquito collections. Data of blood host choice, parity rate, and infection rate for Plasmodium falciparum in A. gambiae s.s. and A. arabiensis were obtained for a sample from Asembo and Seme from 2005.
Anopheles gambiae s.s. adult females from indoor collections predominated from 1970 to 1998 (ca. 85%). Beginning in 1999, A. gambiae s.s decreased proportionately relative to A. arabiensis, then precipitously declined to rarity coincident with increased bed net ownership as national bed net distribution programmes commenced in 2004 and 2006. By 2009, A. gambiae s.s. comprised proportionately ca. 1% of indoor collections and A. arabiensis 99%. In Seme compared to Asembo in 2003, proportionately more larvae were A. gambiae s.s., larval density was higher, and more larval habitats were occupied. As bed net use rose in Seme, the proportion of A. gambiae larvae declined as well. These trends continued to 2009. Parity and malaria infection rates were lower in both species in Asembo (high bed net use) compared to Seme (low bed net use), but host choice did not vary within species in both communities (predominantly cattle for A. arabiensis, humans for A. gambiae s.s.).
A marked decline of the A. gambiae s.s. population occurred as household ownership of bed nets rose in a region of western Kenya over a 10 year period. The increased bed net coverage likely caused a mass effect on the composition of the A. gambiae s.l. species complex, resulting in the observed proportionate increase in A. arabiensis compared to its closely related sibling species, A. gambiae s.s. These observations are important in evaluating the process of regional malaria elimination, which requires sustained vector control as a primary intervention.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Insecticide treated nets (ITNs) and indoor residual spraying (IRS) have been scaled up for malaria prevention in sub-Saharan Africa. However, there are few studies on the benefit of implementing IRS ...in areas with moderate to high coverage of ITNs. We evaluated the impact of an IRS program on malaria related outcomes in western Kenya, an area of intense perennial malaria transmission and moderate ITN coverage (55-65% use of any net the previous night).
The Kenya Division of Malaria Control, with support from the US President's Malaria Initiative, conducted IRS in one lowland endemic district with moderate coverage of ITNs. Surveys were conducted in the IRS district and a neighboring district before IRS, after one round of IRS in July-Sept 2008 and after a second round of IRS in April-May 2009. IRS was conducted with pyrethroid insecticides. At each survey, 30 clusters were selected for sampling and within each cluster, 12 compounds were randomly selected. The primary outcomes measured in all residents of selected compounds included malaria parasitemia, clinical malaria (P. falciparum infection plus history of fever) and anemia (Hb<8) of all residents in randomly selected compounds. At each survey round, individuals from the IRS district were matched to those from the non-IRS district using propensity scores and multivariate logistic regression models were constructed based on the matched dataset.
At baseline and after one round of IRS, there were no differences between the two districts in the prevalence of malaria parasitemia, clinical malaria or anemia. After two rounds of IRS, the prevalence of malaria parasitemia was 6.4% in the IRS district compared to 16.7% in the comparison district (OR = 0.36, 95% CI = 0.22-0.59, p<0.001). The prevalence of clinical malaria was also lower in the IRS district (1.8% vs. 4.9%, OR = 0.37, 95% CI = 0.20-0.68, p = 0.001). The prevalence of anemia was lower in the IRS district but only in children under 5 years of age (2.8% vs. 9.3%, OR = 0.30, 95% CI = 0.13-0.71, p = 0.006). Multivariate models incorporating both IRS and ITNs indicated that both had an impact on malaria parasitemia and clinical malaria but the independent effect of ITNs was reduced in the district that had received two rounds of IRS. There was no statistically significant independent effect of ITNs on the prevalence of anemia in any age group.
Both IRS and ITNs are effective tools for reducing malaria burden and when implemented in an area of moderate to high transmission with moderate ITN coverage, there may be an added benefit of IRS. The value of adding ITNs to IRS is less clear as their benefits may be masked by IRS. Additional monitoring of malaria control programs that implement ITNs and IRS concurrently is encouraged to better understand how to maximize the benefits of both interventions, particularly in the context of increasing pyrethroid resistance.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Coverage of malaria in pregnancy interventions in sub-Saharan Africa is suboptimal. We undertook a systematic examination of the operational, socio-economic and cultural constraints to pregnant ...women's access to intermittent preventive treatment (IPTp), long-lasting insecticide-treated nets (LLINs) and case management in Kenya and Mali to provide empirical evidence for strategies to improve coverage.
Focus group discussions (FGDs) were held as part of a programme of research to explore the delivery, access and use of interventions to control malaria in pregnancy. FGDs were held with four sub-groups: non-pregnant women of child bearing age (aged 15-49 years), pregnant women or mothers of children aged <1 year, adolescent women, and men. Content analysis was used to develop themes and sub-themes from the data.
Women and men's perceptions of the benefits of antenatal care were generally positive; motivation among women consisted of maintaining a healthy pregnancy, disease prevention in mother and foetus, checking the position of the baby in preparation for delivery, and ensuring admission to a facility in case of complications. Barriers to accessing care related to the quality of the health provider-client interaction, perceived health provider skills and malpractice, drug availability, and cost of services. Pregnant women perceived themselves and their babies at particular risk from malaria, and valued diagnosis and treatment from a health professional, but cost of treatment at health facilities drove women to use herbal remedies or drugs bought from shops. Women lacked information on the safety, efficacy and side effects of antimalarial use in pregnancy.
Women in these settings appreciated the benefits of antenatal care and yet health services in both countries are losing women to follow-up due to factors that can be improved with greater political will. Antenatal services need to be patient-centred, free-of-charge or highly affordable and accountable to the women they serve.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Malaria in pregnancy can have devastating consequences for mother and baby. Coverage with the WHO prevention strategy for sub-Saharan Africa of intermittent-preventive-treatment (IPTp) with two doses ...of sulphadoxine-pyrimethamine (SP) and insecticide-treated-nets (ITNs) in pregnancy is low. We analysed household survey data to evaluate the effectiveness of antenatal clinics (ANC) to deliver IPTp and ITNs to pregnant women in Nyando district, Kenya.
We assessed the systems effectiveness of ANC to deliver IPTp and ITNs to pregnant women and the impact on low birthweight (LBW). Logistic regression was used to identify predictors of receipt of IPTp and ITN use during pregnancy.
Among 89% of recently pregnant women who attended ANC at least once between 4-9 months gestation, 59% reported receiving one dose of SP and 90% attended ANC again, of whom 57% received a second dose, resulting in a cumulative effectiveness for IPTp of 27%, most of whom used an ITN (96%). Overall ITN use was 89%, and ANC the main source (76%). Women were less likely to receive IPTp if they had low malaria knowledge (0.26, 95% CI 0.08-0.83), had a child who had died (OR 0.36, 95% CI 0.14-0.95), or if they first attended ANC late (OR 0.20, 95% CI 0.06-0.67). Women who experienced side effects to SP (OR 0.18, CI 0.03-0.90) or had low malaria knowledge (OR 0.78, 95% CI 0.11-5.43) were less likely to receive IPTp by directly observed therapy. Ineffective delivery of IPTp reduced its potential impact by 231 LBW cases averted (95% CI 64-359) per 10,000 pregnant women.
IPTp presents greater challenges to deliver through ANC than ITNs in this setting. The reduction in public health impact on LBW resulting from ineffective delivery of IPTp is estimated to be substantial. Urgent efforts are required to improve service delivery of this important intervention.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Malaria vector control in Africa depends upon effective insecticides in bed nets and indoor residual sprays. This study investigated the extent of insecticide resistance in Anopheles gambiae s.l., ...Anopheles gambiae s.s. and Anopheles arabiensis in western Kenya where ownership of insecticide-treated bed nets has risen steadily from the late 1990s to 2010. Temporal and spatial variation in the frequency of a knock down resistance (kdr) allele in A. gambiae s.s. was quantified, as was variation in phenotypic resistance among geographic populations of A. gambiae s.l.
To investigate temporal variation in kdr frequency, individual specimens of A. gambiae s.s. from two sentinel sites were genotyped using RT-PCR from 1996-2010. Spatial variation in kdr frequency, species composition, and resistance status were investigated in additional populations of A. gambiae s.l. sampled in western Kenya in 2009 and 2010. Specimens were genotyped for kdr as above and identified to species via conventional PCR. Field-collected larvae were reared to adulthood and tested for insecticide resistance using WHO bioassays.
Anopheles gambiae s.s. showed a dramatic increase in kdr frequency from 1996 - 2010, coincident with the scale up of insecticide-treated nets. By 2009-2010, the kdr L1014S allele was nearly fixed in the A. gambiae s.s. population, but was absent in A. arabiensis. Near Lake Victoria, A. arabiensis was dominant in samples, while at sites north of the lake A. gambiae s.s was more common but declined relative to A. arabiensis from 2009 to 2010. Bioassays demonstrated that A. gambiae s.s. had moderate phenotypic levels of resistance to DDT, permethrin and deltamethrin while A. arabiensis was susceptible to all insecticides tested.
The kdr L1014S allele has approached fixation in A. gambiae s.s. populations of western Kenya, and these same populations exhibit varying degrees of phenotypic resistance to DDT and pyrethroid insecticides. The near absence of A. gambiae s.s. from populations along the lakeshore and the apparent decline in other populations suggest that insecticide-treated nets remain effective against this mosquito despite the increase in kdr allele frequency. The persistence of A. arabiensis, despite little or no detectable insecticide resistance, is likely due to behavioural traits such as outdoor feeding and/or feeding on non-human hosts by which this species avoids interaction with insecticide-treated nets.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Ebola: the hidden toll Hamel, Mary J; Slutsker, Laurence
The Lancet infectious diseases,
07/2015, Letnik:
15, Številka:
7
Journal Article
Recenzirano
Odprti dostop
During the past decade, renewed commitment from donors, ministries of health, and international agencies has led to the scale-up of malaria interventions across sub-Saharan Africa, with a ...corresponding reduction in child malaria mortality of 50%.2 The continuous delivery of those life-saving interventions--prompt effective treatment, routine distribution of insecticide-treated bednets, indoor residual spraying, and intermittent preventive treatment of malaria in pregnancy--depends on a reliable, functioning health-care system. An effort in Sierra Leone resulted in successful mass drug administration for more than 2 million people.3 Until service delivery systems are restored, these extraordinary measures, delivered after careful planning and with due attention to safety, are warranted. Because quality routine surveillance data are not available, it is primarily through modelling that the broader indirect health effects of the Ebola epidemic (in this case malaria) can be understood.
Pregnancy-related (PR) deaths are often a result of direct obstetric complications occurring at childbirth.
To estimate the burden of and characterize risk factors for PR mortality, we evaluated ...deaths that occurred between 2003 and 2008 among women of childbearing age (15 to 49 years) using Health and Demographic Surveillance System data in rural western Kenya. WHO ICD definition of PR mortality was used: "the death of a woman while pregnant or within 42 days of termination of pregnancy, irrespective of the cause of death". In addition, symptoms and events at the time of death were examined using the WHO verbal autopsy methodology. Deaths were categorized as either (i) directly PR: main cause of death was ascribed as obstetric, or (ii) indirectly PR: main cause of death was non-obstetric. Of 3,223 deaths in women 15 to 49 years, 249 (7.7%) were PR. One-third (34%) of these were due to direct obstetric causes, predominantly postpartum hemorrhage, abortion complications and puerperal sepsis. Two-thirds were indirect; three-quarters were attributable to human immunodeficiency virus (HIV/AIDS), malaria and tuberculosis. Significantly more women who died in lower socio-economic groups sought care from traditional birth attendants (p = 0.034), while less impoverished women were more likely to seek hospital care (p = 0.001). The PR mortality ratio over the six years was 740 (95% CI 651-838) per 100,000 live births, with no evidence of reduction over time (χ(2) linear trend = 1.07; p = 0.3).
These data supplement current scanty information on the relationship between infectious diseases and poor maternal outcomes in Africa. They indicate low uptake of maternal health interventions in women dying during pregnancy and postpartum, suggesting improved access to and increased uptake of skilled obstetric care, as well as preventive measures against HIV/AIDS, malaria and tuberculosis among all women of childbearing age may help to reduce pregnancy-related mortality.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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