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Infection and Immunity, Ahead of Print. …

Infection and Immunity, Ahead of Print. …

Infection and Immunity, Ahead of Print. …

Antimicrobial Agents and Chemotherapy, Ahead of Print. …

Abstract

The non-endemic monkeypox outbreak in 2022 is the largest outside of Africa in recorded history. The assumption is that monkeypox, an emerging zoonotic disease, has a high potential for epidemic spread with increased human outbreaks in recent years. The vaccinia-based smallpox vaccination has been discontinued globally for more than 40 years. Additionally, there are now more vulnerable populations. Populations who have not received the vaccine are more susceptible to monkeypox viral infection, while smallpox cannot spontaneously recur. As a member of the orthopoxvirus family and because of its potential for rapid adaptation in humans, the monkeypox virus (MPXV) has emerged as a pathogen that needs further study. Many non-endemic countries with no prior history of travel to an endemic region had increased global health concerns after the finding of MPXV cases in May 2022. Here, we summarize the clinical significance of MPXV and its unique infection characteristics. Finally, this review sheds light on worries regarding its resurgence in global health.…

Abstract

Background

Malaria is still a major public health threat in some parts of the world. Many countries are targeting to achieve malaria free status country. This study aimed to determine the sero-prevalence of malaria and the knowledge, attitudes and practices relating to the prevention of malaria among the indigenous adults living in the central forest spine in Peninsular Malaysia.

Methods

A mixed method study was conducted in indigenous settlements in 2020. Blood film for malaria parasite (BFMP) was used to diagnose malaria in this study. A structured questionnaire was used to collect data from the participants. For the qualitative data, in-depth interviews were conducted and data was collected until data saturation was reached. Multiple linear regression was used to determine the predictors after adjusting for confounders. A p-value of < 0.05 is considered as statistically significant. Meaningful statements from the in-depth interviews were assigned to the relevant codes using NVivo version 12 software.

Results

A total of 284 indigenous people participated in the study. The prevalence of malaria in this study was 0%. Those in the middle age group between 25 and 41 years and tested positive for malaria previously were significantly more likely to have better knowledge and attitude scores. Significant correlations were also observed between knowledge-attitude and knowledge-practice. For the qualitative results, most of the respondents were unsure of monkey malaria, but all were aware of human malaria.

Conclusion

The present study highlighted the absence of malaria in the study population and relatively good knowledge, attitudes and practices relating to the prevention of malaria.

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Abstract

Background

Plasmodial species naturally infecting orang-utans, Plasmodium pitheci and Plasmodium silvaticum, have been rarely described and reportedly cause relatively benign infections. Orang-utans at Rescue Rehabilitation Centres (RRC) across the orang-utan natural range suffer from malaria illness. However, the species involved and clinical pathology of this illness have not been described in a systematic manner. The objective of the present study was to identify the Plasmodium species infecting orang-utans under our care, define the frequency and character of malaria illness among the infected, and establish criteria for successful diagnosis and treatment.

Methods

During the period 2017–2021, prospective active surveillance of malaria among 131 orang-utans resident in a forested RRC in West Kalimantan (Indonesia) was conducted. A total of 1783 blood samples were analysed by microscopy and 219 by nucleic acid based (PCR) diagnostic testing. Medical records of inpatient orang-utans at the centre from 2010 to 2016 were also retrospectively analysed for instances of symptomatic malaria.

Results

Active surveillance revealed 89 of 131 orang-utans were positive for malaria at least once between 2017 and 2021 (period prevalence = 68%). During that period, 14 cases (affecting 13 orang-utans) developed clinical malaria (0.027 attacks/orang-utan-year). Three other cases were found to have occurred from 2010–2016. Sick individuals presented predominantly with fever, anaemia, thrombocytopenia, and leukopenia. All had parasitaemias in excess of 4000/μL and as high as 105,000/μL, with severity of illness correlating with parasitaemia. Illness and parasitaemia quickly resolved following administration of artemisinin-combined therapies. High levels of parasitaemia also sometimes occurred in asymptomatic cases, in which case, parasitaemia cleared spontaneously.

Conclusions

This study demonstrated that P. pitheci very often infected orang-utans at this RRC. In about 14% of infected orang-utans, malaria illness occurred and ranged from moderate to severe in nature. The successful clinical management of acute pitheci malaria is described. Concerns are raised about this infection potentially posing a threat to this endangered species in the wild.

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AbstractBackgroundHelicobacter pylori infection induces cellular phenotypes relevant for cancer progression, namely cell motility and invasion. We hypothesised that the extracellular matrix (ECM) could be involved in these deleterious effects.MethodsMicroarrays were used to uncover ECM interactors in cells infected with H. pylori. LAMC2, encoding Laminin γ2, was selected as a candidate gene and its expression was assessed in vitro and in vivo. The role of LAMC2 was investigated by siRNA combined with a set of functional assays. Laminin γ2 and E-cadherin expression patterns were evaluated in gastric cancer cases.ResultsLaminin γ2 was found significantly overexpressed in gastric cancer cells infected with H. pylori. This finding was validated in vitro by infection with clinical isolates and in vivo by using gastric biopsies of infected and non-infected individuals. We showed that Laminin γ2 overexpression is dependent on the bacterial type IV secretion system and on the CagA. Functionally, Laminin γ2 promotes cell invasion and resistance to apoptosis, through modulation of Src, JNK, and AKT activity. These effects were abrogated in cells with functional E-cadherin.ConclusionsThese data highlight Laminin γ2 and its downstream effectors as potential therapeutic targets, and the value of H. pylori eradication to delay gastric cancer onset and progression.

AbstractBackgroundPeople with HIV have been reported to have increased risk of clinical and subclinical cardiovascular disease. Existing studies have focused on men and often have been uncontrolled or lacked adequate HIV-negative comparators.MethodsWe performed echocardiography in participants with, or at risk for, HIV from the Women’s Interagency HIV Study. We evaluated associations of HIV and HIV-related factors with cardiac phenotypes, including left ventricular systolic dysfunction (LVSD), isolated LV diastolic dysfunction (LVDD), left atrial enlargement (LAE), LV hypertrophy (LVH), and increased tricuspid regurgitation velocity (TRV).ResultsOf 1654 participants (age 51 ± 9), 70% were HIV-positive. Sixty-three (5.4%) women with HIV (WWH) had LVSD; 71 (6.5%) had isolated LVDD. Compared to women without HIV (WWOH), WWH had a near-significantly increased risk of LVSD (adjusted RR = 1.69 [95% CI = 1.00, 2.86], p = 0.051). No significant association was noted for HIV seropositivity with other phenotypes, but there was a risk gradient for decreasing CD4 + count among WWH that approached or reached significance for isolated LVDD (ptrend = 0.069), LAE (ptrend = 0.002) and LVH (ptrend = 0.003). WWH with CD4 + count < 200 cells/mm3 had significantly higher prevalence of LAE, LVH and high TRV than WWOH (p < 0.05). There were no consistent associations for viral suppression or antiretroviral-drug exposure.ConclusionsThis study suggests that WWH have a higher risk of LVSD compared to sociodemographically smilar WWOH, but their risk for isolated LVDD, LAE, LVH, and high TRV is increased only with reduced CD4 + count. Although these findings warrant replication, they support the importance of cardiovascular risk-factor and HIV-disease control for heart disease prevention in this population.

AbstractIn Australia, Japanese encephalitis virus circulated in tropical north Queensland between 1995 and 2005. In 2022, a dramatic range expansion across the southern states has resulted in 30 confirmed human cases and six deaths. We discuss the outbreak drivers and estimate the potential size of the human population at risk.

ABSTRACTBackgroundCarbapenem-resistant Klebsiella pneumoniae (CRKp) is the most prevalent carbapenem-resistant Enterobacterales in the United States. We evaluated clustering of CRKp in hospitalized patients in US hospitals.MethodsFrom April 2016 to August 2017, 350 patients with clonal group 258 were included as part of the Consortium on Resistance Against Carbapenems in Klebsiella and other Enterobacteriaceae (CRACKLE-2), a prospective, multicenter, cohort study. A maximum-likelihood tree was constructed using RAxML. Static clusters shared ≤21 single nucleotide polymorphisms (SNP) and a most recent common ancestor. Dynamic clusters incorporated SNP distance, culture timing, and rates of SNP accumulation and transmission using the R program TransCluster.ResultsMost patients were admitted from home (n = 150, 43%) or a long-term care facility (n = 115, 33%). Urine (n = 149, 43%) was the most common site of isolation. In total, 55 static and 47 dynamics clusters were identified involving 210/350 (60%) and 194/350 (55%) patients, respectively. About half of static clusters were identical to dynamic clusters. Static clusters consisted of 33 (60%) intra-system and 22 (40%) inter-system clusters. Dynamic clusters consisted of 32 (68%) intra-system and 15 (32%) inter-system clusters and had fewer SNP differences compared to static clusters (8 versus 9, P= 0.045, 95% CI: [-4, 0]). Dynamic inter-system clusters contained more patients than dynamic intra-system clusters (median [IQR]: 4 [2, 7] vs 2 [2, 2], P= 0.007, 95% CI: [-3, 0]).ConclusionsWidespread intra-system and inter-system transmission of CRKp was identified in hospitalized US patients. Employing different methods for assessing genetic similarity resulted in only minor differences in interpretation.

Nature Medicine, Published online: 03 October 2022; doi:10.1038/s41591-022-02018-4We show that patients who survive the first 30 days of acute SARS-CoV-2 infection have an increased risk of various post-acute neurological disorders after 1 year compared with uninfected contemporaries. The burden of these sequelae (aspects of ‘long COVID’) has serious implications for patients as well as society.

Abstract

Background

Malaria remains a public health problem in Kenya despite sustained interventions deployed by the government. One of the major impediments to effective malaria control is a lack of accurate diagnosis and effective treatment. This study was conducted to assess clinical malaria incidence and treatment seeking profiles of febrile cases in western Kenya.

Methods

Active case detection of malaria was carried out in three eco-epidemiologically distinct zones topologically characterized as lakeshore, hillside, and highland plateau in Kisumu County, western Kenya, from March 2020 to March 2021. Community Health Volunteers (CHVs) conducted biweekly visits to residents in their households to interview and examine for febrile illness. A febrile case was defined as an individual having fever (axillary temperature ≥ 37.5 °C) during examination or complaints of fever and other nonspecific malaria related symptoms 1–2 days before examination. Prior to the biweekly malaria testing by the CHVs, the participants' treatment seeking methods were based on their behaviors in response to febrile illness. In suspected malaria cases, finger-prick blood samples were taken and tested for malaria parasites with ultra-sensitive Alere® malaria rapid diagnostic tests (RDT) and subjected to real-time polymerase chain reaction (RT-PCR) for quality control examination.

Results

Of the total 5838 residents interviewed, 2205 residents had high temperature or reported febrile illness in the previous two days before the visit. Clinical malaria incidence (cases/1000people/month) was highest in the lakeshore zone (24.3), followed by the hillside (18.7) and the highland plateau zone (10.3). Clinical malaria incidence showed significant difference across gender (χ2 = 7.57; df = 2, p = 0.0227) and age group (χ2 = 58.34; df = 4, p < 0.0001). Treatment seeking patterns of malaria febrile cases showed significant difference with doing nothing (48.7%) and purchasing antimalarials from drug shops (38.1%) being the most common health-seeking pattern among the 2205 febrile residents (χ2 = 21.875; df = 4, p < 0.0001). Caregivers of 802 school-aged children aged 5–14 years with fever primarily sought treatment from drug shops (28.9%) and public hospitals (14.0%), with significant lower proportions of children receiving treatment from traditional medication (2.9%) and private hospital (4.4%) (p < 0.0001). There was no significant difference in care givers' treatment seeking patterns for feverish children under the age of five (p = 0.086). Residents with clinical malaria cases in the lakeshore and hillside zones sought treatment primarily from public hospitals (61.9%, 60/97) traditional medication (51.1%, 23/45) respectively (p < 0.0001). However, there was no significant difference in the treatment seeking patterns of highland plateau residents with clinical malaria (p = 0.431).The main factors associated with the decision to seek treatment were the travel distance to the health facility, the severity of the disease, confidence in the treatment, and affordability.

Conclusion

Clinical malaria incidence remains highest in the Lakeshore (24.3cases/1000 people/month) despite high LLINs coverage (90%). The travel distance to the health facility, severity of disease and affordability were mainly associated with 80% of residents either self-medicating or doing nothing to alleviate their illness. The findings of this study suggest that the Ministry of Health should strengthen community case management of malaria by providing supportive supervision of community health volunteers to advocate for community awareness, early diagnosis, and treatment of malaria.

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Tropical Medicine &International Health, Volume 27, Issue 10, Page 841-841, October 2022.

Objective

We aim to assess the effectiveness of contact tracing using real-time location system (RTLS) compared with the conventional (electronic medical records (EMRs)) method via an emerging infectious disease (EID) outbreak simulation exercise. The aims of the study are: (1) to compare the time taken to perform contact tracing and list of contacts identified for RTLS versus EMR; (2) to compare manpower and manpower-hours required to perform contact tracing for RTLS versus EMR; and (3) to extrapolate the cost incurred by RTLS versus EMR.

Design

Prospective case study.

Setting

Sengkang General Hospital, a 1000-bedded public tertiary hospital in Singapore.

Participants

1000 out of 4000 staff wore staff tags in this study.

Interventions

A simulation exercise to determine and compare the list of contacts, time taken, manpower and manpower-hours required between RTLS and conventional methods of contact tracing. Cost of both methods were compared.

Primary and secondary outcome measures

List of contacts, time taken, manpower required, manpower-hours required and cost incurred.

Results

RTLS identified almost three times the number of contacts compared with conventional methods, while achieving that with a 96.2% reduction in time taken, 97.6% reduction in manpower required and 97.5% reduction in manpower-hours required. However, RTLS incurred significant equipment cost and might take many contact tracing episodes before providing economic benefit.

Conclusion

Although costly, RTLS is effective in contact tracing. RLTS might not be ready at present time to replace conventional methods, but with further refinement, RTLS has the potential to be the gold standard in contact tracing methods of the future, particularly in the current pandemic.

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Introduction

Red blood cell (RBC) transfusion primarily aims to improve oxygen transport and tissue oxygenation. The transfusion strategy based on haemoglobin concentration could not accurately reflect cellular metabolism. The ratio of venous-arterial carbon dioxide tension difference to arterial-venous oxygen content difference (P(v-a)CO2/C(a-v)O2) is a good indicator of cellular hypoxia. We aim to explore the influence of P(v-a)CO2/C(a-v)O2 as an RBC transfusion trigger on outcomes in septic shock patients.

Methods and analysis

The study is a single-centre prospective cohort study. We consecutively enrol adult septic shock patients requiring RBC transfusion at intensive care unit (ICU) admission or during ICU stay. P(v-a)CO2/C(a-v)O2 will be recorded before and 1 hour after each transfusion. The primary outcome is ICU mortality. Binary logistic regression analyses will be performed to detect the independent association between P(v-a)CO2/C(a-v)O2 and ICU mortality. A cut-off value for P(v-a)CO2/C(a-v)O2 will be obtained by maximising the Youden index with the receiver operator characteristic curve. According to this cut-off value, patients included will be divided into two groups: one with the P(v-a)CO2/C(a-v)O2 >cut-off and the other with the P(v-a)CO2/C(a-v)O2 ≤cut off. Differences in clinical outcomes between the two groups will be assessed after propensity matching.

Ethics and dissemination

The study has been approved by the Institutional Review Board of Affiliated Hospital of Weifang Medical University (wyfy-2021-ky-059). Findings will be disseminated through conference presentations and peer-reviewed journals.

Trial registration number

ChiCTR2100051748.

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Objectives

Pulmonary disease is a significant cause of morbidity and mortality in adults and children, but most of the world lacks diagnostic imaging for its assessment. Lung ultrasound is a portable, low-cost, and highly accurate imaging modality for assessment of pulmonary pathology including pneumonia, but its deployment is limited secondary to a lack of trained sonographers. In this study, we piloted a low-cost lung teleultrasound system in rural Peru during the COVID-19 pandemic using lung ultrasound volume sweep imaging (VSI) that can be operated by an individual without prior ultrasound training circumventing many obstacles to ultrasound deployment.

Design

Pilot study.

Setting

Study activities took place in five health centres in rural Peru.

Participants

There were 213 participants presenting to rural health clinics.

Interventions

Individuals without prior ultrasound experience in rural Peru underwent brief training on how to use the teleultrasound system and perform lung ultrasound VSI. Subsequently, patients attending clinic were scanned by these previously ultrasound-naïve operators with the teleultrasound system.

Primary and secondary outcome measures

Radiologists examined the ultrasound imaging to assess its diagnostic value and identify any pathology. A random subset of 20% of the scans were analysed for inter-reader reliability.

Results

Lung VSI teleultrasound examinations underwent detailed analysis by two cardiothoracic attending radiologists. Of the examinations, 202 were rated of diagnostic image quality (94.8%, 95% CI 90.9% to 97.4%). There was 91% agreement between radiologists on lung ultrasound interpretation among a 20% sample of all examinations (=0.76, 95% CI 0.53 to 0.98). Radiologists were able to identify sequelae of COVID-19 with the predominant finding being B-lines.

Conclusion

Lung VSI teleultrasound performed by individuals without prior training allowed diagnostic imaging of the lungs and identification of sequelae of COVID-19 infection. Deployment of lung VSI teleultrasound holds potential as a low-cost means to improve access to imaging around the world.

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Objectives

This study examined the association between sexual and reproductive health (SRH) education in peer-group discussion and comprehensive knowledge of HIV among young adolescent girls in rural eastern Ethiopia.

Design

The study analysed data from a large quasi-experimental study involving 3290 young adolescent girls aged 13–17 years. The intervention targeted adolescent girls aged 10–14 years. Data were collected using a comprehensive HIV knowledge tool adopted from the demographic and health survey questionnaire. Multi-level mixed-effect logistic regression analysis was employed to examine associations using STATA/SE V.14 statistical software.

Setting

West Hararghe, rural Ethiopia.

Participants

3290 adolescent girls.

Results

Magnitude of comprehensive knowledge of HIV among those who received SRH education and those who did not receive SRH education was 16.78% (95% CI 14.41% to 19.45%) and 14.01% (95% CI 12.38% to 15.81%), respectively. Overall, 14.84% (95% CI 13.4.% to 16.39%) of the adolescent girls aged 13–17 years had comprehensive knowledge of HIV. The odds of having comprehensive HIV knowledge were higher (1.36 times) among adolescent girls who received SRH education compared with those who did not receive SRH education (adjusted OR 1.36, 95% CI 1.01 to 1.84) after controlling for selected potential confounders. Odds of having comprehensive HIV knowledge were also higher (1.73 times) among older adolescent girls (adjusted OR 1.733 95% CI 1.098 to 2.735) and (3.89 times) among those who attended secondary school (adjusted OR=3.889 95% CI 1.836 to 8.235) compared with young adolescent girls and the uneducated, respectively.

Conclusions

Comprehensive knowledge of HIV among young adolescent girls was very low. Providing SRH education for young adolescent girls improved their comprehensive knowledge of HIV in rural eastern Ethiopia. Initiating sexual education at an early age would benefit HIV prevention efforts.

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Introduction

The COVID-19 pandemic has led to concerns about potential adverse pregnancy outcomes associated with infection, resulting in intensive research. Numerous studies have attempted to examine whether COVID-19 is associated with an increased risk of pregnancy loss. However, studies and reviews to date have drawn differing conclusions. The aim of this systematic review is to provide a summary of all quantitative research on the relationship between pregnancy loss and COVID-19 infection and, if appropriate, to synthesise the evidence into an overall effect estimate.

Methods and analysis

Three publication databases (Embase, PubMed and Cochrane) and four preprint databases (medRxiv, Lancet Preprint, Gates Open Research and Wellcome Open Research) will be searched. Boolean logic will be used to combine terms associated with pregnancy loss and COVID-19. The population of interest are pregnant women. Retrieved results will be assessed in two phases: (1) abstract screening and (2) full text evaluation. All studies which compare pregnancy loss outcomes in women who had COVID-19 versus those who did not quantitatively will be included. Narrative and non-English studies will be excluded. Two reviewers will screen independently, with results compared and discrepancies resolved by the study team. Study quality and risk of bias will be assessed using a quality appraisal tool. Results will be summarised descriptively and where possible synthesised in a meta-analysis.

Ethics and dissemination

This systematic review requires no ethical approval. This review will be published in a peer-reviewed journal and provide an important update in a rapidly evolving field of research.

PROSPERO registration number

CRD42022327437.

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Journal of Medical Virology, Accepted Article.

Journal of Medical Virology, Accepted Article.

Tropical Medicine &International Health, Accepted Article.

Tropical Medicine &International Health, Accepted Article.

Abstract

Background

We aimed to assess the prevalence of Salmonella Typhi through DNA and IgM-antibody detection methods as a prelude to extended surveillance activities at sites in Ghana, Madagascar, and Ethiopia.

Methods

We performed species-specific real-time polymerase reaction (RT-PCR) to identify bacterial nucleic acid, and enzyme-linked immunosorbent assay (ELISA) for detecting HlyE/STY1498-, CdtB/STY1886-, pilL/STY4539- and Vi-antigens in blood and biopsy specimens of febrile and non-febrile subjects. We generated antigen-specific ELISA proxy cut-offs by change-point analyses, and utilized cumulative sum as detection method coupled with 1000 repetitive bootstrap analyses. We computed prevalence rates in addition to odds ratios to assess correlations between ELISA outcomes and participant characteristics.

Results

Definitive positive RT-PCR results were obtained from samples of febrile subjects originating from Adama Zuria/Ethiopia (1.9%, 2/104), Wolayita Sodo/Ethiopia (1.0%, 1/100), Diego/Madagascar (1.0%, 1/100), and Kintampo/Ghana (1.0%, 1/100), and from samples of non-febrile subjects from Wolayita Sodo/Ethiopia (1%, 2/201). While IgM antibodies against all antigens were identified across all sites, prevalence rates were highest at all Ethiopian sites, albeit in non-febrile populations. Significant correlations in febrile subjects aged < 15 years versus ≥ 15 years were detected for Vi (Odds Ratio (OR): 8.00, p = 0.034) in Adama Zuria/Ethiopia, STY1498 (OR: 3.21, p = 0.008), STY1886 (OR: 2.31, p = 0.054) and STY4539 (OR: 2.82, p = 0.022) in Diego/Madagascar, and STY1498 (OR: 2.45, p = 0.034) in Kintampo/Ghana. We found statistical significance in non-febrile male versus female subjects for STY1498 (OR: 1.96, p = 0.020) in Adama Zuria/Ethiopia, Vi (OR: 2.84, p = 0.048) in Diego/Madagascar, and STY4539 (OR: 0.46, p = 0.009) in Kintampo/Ghana.

Conclusions

Findings indicate non-discriminatory stages of acute infections, though with site-specific differences. Immune responses among non-febrile, presumably healthy participants may mask recall and/or reporting bias leading to misclassification, or asymptomatic, subclinical infection signs induced by suppression of inflammatory responses. As most Ethiopian participants were ≥ 15 years of age and not at high-risk, the true S. Typhi burden was likely missed. Change-point analyses for generating ELISA proxy cut-offs appeared robust, though misclassification is possible. Our findings provided important information that may be useful to assess sites prior to implementing surveillance for febrile illness including Salmonella disease.

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Abstract

Background

Clinical trials and individual-level observational data in Israel demonstrated approximately 95% effectiveness of mRNA-based vaccines against symptomatic SARS-CoV-2 infection. Individual-level data are not available in many countries, particularly low- and middle- income countries. Using a novel Poisson regression model, we analyzed ecologic data in Costa Rica to estimate vaccine effectiveness and assess the usefulness of this approach.

Methods

We used national data from December 1, 2020 to May 13, 2021 to ascertain incidence, hospitalizations and deaths within ecologic units defined by 14 age groups, gender, 105 geographic areas, and day of the epidemic. Within each unit we used the proportions of the population with one and with two vaccinations, primarily tozinameran. Using a non-standard Poisson regression model that included an ecologic-unit-specific rate factor to describe rates without vaccination and a factor that depended on vaccine effectiveness parameters and proportions vaccinated, we estimated vaccine effectiveness.

Results

In 3.621 million persons aged 20 or older, there were 125,031 incident cases, 7716 hospitalizations, and 1929 deaths following SARS-CoV-2 diagnosis; 73% of those aged ≥ 75 years received two doses. For one dose, estimated effectiveness was 59% (95% confidence interval 53% to 64%) for SARS-CoV-2 incidence, 76% (68% to 85%) for hospitalizations, and 63% (47% to 80%) for deaths. For two doses, the respective estimates of effectiveness were 93% (90% to 96%), 100% (97% to 100%), and 100% (97% to 100%).

Conclusions

These effectiveness estimates agree well with findings from clinical trials and individual-level observational studies and indicate high effectiveness in the general population of Costa Rica. This novel statistical approach is promising for countries where ecologic, but not individual-level, data are available. The method could also be adapted to monitor vaccine effectiveness over calendar time.

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Abstract

Background

COVID-19 vaccines have been administered in many countries; however, a sufficient vaccine coverage rate is not guaranteed due to vaccine hesitancy. To improve the uptake rate of COVID-19 vaccine, it is essential to evaluate the rate of vaccine hesitancy and explore relevant factors in different populations. An urgent need is to measure COVID-19 vaccine hesitancy among different population groups, hence a validated scale for measuring COVID-19 vaccine hesitancy is necessary. The present study aims to validate the COVID-19 vaccine hesitancy scale among different populations in China and to provide a scale measuring COVID-19 vaccine hesitancy with satisfactory reliability and validity.

Methods

Self-reported survey data were collected from different populations in China from January to March 2021. Based on the Parent Attitudes about Childhood Vaccines scale, 15 items were adapted to evaluate the COVID-19 vaccine hesitancy. Exploratory and confirmatory factor analysis were utilized to identify internal constructs of the COVID-19 vaccine hesitancy scale among two randomly split subsets of the overall sample. Reliability was analyzed with the internal consistency, composite reliability, and the test–retest reliability, and validity was analyzed with the criterion validity, convergent validity, and discriminant validity.

Results

A total of 4227 participants completed the survey, with 62.8% being medical workers, 17.8% being students, 10.3% being general population, and 9.1% being public health professionals. The exploratory factor analysis revealed a three-factor structure that explain 50.371% of the total variance. The confirmatory factor analysis showed that models consisting of three dimensions constructed in different populations had good or acceptable fit (CFI ranged from 0.902 to 0.929, RMSEA ranged from 0.061 to 0.069, and TLI ranged from 0.874 to 0.912). The Cronbach’s α for the total scale and the three subscales was 0.756, 0.813, 0.774 and 0.705, respectively. Moreover, the COVID-19 vaccine hesitancy scale had adequate test–retest reliability, criterion validity, convergent validity, and discriminant validity.

Conclusions

The COVID-19 vaccine hesitancy scale is a valid and reliable scale for identifying COVID-19 vaccine hesitancy among different population groups in China. Given the serious consequences of COVID-19 vaccine hesitancy, future studies should validate it across regions and time to better understand the application of the COVID-19 vaccine hesitancy scale.

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Abstract

Background

Countries in the southern Africa region have set targets for malaria elimination between 2020 and 2030. Malaria vector control is among the key strategies being implemented to achieve this goal. This paper critically reviews published entomological research over the past six decades in three frontline malaria elimination countries namely, Botswana Eswatini and Namibia, and three second-line malaria elimination countries including Mozambique, Zambia, and Zimbabwe. The objective of the review is to assess the current knowledge and highlight gaps that need further research attention to strengthen evidence-based decision-making toward malaria elimination.

Methods

Publications were searched on the PubMed engine using search terms: “(malaria vector control OR vector control OR malaria vector*) AND (Botswana OR Swaziland OR Eswatini OR Zambia OR Zimbabwe OR Mozambique)”. Opinions, perspectives, reports, commentaries, retrospective analysis on secondary data protocols, policy briefs, and reviews were excluded.

Results

The search resulted in 718 publications with 145 eligible and included in this review for the six countries generated over six decades. The majority (139) were from three countries, namely Zambia (59) and Mozambique (48), and Zimbabwe (32) whilst scientific publications were relatively scanty from front-line malaria elimination countries, such as Namibia (2), Botswana (10) and Eswatini (4). Most of the research reported in the publications focused on vector bionomics generated mostly from Mozambique and Zambia, while information on insecticide resistance was mostly available from Mozambique. Extreme gaps were identified in reporting the impact of vector control interventions, both on vectors and disease outcomes. The literature is particularly scanty on important issues such as change of vector ecology over time and space, intervention costs, and uptake of control interventions as well as insecticide resistance.

Conclusions

The review reveals a dearth of information about malaria vectors and their control, most noticeable among the frontline elimination countries: Namibia, Eswatini and Botswana. It is of paramount importance that malaria vector research capacity and routine entomological monitoring and evaluation are strengthened to enhance decision-making, considering changing vector bionomics and insecticide resistance, among other determinants of malaria vector control.

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New England Journal of Medicine, Ahead of Print. …

Journal of Medical Virology, Accepted Article.

The host plays an essential role in parasite transmission. The viability of the host–parasite relationship depends upon development of immune resistance and the induction of disease tolerance. Here I propose that pathogen coevolution of avirulence factors promoting host disease tolerance is an essential feature of the parasitic lifestyle.