Seroprevalence and Shifting Endemicities of Hepatitis A Virus Infection in Two Different Geographical Areas in the Philippines.

INTRODUCTION: Infection with hepatitis A virus (HAV) is often asymptomatic in young children, but most adolescents and adults will have symptoms ranging from nausea and tiredness to acute liver failure and even death. The risk of severe disease is higher in older adults and people with pre-existing liver disease. Immunization is recommended in regions with low HAV endemicity levels, i.e., where people get infected later in life. In the Philippines, recent epidemiologic data on HAV infection are lacking. The objective of this study was to assess age-specific seroprevalence and evaluate risk factors associated with HAV seropositivity. METHODS: People from two geographic areas (urban and rural) were recruited/enrolled and stratified by age group. HAV-specific immunoglobulin G (IgG) antibodies were measured with a chemiluminescent microparticle immunoassay. Sociodemographic parameters, hepatitis medical history, disease knowledge, hygiene measures and sanitation were assessed via a purpose-made questionnaire. Age at midpoint of population immunity (AMPI) was estimated using Kaplan-Meier curves. Logistic regression analyses were carried out to determine factors that were statistically significantly associated (p < 0.05) with HAV seropositivity. RESULTS: Overall, 1242 participants were included in the analysis; 250/602 (41.5%) participants from urban regions and 283/640 (44.2%) participants from rural regions tested positive for HAV IgG antibodies. AMPI was 35 and 37 years for the rural and urban region, respectively. Higher education was associated with lower HAV seropositivity prevalence ratios, while not living in the same region for the last 5 years, regularly consuming street food and lack of handwashing after defecation were associated with a higher likelihood of HAV seropositivity. CONCLUSION: Results suggest that HAV endemicity is low in the Philippines. Factors associated with HAV seropositivity were traveling, consuming street food and lack of basic hygienic gestures. Immunization might be an option to protect vulnerable populations against severe hepatitis A disease.

Hepatitis A virus (HAV) is transmitted via the fecal-oral route through consumption of contaminated food or water or by close contact with an infected person. In children, HAV is usually of no concern, but in adults and people with existing liver disease, HAV infection can lead to severe symptoms and even death. In areas where most people get hepatitis during childhood (high endemicity), vaccination is not required, since people acquire life-long immunity after infection. In regions with low and intermediate HAV endemicity, people may remain at risk of infection later in life and vaccination could be considered to prevent severe HAV disease and its associated complications. In the Philippines, the current endemicity level is unknown. The goal of this study was to determine the endemicity level in the Philippines and to determine risk factors for HAV infection. We measured the proportion of people (by age group) who had previously been infected with HAV. Results showed that by age of 5 years < 20% of the study population was infected by HAV. By the age of 37 years in the urban population and 35 years in the rural population, 50% of people tested positive for HAV antibodies, indicating previous infection. This means that the Philippines has low HAV endemicity. Risk factors for HAV seropositivity were traveling, regularly eating street food and not washing hands after defecation. Vaccination against HAV might be of benefit in the Philippines, especially early in life to prevent most severe outcomes in adulthood.

Infection characteristics of Metagonimus species (Digenea: Heterophyidae) metacercariae in fish from major rivers of Korea.

This article analyzed the infection characteristics of metacercariae of Metagonimus spp. (MsMc) in fish from 9 major water systems in Korea. A total of 19,568 fish in 87 species were examined over a period of 10 years (2011-2020). MsMc were detected in fish from all 44 survey areas in 9 water systems. Most of the surveyed sites showed very low and low infection levels (66.7%), while 33.3% of the areas, such as Tamjin-gang and Seomjin-gang, revealed moderate and high infection levels. High endemicity depends on the abundance of susceptible fish species, especially sweet smelt (Plecoglosus altivelis). The susceptibility index (SI) with MsMc in index fish, Zacco spp., was very low and low levels in 62.0%, moderate in 28.0%, and high in 10.0% regions. The SI was highest in the following order: Yeongam-cheon (283.8), Hoeng-cheon (192.3), Togyo-jeosuji (131.2), Deokcheon-gang (119.1), and Joyang-gang (106.3). The recent infection status of MsMc in P. altivelis was analyzed by the survey localities. In addition, except for P. altivelis, 9 fish species were highly infected with MsMc in some survey areas, including Zacco platypus, Z. koreanus, Z. temminckii, Opsariichthys uncirostris, Rhynchocypris oxycephalus, Carassius auratus, Acheilognathus rhombeus, Onchorhynchus masou, and Tribolodon hakonensis. In Korea, 74 fish species (15 families) are collectively listed as second intermediate hosts of Metagonimus spp. This review provides several novel characteristics of MsMc infection and clarifies the fish species of second intermediate host of Metagonimus spp. in this country.

Accuracy of commercial ELISA and ICT for screening schistosomiasis infections at a low endemicity area in Brazil.

BACKGROUND: Control interventions recommended by the World Health Organization have successfully resulted in low-intensity schistosomiasis transmission areas. To achieve elimination of transmission, new diagnostic screening tools are needed to overcome less than adequate sensitivity of the currently used Kato-Katz faecal thick smear method. Ideally, in-house serological tests should be avoided due to not having a continuous supply of kits as would be necessary for large population studies. Quality assurance provided by manufacturers and proper performance evaluations are also needed. We evaluated the accuracy of two commercially available serology tests as screening methods for detecting light schistosomiasis infections. METHODS: Serum samples were collected in 2015 from individuals living in a low-endemicity locality in northeastern Brazil and deposited in a biorepository. We evaluated immunoglobulin G (IgG) and IgM enzyme-linked immunosorbent assays (ELISAs) and an immunochromatographic test (ICT). The Helmintex method was used to define true-positive samples. RESULTS: Overall sensitivity was close to 90% for both the IgG ELISA and ICT, yet specificity was 28% and 18%, respectively. For the IgM ELISA, the values were estimated to be 55% and 43%, respectively. CONCLUSIONS: Poor specificity and positive predictive values prevent these tests from being recommended for screening populations in low-intensity schistosomiasis-endemic areas.

From Emergence to Endemicity: A Comprehensive Review of COVID-19.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), later renamed coronavirus disease 2019 (COVID-19), was first identified in Wuhan, China, in early December 2019. Initially, the China office of the World Health Organization was informed of numerous cases of pneumonia of unidentified etiology in Wuhan, Hubei Province at the end of 2019. This would subsequently result in a global pandemic with millions of confirmed cases of COVID-19 and millions of deaths reported to the WHO. We have analyzed most of the data published since the beginning of the pandemic to compile this comprehensive review of SARS-CoV-2. We looked at the core ideas, such as the etiology, epidemiology, pathogenesis, clinical symptoms, diagnostics, histopathologic findings, consequences, therapies, and vaccines. We have also included the long-term effects and myths associated with some therapeutics of COVID-19. This study presents a comprehensive assessment of the SARS-CoV-2 virology, vaccines, medicines, and significant variants identified during the course of the pandemic. Our review article is intended to provide medical practitioners with a better understanding of the fundamental sciences, clinical treatment, and prevention of COVID-19. As of May 2023, this paper contains the most recent data made accessible.

Amphibians and Reptiles of the Montagne des Français: An Update of the Distribution and Regional Endemicity.

The harmonious landscape of Montagne des Français is a protected area in the far north of Madagascar. Our herpetofauna surveys were conducted on the eastern and western slopes according to habitat variations within the massif for 2014 and 2020. Our research updates the herpetofauna species richness, spatial distribution ranges, and ecological guilds within the protected area. We used direct opportunistic observations, systematic refuge examinations, and pitfall traps with drift fences at three sites to sample animals. Nineteen amphibian and fifty reptile species were recorded during this study. Three amphibian species and one reptile species, in addition to the snake Langaha pseudoalluaudi, last recorded in 2007, were discovered at Montagne des Français. Here, we present a database update for the herpetofauna species from Montagne des Français and provide a specific morphological description of the morphospecies considered as a new extension or localized distribution. This new database can help site managers develop new strategic conservation plans in response to habitat modification.

Epidemiology and transmission of hepatitis A in Shaanxi (western China) after more than ten years of universal vaccination.

Background: Hepatitis A (HepA) vaccination and economic factors can change the epidemiology of HepA. In China, the implementation of free vaccination for children under 1.5 years of age in 2008 has resulted in a decline in the overall incidence of HepA. Nevertheless, further investigation is required to comprehensively understand the epidemiological patterns of HepA in economically disadvantaged regions of China. Method: In this study, we evaluated the incidence, seroprevalence, and transmission characteristics of HepA in Shaanxi with less economically developed. We obtained data on reported cases of HepA from 2005 to 2020. Blood samples from 1,559 individuals aged 0 to 60 years were tested for anti-hepatitis A (HAV) antibodies. A questionnaire survey and blood sample collection were conducted in two sentinel sites from 2019 to 2021. Result: Between 2008 to 2020, the number of reported cases of HepA decreased from 3.44/100,000 person-years to 0.65/100,000 person-years, indicating an 81.1% decrease, which was particularly pronounced among younger age groups (0-19 years). From 2015-2020, infections were more likely to occur in people in their 40s and those over the age of 60. Farmers were still the most common occupation of HepA in the last decade. The results of the serological investigation showed the highest anti-HAV seroprevalence was observed in adults aged 39-60 years (94.6%) and those aged 28-38 years (87.8%). The 10-15 years group had the lowest seroprevalence at 49.3%. During the study period, a total of 22 cases were reported by sentinel sites, but the common risk factors (like raw food exposure, travel history, and closed contact with patients) were not identified. Conclusion: Given the greater severity of illness in the adult population and the ambiguous transmission routine, enhanced surveillance for HepA and evaluations that identify feasible approaches to mitigate the risk of HAV transmission are urgent priorities.

Genetic Diversity in Natural Populations of the Near-Threatened Species Lignobrycon myersi (Characiformes, Triportheidae): Implications for Species Conservation.

The river basins of Brazil contain a highly diverse ichthyofauna of remarkable endemism, including several threatened species. Accordingly, Lignobrycon myersi is a fish species distributed only in a few rivers from the state of Bahia, northeastern Brazil. Since this species is classified as Near Threatened and is poorly studied, efforts to understand the genetic structure of populations and putative cryptic forms should help define efficient strategies of management and conservation. Herein, the molecular identification and the population genetic diversity of specimens of L. myersi across their range (Almada, Contas, and Cachoeira river basins) were assessed using mitochondrial markers (16S rDNA and D-Loop, respectively). The inferences based on phylogenetics, genetic distance, and species delimitation methods invariably identified all samples as L. myersi. In addition, sequencing of D-loop fragments revealed significant haplotype diversity and a considerable level of population genetic structure. Despite their geographic isolation, these data suggested that populations from Almada and Contas rivers represent a single evolutionary lineage that could be managed as a whole. In contrast, the population from Cachoeira River was highly differentiated from the others and should be managed separately as a unique and endemic unit, particularly focused on the conservation of native habitats.

Schistosomiasis control in Senegal: results from community data analysis for optimizing preventive chemotherapy intervention with praziquantel.

BACKGROUND: Over the past two decades, preventive chemotherapy (PC) with praziquantel (PZQ) is the major strategy for controlling schistosomiasis in Senegal. The objective of this analysis was to update the endemicity of schistosomiasis at community level for better targeting mass treatment with PZQ in Senegal. METHODS: Demographic and epidemiological data from 1610 community health areas were analyzed using the schistosomiasis community data analysis tool of Expanded Special Project for Elimination of Neglected Tropical Diseases which developed by World Health Organization/Africa Office (WHO/AFRO). The tool uses a WHO/AFRO decision tree for areas without epidemiological data to determine whether mass treatment should be continued at community level. Descriptive analysis was performed. RESULTS: Overall, the endemicity of 1610 community health areas were updated based on the data from the district endemicity (33.5%) and the form of Join request for selected PC medicine (40.5%). Up to 282 (17.5%) and 398 (24.7%) of community health areas were classified as moderate and high endemicity. 41.1% of communities were non endemic. High endemicity was more important in Tambacounda, Saint Louis, Matam, Louga and Kedougou. A change in endemicity category was observed when data was disagregted from district level to community level. Implementation units classified non endemic were more important at community level (n = 666) compared to district level (n = 324). Among 540 areas previously classified high endemic at district level, 392 (72.6%) remained high prevalence category, while 92 (17.0%) became moderate, 43 (8.0%) low and 13 (2.4%) non-endemics at community level. Number of implementation units requiring PC was more important at district level (1286) compared to community level (944). Number of school aged children requiring treatment was also more important at district level compared to community level. CONCLUSIONS: The analysis to disaggregate data from district level to community level using the WHO/AFRO schistosomiasis sub-district data optimization tool provide an update of schistosomiasis endemicity at community level. This study has allowed to better target schistosomiasis interventions, optimize use of available PZQ and exposed data gaps.

Genetic connectivity and population expansion inferred from multilocus analysis in Lutjanus alexandrei (Lutjanidae-Perciformes), an endemic snapper from Northeastern Brazilian coast.

Previous studies about the genetic diversity, connectivity and demographic history in Lutjanidae fishes have reported a common pattern of genetic homogeneity and expansion in populations from Western South Atlantic. In the present work, we inferred the population structure, the levels of genetic diversity and the demographic history of the Brazilian snapper Lutjanus alexandrei, a recently described and endemic species from Northeastern coast of Brazil. Five different fragments, including mitochondrial DNA (Control Region, Cyt b and ND4) and nuclear DNA (Myostatin and S7) regions were analyzed in 120 specimens of L. alexandrei from four localities in Northeastern Brazil, representing the first study of population genetics in this species. High levels of genetic diversity were observed following a panmictic pattern, probably related to the larval dispersal by the current tides along the Brazilian coast. In addition, both demographic history and neutrality tests indicated that L. alexandrei has undergone population expansion during Pleistocene. In this sense, the sea level variation from this period could have increased the available resources and suitable habitats for the Brazilian snapper.

Seroprevalence of dengue virus infection in Pune City in India, 2019: A decadal change.

BACKGROUND: The burden of dengue infection needs to be monitored along with tracking of the changes in dengue virus (DENV) transmission intensity for vaccine introduction decisions. METHODS: The seroprevalence of dengue was investigated in Pune City in India, in early 2019 using 1654 sera from apparently healthy human participants enrolled randomly through multistage cluster sampling. We used 797 retrospective human sera from late 2009 for comparison. All sera were assessed for the presence of dengue-specific IgG antibodies. A subset (n = 230) was tested for serotype-specific plaque reduction-neutralizing antibodies against all four serotypes. RESULTS: The dengue IgG seroprevalence of 62.9% (95% CI 59.4-66.1) in 2009 increased to 88.4% (95% CI 86.8-89.8) in 2019. Age-stratified dengue seroprevalence revealed a gradual increase in IgG seropositivity from 70.1% in 0-9 years to 85.0% in 10-19 years. The annual probability of dengue infection estimated as a force of infection was 4.1 (95% CI 3.8-4.5) in 2009, which increased to 10.9 (95% CI 10.2-11.6) in 2019. Analysis of dengue serotype-specific neutralizing antibodies revealed DENV-3 as the dominant serotype. The age of exposure to at least one dengue serotype was reduced in 2019 over 2009. CONCLUSIONS: There was a significant increase in the intensity of dengue virus transmission in Pune City over the decade. Since over 85% of the participants above nine years of age had exposure to DENV by 2019, dengue vaccine introduction can be considered. Moreover, such repeated serosurveys in different regions might inform about the readiness of the population for dengue vaccination.

The Changing Epidemiology of Viral Hepatitis in a Post-Soviet Country-The Case of Kyrgyzstan.

Historically, viral hepatitis has been a considerable public health problem in Central Asian countries, which may have worsened after the dissolution of the Soviet Union. However, up-to-date seroepidemiological studies are lacking. The aim of the present study was, therefore, to provide current estimates of the seroprevalence of viral hepatitis in Kyrgyzstan, one of the economically least developed countries in the region. We conducted a population-based cross-sectional study in 2018 in the capital of Kyrgyzstan, Bishkek (n = 1075). Participants, children and adults, were recruited from an outpatient clinic. The data were collected during face-to-face interviews. A blood sample (6 mL) was collected from each participant and tested with ELISA for the presence of serological markers for five viral hepatitides (A, B, C, D, and E). Post-stratification weighing was performed to obtain nationally representative findings. The overwhelming majority of the study participants were positive for anti-HAV (estimated seroprevalence, 75.3%; 95% confidence interval, 72.5-77.9%). The weighted seroprevalence estimates of HBsAg, anti-HCV, and anti-HDV were 2.2% (1.5-3.3%), 3.8% (2.8-5.1%), and 0.40% (0.15-1.01%), respectively. Anti-HEV seropositivity was 3.3% (2.4-4.5%). Of the 33 HBsAg-positive participants, five (15%) were anti-HDV-positive. Our study confirms that Kyrgyzstan remains a highly endemic country for hepatitis virus A and C infections. However, seroprevalences of HBV and HDV were lower than previously reported, and based on these data, the country could potentially be reclassified from high to (lower) intermediate endemicity. The observed anti-HEV seroprevalence resembles the low endemicity pattern characteristic of high-income countries.

Uncovering the endemic circulation of rabies in Cambodia.

In epidemiology, endemicity characterizes sustained pathogen circulation in a geographical area, which involves a circulation that is not being maintained by external introductions. Because it could potentially shape the design of public health interventions, there is an interest in fully uncovering the endemic pattern of a disease. Here, we use a phylogeographic approach to investigate the endemic signature of rabies virus (RABV) circulation in Cambodia. Cambodia is located in one of the most affected regions by rabies in the world, but RABV circulation between and within Southeast Asian countries remains understudied. Our analyses are based on a new comprehensive data set of 199 RABV genomes collected between 2014 and 2017 as well as previously published Southeast Asian RABV sequences. We show that most Cambodian sequences belong to a distinct clade that has been circulating almost exclusively in Cambodia. Our results thus point towards rabies circulation in Cambodia that does not rely on external introductions. We further characterize within-Cambodia RABV circulation by estimating lineage dispersal metrics that appear to be similar to other settings, and by performing landscape phylogeographic analyses to investigate environmental factors impacting the dispersal dynamic of viral lineages. The latter analyses do not lead to the identification of environmental variables that would be associated with the heterogeneity of viral lineage dispersal velocities, which calls for a better understanding of local dog ecology and further investigations of the potential drivers of RABV spread in the region. Overall, our study illustrates how phylogeographic investigations can be performed to assess and characterize viral endemicity in a context of relatively limited data.

Geospatial Hotspot Analysis and Endemicity Trends of Missing and Unrecovered Children in India.

BACKGROUND: Children constitute a nation's true asset. A country's future relies upon the proper development of its children, which necessitates a supportive environment and sufficient opportunities. Children, under the age of 18 years form a considerable percentage of India's population which imparts a huge responsibility for the nation. Everyday we come across news about a child going missing. The National Crime Record Bureau (NCRB) states that 73,138 children were reported missing overall in 2018. The prevalence increased by 8.9% in 2019, a worrisome situation. The cause behind children going missing is multi-dimensional like poverty, unemployment, loss of livelihood, natural calamities, social conflicts, and migration to urban areas. At present, missing children remain a neglected and non-urgent intervention area for everyone. Only the parents whose children are missing can feel the vacuum and sorrow of the situation. The sociologies of India's missing children merit dimensional and circumstantial examination. The sociological space into which a child goes missing is highly under-researched in India. This study helped in understanding the magnitude of missing cases across India based on existing literature and secondary sources. It also identified the potentially safe and worst areas with regard to missing children. The endemicity helped in identifying the changing trends in each of these areas of interest, which could serve as baseline data for policymakers and law enforcement alike. MATERIALS AND METHODS: This is a cross-sectional analytical type of study. The data of missing and unrecovered children for the past five years (2021-2017) were obtained from open government data portal (https://data.gov.in) and geospatial hotspot analysis was done using the Getis-Order-G statistics on the same using GeoPandas and PySAL libraries of python. The endemicity of missing cases was studied using hierarchical cluster analysis and self-organizing maps using Python. RESULTS: For boys, Uttar Pradesh, Rajasthan, and Madhya Pradesh remained consistent hotspots (high risk of missing cases) across all five years of study whereas Karnataka became a hotspot for 2020 and 2021. Among the cold spots (low risk of missing cases), Andaman and Nicobar Islands remained consistent cold spot across all five years of study and has emerged as a safe haven for boys. The missing girls' data reveals that Uttar Pradesh has consistently been the worst state for girls (along with their neighbors) as it possess the risk of girls going missing all through the study period with Chhattisgarh being included from 2019 onwards. Jharkhand, Gujarat, Sikkim, and Andaman and Nicobar Islands have consistently been cold spots across the board and have emerged as areas with low risk for missing girls. CONCLUSION: This study helps us in understanding the magnitude of missing cases across India and it also identifies which are potentially safe areas as well as worst areas with regard to missing children. The endemicity also helps us in identifying the changing trends in each of these areas of interest. This will serve as a great resource for policy makers and law enforcement alike.

Dengue and zika seropositivity, burden, endemicity, and cocirculation antibodies in Nigeria.

INTRODUCTION: Mosquito-borne infections are of global health concern because of their rapid spread and upsurge, which creates a risk for coinfections. DENV and ZIKV are transmitted by Aedes aegypti and A. albopictus and are prevalent in Nigeria and neighbouring countries. However, their seroprevalence, burden, hidden endemicity and possible cocirculation are poorly understood in Nigeria. METHODS: We conducted a cross-sectional study of 871 participants from three regions of Nigeria. All serum samples were analysed using malaria RDT and the immunoblot molecular diagnostic assay recomLine Tropical Fever for the presence of arboviral antibody serological marker IgG (Mikrogen Diagnostik, Neuried, Germany) with DENV and ZIKV Nonstructural protein 1 (NS 1), DENV and ZIKV Equad (variant of the envelope protein with designated mutations to increase specificity), according to the manufacturer's instructions. RESULTS: The overall IgG antibody seropositivity against DENV-flavivirus was 44.7% (389/871); 95% CI (41.41-47.99), while ZIKV-flavivirus was 19.2% (167/871); 95% CI (0.16-0.21), and DENV-ZIKV-flavivirus cocirculation antibody seropositivity was 6.2%5 (54/871); 95% CI (0.6-0.7) in the three study regions of Nigeria. The study cohort presented similar clinical signs and symptoms of flaviviruses (DENV and ZIKV) in all three study regions. CONCLUSION: This study highlighted an unexpectedly high antibody seropositivity, burden, hidden endemicity, and regional spread of mono- and co-circulating flaviviruses (DENV and ZIKV) in Nigeria.Key messagesDengue flavivirus sero-cross-reactivity drives antibody-dependent enhancement of ZIKV infection.Both viruses share common hosts (humans) and vectors (primarily Aedes aegypti), and are thus influenced by similar biological, ecological, and economic factors, resulting in epidemiological synergy.Additionally, the actual burden in epidemic and interepidemic periods is grossly or chronically unknown and underreported. Despite this trend and the potential public health threat, there are no reliable data, and little is known about these arboviral co-circulation infections.

Prevalence of malaria-helminth co-infections among children living in a setting of high coverage of standard interventions for malaria and helminths: Two population-based studies in Senegal.

Background: Concurrent infections of Plasmodium falciparum with Soil Transmitted Helminths (STH) and Schistosoma spp are still a major public health problem among children living in Sub-Saharan Africa. We conducted two prospective studies among children living in urban and rural settings of Senegal, where control programmes for malaria, STH and schistosomiasis have been sustained, to determine the prevalence of malaria-helminth co-infection. Methods: We enrolled 910 children aged 1-14 years from Saraya and Diourbel districts of Senegal in June and November 2021, respectively. We collected finger-prick blood samples from the children for malaria parasite detection using microscopy and PCR methods. Stool samples were also collected and Kato-Katz and PCR methods were used to detect STH and S. mansoni; and Merthiolate-iodine-formalin (MIF) test for other intestinal protozoans. Urine samples were analyzed using a filtration test, Point of Care Circulating Cathodic Antigens (POC-CCA) and PCR methods for detection of S. haematobium. Statistical analyses were performed to compare the continuous and categorical variables across the two study sites and age groups, as well as using the adjusted Odds ratios (aOR) to explore risk factors for malaria-helminth co-infections. Results: The overall prevalence of polyparasitism with P. falciparum, STH, S. haematobium and S. mansoni among children in the two study sites was 2.2% (20/910) while prevalence of P. falciparum-S. haematobium co-infection was 1.1% (10/910); P. falciparum-S. mansoni 0.7% (6/910) and P. falciparum with any intestinal protozoan 2.4% (22/910). Co-infection was slightly higher among 5-14 year old children (17/629, 2.7%; 95% CI: 1.43-3.97) than 1-4 years (3/281, 1.1%; 95% CI: -0.12-2.32) and, in boys (13/567, 2.3%; 95% CI: 1.27-3.96) than girls (7/343, 2.1%; 95% CI: 0.52-3.48). Children aged 5-14 years (aOR = 3.37; 95% CI: 0.82-13.77, p = 0.09), who were boys (aOR = 1.44; 95% CI: 0.48-4.36, p = 0.51) and lived in Saraya (aOR = 1.27; 95% CI: 0.24-6.69, p = 0.77) had a higher risk of malaria-helminth co-infection than other age group, in girls and those who lived in Diourbel. Living in houses with spaces between the walls and roofs as well as frequent contacts with water during swimming were statistically significant risk factors for malaria-helminth co-infection. Conclusions: The prevalence of malaria-helminth co-infection is low in two districts in Senegal, possibly due to sustained implementation of effective control measures for malaria and NTDs. These findings could help to develop and implement strategies that would lead to elimination of malaria and helminths in the study areas.

Concordance between Ov16 Rapid Diagnostic Test(RDT) and Ov16 Enzyme-Linked Immunosorbent Assay (ELISA) for the Diagnosis of Onchocerciasis in Areas of Contrasting Endemicity in Cameroon.

The diagnosis of onchocerciasis in endemic areas has been demanding given the need to replace the invasive skin snip method with a more sensitive and specific rapid point-of-contact tool. Filarial antigen detection tests are better alternative methods in diagnosing Onchocercal infections, as they detect infections and could be used to monitor transmission in endemic areas following mass drug administration. With the shift in paradigme from control to elimination, a rapid point- of-contact tool is required to support elimination programs. This was a cross-sectional, community-based study conducted in 50 villages selected from six health districts using a systematic sampling technique. Individuals ≥17 years who had lived in the community for a duration of 5 years and above provided blood specimens for IgG4 antibodies testing against O. volvulus antigens. Data were analyzed using SPSS v.20 and expectation maximization to classify optical densities for positive and negative samples from ELISA results. The kappa statistics was used to measure the level of agreement between the two tests. In a total of 5001 participants which were recruited for the study, 4416 (88.3 %) participant samples passed the plate quality control criteria and were considered for the test comparison analysis. Out of the 4416 participants, 292 (6.6 %) tested positive with Ov16 RDT and 310 (7.0 %) with Ov16 ELISA. All those who tested positive with the rapid test agreed positive with ELISA. The overall percentage agreement was 99.2 %, the Kappa score of 0.936. The results obtained indicate an excellent agreement between ELISA and RDT as measured by kappa (0.936) which was statistically significant (P<0.001). Our experience with the Ov16 ELISA biplex rapid test was favorable. However, the Ov16 RDT test may be more appropriate to use in remote areas for the point diagnosis of onchocerciasis in view towards achieving elimination in Africa.

Antibody seropositivity and endemicity of chikungunya and Zika viruses in Nigeria.

Mosquito-borne infections are of global health concern because of their rapid spread and upsurge, which creates a risk for coinfections. chikungunya virus (CHIKV), an arbovirus disease transmitted by Aedes aegypti or A. albopictus, and malaria, a parasitic disease transmitted by Anopheles gambiae, are prevalent in Nigeria and neighbouring countries, but their burden and possible coinfections are poorly understood. In this study, we investigated the antibody seropositivity and endemicity of chikungunya and Zika viruses (ZIKV) in three regions of Nigeria. A cross-sectional sero-survey was conducted on 871 participants. Samples were collected from outpatients by simple random sampling. Analyses of the samples were performed using recomLine Tropical Fever for the presence of antibody serological marker IgG immunoblot with CHIKV VLP (virus like particle), ZIKV NS1 and ZIKV Equad according to manufacturers' instructions and malaria RDT for malaria parasite. There was a significantly higher antibody seropositivity against CHIKV in the central region than in the northern and southern regions (69.5%, 291/419), while ZIKV-seropositivity (22.4%, 34/152) and CHIKV-ZIKV co-circulating antibody seropositivity (17.8%, 27/152) were notably higher in the southern region than in the central and northern regions. This investigation revealed an unexpectedly high antibody seropositivity and concealed endemicity of CHIKV and ZIKV in three Nigerian regions. The seropositivity of detectable antibodies differed among the three geographical locations. Supplementary Information: The online version contains supplementary material available at 10.1186/s44149-023-00070-2.

Ceftazidime-avibactam resistance in Klebsiella pneumoniae sequence type 37: a decade of persistence and concealed evolution.

The first reports of carbapenem-resistant Enterobacterales in our hospital date back to 2006. In that period, few ertapenem-resistant but meropenem-susceptible Klebsiella pneumoniae isolates belonging to sequence type (ST) 37 were retrieved from clinical samples. These strains produced the CTX-M-15 extended spectrum ß-lactamase, OmpK35 was depleted due to a nonsense mutation, and a novel OmpK36 variant was identified. Yet, starting from 2010, Klebsiella pneumoniae carbapenemase (KPC)-producing ST512 isolates started prevailing and ST37 vanished from sight. Since 2018 the clinical use of the combination of ceftazidime-avibactam (CZA) has been introduced in clinical practice for the treatment of bacteria producing serine-ß-lactamases, but KPC-producing, CZA-resistant K. pneumoniae are emerging. In 2021, four CZA-resistant ST37 isolates producing KPC variants were isolated from the same number of patients. blaKPC gene cloning in Escherichia coli was used to define the role of those KPC variants on CZA resistance, and whole genome sequencing was performed on these isolates and on three ST37 historical isolates from 2011. CZA resistance was due to mutations in the blaKPC genes carried on related pKpQIL-type plasmids, and three variants of the KPC enzyme have been identified in the four ST37 strains. The four ST37 isolates were closely related to each other and to the historical isolates, suggesting that ST37 survived without notice in our hospital for 10 years, waiting to re-emerge as a CZA-resistant K. pneumoniae clone. The ancestor of these contemporary isolates derives from ST37 wild-type porin strains, with no other mutations in chromosomal genes involved in conferring antibiotic resistance (parC, gyrA, ramR, mgrB, pmrB).

Genetic basis underlying Lassa fever endemics in the Mano River region, West Africa.

Lassa fever (LF), a haemorrhagic fever disease caused by Lassa virus (LASV), is a serious public health burden in West Africa. The Mano River region (Sierra Leone, Guinea, Liberia, and Côte d'Ivoire) has been an endemic focus of the disease over the past decades. Here, we deciphered the genetic basis underlying LF endemics in this region. Clade model and type I functional divergence analyses revealed that the major LASV group, Kenema sub-clade, which is currently circulating in the Eastern Province of Sierra Leone, has been affected by different selective pressure compared to isolates from the other areas with effects on the viral RNA-dependent RNA polymerase (L protein) and probably nucleoprotein (NP). Further, contingency analysis showed that, in the early endemic, the sub-clade has undergone adaptive diversification via acceleration of amino acid substitutions in L protein. These findings highlight the key viral factor and local adaptation regarding the endemicity of LF.

Seroprevalence and associated risk factors for hepatitis B virus among pregnant women attending health facility in Osogbo, Nigeria

Background Hepatitis B virus (HBV) infection among pregnant women has a high rate of vertical transmission and consequential effects on fetal and neonatal outcomes. The aim of this study was to determine the prevalence and associated risk factors of infection among pregnant women attending antenatal care services in Osogbo, Nigeria. Methodology This hospital based cross-sectional study was conducted among pregnant women attending routine antenatal care clinic between April and June 2021. Systematic random sampling technique was used to recruit 240 pregnant women, their data were collected by face to face interview using a pretested questionnaire, while blood sample was collected aseptically to determine hepatitis B surface antigen by enzyme linked immunosorbent assay test kit. Univariate and multivariate logistic regression were used to examine the association between explanatory variables and outcome variable. Results The mean age and seroprevalence of the study population were 27.50 ± 4.4 years and 5.8% respectively. The significant risk factors for HBV infection were tattooing (aOR = 5.22; 95% CI = 0.52­8.01; p = 0.0000), history of multiple sexual partners (aOR = 2.88; 95% CI = 1.92­12.42; p = 0.0044); and past history of contact with HBV patient (aOR = 2.17; 95% CI = 1.21­15.32; p = 0.0310) were significant predictors of HBV infection. Conclusion The seroprevalence of HBV from this study was of intermediate endemicity. We therefore, advocate for continuous health education programs on the mode of HBV transmission, high-risk behaviors and methods of preventions at antenatal care clinics to raise the awareness of mothers and limit the spread of infection.