Measles incidence in South Africa: a six-year review, 2015-2020

In 2012 the World Health Organization (WHO) aimed to eliminate measles in five regions by 2020. This retrospective descriptive study reviewed measles surveillance data in South Africa for the period 2015—2020 to document the epidemiology of measles and the progress made towards meeting the 2020 measles elimination goal.

A total of 22,578 specimens were tested over the period 2015—2020 yielding 401 (1.8%) confirmed measles cases, 321 (1.4%) compatible and 21,856 (96.8%) discarded cases. The most affected age group was 0–4 year olds. At the provincial level, South Africa achieved adequate surveillance, defined as more than two cases of febrile rash notified annually per 100 000 popoulation, except for KwaZulu-Natal and Limpopo in 2020, probably due to COVID-19 lockdown restrictions. Of confirmed cases, only 26% were vaccinated, 3% were too young to receive vaccines, 5% were not vaccinated, and 65% had unknown vaccination status. Measles vaccine effectiveness amongst 1–4 year olds was 80%. Using the standard case definition, South Africa achieved the measles elimination target of less than one case per one million nationally in years 2015, 2016 and 2020. The years 2017 to 2019 had incidence rates exceeding one per million nationally. Using a narrow case definition, that excluded positive rubella cases, improved the indicators with only the year 2017 having an incidence rate of more than one per million.

South Africa displays intermittent measles outbreaks approximately six-yearly interspersed by inter-epidemic periods in which the country meets measles elimination targets. Intense effort is needed to increase the vaccine coverage to avoid periodic outbreaks. Enhanced molecular testing of each case will be required as measles incidence declines regionally.

A retrospective 5-year review of rubella in South Africa prior to the introduction of a rubella-containing vaccine

South Africa has yet to introduce a rubella-containing vaccine (RCV) into its Expanded Programme on Immunisation (EPI). Here we evaluated the incidence of laboratory-confirmed rubella and congenital rubella syndrome (CRS) cases over the years 2015 to 2019, to document the epidemiology of rubella and CRS within South Africa prior to a RCV introduction. This retrospective study evaluated the number of laboratory-confirmed rubella cases reported through the national febrile rash surveillance system. A positive test for rubella immunoglobulin M (IgM) antibodies was considered a confirmed rubella case. For CRS cases, we reported laboratory-confirmed CRS cases collected from 28 sentinel-sites from all nine provinces of South Africa. From 2015-2019, 19 773 serum samples were tested for rubella IgM antibodies, 6 643 (33.6%) were confirmed rubella cases. Rubella was seasonal, with peaks in spring (September to November). Case numbers were similar between males (n = 3 239; 50.1%) and females (n = 3 232; 49.9%). The highest burden of cases occurred in 2017 (n = 2 526; 38%). The median age was 5 years (IQR: 3-7 years). Importantly, of females with rubella, 5.0% (161 of 3 232) of the cases were among women of reproductive age (15-44 years). A total of 62 CRS cases were reported, the mortality rate was 12.9% (n = 8), and the most common birth defect was congenital heart disease. In conclusion, rubella is endemic in South Africa. Children below the age of 10 years were the most affected, however, rubella was also reported among women of reproductive age. The baseline data represented here provides insight into the burden of rubella and CRS in South Africa prior to the introduction of a RCV, and can enable planning of RCV introduction into the South African EPI.

Congenital Rubella Syndrome Surveillance in South Africa Using a Sentinel Site Approach: A Cross-sectional Study

Background

Congenital rubella syndrome (CRS) includes disorders associated with intrauterine rubella infection. Incidence of CRS is higher in countries with no rubella-containing vaccines (RCV) in their immunization schedules. In the World Health Organization African region, RCVs are being introduced as part of the 2012–2020 global measles and rubella strategic plan. This study aimed to describe the epidemiology of confirmed CRS in South Africa prior to introduction of RCVs in the immunization schedule.

Methods

This was a descriptive study with 28 sentinel sites reporting laboratory-confirmed CRS cases in all 9 provinces of South Africa. In the retrospective phase (2010 to 2014), CRS cases were retrieved from medical records, and in the prospective phase (2015 to 2017) clinicians at study sites reported CRS cases monthly.

Results

There were 42 confirmed CRS cases in the retrospective phase and 53 confirmed CRS cases in the prospective phase. Most frequently reported birth defects were congenital heart disease and cataracts. The median age of mothers of CRS cases was 21 years in the retrospective phase (range: 11 to 38 years) and 22 years in the prospective phase (range: 15 to 38 years).

Conclusion

Baseline data on laboratory-confirmed CRS will enable planning and monitoring of RCV implementation in the South African Expanded Programme on Immunization program. Ninety-eight percent of mothers of infants with CRS were young women 14–30 years old, indicating a potential immunity gap in this age group for consideration during introduction of RCV.

Measles seroprevalence after reactive vaccination campaigns during the 2015 measles outbreak in four health zones of the former Katanga Province, Democratic Republic of Congo

BACKGROUND

Measles continues to circulate in the Democratic Republic of Congo, and the country suffered from several important outbreaks over the last 5 years. Despite a large outbreak starting in the former province of Katanga in 2010 and the resulting immunization activities, another outbreak occurred in 2015 in this same region. We conducted measles seroprevalence surveys in four health zones (HZ) in the former Katanga Province in order to assess the immunity against measles in children 6 months to 14 years after the 2015 outbreak.

METHODS

We conducted multi-stage cluster surveys stratified by age group in four HZs, Kayamba, Malemba-Nkulu, Fungurume, and Manono. The age groups were 6-11 months, 12-59 months, and 5-14 years in Kayamba and Malemba-Nkulu, 6-59 months and 5-14 years in Manono and Fungurume. The serological status was measured on dried capillary blood spots collected systematically along with vaccination status (including routine Extended Program of Immunization (EPI), and supplementary immunization activities (SIAs)) and previous self-reported history of suspected measles.

RESULTS

Overall seroprevalence against measles was 82.7% in Kayamba, 97.6% in Malemba-Nkulu, 83.2% in Manono, and 74.4% in Fungurume, and it increased with age in all HZs. It was 70.7 and 93.8% in children 12-59 months in Kayamba and Malemba-Nkulu, and 49.8 and 64.7% in children 6-59 months in Fungurume and Manono. The EPI coverage was low but varied across HZ. The accumulation of any type of vaccination against measles resulted in an overall vaccine coverage (VC) of at least 85% in children 12-59 months in Kayamba and Malemba-Nkulu, 86.1 and 74.8% in children 6-59 months in Fungurume and Manono. Previous measles infection in 2015-early 2016 was more frequently reported in children aged 12-59 months or 6-59 months (depending on the HZ).

CONCLUSION

The measured seroprevalence was consistent with the events that occurred in these HZs over the past few years. Measles seroprevalence might prove a valuable source of information to help adjust the timing of future SIAs and prioritizing support to the EPI in this region as long as the VC does not reach a level high enough to efficiently prevent epidemic flare-ups.

Detection of viral RNA by RT-PCR from serum for molecular diagnosis of measles

Measles continues to be a cause of morbidity and mortality in Côte d'Ivoire although the death rates are weak (2.4%). The monitoring and elimination programme of this disease require a laboratory confirmation testing by diverse methods of diagnosis needing diverse biological products. Serum is usually used for IgM detection. This study has therefore assessed the importance of the measles virus RNA detection from sera of measles suspected cases for confirmation of the case and determination of the genotype. A total of 45 sera tested were split into two groups according to the interval between the rash appearance and the day of blood collection: Group 1 (day 1 to day 3); group (2 day 4 to day 7). Four sera from Group 1 of the 45 (8.9 %) were positive by RT-PCR technique while 10 (22.2%) sera were positive for IgM anti- measles virus by ELISA test. RT-PCR and ELISA showed the same performance in group 1 with a positivity rate of 13.79 %. The B3 genotype was found. This result showed that the viral RNA can be detected in the serum but only from those sera collected the first 3 days after the rash appearance and could be used as palliative in case it is impossible to obtain other biological products.

RNA structure prediction from evolutionary patterns of nucleotide composition

Structural elements in RNA molecules have a distinct nucleotide composition, which changes gradually over evolutionary time. We discovered certain features of these compositional patterns that are shared between all RNA families. Based on this information, we developed a structure prediction method that evaluates candidate structures for a set of homologous RNAs on their ability to reproduce the patterns exhibited by biological structures. The method is named SPuNC for ‘Structure Prediction using Nucleotide Composition’. In a performance test on a diverse set of RNA families we demonstrate that the SPuNC algorithm succeeds in selecting the most realistic structures in an ensemble. The average accuracy of top-scoring structures is significantly higher than the average accuracy of all ensemble members (improvements of more than 20% observed). In addition, a consensus structure that includes the most reliable base pairs gleaned from a set of top-scoring structures is generally more accurate than a consensus derived from the full structural ensemble. Our method achieves better accuracy than existing methods on several RNA families, including novel riboswitches and ribozymes. The results clearly show that nucleotide composition can be used to reveal the quality of RNA structures and thus the presented technique should be added to the set of prediction tools.

Evolutionary rates vary among rRNA structural elements

Understanding patterns of rRNA evolution is critical for a number of fields, including structure prediction and phylogeny. The standard model of RNA evolution is that compensatory mutations in stems make up the bulk of the changes between homologous sequences, while unpaired regions are relatively homogeneous. We show that considerable heterogeneity exists in the relative rates of evolution of different secondary structure categories (stems, loops, bulges, etc.) within the rRNA, and that in eukaryotes, loops actually evolve much faster than stems. Both rates of evolution and abundance of different structural categories vary with distance from functionally important parts of the ribosome such as the tRNA path and the peptidyl transferase center. For example, fast-evolving residues are mainly found at the surface; stems are enriched at the subunit interface, and junctions near the peptidyl transferase center. However, different secondary structure categories evolve at different rates even when these effects are accounted for. The results demonstrate that relative rates and patterns of evolution are lineage specific, suggesting that phylogenetically and structurally specific models will improve evolutionary and structural predictions.

Identical genotype B3 sequences from measles patients in 4 countries, 2005

Surveillance of measles virus detected an epidemiologic link between a refugee from Kenya and a Dutch tourist in New Jersey, USA. Identical genotype B3 sequences from patients with contemporaneous cases in the United States, Canada, and Mexico in November and December 2005 indicate that Kenya was likely to have been the common source of virus.

Evaluating the evaluators: interrater reliability on EMT licensing examinations

INTRODUCTION

Current methods of evaluating the technical competence of Michigan emergency medical technician (EMT) licensure candidates are subjective and potentially unreliable. Evaluators are required to attend a workshop before evaluating practical examination candidates. Despite the workshop, there is too much score variation and not enough observational consistency on the standardized examination.

OBJECTIVE

To determine the level of rater reliability for evaluators of EMT practical examinations.

METHODS

Data were collected from 104 licensed instructor-coordinators (ICs). Participants watched and scored two practical examinations simulated on videotape, one passing and one failing performance. Variation in student score and level of evaluator agreement concerning skill performance were determined. Michigan's basic EMT practical examination scoring instrument was used.

RESULTS

Nine basic EMT, 9 EMT specialist, and 86 EMT-paramedic ICs participated. Thirty-four percent had high school diplomas, 43% associate's degrees, 19% bachelor's degrees, 3% master's degrees, and 1% a doctoral degree. The ICs averaged 14 years of provider experience, and 6.35 years as an IC. The average score for scenario 1 (passing) was 86.4% (SD = 9.15, range = 53). An 80% score is required to pass. Nine ICs (9%) failed the student. Scenario 1 evaluator agreement was 79.4%. The average score for scenario 2 (failing) was 60.9% (SD = 11.57, range = 57). Seventeen ICs (18%) gave the student a passing score. Scenario 2 evaluator agreement was 67.8%. There was no significant difference in student scores based on evaluator level of education, licensure, or evaluator workshop attendance for either scenario.

CONCLUSION

Notable variation in scores given by evaluators for a single observed student, combined with low levels of evaluator agreement about skill performance, suggests that evaluators do not reliably rate student performance using the Michigan practical examination instrument.

The effect of manure and litter handling and indoor climatic conditions on ammonia emissions from a battery cage and an aviary housing system for laying hens

Ammonia emissions from both traditional and new welfare-based housing systems for laying hens must be reduced to prevent detrimental effects on the environment. In a comparative study, the effect of manure handling (variation in drying and removal frequency) in a battery cage and the effect of manure handling (as in battery cage system) and litter treatment (removal of litter) in a Tiered Wire Floor (TWF) aviary system on the emission of ammonia were investigated. Each system housed 6480 hens, treatments were varied in time, and effects were analysed by means of time-series analysis. The hens in the TWF system dropped 22.5% of their excreta in the litter and the remaining part, like all manure in the battery cage system, was dropped on the manure belts. The estimated emission from the manure on the belts in both systems was 18.8 g/h (daily mean, manure removal twice a day), whereas the emission from the litter in the TWF system amounted to 62.5 g/h. Emission from the belt manure on a typical day increased by 14, 39, 109 and 177% from the 1st until the 4th day after manure removal. The effect of increasing temperature and water vapour pressure difference on emission was +17% and -22% per degree and per kPa, respectively. Drying of manure on the belts increased the dry matter content of the manure and showed a tendency towards lower emissions. The dry matter content of the litter varied between 780 and 840 g/kg, the mean total nitrogen content was 3.3% of the dry matter, and the layer thickness varied between 2 and 9 cm. Both the ammonia content, which ranged between 20 and 190 mg/kg, and the layer thickness of the litter influenced the emission from the litter positively.

Control of cAMP-induced gene expression by divergent signal transduction pathways

A compilation of literature data and recent experiments led to the following conclusions regarding cyclic adenosine 3':5' monophosphate (cAMP) regulation of gene expression. Several classes of cAMP-induced gene expression can be discriminated by sensitivity to stimulation kinetics. The aggregation-related genes respond only to nanomolar cAMP pulses. The prestalk-related genes respond both to nanomolar pulses and persistent micromolar stimulation. The prespore specific genes respond only to persistent micromolar stimulation. The induction of the aggregation- and prestalk-related genes by nanomolar cAMP pulses may share a common transduction pathway, which does not involve cAMP, while involvement of the inositol 1,4,5-trisphosphate (IP3)/Ca2+ pathway is unlikely. Induction of the expression of prespore and prestalk-related genes by micromolar cAMP stimuli utilizes divergent signal processing mechanisms. cAMP-induced prespore gene expression does not involve cAMP and probably also not cyclic guanosine 3'.5' monophosphate (cGMP) as intracellular intermediate. Involvement of cAMP-induced phospholipase C (PLC) activation in this pathway is suggested by the observation that IP3 and 1,2-diacylglycerol (DAG) can induce prespore gene expression, albeit in a somewhat indirect manner and by the observation that Li+ and Ca2+ antagonists inhibit prespore gene expression. Cyclic AMP induction of prestalk-related gene expression is inhibited by IP3 and DAG and promoted by Li+, and is relatively insensitive to Ca2+ antagonists, which indicates that PLC activation does not mediate prestalk-related gene expression. Neither prespore nor prestalk-related gene expression utilizes the sustained cAMP-induced pHi increase as intracellular intermediate.

Relations among self-esteem, depression and anxiety of children

930 boys and girls enrolled in Grades 2 through 9 participated in a study of the relations among self-esteem, depression, and anxiety. The criterion measures correlated significantly for all children, boys and girls in both elementary and junior high groups. Depression correlated higher with total self-esteem for all children, boys and girls in elementary and junior high school groups.

Iron uptake by Chinese hamster fibroblasts from human transferrin

The manner of uptake or iron by Chinese hamster fibroblasts, type DON, from human transferrin was investigated by means of replacement studies, in which the cells that were incubated with 125I-labelled human transferrin were chased with non-radioactive transferrin for only a few minutes. The results did not support the reversible endocytosis hypothesis for the uptake of iron from transferrin. The uptake of iron measured as 59Fe during several cell divisions was found to be a function of time and cell number. It was found that the total uptake of iron in the harvests was directly proportional to the incubation, and that the uptake per 10(6) cells levelled off in the course of time.

Polynuclear iron compounds in human transferrin preparations

During commonly used saturation procedures of transferrin with iron compounds, both as ferri and ferrous, polynuclear iron compounds are easily formed, even when nitrilotriacetate (NTA) is used as a strong iron ligand. The presence of these nonspecific bound irons is demonstrated with Mossbauer spectroscopy and with electronic optical spectroscopy. But no evidence, however, has been found of two different iron binding sites. Because dialysis is not able to remove all polynuclear iron, an easy method with gel filtration has been developed that does remove the polynuclear iron. Some notes are made about the often used method, in transferrin biochemistry, of saturation determination, i.e. the quotient of the absorbances of 470 and 280 nm.

Analysis of the urine of the okapi (Okapia johnstoni)

The urine of six adult and two juvenile okapis housed in The Royal Rotterdam Zoological and Botanical Gardens were analysed qualitatively for the presence of protein, glucose, bilirubin, nitrite, blood and ketones and the pH was measured. Quantitative analyses were undertaken for osmolality, urea, creatinine and glucose. The results of the analyses were generally unremarkable with the exceptions of pH, glucose and in some cases the urea/creatinine ratios. However, with the exception of the glucose these other results are physiologically normal. One possible explanation for the presence of glucose in the urine of the okapis is dietary. In the wild these animals are folivorous and thus they may not be able to cope with the high level of sugar presented to them in their captive diet. However, it must be emphasised that this condition has no apparent ill effects on the animals which are in good health and are breeding successfully.

Porphyrin synthesis in blood cells of patients with erythropoietic protoporphyria

The protoporphyrin accumulation observed in the red blood cells of patients with erythropoietic protoporphyria can be explained by decreased activity of the enzyme heme synthetase or by increased production of porphyrins in the affected cells. In literature experimental evidence both for a partial heme synthetase deficiency and for increased porphyrin biosynthesis has been presented. In a group of ten patients with erythropoietic protoporphyria the biosynthesis of porphyrins from delta-aminolevulinic acid and from glycine-succinic acid appeared to be normal in peripheral blood cells. These results are consistent with the partial heme synthetase deficiency previously found to be the basic defect of this disease.