A diphtheria outbreak in Johor Bahru, Malaysia: Public health investigation and response

INTRODUCTION

Diphtheria is an acute infectious disease caused by Corynebacterium diphtheriae. Although the incidence of diphtheria worldwide has rapidly declined following the largely successful diphtheria toxoid-based vaccines, concerns persist for those who were unvaccinated or incompletely vaccinated. In this report, we describe a recent diphtheria outbreak in Malaysia involving four confirmed diphtheria cases.

METHODOLOGY

The outbreak investigation efforts and epidemiological characteristics of a diphtheria outbreak in Malaysia are described. For all suspected cases, swabs were taken and sent for isolation of Corynebacterium diphtheriae and confirmation of toxigenic strains.

RESULTS

The index case was a two-year-old child living with his family in a welfare home. Following contact tracing efforts and investigation for suspected cases, seven samples came back as culture positive for Corynebacterium diphtheriae. Confirmation of toxigenic strains was performed using PCR and Elek's test, which showed 100% correlation in positivity for four of the samples. All four confirmed cases were below 18 years of age, and three of them did not have complete vaccination history (two unvaccinated, one unknown). The index case eventually succumbed due to severe diphtheria with multiorgan failure while all the other cases were discharged healthy.

CONCLUSIONS

In Malaysia, despite good vaccination coverage, sporadic diphtheria outbreaks still occur. The rising trend of cases reported over the recent years underscores the need to remain vigilant. Addressing pockets of unvaccinated children and potential waning immunity levels in the population remains pivotal.

Trends in Adult and Elderly Vaccination: Focus on Vaccination Practices in Tunisia and Morocco

Vaccine preventable diseases (VPDs) are a prevailing concern among the adult population, despite availability of vaccines. Unlike pediatric vaccination programs, adult vaccination programs lack the required reach, initiative, and awareness. Clinical studies and real-world data have proven that vaccines effectively reduce the disease burden of VPDs and increase life expectancy. In Tunisia and Morocco, the national immunization program (NIP) focuses more on pediatric vaccination and have limited vaccination programs for adults. However, some vaccination campaigns targeting adults are organized. For example, influenza vaccination campaigns prioritizing at risk adults which includes healthcare professionals, elderly, and patients with comorbidities. Women of childbearing age who have never been vaccinated or whose information is uncertain are recommended to receive tetanus vaccination. Tunisia NIP recommends rubella vaccine mainly for women of childbearing age, while in Morocco, national vaccination campaigns were organized for girls and women (up to 24 years of age) to eliminate rubella. Further, travelers from both countries are recommended to follow all requirements and recommendations in the travel destination. The objective of this manuscript is to provide an overview of the global disease burden of common VPDs including (but not limited to) meningococcal diseases, pneumococcal diseases, hepatitis, and influenza. The review also provides an overview of clinical data and guidelines/recommendations on adult vaccination practices, with special focus on Tunisia and Morocco. Some European and North American countries have concrete recommendations and strategies for adult vaccination to keep the VPDs in check. In Morocco and Tunisia, although, there are sporadic adult vaccination initiatives, the efforts still need upscaling and endorsements to boost vaccination awareness and uptake. There is a need to strengthen strategies in both countries to understand the disease burden and spread awareness. Additional studies are needed to generate economic evidence to support cost-effectiveness of vaccines. Integration of private and public healthcare systems may further improve vaccination uptake in adults.

Mental Health Conditions and Severe COVID-19 Outcomes after Hospitalization, United States

Among 664,956 hospitalized COVID-19 patients during March 2020-July 2021 in the United States, select mental health conditions (i.e., anxiety, depression, bipolar, schizophrenia) were associated with increased risk for same-hospital readmission and longer length of stay. Anxiety was also associated with increased risk for intensive care unit admission, invasive mechanical ventilation, and death.

Analyzing and Modeling the Spread of SARS-CoV-2 Omicron Lineages BA.1 and BA.2, France, September 2021-February 2022

We analyzed 324,734 SARS-CoV-2 variant screening tests from France enriched with 16,973 whole-genome sequences sampled during September 1, 2021–February 28, 2022. Results showed the estimated growth advantage of the Omicron variant over the Delta variant to be 105% (95% CI 96%–114%) and that of the BA.2 lineage over the BA.1 lineage to be 49% (95% CI 44%–52%). Quantitative PCR cycle threshold values were consistent with an increased ability of Omicron to generate breakthrough infections. Epidemiologic modeling shows that, in spite of its decreased virulence, the Omicron variant can generate important critical COVID-19 activity in hospitals in France. The magnitude of the BA.2 wave in hospitals depends on the level of relaxing of control measures but remains lower than that of BA.1 in median scenarios.

Suspected Cat-to-Human Transmission of SARS-CoV-2, Thailand, July-September 2021

A veterinarian in Thailand was diagnosed with COVID-19 after being sneezed on by an infected cat owned by an infected patient. Genetic study supported the hypothesis of SARS-CoV-2 transmission from the owner to the cat, and then from the cat to the veterinarian.

Multisystem Inflammatory Syndrome after Breakthrough SARS-CoV-2 Infection in 2 Immunized Adolescents, United States

Eight weeks after having laboratory-confirmed SARS-CoV-2 breakthrough infections, 2 otherwise healthy, fully immunized adolescent patients in the United States who were experiencing related signs and symptoms were diagnosed with multisystem inflammatory syndrome in children. Our findings indicate that COVID-19 vaccination does not completely protect adolescents against multisystem inflammatory syndrome.

Zoster Meningitis in an Immunocompetent Child after COVID-19 Vaccination, California, USA

Varicella zoster virus reactivation after COVID-19 vaccination has been reported in older or immunocompromised adults. We report zoster meningitis from live-attenuated varicella vaccine reactivation in an immunocompetent child after COVID-19 vaccination. This type of case is rare; COVID-19 and varicella vaccines remain safe and effective for appropriate recipients in the pediatric population.

SARS-CoV-2 Neutralizing Antibodies in Chile after a Vaccination Campaign with Five Different Schemes

Using levels of neutralizing antibodies (nAbs), we evaluate the successful Chilean SARS-CoV-2 vaccine campaign, which combines different vaccine technologies and heterologous boosters. From a population-based study performed in November 2021, we randomly selected 120 seropositive individuals, organized into six groups of positive samples (20 subjects each) according to natural infection history and the five most frequent vaccination schemes. We conclude that the booster dose, regardless of vaccine technology or natural infection, and mRNA vaccines significantly improve nAbs response.

Identification and molecular characterization of penicillin-nonsusceptible Streptococcus pneumoniae isolates recovered from invasive infections in a pre-pneumococcal vaccine era

BACKGROUND

Given the significant role of penicillin-nonsusceptible Streptococcus pneumoniae in inducing severe infectious diseases, identifying serotypes and genotypes that can mediate antimicrobial resistance has become a pillar of treatment strategies. This study aims to determine the correlation between the minimum inhibitory concentration of antimicrobial agents and amino acid mutations in penicillin-binding proteins. Moreover, molecular serotyping and multiple-locus variable number tandem repeat analysis typing were first-ever performed to characterize the invasive penicillin-nonsusceptible S. pneumoniae isolates in Iran.

METHODS

Of 149 isolates, antimicrobial susceptibility tests were performed against penicillin, ceftriaxone, and cefotaxime by the MIC Test Strip, and sequence analysis of the pbp genes was performed through PCR-sequencing method. All penicillin-nonsusceptible S. pneumoniae isolates were serotyped and genotyped by sequential multiplex PCR and multiple-locus variable-number tandem repeat analysis, respectively.

RESULTS

Among pneumococcal isolates, 53 isolates were classified as penicillin-nonsusceptible S. pneumoniae, of which 38 (71.7%) and 15 (28.3%) were resistant and intermediate to penicillin, respectively. Furthermore, ceftriaxone- and cefotaxime-nonsusceptible pneumococci constituted 33 (62.2%) and 29 cases (54.7%), respectively. Of note, there were 8 and 41 different serotypes and multiple-locus variable-number tandem repeat analysis types, respectively.

CONCLUSIONS

Due to the increasing resistance to antimicrobial agents, the most efficient approach to preventing pneumococcal infection mortality as vaccine-preventable diseases is focusing on wide-spectrum vaccination. Based on our findings, the 13-valent pneumococcal conjugate vaccine could considerably reduce the incidence of invasive pneumococcal diseases due to the high rate of serotype coverage.

Serial Intervals for SARS-CoV-2 Omicron and Delta Variants, Belgium, November 19-December 31, 2021

We investigated the serial interval for SARS-CoV-2 Omicron BA.1 and Delta variants and observed a shorter serial interval for Omicron, suggesting faster transmission. Results indicate a relationship between empirical serial interval and vaccination status for both variants. Further assessment of the causes and extent of Omicron dominance over Delta is warranted.

Effectiveness of immunization activities on measles and rubella immunity among individuals in East Sepik, Papua New Guinea: A cross-sectional study

Objectives

This study aimed to assess measles and rubella immunity by measuring virus-specific immunoglobulin G (IgG) prevalence among individuals and evaluate the effectiveness of recent supplementary immunization activities (SIAs) by comparing the antibody positivity rates of the SIA target age groups in 2015 with those in 2019 as measles and rubella are endemic in Papua New Guinea.

Methods

A cross-sectional study. The measles- and rubella-specific IgG levels of patients aged ≥1 year at two clinics in East Sepik province, Papua New Guinea were assessed with commercially available virus-specific IgG EIA kits.

Results

In total, 297 people participated in the study and 278 samples with sufficient volume, relevant information, and age inclusion criteria were analyzed. The overall IgG prevalence rates were 62.6% for measles and 82.0% for rubella. The age groups targeted in the 2019 SIAs had a higher IgG prevalence than those targeted in the 2015 SIAs for both the infectious diseases. Moreover, the IgG prevalence for rubella was higher than measles in these groups.

Conclusions

The anti-measles and anti-rubella IgG prevalence in the target groups were lower than those required for herd immunity. The immunization program should be emphasized to eliminate measles and rubella. Further population-based studies are warranted.

Estimating Relative Abundance of 2 SARS-CoV-2 Variants through Wastewater Surveillance at 2 Large Metropolitan Sites, United States

Monitoring severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) is critical for public health management of coronavirus disease. Sequencing is resource-intensive and incompletely representative, and not all isolates can be sequenced. Because wastewater SARS-CoV-2 RNA concentrations correlate with coronavirus disease incidence in sewersheds, tracking VOCs through wastewater is appealing. We developed digital reverse transcription PCRs to monitor abundance of select mutations in Alpha and Delta VOCs in wastewater settled solids, applied these to July 2020-August 2021 samples from 2 large US metropolitan sewersheds, and compared results to estimates of VOC abundance from case isolate sequencing. Wastewater measurements tracked closely with case isolate estimates (Alpha, r_p 0.82-0.88; Delta, r_p 0.97). Mutations were detected in wastewater even at levels <5% of total SARS-CoV-2 RNA and in samples available 1-3 weeks before case isolate results. Wastewater variant monitoring should be strategically deployed to complement case isolate sequencing.

SARS-CoV-2 Seroprevalence after Third Wave of Infections, South Africa

By November 2021, after the third wave of severe acute respiratory syndrome coronavirus 2 infections in South Africa, seroprevalence was 60% in a rural community and 70% in an urban community. High seroprevalence before the Omicron variant emerged may have contributed to reduced illness severity observed in the fourth wave.

Estimating Relative Abundance of 2 SARS-CoV-2 Variants through Wastewater Surveillance at 2 Large Metropolitan Sites, United States

Monitoring severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) is critical for public health management of coronavirus disease. Sequencing is resource-intensive and incompletely representative, and not all isolates can be sequenced. Because wastewater SARS-CoV-2 RNA concentrations correlate with coronavirus disease incidence in sewersheds, tracking VOCs through wastewater is appealing. We developed digital reverse transcription PCRs to monitor abundance of select mutations in Alpha and Delta VOCs in wastewater settled solids, applied these to July 2020-August 2021 samples from 2 large US metropolitan sewersheds, and compared results to estimates of VOC abundance from case isolate sequencing. Wastewater measurements tracked closely with case isolate estimates (Alpha, rp 0.82-0.88; Delta, rp 0.97). Mutations were detected in wastewater even at levels <5% of total SARS-CoV-2 RNA and in samples available 1-3 weeks before case isolate results. Wastewater variant monitoring should be strategically deployed to complement case isolate sequencing.

Emerging Novel Reassortant Influenza A(H5N6) Viruses in Poultry and Humans, China, 2021

A novel highly pathogenic avian influenza A(H5N6) clade 2.3.4.4b virus was isolated from a poultry market in China that a person with a confirmed case had visited. Most genes of the avian and human H5N6 isolates were closely related. The virus also exhibited distinct antigenicity to the Re-11 vaccine strain.

Detection of SARS-CoV-2 B.1.351 (Beta) Variant through Wastewater Surveillance before Case Detection in a Community, Oregon, USA

Genomic surveillance has emerged as a critical monitoring tool during the SARS-CoV-2 pandemic. Wastewater surveillance has the potential to identify and track SARS-CoV-2 variants in the community, including emerging variants. We demonstrate the novel use of multilocus sequence typing to identify SARS-CoV-2 variants in wastewater. Using this technique, we observed the emergence of the B.1.351 (Beta) variant in Linn County, Oregon, USA, in wastewater 12 days before this variant was identified in individual clinical specimens. During the study period, we identified 42 B.1.351 clinical specimens that clustered into 3 phylogenetic clades. Eighteen of the 19 clinical specimens and all wastewater B.1.351 specimens from Linn County clustered into clade 1. Our results provide further evidence of the reliability of wastewater surveillance to report localized SARS-CoV-2 sequence information.

Dynamics of SARS-CoV-2 Antibody Response to CoronaVac followed by Booster Dose of BNT162b2 Vaccine

We evaluated the longitudinal dynamics of antibody response to the SARS-CoV-2 vaccine CoronaVac and the effect of a booster dose of BNT162b2 vaccine. We found a robust antibody response after the second dose of CoronaVac that wanes over time. The response was recovered by BNT162b2, which boosted anti-spike antibody titers.

Impact of the SARS-CoV-2 pandemic on vaccine-preventable disease campaigns

BACKGROUND

The COVID-19 pandemic has contributed to the widespread disruption of immunization services, including the postponement of mass vaccination campaigns.

METHODS

In May 2020, the World Health Organization (WHO) and partners started monitoring COVID-19-related disruptions to mass vaccination campaigns against cholera, measles, meningitis A, polio, tetanus-diphtheria, typhoid and yellow fever through the Immunization Repository Campaign Delay Tracker. The authors reviewed the number and target population of reported preventive and outbreak response vaccination campaigns scheduled, postponed, canceled and reinstated, at four time-points: May 2020, December 2020, May 2021 and December 2021.

FINDINGS

Mass vaccination campaigns across all vaccines were disrupted heavily by COVID-19. In May 2020, 105 of 183 (57%) campaigns were postponed or canceled in 57 countries due to COVID-19, with an estimated 796 million postponed or missed vaccine doses. Campaign resumption was observed beginning in July 2020. In December 2021, 77 of 472 (16%) campaigns in 54 countries, mainly in the African Region, were still postponed or canceled due to COVID-19, with about 382 million postponed or missed vaccine doses.

INTERPRETATION

There is likely high risk of vaccine-preventable disease outbreaks due to an increased number of susceptible persons resulting from the large-scale mass vaccination campaign postponement caused by COVID-19 across all regions.

Optimizing Immunization Strategies in Adult Patients With Chronic Liver Disease and Liver Transplant Recipients

Patients with chronic liver disease (CLD) and liver transplant recipients are at increased risk for infections from vaccine-preventable diseases. Gastroenterologists and hepatologists should assess patient immunization history, and necessary vaccinations should be given as soon as possible. Vaccines demonstrate superior immunogenicity when given earlier in the course of liver disease and prior to transplant. This article summarizes recommendations from the Advisory Committee on Immunization Practices for vaccinations in patients with CLD and liver transplant recipients, and includes a discussion of the influenza, herpes zoster, hepatitis A, hepatitis B, pneumococcal, human papillomavirus, and COVID-19 vaccines.

Tick-borne encephalitis (TBE) in Switzerland: does the prolongation of vaccine booster intervals result in an increased risk of breakthroughs?

BACKGROUND

In 2006, the Swiss Federal Office of Public Health (FOPH) decided recommending a prolongation of vaccine booster intervals after the third dose for the prevention of tick-borne encephalitis (TBE) from 3 to 10 years.

METHODS

To ascertain whether this amendment resulted in an increased rate of vaccine breakthroughs, we conducted a retrospective analysis of surveillance data collected 2000-19 by mandatory reporting to the Swiss FOPH. Fractions of breakthroughs [with 95% confidence intervals (CIs)]-0-3 years vs >3-10 years after the third vaccination dose-were compared across time periods and age groups.

RESULTS

Among 3205 notified TBE cases, known vaccination status was reported in 2562 (79.9%), including 103 patients with ≥3 vaccine doses (4.0%). Among those, there were 39 patients who had received the last dose within 3 years and 48 patients in the >3-10 years group. During the 2010-19 period in which the new booster strategy was implemented there were 23 and 38 breakthroughs, respectively, and the annual breakthrough rate was 7.7 (95% CI 5.0-11.7) cases during the first 3 years after the last dose, and 5.4 (95% CI 3.9-7.5) cases in following 7 years. We observed no significant trend of TBE breakthroughs with increasing age. Increasing numbers of TBE and of vaccine breakthroughs over time have been associated with spreading endemicity and higher vaccination coverage in Switzerland.

CONCLUSIONS

There is no indication that extended booster intervals resulted in an increased rate of breakthroughs, but there was a marked public health benefit with respect to increased acceptability of TBE immunization in the general population.

Durability of Antibody Response and Frequency of SARS-CoV-2 Infection 6 Months after COVID-19 Vaccination in Healthcare Workers

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies decay but persist 6 months postvaccination; lower levels of neutralizing titers persist against Delta than wild-type virus. Of 227 vaccinated healthcare workers tested, only 2 experienced outpatient symptomatic breakthrough infections, despite 59/227 exhibiting serologic evidence of SARS-CoV-2 infection, defined as presence of nucleocapsid protein antibodies.

Hantavirus Pulmonary Syndrome in a COVID-19 Patient, Argentina, 2020

We describe a patient in Argentina with severe acute respiratory syndrome coronavirus 2 infection and hantavirus pulmonary syndrome (HPS). Although both coronavirus disease and HPS can be fatal when not diagnosed and treated promptly, HPS is much more lethal. This case report may contribute to improved detection of co-infections in HPS-endemic regions.

Diminishing Immune Responses against Variants of Concern in Dialysis Patients 4 Months after SARS-CoV-2 mRNA Vaccination

Patients undergoing chronic hemodialysis were among the first to receive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccinations because of their increased risk for severe coronavirus disease and high case-fatality rates. By using a previously reported cohort from Germany of at-risk hemodialysis patients and healthy donors, where antibody responses were examined 3 weeks after the second vaccination, we assessed systemic cellular and humoral immune responses in serum and saliva 4 months after vaccination with the Pfizer-BioNTech BNT162b2 vaccine using an interferon-γ release assay and multiplex-based IgG measurements. We further compared neutralization capacity of vaccination-induced IgG against 4 SARS-CoV-2 variants of concern (Alpha, Beta, Gamma, and Delta) by angiotensin-converting enzyme 2 receptor-binding domain competition assay. Sixteen weeks after second vaccination, compared with 3 weeks after, cellular and humoral responses against the original SARS-CoV-2 isolate and variants of concern were substantially reduced. Some dialysis patients even had no detectable B- or T-cell responses.