Streptococcus pneumoniae serotypes/serogroups causing invasive disease in Riyadh, Saudi Arabia: extent of coverage by pneumococcal vaccines

Cost-effectiveness and budget impact analysis of PPV23 vaccination for the Malaysian Hajj pilgrims

The potential occurrence of disease outbreaks during the hajj season is of great concern due to extreme congestion in a confined space. This promotes the acquisition, spread and transmission of pathogenic microorganisms and pneumococcal disease are one of the most frequent infections among Hajj pilgrims. This study aimed to assess the cost-effectiveness and budget impact of introducing the PPV23 to Malaysian Hajj pilgrims. A decision tree framework with a 1-year cycle length was adapted to evaluate the cost-effectiveness of a PPV23 vaccination program with no vaccination. The cost information was retrieved from the Lembaga Tabung Haji Malaysia (LTH) database. Vaccine effectiveness was based on the locally published data and the disease incidence specifically related to Streptococcus pneumoniae was based on a literature search. Analyses were conducted from the perspective of the provider: Ministry of Health and LTH Malaysia. The incremental cost-effectiveness ratios (ICER), cases averted, and net cost savings were estimated. Findings from this study showed that PPV23 vaccination for Malaysian Hajj pilgrims was cost-effective. The PPV23 vaccination programme has an ICER of MYR -449.3 (US$-110.95) per case averted. Based on the national threshold value of US$6,200-US$8,900 per capita, the base-case result shows that introduction of the PPV23 vaccine for Malaysian Hajj pilgrims is very cost-effective. Sensitivity analysis revealed parameters related to annual incidence and hospitalised cost of septicemia and disease without vaccination as the key drivers of the model outputs. Compared with no vaccination, the inclusion of PPV23 vaccination for Malaysian Hajj pilgrims was projected to result in a net cost saving of MYR59.6 million and 109,996 cases averted over 5 years period. The PPV23 vaccination program could substantially offer additional benefits in reducing the pneumococcal disease burden and healthcare cost. This could be of help for policymakers to consider the implementation of PPV23 vaccination for Malaysian performing hajj.

The Saudi Thoracic Society pneumococcal vaccination guidelines-2016

Streptococcus pneumoniae (pneumococcus) is the leading cause of morbidity and mortality worldwide. Saudi Arabia is a host to millions of pilgrims who travel annually from all over the world for Umrah and the Hajj pilgrimages and are at risk of developing pneumococcal pneumonia or invasive pneumococcal disease (IPD). There is also the risk of transmission of S. pneumoniae including antibiotic resistant strains between pilgrims and their potential global spread upon their return. The country also has unique challenges posed by susceptible population to IPD due to people with hemoglobinopathies, younger age groups with chronic conditions, and growing problem of antibiotic resistance. Since the epidemiology of pneumococcal disease is constantly changing, with an increase in nonvaccine pneumococcal serotypes, vaccination policies on the effectiveness and usefulness of vaccines require regular revision. As part of the Saudi Thoracic Society (STS) commitment to promote the best practices in the field of respiratory diseases, we conducted a review of S. pneumoniae infections and the best evidence base available in the literature. The aim of the present study is to develop the STS pneumococcal vaccination guidelines for healthcare workers in Saudi Arabia. We recommend vaccination against pneumococcal infections for all children <5 years old, adults ≥50 years old, and people ≥6 years old with certain risk factors. These recommendations are based on the presence of a large number of comorbidities in Saudi Arabia population <50 years of age, many of whom have risk factors for contracting pneumococcal infections. A section for pneumococcal vaccination before the Umrah and Hajj pilgrimages is included as well.

Epidemiology of invasive pneumococcal disease in Saudi Arabian children younger than 5years of age

This study evaluated the incidence, serotype distribution, and antimicrobial susceptibility of invasive pneumococcal disease (IPD) in Saudi Arabian children. This multicenter, prospective, clinical surveillance study included children under 5 years of age, residents of one of the seven study health areas, who were brought to a study hospital with suspicion of IPD. Bacterial isolates from sterile site samples, collected less than 24 h after hospital visit/admission, were identified, serotyped, and tested for antibiotic susceptibility. Between June 2007 and January 2009, 631 episodes of suspected IPD were recorded, and 623 were included in the analysis. One child (0.2%) had previously received one dose of a pneumococcal vaccine. Forty-seven episodes were positive for Streptococcus pneumoniae and three for Haemophilus influenzae. The incidence of confirmed IPD cases was estimated to be 2.5–21.6 per 100,000 children (<5 years). Among the 46 S. pneumoniae isolates serotyped and tested for antibiotic susceptibility, the most common serotypes were 5 and 23F (20% each), 6B (17%), and 1 and 14 (11% each). Sixty-three percent of isolates were multidrug-resistant. Vaccination of Saudi Arabian children with expanded-coverage conjugate pneumococcal vaccines containing serotypes 1 and 5 could have a substantial impact to prevent IPD in this population.

Distribution of serotypes and antibiotic susceptibility patterns among invasive pneumococcal diseases in Saudi Arabia

BACKGROUND

Streptococcus pneumoniae causes life-threatening infections such as meningitis, pneumonia, and febrile bacteremia, particularly in young children. The increasing number of drug-resistant isolates has highlighted the necessity for intervening and controlling disease. To achieve this, information is needed on serotype distribution and patterns of antibiotic resistance in children.

METHODS

All cases of invasive pneumococcal disease (IPD) in children aged less than 15 yr recorded at King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia, were reviewed for serotyping and antibiotic susceptibility. Isolates were collected from 78 consecutive patients with IPD between 2009 and 2012. All collected isolates were subjected to serotyping by co-agglutination, sequential multiplex PCR, and single PCR sequetyping as previously described.

RESULTS

The most frequently isolated IPD serotypes were 23F, 6B, 19F, 18C, 4, 14, and 19A, which are listed in decreasing order and cover 77% of total isolates. The serotype coverage for the pneumococcal conjugate vaccine (PCV)7, PCV10, and PCV13 was 77%, 81%, and 90%, respectively. Results from sequential multiplex PCR agreed with co-agglutination results. All serotypes could not be correctly identified using single PCR sequetyping. Minimum inhibitory concentration showed that 50 (64%) isolates were susceptible to penicillin, whereas 70 (90%) isolates were susceptible to cefotaxime.

CONCLUSIONS

The most common pneumococcal serotypes occur with frequencies similar to those found in countries where the PCV has been introduced. The most common serotypes in this study are included in the PCVs. Addition of 23A and 15 to the vaccine would improve the PCV performance in IPD prevention.

Global prevailing and emerging pediatric pneumococcal serotypes

Streptococcus pneumoniae is the leading cause of vaccine-preventable deaths among children younger than 5 years of age worldwide. The 7-valent pneumococcal conjugate vaccine (PCV7) is currently licensed in more than 90 countries and has contributed to significant declines in the incidence of invasive pneumococcal disease (IPD). Recent studies report an increased incidence of IPD caused by non-PCV7 vaccine serotypes (NVTs). Seroepidemiology of IPD caused by NVTs following the introduction of PCV7 is of interest, and this article provides a comprehensive global summary of the prevailing and emerging serotypes causing IPD in children. Currently, globally emerging or persistent NVTs include serotypes 1, 3, 5, 6A, 7F and 19A. Serotypes included in the recently licensed 10-valent pneumococcal Haemophilus influenzae protein D conjugate vaccine (PCV10) and 13-valent pneumococcal conjugate vaccine (PCV13) account for pneumococcal disease burdens in most developed countries of 65-85% and 80-90%, respectively. The seroprevalence of NVTs after widespread use of PCV10 and PCV13 requires ongoing monitoring.

Distribution of serotypes and antibiotic resistance of invasive pneumococcal disease isolates among children aged 5 years and under in Saudi Arabia (2000-2004)

To determine vaccine coverage of invasive pneumococcal disease (IPD) in Saudi Arabian children aged 5 years and under, 350 IPD isolates were tested for antibiotic susceptibility. Of these 46%, 42% and 12% were penicillin-sensitive, pencillinintermediate, and penicillin-resistant, respectively. Rates of resistance to erythromycin and cefotaxime were 26% and 6%, respectively. The potential serotype coverage of the PCV7 vaccine in Saudi Arabia among children <5 years of age is 62%, and vaccine coverage significantly improved in children <2 years of age, to reach 83% against IPD isolates. PCV7 is expected to have a substantial impact on the burden of invasive and antibiotic-resistant pneumococcal disease in Saudi Arabia.

Emergence and trends of penicillin non-susceptible Streptococcus pneumoniae in Saudi Arabia and Kuwait - perspective and outstanding issues

For many years in the past Streptococcus pneumoniae was uniformly susceptible to penicillin until the sudden and unexpected emergence of clinical infections caused by penicillin-resistant S. pneumoniae (PRSP) in 1967. Within the following decade, reports of nosocomial and community outbreaks of infections due to PRSP became widespread all over the world. Recent reports suggest that the incidence of resistance rates is rising in many countries although there are geographical variations in the prevalence and patterns of resistance between countries. The problem of antibiotic resistance is further compounded by the emergence of resistance to many beta-lactam antibiotics. The first report of PRSP in Saudi Arabia was in 1991. Barely a year after, PRSP infection was reported in Kuwait in 1992. Since then, studies from various parts of these countries have recorded prevalence rates ranging from 6.2% in Riyadh to 34% in Jeddah and 20% to 56% in neighboring Kuwait. These suggest considerable variation in the prevalence of PRSP in different cities in the Saudi Kingdom and Kuwait. The mechanism of resistance is due to chromosomally mediated alteration of penicillin-binding proteins (PBPs), which are target sites for beta-lactam antibiotics. It would appear that the spread of PRSP strains in Saudi Arabia is driven by the selective pressure created by excessive use and misuse of antimicrobial agents made possible by the easy availability of these agents, often frequently obtainable over the counter. In Kuwait, irrational and misguided use of antibiotics may be the major driving force favoring the spread of PRSP. The serotypes of strains encountered in Saudi Arabia and Kuwait are almost identical, with serotypes 19, 6, 15, 14 and 23 being the most common; together they constitute about 70% of the isolates circulating in these countries. In general, almost 90% of the serotypes included in the 23-polyvalent vaccine are present in the general population. However, a much lower percentage of these serotypes is found in the conjugated vaccines, which are more relevant to our communities. This paper reviews the emergence and the steady increase in the prevalence of penicillin-resistant pneumococcal strains in Saudi Arabia and Kuwait during the last 10 years. It discusses the trends, mechanisms of resistance and factors associated with the emergence, dissemination, and colonization of resistant organisms and suggests options available to clinicians for management of infections due to PRSP.

The epidemiology of pneumococcal, meningococcal, and Haemophilus disease in the Middle East and North Africa (MENA) region--current status and needs

Information about the burden and epidemiological characteristics of meningitis and other invasive disease caused by Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis is of great value to healthcare decision makers to prioritize public health interventions. A group of regional experts in the Eastern Mediterranean and North African regions formed the MENA Vaccine-Preventable Diseases Regional Advisory Group to collate and discuss such information on an annual basis. This paper provides an up-to-date summary of the available epidemiological data regarding these pathogens in these regions. In doing so, it highlights the need for additional surveillance studies to better measure the burden of these diseases, as well as the potential impact of introduction of new vaccines against these pathogens.