The burden of pertussis in low- and middle-income countries since the inception of the Expanded Programme on Immunization (EPI) in 1974: a systematic review protocol

Type 5 secretion system antigens as vaccines against Gram-negative bacterial infections

Infections caused by Gram-negative bacteria are leading causes of mortality worldwide. Due to the rise in antibiotic resistant strains, there is a desperate need for alternative strategies to control infections caused by these organisms. One such approach is the prevention of infection through vaccination. While live attenuated and heat-killed bacterial vaccines are effective, they can lead to adverse reactions. Newer vaccine technologies focus on utilizing polysaccharide or protein subunits for safer and more targeted vaccination approaches. One promising avenue in this regard is the use of proteins released by the Type 5 secretion system (T5SS). This system is the most prevalent secretion system in Gram-negative bacteria. These proteins are compelling vaccine candidates due to their demonstrated protective role in current licensed vaccines. Notably, Pertactin, FHA, and NadA are integral components of licensed vaccines designed to prevent infections caused by Bordetella pertussis or Neisseria meningitidis. In this review, we delve into the significance of incorporating T5SS proteins into licensed vaccines, their contributions to virulence, conserved structural motifs, and the protective immune responses elicited by these proteins.

Pertussis outbreak investigation in Likimsa-Bokore kebele, Meda Walebu district, Bale zone, Oromia region, Ethiopia, 2019: a descriptive cross-sectional study

Introduction

pertussis is a major cause of childhood morbidity and mortality. Globally, an estimated 45 millions cases and 400,000 deaths occur every year. Meda Walebu surveillance office reported a pertussis outbreak among the residents of the Liqimsa-Bokore kebele communities. We investigated to describe the magnitude of the pertussis outbreak in Likimsa-Bokore kebele of Meda-Walebu district, Bale Zone, Southeast Ethiopia.

Methods

we conducted a descriptive cross-sectional study in April 2019. We identified pertussis cases recorded on the line list. Suspected cases of pertussis were defined as any resident of Likimsa-Bokore kebele with cough illness and any of the following: paroxysms of coughing, inspiratory whooping, post-tussive vomiting, or apnea. The pentavalent vaccine coverage data were extracted from the Bale zone health management information system department database. Microsoft Excel pivot table and SPSS version 23 software cleaned and analyzed the data.

Results

in three months period, a total of 439 suspected cases of pertussis were reported from Likimsa-Bokore kebele of the Meda-Walebu district. Half of the cases 220(50.1%) have occurred in females and the majority of cases 256 (58.3%) occurred in under five years children. The median age of cases was 4 years ranging from 2 months to 30 years (interquartile range= 4 years). The overall Attack Rate (AR) was 55 per 1000 population with a case fatality rate of 0.7% (3 deaths/439). Children less than five years were the most affected age group with an AR of 198 per 1000 population. The administrative pentavalent vaccine coverage of the district was above 100% during the year 2015-2018.

Conclusion

the overall attack rate of pertussis outbreak was high. Children under five years were the most affected age group irrespective of high administrative coverage of the pentavalent vaccine. Strengthening routine immunization management and intensified surveillance system is required for early detection, investigation, and response activities.

Pertussis outbreak investigation in Northwest Ethiopia: A community based study

Background

Pertussis or whooping cough is a vaccine-preventable, highly contagious, respiratory illness caused by Bordetella pertussis or Bordetella parapertussis. Infants and young children have remained most susceptible to pertussis-related morbidity and mortality. The aim of this study was to investigate pertussis infection and analyze the associated factors involved in the occurrence of the cases.

Methods

Community-based case-control was conducted in Dahena district, Northwest Ethiopia, from March 27—April 30, 2019. All cases ages 1–18 years old were identified by using the clinical standard case definition of pertussis adopted from World Health Organization (WHO). Data was collected using a structured questionnaire via face-to-face interviews. The data collected was cleaned, coded and entered into Epi info version 7.2.1.0 and exported to SPSS version 23 for statistical analysis. Bivariable and multivariable logistic regression analysis were employed to identify predictors. Factors with a p-value of < 0.05 were considered as independent risk factors of pertussis infection in multivariable logistic regression analysis.

Result

A total of 122 pertussis cases were enrolled from the Azila cluster of the Dahena district. Of these figures, 64 (52.5%) were females. The overall attack rate (AR) of pertussis cases in the cluster was 8.6/10000 population. The sex-specific AR of females was 8.9/10000 population. The multivariable logistic regression analysis showed that; being unvaccinated 4.17 (AOR, 4.17, 95% CI, 1.914–9.091), contact to cases 2.93 (AOR: 2.93, 95% CI 1.223–6.996), and living in a house with no window 2.6 (AOR: 2.6(95% CI 1.071 to 6.322) were the independent significantly risk factors for pertussis infection.

Conclusion

The contributing factor for pertussis infection was associated with case-contact, living in the house without windows and being unvaccinated. Wag Hemra Zone and Dahena district health office should encourage the vaccination activities of the cluster health center and awareness for the community should be practiced to limit disease transmission.

Seroprevalence of pertussis in Madagascar and implications for vaccination

Pertussis is a highly contagious infectious disease and remains an important cause of mortality and morbidity worldwide. Over the last decade, vaccination has greatly reduced the burden of pertussis. Yet, uncertainty in individual vaccination coverage and ineffective case surveillance systems make it difficult to estimate burden and the related quantity of population-level susceptibility, which determines population risk. These issues are more pronounced in low-income settings where coverage is often overestimated, and case numbers are under-reported. Serological data provide a direct characterisation of the landscape of susceptibility to infection; and can be combined with vaccination coverage and basic theory to estimate rates of exposure to natural infection. Here, we analysed cross-sectional data on seropositivity against pertussis to identify spatial and age patterns of susceptibility in children in Madagascar. A large proportion of individuals surveyed were seronegative; however, there were patterns suggestive of natural infection in all the regions analysed. Improvements in vaccination coverage are needed to help prevent additional burden of pertussis in the country.

The burden of laboratory-confirmed pertussis in low- and middle-income countries since the inception of the Expanded Programme on Immunisation (EPI) in 1974: a systematic review and meta-analysis

BACKGROUND

An effective vaccine against Bordetella pertussis was introduced into the Expanded Programme on Immunisation (EPI) by WHO in 1974, leading to a substantial global reduction in pertussis morbidity and mortality. In low- and middle-income countries (LMICs), however, the epidemiology of pertussis remains largely unknown. This impacts negatively on pertussis control strategies in these countries. This study aimed to systematically and comprehensively review published literature on the burden of laboratory-confirmed pertussis in LMICs over the 45 years of EPI.

METHODS

Electronic databases were searched for relevant literature (1974 to December 2018) using common and MeSH terms for pertussis. Studies using PCR, culture or paired serology to confirm Bordetella pertussis and parapertussis in symptomatic individuals were included if they had clearly defined numerators and denominators to determine prevalence and mortality rates.

RESULTS

Eighty-two studies (49,167 participants) made the inclusion criteria. All six WHO regions were represented with most of the studies published after 2010 and involving mainly upper middle-income countries (n = 63; 77%). PCR was the main diagnostic test after the year 2000. The overall median point prevalence of PCR-confirmed Bordetella pertussis was 11% (interquartile range (IQR), 5-27%), while culture-confirmed was 3% (IQR 1-9%) and paired serology a median of 17% (IQR 3-23%) over the period. On average, culture underestimated prevalence by 85% (RR = 0.15, 95% CI, 0.10-0.22) compared to PCR in the same studies. Risk of pertussis increased with HIV exposure [RR, 1.4 (95% CI, 1.0-2.0)] and infection [RR, 2.4 (95% CI, 1.1-5.1)]. HIV infection and exposure were also related to higher pertussis incidences, higher rates of hospitalisation and pertussis-related deaths. Pertussis mortality and case fatality rates were 0.8% (95% CI, 0.4-1.4%) and 6.5% (95% CI, 4.0-9.5%), respectively. Most deaths occurred in infants less than 6 months of age.

CONCLUSIONS

Despite the widespread use of pertussis vaccines, the prevalence of pertussis remains high in LMIC over the last three decades. There is a need to increase access to PCR-based diagnostic confirmation in order to improve surveillance. Disease control measures in LMICs must take into account the persistent significant infant mortality and increased disease burden associated with HIV infection and exposure.

Pertussis outbreak in southern Ethiopia: challenges of detection, management, and response

Background

Despite the availability of effective vaccines, pertussis remains endemic with high fatality rates in low and middle-income countries (LMIC). This study aims to describe an outbreak of pertussis in a health district of Ethiopia. The study highlights the challenges faced by the health system in identifying pertussis cases and appropriately responding to the outbreak at the district level.

Methods

A descriptive cross-sectional study was conducted using data sourced from the District Public Health Emergency and Management (PHEM) surveillance service and outbreak management field reports. Stratified attack rates and fatality rates for pertussis are described. Systemic problems leading to the outbreak are explored and narrated. A modified CDC pertussis case definition was employed with a polymerase chain reaction used to confirm cases.

Results

From September 2018 to January 2019, 1840 suspected, probable, and confirmed pertussis cases and six deaths were identified. Pertussis cases ranged from 1 month to 51 years in age. An outbreak occurred in 14 out of the 24 villages of Dara Malo district. The overall attack rate was 1708 per 100,000 population with a fatality rate of 3.3 per 1000 pertussis cases. The highest attack rate of 12,689/100,000 was seen in infants. Among confirmed, probable and suspected pertussis cases, only 41.1% had completed the three-dose pertussis vaccine’s primary schedule. The household survey revealed a population coverage of 73.4 and 40.8% for Pentavalent vaccine dose one and three respectively. Investigations suggested the existence of a poor cold chain management system in the study area.

Conclusions

There is an urgent need to build capacity to strengthen routine vaccination services and improve the maintenance of the vaccine cold chain. Other LMICs are urged to take lessons learned from this outbreak to strengthen their own vaccination programs and capacitate health workers to manage local outbreaks.

Pertussis outbreak investigation in Janamora district, Amhara Regional State, Ethiopia: a case-control study

Introduction

On April 17/2017 Janamora district, Amhara regional state health officials reported an increasing number of people with a cough. The objectives of this study was to investigate the outbreak, describe risk factors and implement control measures.

Methods

We conducted a community based unmatched 1:1 case-control study April 22-May 10, 2017. We used a probable case definition (≥2 weeks cough with vomiting, apnea, or inspiratory whoop) to identify suspected pertussis cases. Neighbors of cases were considered as controls. We conducted a door-to-door active case search and reviewed medical records, assessed vaccination status by parental interview or vaccination card. We implemented multivariable logistic regression to identify independent factors associated with the outbreak.

Results

We investigated 60 cases and 60 controls. Most (68.3%) of the cases were under the age of 15. The majority (86.6%) of pertussis suspected cases, and 83.4% controls had not received any pertussis vaccine. The overall attack rate was 0.13% and the case fatality rate was 3.3%. The age-specific attack rate for under-five children was 0.33%. Females were more likely to have pertussis (AOR: 2.91; 95% CI: 1.17-7.22), contact with pertussis suspected person (AOR: 6.29; 95% CI: 2.53-15.62) and living in a relatively poorly ventilated house (AOR: 3.01; 95% CI: 1.17-7.70) were also significant risk factors of pertussis.

Conclusion

Weak supplementary immunization activities might have contributed to the outbreak. Treating household contacts and integration of diagnostic laboratory test of pertussis into the local health system is of paramount importance to detect outbreaks early on.

Outbreak of suspected pertussis in Kaltungo, Gombe State, Northern Nigeria, 2015: the role of sub-optimum routine immunization coverage

Introduction

Despite the availability of vaccines, pertussis outbreaks still occur in developing countries. In December 2015 we investigated a pertussis outbreak in Kaltungo, Nigeria to identify determinants of infection and institute control measures.

Methods

We enrolled 155 cases and 310 unmatched controls. We defined cases as residents of Kaltungo with paroxysmal or whooping cough lasting 2 weeks with or without vomiting and randomly selected neighborhood controls. Using structured questionnaire, we collected data on socio-demographics, clinical and risk factors. We collected twelve nasopharyngeal swabs for laboratory analysis using Polymerase Chain Reaction.

Results

Median age was 24 months (range 1-132 months) for cases and 27 months (range 1-189 months) for controls. Female cases and controls were 86 (55.5%) and 150 (48.4%) respectively. A total of 83 (56.6%) cases were in age group 12-59 months. Age-specific-attack-rate was 83/1,786 (4.7%); Age-specific-case-fatality-rate was 21/83 (25.3%); Age-specific-proportional-mortality-ratio was 21/24 (87.5%). A total of 61 (39.4%) zero doses and 30.1% Pentavalent dropouts were documented. Multivariate analysis revealed parental refusal (adjusted OR = 27.8; CI = 8.8-87.7), contact with a case (AOR = 7.9, CI = 4.3-14.7, P = 0.000), belonging to the Muslim faith (AOR = 2.0; CI = 1.1-3.5) and having mothers with informal education only (AOR = 4.7, CI-2.6-8.4) as independent predictors of pertussis infection.

Conclusion

Sub-optimal vaccination due to parental refusal and informal education of mothers were major determinants of pertussis infection. We conducted awareness campaigns of key immunization messages targeted at the informal education sector. We ensured appropriate case management, contact vaccination and health education in public gatherings, worship places and schools.

Recommendations to control pertussis prioritized relative to economies: A Global Pertussis Initiative update

Pertussis is a vaccine-preventable disease that causes morbidity and mortality, particularly in infants and children <5 years of age. The Global Pertussis Initiative (GPI) recommendations represent a systematic evaluation and prioritization of strategies to prevent pertussis-related infant and child deaths, reduce global disease burden and prevent resurgence through vaccination strategies and public health policies at national, regional and local levels. The GPI recommendations are based on clinical trials and observational and surveillance data, which are essential in the planning, implementation and evaluation of vaccination practices and best use of available resources. Many low- and middle-income countries (LMIC) continue to use whole-cell pertussis (wP) vaccines for primary vaccination, while most high-income countries have replaced wP with the less-reactogenic acellular pertussis (aP) vaccines. This present manuscript pertains to discussions held during the GPI's meeting on November 11-13, 2016, in Cape Town, Republic of South Africa. The GPI recommends that LMIC aim for high coverage of infant series pertussis vaccines as a priority. In LMIC and countries with constrained vaccine funding, if wP vaccines are currently used, wP should continue to be used. Furthermore, given that protection against disease and death due to pertussis in neonates is a key priority of the GPI, it recommends that ap immunization in pregnancy should be implemented as a priority in all countries if resources allow. Given that surveillance and epidemiology data on which to base vaccine decisions are important, the GPI also suggests that, in areas where wP vaccines are implemented, standardization and calibration of wP vaccines are checked, considering the many different manufacturers and variable standards of production and quality control. In addition, as immunity to pertussis wanes following the primary infant series of vaccination, the GPI further recommends that toddlers, adolescents, healthcare and childcare workers receive booster vaccine doses, where resources allow.

Assessing the Importance of Domestic Vaccine Manufacturing Centers: An Overview of Immunization Programs, Vaccine Manufacture, and Distribution

Vaccines have significantly reduced the detrimental effects of numerous human infectious diseases worldwide, helped to reduce drastically child mortality rates and even achieved eradication of major pathogens, such as smallpox. These achievements have been possible due to a dedicated effort for vaccine research and development, as well as an effective transfer of these vaccines to public health care systems globally. Either public or private institutions have committed to developing and manufacturing vaccines for local or international population supply. However, current vaccine manufacturers worldwide might not be able to guarantee sufficient vaccine supplies for all nations when epidemics or pandemics events could take place. Currently, different countries produce their own vaccine supplies under Good Manufacturing Practices, which include the USA, Canada, China, India, some nations in Europe and South America, such as Germany, the Netherlands, Italy, France, Argentina, and Brazil, respectively. Here, we discuss some of the vaccine programs and manufacturing capacities, comparing the current models of vaccine management between industrialized and developing countries. Because local vaccine production undoubtedly provides significant benefits for the respective population, the manufacture capacity of these prophylactic products should be included in every country as a matter of national safety.

Pertussis outbreak investigation of Mekdela district, South Wollo zone, Amhara region, North-West Ethiopia

Background

Pertussis is a highly contagious respiratory illness caused by Bordetella pertussis. It is one of the most common vaccine-preventable bacterial infections that affects all susceptible individuals, regardless of age. Investigation was done to verify the existence of an outbreak and to identify associated risk factors contributed for the occurrence of an outbreak in Tork and Warkaye villages of Mekdela district.

Methods

Unmatched community based case control and descriptive cross sectional investigation were conducted with one to two ratios. We used structured questionnaire to collect data from cases and controls.

Results

A total of 215 cases and eight deaths were identified with an overall attack rate of 1.3 per 1000 population. The mean age of the cases was 3.7 years which was ranged from 3 months to 45 years. The more affected groups were females. On multivariate logistic regression analysis, the risk factor that remained independently statically significant associated with developing pertussis was presence of infected person in the family AOR (adjusted odds ratio): 5.859, (95% CI 2.526–13.589). But previously sick with pertussis AOR: 0.053, (95% CI 0.006–0.460) and receiving full dose of vaccine AOR: 0.256, (95% CI 0.080–0.818) were remained as protective factors from pertussis infection.

Conclusions

The suspected pertussis outbreak was occurred in remote pocket villages/kebeles of Mekdela district. Routine immunization was not given regularly and functional refrigerators were not available in the health posts. Routine immunization services and treatment of infected patients with appropriate antibiotics should be intensified.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-017-2735-1) contains supplementary material, which is available to authorized users.

Rapid Health Needs Assessment after Typhoons Bolaven and Tembin Using the Public Health Assessment for Emergency Response Toolkit in Paju and Jeju, Korea 2012

Following natural disasters, rapid health needs assessments are required to quickly assess health status and help decision making during the recovery phase. The Korean Centers for Disease Control and Prevention (KCDC) developed the Public Health Assessment for Emergency Response (PHASER) Toolkit which was optimized for a weather disaster in Korea. The goal of this study is to assess public health needs following the 2012 typhoons Bolaven and Tembin in both urban and rural areas in Korea. We conducted pilot trials using the PHASER toolkit to assess health needs following typhoons Bolaven and Tembin in Paju and Jeju during summer 2012. We sampled 400 households in Jeju and 200 households in Paju using a multistage cluster sampling design method. We used a standardized household tracking sheet and household survey sheet to collect data on the availability of resource for daily life, required health needs, clinical results and accessibility of medical services. The primary outcomes were clinical results and accessibility of medical service after the typhoons. We completed surveys for 190 households in Paju and 386 households in Jeju. Sleeping disorders were identified in 6.8% (95% confidence interval [CI], 2.8%-10.8%) surveyed in Paju and 17.4% (95% CI, 12.8%-22.0%) in Jeju. We used the PHASER toolkit to assess healthcare needs rapidly after 2 typhoons in Korea. Sleeping disorders were frequently identified in both Paju and Jeju following the 2 typhoons.

Population-Based Pertussis Incidence and Risk Factors in Infants Less Than 6 Months in Nepal

BACKGROUND.

Pertussis is estimated to cause 2 percent of childhood deaths globally and is a growing public health problem in developed countries despite high vaccination coverage. Infants are at greatest risk of morbidity and mortality. Maternal vaccination during pregnancy may be effective to prevent pertussis in young infants, but population-based estimates of disease burden in infants are lacking, particularly in low-income countries. The objective of this study was to estimate the incidence of pertussis in infants less than 6 months of age in Sarlahi District, Nepal.

METHODS.

Nested within a population-based randomized controlled trial of influenza vaccination during pregnancy, infants were visited weekly from birth through 6 months to assess respiratory illness in the prior week. If any respiratory symptoms had occurred, a nasal swab was collected and tested with a multitarget pertussis polymerase chain reaction (PCR) assay. The prospective cohort study includes infants observed between May 2011 and August 2014.

RESULTS.

The incidence of PCR-confirmed Bordetella pertussis was 13.3 cases per 1000 infant-years (95% confidence interval, 7.7-21.3) in a cohort of 3483 infants with at least 1 day of follow-up.

CONCLUSIONS.

In a population-based active home surveillance for respiratory illness, a low risk for pertussis was estimated among infants in rural Nepal. Nepal's immunization program, which includes a childhood whole cell pertussis vaccine, may be effective in controlling pertussis in infants.

Highlights of the 11th International Bordetella Symposium: from Basic Biology to Vaccine Development

Pertussis is a severe respiratory disease caused by infection with the bacterial pathogen Bordetella pertussis The disease affects individuals of all ages but is particularly severe and sometimes fatal in unvaccinated young infants. Other Bordetella species cause diseases in humans, animals, and birds. Scientific, clinical, public health, vaccine company, and regulatory agency experts on these pathogens and diseases gathered in Buenos Aires, Argentina from 5 to 8 April 2016 for the 11th International Bordetella Symposium to discuss recent advances in our understanding of the biology of these organisms, the diseases they cause, and the development of new vaccines and other strategies to prevent these diseases. Highlights of the meeting included pertussis epidemiology in developing nations, genomic analysis of Bordetella biology and evolution, regulation of virulence factor expression, new model systems to study Bordetella biology and disease, effects of different vaccines on immune responses, maternal immunization as a strategy to prevent newborn disease, and novel vaccine development for pertussis. In addition, the group approved the formation of an International Bordetella Society to promote research and information exchange on bordetellae and to organize future meetings. A new Bordetella.org website will also be developed to facilitate these goals.

Is Pertussis Infection Neglected in China? Evidence from a Seroepidemiology Survey in Zhejiang, an Eastern Province of China

Background

The resurgence of pertussis has occurred in many countries. However, the epidemiological profiles of pertussis cannot be well understood by the current surveillance system in China. This study was designed to investigate the age specific serologic evidence of antibodies against pertussis, and to offer information regarding the existence of pertussis infection in Zhejiang Province, China.

Methods

A cross-sectional serosurvey was carried out in 6 counties of Zhejiang Province during September and October of 2014. The immunoglobulin G-pertussis toxin (IgG-PT) levels were measured quantitatively with a commercially available enzyme-linked immunosorbent assay (ELISA). The antibody activities were expressed in the Food and Drug Administration (FDA)-U/ml and a level ≥30 FDA-U/ml was considered seropositive. An IgG-PT >80 FDA-U/ml indicated recent pertussis infection if the patient had not received immunization with the pertussis vaccine within the last year.

Results

The mean IgG-PT seropositivity rate among the 2107 subjects was 33.32% with a geometric mean concentration of 17.73 (95% confidence interval: 16.90–18.60) FDA-U/ml. The difference in the seropositivity rates reached significant means among the different age groups (waldχ² = 198.41, P<0.0005), and children aged 3 years had the highest percentage (63.24%) of undetectable IgG-PT level. Of the 1707 subjects ≥3 years of age, 169 (9.90%) had evidence of a recent infection. The highest proportion of IgG-PT levels ≥80 FDA-U/ml was found in ≥60 years age group followed by 11–15 and 16–25 years age groups.

Conclusions

This study indicates the rather lower IgG-PT level sustained 1 year after the acellular pertussis vaccine booster dose, and substantial proportion of population susceptibility to pertussis in Zhejiang Province, China. Moreover, pertussis infection is not uncommon; it was estimated that 10% of subjects were recently infected approximately within the last 100 days. We highly suggest that the surveillance capacity should be strengthened and consider introducing booster dose that protect against pertussis in 6 years old children.

Pertussis vaccination during pregnancy in Vietnam: Results of a randomized controlled trial Pertussis vaccination during pregnancy

A pertussis vaccination during pregnancy has recently been adopted in several countries to indirectly protect young infants. This study assessed the effect of adding a pertussis component to the tetanus vaccination, in the pregnancy immunization program in Vietnam. A randomized controlled trial was performed. Pregnant women received either a Tdap (tetanus, diphtheria acellular pertussis) vaccine or a tetanus only vaccine between 19 and 35 weeks' gestational age. Immunoglobulin G (IgG) against tetanus (TT), diphtheria (DT), pertussis toxin (PT), filamentous hemaglutinin (FHA) and pertactin (Prn) were measured using commercial ELISA tests, at baseline, 1 month after maternal vaccination, at delivery, and in infants from cord blood and before and after the primary series (EPI: month 2-3-4) of a pertussis containing vaccine. Significantly higher geometric mean concentrations (GMC) were observed for all 3 measured pertussis antigens in the offspring of the Tdap group, up to 2 months of age. One month after completion of the primary infant vaccination schedule, anti-Prn GMC, but not anti-PT and anti-FHA GMCs, was significantly (p=0.006) higher in the control group. Maternal antibodies induced by vaccination during pregnancy close the susceptibility gap for pertussis in young infants. Limited interference with the infant vaccine responses was observed. Whether this interference effect disappears with the administration of a fourth vaccine dose is further studied.