Detection of Bordetella pertussis in Infants Suspected to have Whooping Cough

Burden of pertussis in infants in the Eastern Mediterranean Region and the impact of maternal vaccination: a systematic review

BACKGROUND

Despite vaccine availability, Pertussis remains a global public health challenge, especially among infants. The Eastern Mediterranean Region (EMR) presents a diverse epidemiological landscape with varying vaccination coverages and healthcare infrastructures. This systematic review aimed to assess the burden of pertussis in infants < 1 year of age in the EMR and evaluate the use and impact of pertussis vaccination during pregnancy.

METHODS

Following PRISMA guidelines, we conducted a systematic search of Scopus, Embase, CINAHL Ultimate, and PubMed from inception until April 30, 2024. Studies included reported on pertussis burden in infants or maternal vaccination. Data extraction and quality assessment were performed in duplicate, focusing on incidence, age distribution, disease severity, and vaccination uptake and impact when data were available.

RESULTS

Thirty-six studies were included, the majority from Iran (N = 11), Morocco (N = 5), Tunisia (N = 5), and Oman (N = 3), with underrepresentation of other EMR countries. The incidence of PCR-confirmed pertussis among children with suspected pertussis varied significantly, from 6.7% to 8.9% (Morocco 2018-2019) to 50.4% and 51.6% (Palestine 2004-2008) among children < 12 and < 6 months, respectively, and between 16.3% (Tunisia 2007-2016) to 73.0% (Morocco 2013-2015) in children < 2 months. Age distribution data indicated the highest burden was in infants < 2 months regardless of the population studied. High hospitalization rates and severe complications, including seizures and the need for ventilatory support, were frequently reported in infants < 6 months of age. Only one study from Saudi Arabia addressed maternal pertussis vaccination, reflecting low vaccine uptake and awareness among pregnant women.

CONCLUSIONS

This review underscores the substantial burden of pertussis among infants in the EMR and the lack of data on maternal immunization. The findings emphasize the need for enhanced surveillance and targeted public health interventions to reduce disease incidence. Future research should prioritize underrepresented countries to ensure comprehensive data for informed public health strategies.

TRIAL REGISTRATION

PROSPERO (CRD42024573471).

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.

Secondary Use of Laboratory Data: Potentialities and Limitations

Clinical databases have been developed in recent years especially during the course of all medical concerns including laboratory results. The information produced by the diagnostic laboratories have great impact on health care system with various secondary uses. These uses are sometimes as publishing new extracted information of laboratory reports which have been widely applied in the scientific journals. Nowadays, some large scale or national databases are also formed from the integration of these data from smaller centers in the field of human health in many countries. These databases are beneficial for different stakeholders who may need this information. Unfortunately, reviewing some of these uses has indicated lots of errors in quality control, test validity, uniformity and so on. More importantly, some of the diagnostic procedures have been applied in the clinical diagnostic laboratories without even preliminary clinical evaluation studies. Therefore, any taken conclusion from these analyzed data may not be reliable. This use requires checking the several specifications that have been notified in this study. Current review also intends to show how the correct information should be to extract for the scientific reports, or integrated in large scale databases.

Pertussis detection in children with cough of any duration

Background

The diagnosis of pertussis in clinical practice continues to be a challenge worldwide as the symptoms are variable. We aimed to determine the prevalence of pertussis in Chinese children irrespective of cough duration and explore the clinical characteristics of children with pertussis with different cough durations.

Methods

This was a prospective study of children 1 month to 11 years of age with different cough durations in one large Chinese hospital. Bilateral deep posterior nasopharyngeal swabs and venepuncture for full blood count, CRP and serology and sputum were obtained when possible for investigation. E-test strips were used for testing the susceptibility of the B.pertussis isolates against erythromycin, azithromycin, sulphamethoxazole/trimethoprim, levofloxacin, amoxicillin and doxycycline. Demographic, clinical and laboratory information on culture and antimicrobial susceptibility testing was collected from children, and analyzed using SAS v.10 (SAS Institute Inc., USA).

Results

After exclusions we analyzed 312 children. Ninety-seven (31.1%) children had laboratory evidence of pertussis. When grouped by cough duration, few characteristics were significant between children with and without pertussis. Of the 36 isolates, 72.2% (26/36)could not be inhibited by erythromycin and azithromycin at all. The MIC50 and MIC90 to amoxicillin were 0.75 mg/L and 1 mg/L respectively, sensitive to amoxicillin by the EUCAST points.

Conclusions

The “one-size-fits-all” clinical pertussis case definition is no longer optimal to recognize this disease. A large comprehensive study of children with all types of cough is required to make substantial inroads into increasing both the sensitivity and specificity in pertussis diagnosis, which will have a beneficial impact on public health. Amoxicillin maybe an alternative for children with marolide-resistant B.pertussis infection; however, local sensitivities are required to inform clinical practice.

Identfication of viral and bacterial etiologic agents of the pertussis-like syndrome in children under 5 years old hospitalized

BACKGROUND

Acute respiratory infections (ARIs) represent an important cause of morbidity and mortality in children, remaining a major public health concern, especially affecting children under 5 years old from low-income countries. Unfortunately, information regarding their epidemiology is still limited in Peru.

METHODS

A secondary data analysis was performed from a previous cross-sectional study conducted in children with a probable diagnosis of Pertussis from January 2010 to July 2012. All samples were analyzed via Polymerase Chain Reaction (PCR) for the following etiologies: Influenza-A, Influenza-B, RSV-A, RSV-B, Adenovirus, Parainfluenza 1 virus, Parainfluenza 2 virus, Parainfluenza 3 virus, Mycoplasma pneumoniae and Chlamydia pneumoniae.

RESULTS

A total of 288 patients were included. The most common pathogen isolated was Adenovirus (49%), followed by Bordetella pertussis (41%) from our previous investigation, the most prevelant microorganisms were Mycoplasma pneumonia (26%) and Influenza-B (19.8%). Coinfections were reported in 58% of samples and the most common association was found between B. pertussis and Adenovirus (12.2%).

CONCLUSIONS

There was a high prevalence of Adenovirus, Mycoplasma pneumoniae and other etiologies in patients with a probable diagnosis of pertussis. Despite the presence of persistent cough lasting at least two weeks and other clinical characteristics highly suspicious of pertussis, secondary etiologies should be considered in children under 5 years-old in order to give a proper treatment.

Identification of Etiologic Agents of the Pertussis-like Syndrome in Children by Real-time PCR Method

The aim of this study was to recognize the identity and frequency of etiologic agents of the pertussis-like syndrome in children &lt; 2 years of age. A cross-sectional hospital-based study conducted from August 2014 to August 2015. All children &lt; 2 years of age (n=100) who were suspected as pertussis infected were enrolled in this study and tested for Bordetella pertussis, adenovirus (Adv), respiratory syncytial virus (RSV), human metapneumovirus (hMPV), and influenza virus A (INF-A) by real-time PCR technique. RSV was the most detected pathogen (20%), followed by B. pertussis (18%), Adv (16%), INF-A (11%), and hMPV (10%). Co-infection was observed in 8 patients (11%) and the combinations of RSV/INF-A (n=3, 4%), and AdV/B. pertussis (n=3, 4%) were more frequent. RSV, B. pertussis, and hMPV were more frequent pathogens among infants &lt; 4 months of age. However, Adv and INF-A were more frequent pathogens among children &gt; 6 months of age. In this study, RSV was the most frequent identified pathogen (n=20, 20%), followed by B. pertussis (n=18, 18%) and AdV (n=16, 16%). Pertussis was more frequent in spring (8%) and summer (6%). In addition, clinical symptoms of pertussis were the same as some viral pathogens, which can lead to misdiagnosis of infection. Therefore, diagnosis of pertussis should be established on the bases of both the clinical symptoms and the laboratory methods.

Old Disease and New Challenges: Major Obstacles of Current Strategies in the Prevention of Pertussis

Context

Universal immunization against Bordetella pertussis has partially controlled the burden of the disease and its transmission. However, according to recent data, the epidemiology of this vaccine-preventable disease has changed. Now, younger infants, adolescents, and adults are at greater risk of infection. This article has studied the interaction between the various factors involved in the changing epidemiology of pertussis and the major obstacles faced by the current strategies in its prevention.

Evidence Acquisition

In this narrative review, the most recently published sources of information on pertussis control measures, consisting of textbooks and articles, have been reviewed. We focused on the more recent data about the changing epidemiology or pertussis in Scopus through the use of the MeSH-term words [pertussis] or [whooping cough] and [epidemiology] or [outbreak] or [resurgence], but our search was not restricted to this particular strategy; we also tried to find all of the most recent available data in the general field through other means.

Results

Primary and booster doses of the pertussis vaccine seem to partially control transmission of the disease, but despite the different preventive strategies available, pertussis continues to cause mortality and morbidity among high-risk groups.

Conclusions

Adding booster doses of acellular pertussis vaccine to the current national immunization practices with whole-cell vaccines for young adults and pregnant women seems to be a good option for controlling mortality and morbidity among high-risk groups such as very young infants.

High prevalence of Bordetella pertussis in children under 5 years old hospitalized with acute respiratory infections in Lima, Peru

Background

Pertussis diagnosis may go unrecognized when other pathogens, such as respiratory syncytial virus (RSV) circulate.

Methods

A prospective cross-sectional study was conducted in Lima, Peru from January 2009 to September 2010. A total of 596 children under 5 years old admitted with clinical diagnoses of acute respiratory infections were test for B. pertussis and RSV detection by polymerase chain reaction (PCR).

Results

The pertussis toxin and IS481 genes were detected in 19.12 % (114/596) of the cases and the respiratory syncytial viruses (RSV-A and RSV-B) were identified in 17.28 % (103/596) of patients. Infants under 3 months old were the most frequently affected by this pathogens in 43 % (49/114) and 35.9 % (37/103) respectively. An increase of B. pertussis was observed from February to March and from October to November with a Seasonal index between 1.32 and 1.51 and 1.24–3.5 respectively.

Conclusions

Epidemiologic surveillance for B. pertussis is essential in Peru, especially in children that could most benefit from the vaccine. B. pertussis should be suspected in infants hospitalized for acute respiratory symptoms for early treatment and prevent complications.

Detection of Bordetella pertussis using a PCR test in infants younger than one year old hospitalized with whooping cough in five Peruvian hospitals

OBJECTIVES

To report the incidence, epidemiology, and clinical features of Bordetella pertussis in Peruvian infants under 1 year old.

PATIENTS AND METHODS

A prospective cross-sectional study was conducted in five hospitals in Peru from January 2010 to July 2012. A total of 392 infants under 1 year old were admitted with a clinical diagnosis of whooping cough and tested for B. pertussis by PCR.

RESULTS

The pertussis toxin and IS481 genes were detected in 39.54% (155/392) of the cases. Infants aged less than 3 months were the most affected, with a prevalence of 73.55% (114/155). The most common household contact was the mother, identified in 20% (31/155) of cases. Paroxysm of coughing (89.03%, 138/155), cyanosis (68.39%, 106/155), respiratory distress (67.09%, 104/155), and breastfeeding difficulties (39.35%, 61/155) were the most frequent symptoms reported.

CONCLUSION

An increase in pertussis cases has been reported in recent years in Peru, despite national immunization efforts. Surveillance with PCR for B. pertussis is essential, especially in infants less than 1 year old, in whom a higher rate of disease-related complications and higher mortality have been reported.