Pertussis - History, Epidemiology, And How To Avoid It
Pertussis is a serious respiratory infection caused by Bordetella pertussis, which was linked to 16 million cases and 195,000 deaths worldwide in 2008. Over the last five years, large outbreaks of pertussis have been reported, and the disease's reemergence has sparked international interest in learning more about the pathogen's virulence and genetic evolution.
Pertussis with a high risk of death is a common clinical symptom with a 70% mortality rate. The seriousness criteria are met by a lung infection accompanied by aspiratory hypertension and a hyperleukocytosis of more than 50 G/L. Pertussis (whooping cough) is caused by Bordetella pertussis, a highly contagious respiratory infection that can be prevented by using a neutralizer.
Yuanfang Chao, a Chinese medical scholar during the Sui Dynasty in the seventh century, described a pertussis-like illness as "the cough of 100 days." A thousand years later, in France (1578), Guillaume De Baillou described whooping cough in children for the first time in Paris; he named the illness "quinte" because of the 5-hour periodicity of paroxysms seen in acute episodes of disease.
According to new research, the first pertussis epidemics were recorded in Persia (modern-day Iran). Although pertussis outbreaks were first documented in Europe in the 16th century, the causative agent was not identified until 300 years later. In 1883, a German scientist at the University of Bonn named Carl Burger discovered bacteria rods in a stained sputum sample from a patient with clinical pertussis. Small Gram-negative bacilli were discovered in the sputum of Jules Bordet's 5-month-old daughter who developed whooping cough seventeen years later. Bordet, on the other hand, was unable to grow these bacilli in the available culture media. Bordet's son got pertussis six years later, but by then, Bordet and Gengou had isolated and grown B. pertussis for the first time in history.
Bordet received the Nobel Prize in Physiology or Medicine in 1919 for his work on antimicrobial immunology, which included extensive research on B. pertussis and helped to identify the organism as the cause of whooping cough.
The family Alcaligenaceae includes ten genetically distinct species of Bordetella. Although B. pertussis has long been thought to be the sole cause of whooping cough, other bacteria (such as B. parapertussis and B. holmesii) can cause coughing that is similar to whooping cough. B. pertussis is a Gram-negative, pleomorphic aerobic coccobacillus that grows best between 35°C and 37°C on Bordet-Gengou or Regan-Lowe agar. It can be distinguished from other Bordetella species by its growth and biochemical characteristics. In contrast to B. parapertussis, which is less fastidious, oxidase negative, and urease positive, and produces a brown pigment on heart infusion, Regan-Lowe, or Mueller-Hinton agar, B. pertussis is a fastidious, nonmotile, catalase and oxidase-positive species. On blood-supplemented medium and synthetic medium containing appropriate growth factors, such as nicotinamide, Bordetella species grow slowly.
B. pertussis is a human pathogen, whereas B. bronchiseptica, B. parapertussis, and B. holmesii can infect a variety of mammals, including humans. The virulence factors of B. pertussis include toxins like pertussis toxin (PT), adenylate cyclase toxin (AC), dermonecrotic toxin (DNT), and tracheal cytotoxin (TCT). B. pertussis virulence is influenced by surface structures such as filamentous hemagglutinin (FHA), fimbriae (FIM), pertactin (PRN), the type III secretion system, and lipopolysaccharide (LPS), as well as metabolic proteins such as BrkA, BapC, and BatB. The bvgAS genes in B. pertussis positively regulate a number of virulence factors, including PT, AC, DNT, FHA, TcfA, pertactin, FIM, BrkA, BipA, BcfA, and Vag8. Pertussis pathogenicity is dependent on the B. pertussis BvgAS two-component signal transduction system.
Pertussis is a disease that affects both developing and developed countries, with sporadic outbreaks occurring around the world. According to Crowcroft et al., there were 48.5 million cases of pertussis worldwide in 1999, with 295,000 deaths. According to Black et al., pertussis killed 195,000 people globally in 2008. A large number of people died in Africa (83,580). In 2013, there were 136,000 cases reported worldwide.
For a variety of reasons, calculating the global pertussis disease burden is difficult. To begin with, many countries' surveillance infrastructure is insufficient, making timely reporting of clinically suspected pertussis cases difficult. Second, in developing countries, laboratory infrastructure for routine pertussis testing is limited, and molecular diagnostic tests such as PCR are not widely used. Finally, in areas where trained health professionals are scarce, inconsistent clinical diagnosis of pertussis disease may obstruct case reporting. Furthermore, according to the WHO, the use of a standardized set of pertussis case definitions within an overall surveillance framework for vaccine-preventable diseases or communicable diseases has been inconsistent.
Pertussis has increased in prevalence among adolescents and adults over the last two to three decades. Pertussis incidence in adults was estimated to range from 133 to 507 per 100,000 person-years in population-based studies conducted between 1991 and 1999, equating to over one million cases per year in North America. Pertussis cases were around 28 and 21 per 100,000 among people aged 11 to 19 and those aged 20 and older in 2013. Although there are few published data on vaccine coverage by age, city, or state, differences in pertussis prevalence among adolescents and adults have been observed across states.
For example, between 1989 and 1998, the incidence of pertussis increased in Massachusetts, with 92% of cases reported among adolescents and adults by 1998. In this age group, only 47% of cases were reported across the country. During the 2014 pertussis outbreak in California, the majority of cases were reported among adolescents aged 9 to 16, with whites being affected more than other racial/ethnic groups. The waning immunity that occurs several years after primary childhood immunization has been blamed for part of the rise in reported cases among adolescents and adults. This waning immunity is likely to facilitate pertussis transmission among household contacts.
Pertussis is a highly contagious disease that spreads quickly through the air. The human nasopharynx is colonized by both commensal bacteria and pathogens like B. pertussis. Pertussis-containing droplets are produced when infected people cough or sneeze. Studies of disease transmission have been used to calculate the basic reproductive number (R0) for various infectious diseases, including pertussis. R0 secondary cases are produced by a confirmed primary case in an entirely susceptible population. According to R0 estimates, pertussis is much more contagious than polio, smallpox, rubella, mumps, and diphtheria.
Whether acquired through natural infection or vaccination, pertussis immunity is not long lasting. Pertussis infection lasts 3.5 to 30 years; whole-cell pertussis vaccine lasts 5 to 14 years; and acellular vaccine lasts 4 to 7 years. As their immune systems deteriorate, adolescents and adults become more vulnerable to B. pertussis infection. The length of time since their last B. pertussis vaccination or illness appears to have a strong correlation with the severity of their illness.
IgG or IgA enzyme-linked immunosorbent assays (ELISAs) were used to measure antibodies to PT, FHA, PRN, or FIM in acellular pertussis vaccine trials involving adolescents and adults. In the year 2000, Van der Wielen and colleagues examined the immunogenicity and safety of acellular pertussis vaccines in 299 adults. At baseline, before vaccination, IgG antibody titers to PT, FHA, and PRN were 73.1%, 98.2%, and 74.5%, respectively. One month after vaccination, IgG titers to PT, FHA, and PRN were 96.8%, 100%, and 98.9%.
Tdap guidelines for older children, pregnant women, and adults, as well as current DTaP immunization guidelines for infants and children, provide crucial information on the use of pertussis-containing vaccines in outbreak-affected populations. When possible, review individual immunization histories to identify children who may require additional vaccines, as well as adolescents and adults who may require their first or repeat Tdap doses. All pregnant women should have their immunization histories reviewed and a vaccine offered to protect both the mother and her baby during delivery, according to new Tdap guidelines.
Infants under the age of three months accounted for 83% of whooping cough deaths in the last decade. Household members were the main source of pertussis infection for children, according to experts. Although the source of infection (SOI) has not been identified in more than 50% of infant cases, mothers have been identified as the primary SOI in an estimated 35% of infections in the US. A number of reports from Australia and the Netherlands have revealed that older children have become the most common SOI to their younger siblings.
Vaccination protection tends to wane over time, even in countries with high childhood vaccination coverage (sometimes defined as 70%). Crowcroft et al. estimated in 2003 that 10% of susceptible children became infected with B. pertussis one year after receiving full vaccination, 60% by five years, and 100% by fifteen years. It's also estimated that 80% of current pertussis cases are due to waning immunity in previously immunized household members. Booster vaccinations for older children, adolescents, and adults are critical, according to these findings. Because the disease is often overlooked and unrecognized in this age group, recent immunization efforts have focused on adults. Furthermore, adolescents and adults are the most common carriers of B. pertussis to newborns and infants, putting them at risk of infection. As a result, Tdap, an acellular pertussis vaccine for adolescents and adults, was developed.
Although pertussis is typically described as being highly infectious, efficient transmission requires close contact or prolonged exposure.
Some people may not know they have whooping cough because they do not have any symptoms or have only mild symptoms. They can still spread the disease to other people.
Pertussis is a highly contagious acute respiratory disease caused by the bacteria Bordetella pertussis. This disease has 3 stages: catarrhal, paroxysmal, and convalescent.
The incubation period of pertussis is commonly 7 through 10 days, with a range of 4 through 21 days. The clinical course of the illness is divided into three stages: catarrhal, paroxysmal, and convalescent.
Large pertussis outbreaks have been reported over the last five years, and the disease's reemergence has sparked international interest in learning more about the pathogen's virulence and genetic evolution. Pertussis cases and deaths are reported annually among children and adults, despite the fact that many countries have achieved high vaccination coverage among infants. Due to factors such as low awareness of pertussis among health care professionals, a lack of standardized and efficient diagnostic assays, and weak surveillance infrastructure in many countries, underreporting, particularly among adolescents and adults, remains a multifaceted challenge in existing surveillance systems.