Protective effect of exclusive breastfeeding and effectiveness of maternal vaccination in reducing pertussis-like illness

Abstract Objective: To assess the protective effect of exclusive breastfeeding and the effectiveness of maternal vaccination in reducing pertussis-like illness. Method: This was a case-control study conducted in sentinel hospitals for pertussis in Recife between July 2016 and July 2018. Cases included children aged under six months with symptoms compatible with pertussis (pertussis-like illness). Controls included children aged under six months, living in the metropolitan region of Recife with no diagnosis of pertussis-like illness and matched by the same hospital and birth date. Results: Seventy-three cases and 194 controls were included. The diagnosis of pertussis-like illness was predominantly clinical (97,2%). Amongst the main symptoms, paroxysmal cough was observed in 95.89% of cases and vomiting in 53.4%. There were 29 hospitalized cases and no deaths. Out of the 73 cases, 47 were born to mothers vaccinated against pertussis during pregnancy, and the mothers of 144 of the 194 controls had been vaccinated. The protective effect of breastfeeding was of 74% (95% CI;38%, 89%). Children younger than six months, who were exclusively breastfed and with mothers vaccinated against pertussis during pregnancy were 5 times less likely to develop pertussis-like illness, corresponding to a protection of 79% (95% CI;31%, 94%). The effectiveness of maternal vaccination against pertussis-like illness in children under six months was low (27%) and not statistically significant (CI 95%; −34% a 60%). Conclusions: Exclusive breastfeeding protects children under six months from pertussis-like illness and may be enhanced when associated with maternal vaccination. These strategies should be encouraged because they also protect against pertussis-like illnesses.

Clinical repercussions in pertussis infants post-Tdpa vaccination of pregnant woman: An immunization success?

INTRODUCTION: In 2014, there was an epidemic of pertussis in Brazil that caused the death of 129 infants. To control the disease amongst infants under 6 months of age, and especially those under 2 months, the Brazilian Ministry of Health introduced Tdap immunization for all pregnant women. METHODS: This study aimed to describe the morbidity and mortality variables of pertussis cases in 969 infants aged under 6 months, comparing the periods before and after the introduction of Tdap vaccine in pregnant women. Data was extracted from the Information System on Notifiable Diseases (SINAN) including every case of pertussis that occurred in the metropolitan region of Recife-Brazil in infants under 6 months from January 2009 to October 2018. In order to analyze the variables, patients were divided into two groups Pre-Tdap(2009-2014), and Post-Tdap (2016-2018). RESULTS: There were no significant differences between the age groups and gender distribution in the period compared. In the Post- Tdap group compared with the Pre-Tdap group, the clinical presentation of pertussis in infants differed with more paroxysmal cough, and more vomiting, less apnea, and cyanosis. During this period, there were fewer complications and no deaths occurred. CONCLUSIONS: Maternal immunization with Tdap decreased disease severity, complication rates, and no deaths occurred in infants under 6 months of age diagnosed with pertussis.

Protective effect of exclusive breastfeeding and effectiveness of maternal vaccination in reducing pertussis-like illness.

OBJECTIVE: To assess the protective effect of exclusive breastfeeding and the effectiveness of maternal vaccination in reducing pertussis-like illness. METHOD: This was a case-control study conducted in sentinel hospitals for pertussis in Recife between July 2016 and July 2018. Cases included children aged under six months with symptoms compatible with pertussis (pertussis-like illness). Controls included children aged under six months, living in the metropolitan region of Recife with no diagnosis of pertussis-like illness and matched by the same hospital and birth date. RESULTS: Seventy-three cases and 194 controls were included. The diagnosis of pertussis-like illness was predominantly clinical (97,2%). Amongst the main symptoms, paroxysmal cough was observed in 95.89% of cases and vomiting in 53.4%. There were 29 hospitalized cases and no deaths. Out of the 73 cases, 47 were born to mothers vaccinated against pertussis during pregnancy, and the mothers of 144 of the 194 controls had been vaccinated. The protective effect of breastfeeding was of 74% (95% CI;38%, 89%). Children younger than six months, who were exclusively breastfed and with mothers vaccinated against pertussis during pregnancy were 5 times less likely to develop pertussis-like illness, corresponding to a protection of 79% (95% CI;31%, 94%). The effectiveness of maternal vaccination against pertussis-like illness in children under six months was low (27%) and not statistically significant (CI 95%; -34% a 60%). CONCLUSIONS: Exclusive breastfeeding protects children under six months from pertussis-like illness and may be enhanced when associated with maternal vaccination. These strategies should be encouraged because they also protect against pertussis-like illnesses.

Primary dengue haemorrhagic fever in patients from northeast of Brazil is associated with high levels of interferon-ß during acute phase.

Dengue is an acute febrile disease caused by the mosquito-borne dengue virus (DENV) that according to clinical manifestations can be classified as asymptomatic, mild or severe dengue. Severe dengue cases have been associated with an unbalanced immune response characterised by an over secretion of inflammatory cytokines. In the present study we measured type I interferon (IFN-I) transcript and circulating levels in primary and secondary DENV infected patients. We observed that dengue fever (DF) and dengue haemorrhagic fever (DHF) patients express IFN-I differently. While DF and DHF patients express interferon-α similarly (52,71 ± 7,40 and 49,05 ± 7,70, respectively), IFN- ß were associated with primary DHF patients. On the other hand, secondary DHF patients were not able to secrete large amounts of IFN- ß which in turn may have influenced the high-level of viraemia. Our results suggest that, in patients from our cohort, infection by DENV serotype 3 elicits an innate response characterised by higher levels of IFN- ß in the DHF patients with primary infection, which could contribute to control infection evidenced by the low-level of viraemia in these patients. The present findings may contribute to shed light in the role of innate immune response in dengue pathogenesis.

Pertussis may be the cause of prolonged cough in adolescents and adults in the interepidemic period

Objective: This study was aimed to evaluate the prevalence of pertussis in adolescents and adults with cough lasting more than 14 days and less than 30 days. Methods: This is a prospective observational study in interepidemic period of pertusis. Ten public health outpatient clinics in the city of Recife, Brazil, were randomly selected for the study. The study population consisted of individuals aged 10 years and over with cough that had lasted between 14 and 30 days. Nasopharyngeal swabs were collected for culture and PCR in order to identify Bordetella pertussis. We adopted the Centers for Disease Control and Prevention in the US (CDC) definition of cases of pertussis. Results: A total of 192 individuals were identified as suspected cases. Their mean age was 40.7 years. Pertussis was confirmed in 10 of the 192 suspected cases, with an estimated prevalence of 5.21% (95% confidence interval 2.03-8.38). All cases met the clinical case definition for pertussis; one suspect had both culture and PCR positive. PCR confirmed 100% of the cases, 7/10 by PCR and 3/10 by epidemiological linkage with a case confirmed by PCR. Conclusion: During an interepidemic period, 1 in 20 cases of prolonged cough had pertussis, suggesting this is an important cause of prolonged cough in adolescents and adults. .

Pertussis may be the cause of prolonged cough in adolescents and adults in the interepidemic period.

OBJECTIVE: This study was aimed to evaluate the prevalence of pertussis in adolescents and adults with cough lasting more than 14 days and less than 30 days. METHODS: This is a prospective observational study in interepidemic period of pertusis. Ten public health outpatient clinics in the city of Recife, Brazil, were randomly selected for the study. The study population consisted of individuals aged 10 years and over with cough that had lasted between 14 and 30 days. Nasopharyngeal swabs were collected for culture and PCR in order to identify Bordetella pertussis. We adopted the Centers for Disease Control and Prevention in the US (CDC) definition of cases of pertussis. RESULTS: A total of 192 individuals were identified as suspected cases. Their mean age was 40.7 years. Pertussis was confirmed in 10 of the 192 suspected cases, with an estimated prevalence of 5.21% (95% confidence interval 2.03-8.38). All cases met the clinical case definition for pertussis; one suspect had both culture and PCR positive. PCR confirmed 100% of the cases, 7/10 by PCR and 3/10 by epidemiological linkage with a case confirmed by PCR. CONCLUSION: During an interepidemic period, 1 in 20 cases of prolonged cough had pertussis, suggesting this is an important cause of prolonged cough in adolescents and adults.