Laboratory-based surveillance in Latin America: attributes and limitations in evaluation of pneumococcal vaccine impact

Abstract

Disease surveillance data are needed to monitor trends in disease activity, inform decision-making in public health and evaluate disease prevention/control measures. The Sistema Regional de Vacunas (SIREVA) supports laboratory-based surveillance of invasive pneumococcal disease (IPD) in Latin American countries, providing information on identification, distribution, and anti-microbial susceptibility of pneumococcal strains. We estimated the proportion of pneumococcal meningitis and sepsis/bacteremia cases captured by SIREVA, by comparing the number of SIREVA-reported isolates in Argentina, Brazil, Chile, Colombia, Ecuador and Mexico with the estimated expected number of cases based on regional estimates of disease incidence. In all six countries, the number of isolates reported by SIREVA was consistently lower than the number of cases expected, across all years with data available. The proportion of SIREVA-reported isolates was highest in Chile (43-83%) and lowest in Mexico (1.4-3.5%). Passive surveillance systems such as SIREVA are important tools for monitoring circulating strains that could be related to pneumococcal disease, but our results show that SIREVA is likely to underestimate pneumococcal disease incidence. This under-reporting will limit the precision of surveillance data in monitoring changes in the incidence of IPD after vaccine introduction, and this should be considered when assessing the impact of vaccination programs.

Invasive pneumococcal disease in Latin America and the Caribbean: Serotype distribution, disease burden, and impact of vaccination. A systematic review and meta-analysis

“…Considering these findings, ongoing surveillance is needed to monitor serotype dynamics and guide optimal PCV formulation. National passive surveillance systems such as SIREVA are valuable tools to monitor serotype distribution and antimicrobial resistance but do not provide disease burden data, so they are unsuitable for evaluating pneumococcal vaccines’ impact and could underestimate IPD incidence [ 186 ].…”

How large could the public health impact of introducing recombinant zoster vaccination for people aged ≥50 years in five Latin American countries be?

“…However, this is likely a gross underestimation, as has been shown with data of other pathologies from passive surveillance in Mexico. 54 This is because these data were based only on inpatient and emergency cases that were notified to the Mexico Health Secretariat and General Health Information Office, HZ is not a mandatorily notifiable disease, and HZ is often not captured as a primary diagnosis in the surveillance system.…”

Assessing the Underestimation of Adult Pertussis Disease in Five Latin American Countries

“…It illustrates the potential magnitude of underestimation of pertussis, and there is considerable uncertainty in the estimates, as indicated by the broad 90% limits around the median values. In a study comparing the number of isolates of invasive pneumococcal disease reported to surveillance with the expected number of cases based on regional disease incidence data, Chile had the highest rate of reporting (43–83%) of the six Latin American countries in the study [ 41 ]. Other researchers have reported wide variations in pertussis prevalence between countries; in a study in 12 European countries conducted in 2007–2010, the percentage of adult patients presenting to primary care with acute cough who were found to have B. pertussis ranged from 0% in Italy to 6.2% in Sweden [ 42 ].…”