Healthcare-seeking behaviour of primary caregivers for acute otitis media in children aged 6 months to <30 months in Panama: results of a cross-sectional survey.

BACKGROUND: Acute otitis media (AOM) is the most common bacterial childhood infection. However, caregivers with children having mild episodes often do not seek healthcare services, which may lead to an under-appreciation of the disease experienced by the community. The objectives of this survey were to estimate the proportion of primary caregivers who went to a healthcare facility when they suspected that their child aged 6 to <30 months was having an AOM episode during the past 6 months and to assess what factors influenced their decision. METHODS: This observational, cross-sectional survey of primary caregivers (≥18 years), with at least one child aged 6 to <30 months was performed in 19 healthcare facilities in Panama (March to May 2013). A 28-item paper questionnaire was administered to assess demographic data, AOM symptoms, as well as potential healthcare-seeking behaviour and factors influencing this behaviour. Potential confounding effects were individually assessed using Chi-squared or Cochran-Mantel-Haenszel tests, and all together in logistic regression models. RESULTS: The total number of eligible participants was 1330 (mean age 28.5 ± 8.0 years). Of these, 245 participants had at least one child whom they suspected had an AOM episode during the past 6 months. Of the 245 participants, 213 (86.9%) sought healthcare at a facility. Several factors were associated with healthcare usage: perceived severity of illness (p = 0.001), occupational status of the caregiver (p = 0.002), household income (p = 0.016) and length of time since the last suspected AOM episode (p = 0.032). CONCLUSIONS: When confronted with a child with obvious symptoms of AOM, the majority of caregivers reported seeking healthcare. This behaviour appeared to be associated with factors related to the severity of the illness, the length of time since the last episode, as well as with the income and occupational status of the caregivers themselves. As many episodes of AOM present with non-specific respiratory symptoms, our results apply only to caregivers who were confronted with children with an obvious symptom.

Vaccination reduces macrophage infiltration in bronchus-associated lymphoid tissue in pigs infected with a highly virulent Mycoplasma hyopneumoniae strain.

BACKGROUND: Mycoplasma hyopneumoniae is the causative agent of enzootic pneumonia and is responsible for significant economic losses to the pig industry. To better understand the mode of action of a commercial, adjuvanted, inactivated whole cell vaccine and the influence of diversity on the efficacy of vaccination, we investigated samples from vaccinated and non-vaccinated pigs experimentally infected with either a low (LV) or a highly virulent (HV) M. hyopneumoniae strain. Non-vaccinated and sham-infected control groups were included. Lung tissue samples collected at 4 and 8 weeks post infection (PI) were immunohistochemically tested for the presence of T-lymphocytes, B-lymphocytes and macrophages in the bronchus-associated lymphoid tissue (BALT). The number of M. hyopneumoniae organisms in bronchoalveolar lavage (BAL) fluid was determined using quantitative PCR at 4 and 8 weeks PI. Serum antibodies against M. hyopneumoniae were determined at 0, 2, 4, 6 and 8 weeks PI. RESULTS: The immunostaining revealed a lower density of macrophages in the BALT of the vaccinated groups compared to the non-vaccinated groups. The highest number of M. hyopneumoniae organisms in the BAL fluid was measured at 4 weeks PI for the HV strain and at 8 weeks PI for the LV strain. Vaccination reduced the number of organisms non-significantly, though for the HV strain the reduction was clinically more relevant than for the LV strain. At the level of the individual pigs, a higher lung lesion score was associated with more M. hyopneumoniae organisms in the lungs and a higher density of the investigated immune cells in the BALT. CONCLUSIONS: In conclusion, the infiltration of macrophages after infection with M. hyopneumoniae is reduced by vaccination. The M. hyopneumoniae replication in the lungs is also reduced in vaccinated pigs, though the HV strain is inhibited more than the LV strain.

Effect of challenge of pigs previously immunised with inactivated vaccines containing homologous and heterologous Mycoplasma hyopneumoniae strains.

BACKGROUND: Mycoplasma hyopneumoniae is the primary cause of enzootic pneumonia in pigs. Although vaccination is an important control tool, the results observed under field conditions are variable. This may be due to antigenic differences between the strains circulating in pig herds and the vaccine strain. This study compared the protective efficacy of four bacterins against challenge infection with a highly virulent field strain of M. hyopneumoniae. Seventy eight, one-week old piglets were randomly assigned to five treatment groups (A, B, C, D, E), 14 piglets each, and a negative control group (F) consisting of 8 piglets. All pigs were injected at 1 (D7) and 4 weeks of age (D28), with 2 ml of either a placebo or a bacterin based on selected M. hyopneumoniae strains, namely A (F7.2C), B (F20.1L), C (B2V1W20 1A-F), D (J strain), E (placebo; positive control), F (placebo; negative control). At D56, all pigs except those of group F were challenged intratracheally with 7 ml culture medium containing 107 CCU/ml of M. hyopneumoniae strain F7.2C. All pigs were euthanized and necropsied at D84. The severity of coughing and pneumonia lesions were the main parameters. Immunofluorescence (IF) testing, nested PCR testing of bronchoalveolar lavage (BAL) fluid and serology for M. hyopneumoniae were also performed. RESULTS: The different bacterins only slightly improved clinical symptoms (average 0.38 in vaccinated groups vs. 0.45 in group E) and histopathological lung lesions (average 3.20 in vaccinated groups vs. 3.45 in group E), but did not improve macroscopic lung lesions (score 4.30 vs. 4.03 in group E). None of the vaccines was significantly and/or consistently better or worse than the other ones. All bacterins evoked a serological response in the vaccinated animals. All pigs, except those from group F, were positive with nPCR in BAL fluid at D84. CONCLUSION: The bacterins did not induce a clear overall protection against challenge infection, and there were no significant differences in protective efficacy between bacterins containing homologous and heterologous M. hyopneumoniae strains. Further research is necessary to better characterize the antigens involved in protection and to elucidate the protective immunity responses following M. hyopneumoniae vaccination and/or infection.