|Year : 2016 | Volume
| Issue : 3 | Page : 203-207
Impact of climate on bacteriology of chronic suppurative otitis media without cholesteatoma
Surender Kumar1, Leena Goel2, Harish Chander Goel3, Lohith Shivappa4
1 Department of ENT, Asilo Hospital, Mapusa, Goa, India
2 Department of Anaesthesia, Goa Medical College, Bambolim, Goa, India
3 Department of ENT, Goa Medical College, Bambolim, Goa, India
4 Department of ENT, Subbaiah Medical College, Shimoga, Karnataka, India
|Date of Web Publication||8-Aug-2016|
Dr. Surender Kumar
Department of ENT, Asilo Hospital, Mapusa - 403 507, Goa
Source of Support: None, Conflict of Interest: None
Introduction: Climate change with global warming is concerning humanity of the various effect of this change in temperature and humidity, there is a distinct possibility of change in bacteriology of chronic suppurative otitis media with change in the climate parameters. Aims: The objective of this study is to evaluate effect of climate on bacteriology of Chronic Suppurative Otitis Media without cholesteatoma in various seasons. Methods: Assesement of type and incidence of different bacterias in four different seasons in one year was carried out in 202 patients and their sensitivity was assessed to commonly available antibiotics. Results: The study found that annually Staphylococcus aureus had highest incidence followed by Pseudomonas. On study of organisms according to seasons, Pseudomonas had a higher incidence than other organisms during monsoon season. Conclusion: Staphylococcus aureus is the most common isolate in other seasons while Pseudomonas aerugenosa is most common during the monsoon season. Therefore, it is recommended that during monsoon season (June - September), empirical treatment should be started with antibiotics sensitive to Pseudomonas while in other seasons treatment can be continued with antibiotics sensitive to Staphylococcus.
Keywords: Chronic suppurative otitis media, Culture and antibiotic sensitivity, Pseudomonas aeruginosa, Staphylococcus aureus
|How to cite this article:|
Kumar S, Goel L, Goel HC, Shivappa L. Impact of climate on bacteriology of chronic suppurative otitis media without cholesteatoma. Indian J Otol 2016;22:203-7
|How to cite this URL:|
Kumar S, Goel L, Goel HC, Shivappa L. Impact of climate on bacteriology of chronic suppurative otitis media without cholesteatoma. Indian J Otol [serial online] 2016 [cited 2019 Jul 16];22:203-7. Available from: http://www.indianjotol.org/text.asp?2016/22/3/203/187986
| Introduction|| |
Climatologists have reported upward trends in global temperatures, which is concerning everyone in the world. Besides other deleterious effects, variation in temperature has been reported as a major cause in many infectious diseases by shifting the geographic range of the insect vectors, lengthening the reproductive cycles of insects, and by shortening the incubation period of pathogens. It has been reported that a 3°C warming in the United States could increase the range of some mosquito species that can carry the dengue and yellow fever viruses.Staphylococcus, Streptococcus, and enteric bacteria tend to colonize humans more readily in warmer climates, and high temperatures and humidity reportedly increase the overall frequency of isolation of Gram-negative bacteria.,, Goa being on the western coast of the Indian peninsula, in the Konkan coastal belt, has been classified as heavy rainfall zone by the Indian Meteorological Department. It shows a great variation in climatic parameters in various seasons.
As intestinal pathogens have proven seasonal variations and similar pathogens are also encountered in chronic suppurative otitis media (CSOM), the present study has been undertaken to study the effect of climatic parameters in various seasons on the bacteriology of CSOM without cholesteatoma so that an empirical antibiotic policy can be established for treating patients with CSOM without cholesteatoma in different seasons till a definitive culture and antibiotic sensitivity report is ready, which usually takes around 5–7 days.
| Materials and Methods|| |
The present study was carried out in 202 patients, in the age group of 7–64 years of either sex visiting the Department of Otorhinolaryngology and Head and Neck Surgery from January 2013 to December 2013. All the patients having unilateral or bilateral active CSOM without cholesteatoma and not having received any medical treatment for 4 weeks were included in the study. Thirty-six patients had bilateral disease; therefore, 238 ears were included in the study. Patients with acute complications and with CSOM atticoantral disease were excluded from the study. Secretions were gently obtained from the remnant tympanic membrane or from middle ear through a perforated tympanic membrane under microscope. Culture specimen was obtained with a sterile swab without touching the external auditory canal. Two swabs one from each ear were obtained in patients having bilateral disease. Swabs of discharge were sent immediately to the Microbiology Department for culture. The dominant microorganism on the culture medium was selected and the identification was performed with the biochemical identification method by the Microbiology Department. Specimens reported as sterile or mixed flora with more than two organisms were excluded from the study.
Data on monthly mean temperature (MT), mean maximum temperature (MMxT), mean minimum temperature (MMnT), mean atmospheric pressure (sea level pressure [SLP], mean SLP [MSLP], vapor pressure [VP] at 0830 and 1730 h), and mean humidity (at 0830 and 1730 h) were obtained from the regional Indian Meteorological Department, Government of India.
The following seasons have been classified as per the climatic division by the Indian Meteorological Department:
- Winter season: January–February
- Premonsoon season: March–May
- Southwest monsoon season: June–September
- Postmonsoon season: October–December.
The correlation between the aerobic bacterial colonization and the climatic parameters in different seasons was assessed by SPSS/Microsoft developed by IBM Corporation and P < 0.05 was considered significant.
| Results|| |
The study comprised a total of 202 patients, of whom 109 were males and 93 were females. The study had more number of males than females at the ratio of 1.17:1. Out of the total 238 ears examined in a total of 202 patients, 166 (82.17%) patients had unilateral disease, while 36 (17.82%) patients had bilateral disease. Out of 238 ears examined, 128 (53.78%) patients had disease in the right ear, while 110 (46.03%) patients had disease in the left ear. According to the modified Kuppuswamy's classification of socioeconomic status, most patients, that is, 120 patients (59.40%) belonged to lower class, 40 patients (19.80%) belonged to lower-middle class, 30 patients (14.85%) belonged to middle class, and 10 patients (4.95%) belonged to upper-middle class. Least number of patients belonged to upper class which contained two patients (0.99%) only.
The study was conducted in the age group of 7–64 years with a mean age of 30 years and maximum number of patients belonged to the age group of 11–20 years. The distribution of patients according to various age groups is shown in [Table 1].
Annual incidence of organisms' culture
Annual incidence of organisms' culture is shown in [Table 2]. Maximum number of organisms grown were Staphylococcus 84, followed by Pseudomonas 64.
Group of organisms in relation to different seasons
After excluding 32 cultures which were reported sterile or mixed flora from the study, 206 organisms were grouped into five groups depending on the number of organisms for the purpose of comparison and discussion in different seasons [Table 3]:
- Group 1: Staphylococcus: Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), and coagulase-negative Staphylococcus (CONS)
- Group 2: Pseudomonas
- Group 3: Enterobacteriacea: Klebsiella, Proteus, E. coli, Enterobacter, Citrobacter
- Group 4: Culture having two organisms (e.g., Staphylococcus + Pseudomonas, Pseudomonas + Proteus)
- Group 5: Others: Acinetobacter and Enterococcus.
There is not much significant variation in MT in all the four seasons which ranged from 25.7 to 28.8°C, however there is a significant change in relative humidity (RH) (%), which ranged from 54% in winter to 93% during monsoon as noted at 1730 h. Climatic data obtained from the regional Indian Meteorological Department, Government of India, on MMxT, MMnT, MT in °C, SLP, MSLP, VP at 0830 and 1730 h in hPa, and RH in percentage in each season are shown in [Table 4].
| Discussion|| |
The present study comprised a total of 202 patients between the ages of 7 and 64 years with a mean age of 30 years. Maximum number of patients belonged to the age group of 11–20 years (25.75%) followed by 21–30 years (22.77%). However, other studies such as Nwabuisi and Ologe, Jha et al., Khanna et al., Poorey and Lyer, and Mansoor et al. reported the peak incidence in the age group of 0–10 years. The higher age group in the present study may be due to the fact that the study was undertaken in a tertiary care hospital.
In the present study, organisms when analyzed in various seasons showed a good variation in their growth pattern. Staphylococcus genus which includes S. aureus, CONS, and MRSA remained the most common isolate among all organisms. Out of the total 98 Staphylococcus, 17 were isolated in winter, 23 in premonsoon, 32 in monsoon, and 26 in postmonsoon season.
Although there is a variation in the isolation of Staphylococcus in different seasons, it did not show any statistical significance (P = 0.188) when compared among all the seasons. It signifies that Staphylococcus does not show any change in the growth pattern with seasonal variation which correlates with other studies also. Yildirim et al. also did not find any correlation between the growth of Staphylococcus with change in climate in their 3-year study of the impact of climate on the bacteriology of CSOM. The nonvariation of Staphylococcus may be because of its ability to grow in a wide range of temperature from 10°C to 42°C, although optimum temperature is 37°C. The MT in different seasons was in the range of 25.7–28.8°C in the present study, therefore it had a minimum effect on the growth of Staphylococcus in different seasons.
Out of the total 64 Pseudomonas, 11 were isolated in winter, 17 in premonsoon, 27 in monsoon, and 9 in postmonsoon seasons. Pseudomonas showed a significant increase in growth in monsoon season as compared with other seasons with P = 0.006, which is highly significant. Yildirim et al. from Turkey did not find any correlation between the growth of Pseudomonas with change in climate in their 3-year study of the impact of climate on the bacteriology of CSOM. The controversy may be due to different climatic parameters. According to their study, the range of MMxT was from −0.4°C to 23.5°C, range of MT was from −3.5°C to 32.7°C, and range of humidity was from 53.7% to 79.6%, while in the present study, it is from 28.3°C to 33.8°C for MMxT and 25.5°C to 30.3°C for MT and 54–95% for humidity. Pseudomonas has been reported to grow more in moist and humid environment. In two studies, variation of mean humidity was less in Turkey, i.e., 53.7–79.6% as compared to the present study at 54–95%. Therefore, it concludes that higher humidity predisposes more growth of Pseudomonas as compared to other organisms.
Out of the total twenty organisms of Enterobacteriaceae family, three were isolated in winter, four in premonsoon, eight in monsoon, and five in postmonsoon season. This is probably because of minimum variation of temperature in the present study in all the seasons. A higher seasonal temperature has been reported with more growth of Enterobacteriaceae organisms in various seasons.
Out of the total twenty isolates of culture showing two organisms, two were isolated in winter, five in premonsoon, seven in monsoon, and six in postmonsoon. Although isolates are showing variations in growth among seasons, it was found statistically insignificant (P = 0.4325). The only important point to be noticed was that most of the combinations were with either Staphylococcus or Pseudomonas which increase during monsoon and postmonsoon seasons.
Only three Acinetobacter and one Enterococcus were isolated in the whole year. They did not show any statistically significant variation in the growth (P = 0.1116). This may be due to very small sample size.
Out of the total 238 culture reports, 24 culture reports were sterile and eight showed mixed flora (more than two organisms). Mixed flora may be encountered because of contamination from the external auditory canal while taking the sample. Sterile culture reports might be because of oral antibiotics given to patients by peripheral health centers before referring them to tertiary care centers or may be because of delay in processing the sample due to various reasons.
| Conclusion|| |
The study showed a significant increase in the growth of Pseudomonas aeruginosa during monsoon season because of increase in humidity which favors the growth of Pseudomonas; however, S. aureus is the most common isolate growth in all seasons combined together. Humidity plays a significant role in increasing the growth of Pseudomonas. Therefore, it is recommended that in monsoon season, empirical treatment should be combined with antibiotics sensitive to both Pseudomonas and Staphylococcus, while in other seasons, treatment with antibiotics sensitive to Staphylococcus may suffice.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4]