Changing patterns of Vibrio cholerae in Sevagram between 1990 and 2005

Changing epidemiology and antimicrobial resistance in Vibrio cholerae: AMR surveillance findings (2006-2016) from Nepal

BACKGROUND

In Nepal, cases of Cholera occur annually either as sporadic or as outbreaks claiming the lives of many in rural areas. The present study is a laboratory based surveillance which aims to analyze the changing epidemiology and antimicrobial susceptibility trend of V. cholerae strains isolated or referred to National Public Health Laboratory (NPHL) over a period of 11 years (2006-2016).

METHODS

Specimens of fresh stool /rectal swab either received at sentinel sites or NPHL were processed following standard microbiological techniques. Suspected colonies on selective medium were identified using routine biochemical tests and confirmed by serotyping. Antimicrobial susceptibility testing was performed following Kirby Baeur disc diffusion method.

RESULTS

Of the 836 confirmed isolates, 87% (728/836) were V.cholerae O1 Ogawa,12% (103/836) were V.cholerae O1 Inaba and only 6 isolates were V.cholerae O1 Hikojima. In 2006 all the Vibrio isolates were of Inaba serotype, followed by all 3 serotypes during 2007.During 2008-2014 only Ogawa serotype was isolated while few cases of Inaba again surfaced in 2015. Resistance to ampicillin decreased from 93% in 2006 to 18% by 2010 and again raised to 100% by 2016.Cotrimoxazole resistance remained at constant range (77-100%).Nalidixic acid resistance was 100% since 2006.Ciprofloxacin and tetracycline resistance emerged in 2007, reached a peak during 2010-2012 and declined to 0 by 2016.Susceptibility to Furazolidone has re-emerged.63.6% of the isolates were Multi drug resistant.

CONCLUSION

With changing epidemiology and antibiogram of V.cholerae in Nepal, the present study reflects the importance of continuous monitoring, which could be used by policy makers and health professionals for better management of outbreaks. Decline in tetracycline and ciprofloxacin resistance along with emerging sensitivity to furazolidone shows that these drugs could make an effective comeback in future.

Phenotypic and antibiogram pattern of V. cholerae isolates from a tertiary care hospital in Mumbai during 2004-2013: a retrospective cross-sectional study

OBJECTIVES

Cholera is a major gastroenteric disease with reports on fluctuation and resistance. Hence, the objective is to determine the trend in seasonality, resistance pattern, prevalent biotypes, serotypes and phage types between 2004 and 2013 among Vibrio cholerae isolates.

DESIGN

A retrospective cross-sectional study.

SETTINGS

A single-centre study was carried out at a tertiary care hospital in a metropolitan city (Mumbai) of a developing country (India).

METHODS

Records of stool specimen cultures of patients with suspected cholera from January 2004 to December 2013 were analysed. The organisms were identified as per standard protocol. Antimicrobial susceptibility testing was performed as per Clinical Laboratory Standard Institute. Biotyping, serotyping and phage typing were carried out. From the confirmed cases of cholera, demographic and laboratory details were noted. Descriptive analysis was used and the data were presented in the form of percentages.

RESULTS

Vibrio cholerae was predominant in males and was isolated from 9.41% (439/4664) of stool specimens. Variability was found in terms of the gross appearance of stool specimens, seasonal trend and antibiotic resistance pattern. The antimicrobial susceptibility showed a waxing and waning pattern for most of the antibiotics (ampicillin, cefuroxime, chloramphenicol, tetracycline) tested, while for a few others the strains were either uniformly sensitive (gentamicin, norfloxacin) or resistant (trimethoprim-sulfamethoxazole, nalidixic acid). All isolates belonged to subgroup O1 and biotype El Tor. The most common serotype was Ogawa. The predominant phage type was T2 (old scheme) and T27 (new scheme).

CONCLUSIONS

The predominant biotype, serotype and phage type were El Tor, Ogawa and T27 phage, respectively. The changing trends in antimicrobial resistance pattern over the years necessitate continued epidemiological and microbiological surveillance of the disease.

Cholera outbreak caused by drug resistant Vibrio cholerae serogroup O1 biotype ElTor serotype Ogawa in Nepal; a cross-sectional study

BACKGROUND

Cholera is a major cause of mortality and morbidity in underdeveloped countries including Nepal. Recently drug resistance in Vibrio cholerae has become a serious problem mainly in developing countries. The main objectives of our study were to investigate the occurrence of Vibrio cholerae in stool samples from patients with watery diarrhea and to determine the antimicrobial susceptibility patterns of V. cholerae isolates.

METHODS

A total of 116 stool samples from patients suffering from watery diarrhea during July to December 2012 were obtained from outbreak areas from all over Nepal. Alkaline peptone water and thiosulphate citrate bile salt sucrose agar (TCBS) were used to isolate the Vibrio cholerae. The isolates were identified with the help of colony morphology, Gram's staining, conventional biochemical testing, serotyping and biotyping. Antimicrobial susceptibility testing was performed by determining the minimum inhibitory concentration (MIC) by agar dilution method.

RESULTS

Vibrio cholerae was isolated from 26.72 % of total samples. All isolated Vibrio cholerae were confirmed to be Vibrio cholerae serogoup O1 biotype El Tor and serotype Ogawa. All isolates were resistant to ampicillin and cotrimoxazole. Twenty nine isolates were resistant toward two different classes of antibiotics, one strain was resistant to three different classes of antibiotics and one strain was resistant to four different classes of antibiotics. According to the definition of the multidrug resistant bacteria; 6.45 % of the strains of Vibrio cholerae were found to be multidrug resistant.

CONCLUSIONS

Cholera due to multidrug resistant Vibrio cholerae is also possible in Nepal. According to the antimicrobial susceptibility pattern of Vibrio cholerae in our study we recommend to use any antibiotics among tetracycline, doxycycline, levofloxacin, azithromycin, chloramphenicol and ciprofloxacin for preliminary treatment of cholera in Nepal.

Continuing challenge of infectious diseases in India

In India, the range and burden of infectious diseases are enormous. The administrative responsibilities of the health system are shared between the central (federal) and state governments. Control of diseases and outbreaks is the responsibility of the central Ministry of Health, which lacks a formal public health department for this purpose. Tuberculosis, malaria, filariasis, visceral leishmaniasis, leprosy, HIV infection, and childhood cluster of vaccine-preventable diseases are given priority for control through centrally managed vertical programmes. Control of HIV infection and leprosy, but not of tuberculosis, seems to be on track. Early success of malaria control was not sustained, and visceral leishmaniasis prevalence has increased. Inadequate containment of the vector has resulted in recurrent outbreaks of dengue fever and re-emergence of Chikungunya virus disease and typhus fever. Other infectious diseases caused by faecally transmitted pathogens (enteric fevers, cholera, hepatitis A and E viruses) and zoonoses (rabies, leptospirosis, anthrax) are not in the process of being systematically controlled. Big gaps in the surveillance and response system for infectious diseases need to be addressed. Replication of the model of vertical single-disease control for all infectious diseases will not be efficient or viable. India needs to rethink and revise its health policy to broaden the agenda of disease control. A comprehensive review and redesign of the health system is needed urgently to ensure equity and quality in health care. We recommend the creation of a functional public health infrastructure that is shared between central and state governments, with professional leadership and a formally trained public health cadre of personnel who manage an integrated control mechanism of diseases in districts that includes infectious and non-infectious diseases, and injuries.