For the past one week, Kathmandu has witnessed approximately more than 20 patients with acute gastroenteritis being admitted to Sukraraj Tropical and Infectious Disease Hospital (STIDH), especially from Kuleswor and Kalimati areas. From the beginning of August, there was a sudden increase in the number of patients with acute gastroenteritis. Although patients with acute diarrhea have been increasingly seen since July shortly after the onset of rainy season, finding of a significant number of patients over a single night from the same areas has compelled healthcare workers to think about the cause of this unexpected outbreak of diarrhea.Rapid test called "Hanging Drop Test" was performed and tested positive in admitted patients. Thereafter, it was assumed that it might be cholera epidemic; hence stool samples were sent for further confirmation by stool culture, regarded as a gold standard method for detecting cholera. It turned out to be culture positive for Vibrio Cholera.
Cholera (locally known as haija) is a well known disease among Nepali community and was first scientifically described in 1885 by a British residency surgeon. His finding was published in The British Medical Journal. Cholera has been detected in Kathmandu as well as in other parts of the country each year. Notably, the outbreak of cholera in Jajarkot in 2009 was one of the deadliest outbreaks in the recent times that killed over 500 people and infected thousands of others.
Epidemiology and Disease Control Division (EDCD) had predicted that soon after the April 25 earthquake that there was a slim chance of an outbreak of Infectious Diseases (especially water-borne diseases) in Nepal, despite the fact that post-quake assessment carried out by EDCD showed that 74 percent of water samples collected from the affected areas was not suitable for drinking purpose.
Indeed, there is still an increased risk of waterborne diseases outbreaks, especially in earthquake-displaced populations, where the source of drinking water may be the same. In light of the current cholera epidemic in Kathmandu, risk of outbreak of cholera in other parts of the country, particularly in earthquake displaced populations has greatly increased. Cholera can quickly lead patients to severe dehydration and even death within hours, if not treated immediately.
Cholera is caused by a bacteria called Vibrio Cholerae and transmitted most frequently through water sources contaminated with this bacteria. Virtually, all the patients admitted to STIDH used drinking water without filtration and boiling. Most of them are using bottled water for drinking purpose but not from branded companies. Some of them have been using filters for drinking water; however, it was not known what type of filters they were using. Generally good filters are designed to prevent bacteria, protozoa and other particles from passing through its filters.
A study carried out in Bangladesh showed that filtering water through sari can reduce cholera by up to 48 percent. However, boiling drinking water is the best option to avoid microorganisms that cause diseases in humans. I was surprised to find that patients, despite knowing well that drinking water must be boiled before use, weren't careful enough. Personal hygiene education and promotion may require a change or further modifications. Armed with this experience, policymakers must work together with healthcare providers, I/NGOs, Nepal Health Research Council, stakeholders and other activists to develop or revise current personal hygiene education.
Many patients admitted to STIDH had lost their consciousness due to severe dehydration on admissions, and required fluid replacement immediately in order to save their lives. Approximately one in 10 (5 to 10 percent) people infected with cholera will have severe dehydration. Most patients had history of sudden onset of watery diarrhea followed by multiple episodes of vomiting. Abdominal pain and leg cramps are other common associated signs seen in these patients. Cholera symptoms can appear from two hours to five days after infection.
In the current outbreak, most of the patients had experienced sudden onset of watery diarrhea and vomiting from two to 10 hours after consuming contaminated water. None of these patients had developed fever. Fever is rare in cholera but can predict secondary infection if it develops. Based on these signs and symptoms, it was presumed that these patients might have been infected with Vibrio cholera.
Signs and symptoms, however, themselves are not sufficient to confirm Vibrio cholera. Hanging Drop Test is a rapid, simple, and easy method. It is useful especially when laboratory is not sufficiently equipped or there is no skilled lab technician. In STIDH, at first Hanging Drop Tests were performed in patients with watery diarrhea because the first day of the outbreak was a public holiday (Saturday). Some of the stool samples from the admitted patients tested positive in Hanging Drop Tests. The next day, these stool samples were sent to National Public Health Laboratory for further confirmation by culture method.
Culture method is an internationally accepted gold standard method, and has been performed routinely in Nepal. One after another, these stool samples turned out to be culture positive for Vibrio cholera. To date, a total of 32 samples were confirmed Vibrio cholera by culture method. Two types of serotypes were identified in patients. Inaba and Ogawa serotype were responsible for the current outbreak.
Inaba serotype reappeared after an interval of eight years in Nepal. It is worth noting that a woman who had lost her consciousness on admission was found to be infected with Inaba serotype. It is highly likely that any disease serotype reappeared after a long period of time may cause severe illness in humans because organisms may have genetically changed and/or previous antibodies may not be able to fight or recognize the same serotype, if re-infected.
Given the backdrop of cholera disease severity, it is a matter of great concern if this organism reached or was introduced into earthquake or natural disaster displaced populations. More than 80 percent people infected with cholera may not display signs and symptoms and therefore could spread the disease from one place to another. Currently, many asymptomatic people infected with this organism may have been spreading the bacteria to other parts of the capital or even beyond the capital. In fact, some of the patients were admitted from beyond the cluster areas, meaning that there may be more cases of cholera being treated in nearby hospitals elsewhere. Currently, concerned bodies are only focusing on Kalimati and Kuleswor areas. They must focus on other areas too, if this outbreak is to be brought under control quickly and effectively. Moreover, the government should facilitate in putting preventive measures in place in earthquake-affected areas, where rehydration fluids, medicines, and skilled healthcare providers are lacking.
Cholera is endemic and a huge public health burden in Nepal, therefore hunting for the source after the outbreak and depending merely on hospital treatment may not be enough for the next possible cholera epidemics in future. The government should take initiative in introducing cholera vaccine into routine immunization program in order to prevent further mortality. The World Health Organization should play a more proactive role. Furthermore, current epidemic suggests that there is a need for modification in personal hygiene education.
The author is a Medical Officer at Sukraraj Tropical and Infectious Disease Hospital
drsherbdr@yahoo.com
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