Generally, there are two phases of outbreak of infectious diseases following earthquakes or natural disasters. These phases are based on incubation period, which refers to the time from moment of exposure to an infectious agent to appearance of first signs and symptoms. Air-borne, water-borne, and vector-borne diseases, animal bites, tetanus, measles, and chickenpox are commonly seen after natural disasters, although there is no direct evidence that dead bodies could contribute to an epidemic.In the first phase, diseases with short incubation period are seen. For example, Sukraraj Tropical and Infectious Disease Hospital (STIDH) mostly observed air-borne influenza-like illnesses in patients shortly after the big April 25 earthquake. Shigella dysentery, a water-borne disease was detected in patients with acute diarrhea.
Although cholera has a short incubation, it has so far not been reported after the earthquake. However, that doesn't mean it will not appear in the future, and hence we must be prepared because it can kill healthy persons within hours. Cholera could still pose as a major public health risk if precautions are not taken. Nepal should learn from Haiti's cholera outbreak. The earthquake struck the country in January 2010, while cholera broke out in mid-October (nine months later), causing at least 8,000 deaths.
In the second phase, diseases with long incubation may become apparent. Both endemic and imported pathogens might emerge during this period. Typhoid, Hepatitis A and E, chickenpox, measles, vector-borne diseases, and tetanus are some communicable diseases which may be seen in quake-hit areas.
The monsoon is arriving soon, further increasing the risk of water and food-borne diseases, including vector-borne viruses such as Dengue virus, Chikungunya virus, West Nile virus, and Crimean-Congo hemorrhagic fever (CCHF). Monsoon rains make conditions favorable for mosquitoes, which ultimately results in increased transmission of Dengue, Chikungunya, and Malaria. Dengue virus has been detected in Nepal since 2004, while Chikungunya virus was first reported by STIDH in 2013.
A study carried out by Epidemiology and Disease Control Department (EDCD) showed that Aedes species of mosquito, responsible for Dengue, Chikungunya and West Nile transmission, have been widely circulating in Kathmandu. Recently, West Nile virus was reported in Nepal, a comparatively less known viral disease here. Last year, several patients with high fever and low platelet count were admitted to STIDH and they recovered, but diagnosis wasn't possible. It indicates the existence of unknown hemorrhagic fever. Since Nepal shares large and often porous border with India, possibility of virus outbreaks cannot be ruled out.
Typhoid, a water-borne disease, is endemic to Nepal, transmitted through contaminated food and water. Since many people are living in makeshift shelters sharing water and food, there is risk of outbreak of typhoid. As a matter of fact, STIDH has been treating patients with suspected typhoid after the earthquake. One victim who developed intestinal perforation due to typhoid has been reported recently in Bhaktapur. Although vaccine against typhoid is available, people are largely unaware of it.
Hepatitis (A and E) is another common water-borne disease. Patients suspected of hepatitis were also seen in STIDH after the earthquake. They could spread it to other healthy people who are living in the same shelters and use the same latrines. Thus, vaccinations in displaced populations are needed to avoid outbreak of infectious hepatitis. Both hepatitis A and E are endemic to Nepal, and the last outbreak of Hepatitis E was in Biratnagar in 2014.
Leptospirosis is a common bacterial infection during rainy season. This is the fourth most common cause of fever in Nepal. Unfortunately, leptospirosis is completely ignored by physicians and sometimes misdiagnosed as hepatitis when laboratory facilities are not available. There are several incidents of leptospirosis outbreaks following natural disasters worldwide, and we too should be prepared.
Chickenpox, an airborne and highly contagious virus, was also seen after the earthquake, suggesting this virus may have circulated among earthquake victims/survivors. STIDH has treated at least five patients with chickenpox after the earthquake and many more patients might have been treated elsewhere.
Tetanus spreads through contamination of cuts, burns and wounds with tetanus spores found in soil. Tetanus cases have also increased following the earthquake. Many are unaware about tetanus boosters; hence quake survivors are susceptible. Volunteers, who have been helping in removing debris in affected areas, should also take tetanus shots.
People bitten by animals like dogs (both domestic and stray), snakes, mice, and other wild animals are increasingly seeking medical attention following the earthquake. So far, hundreds of people have been given rabies shots after being bitten by animals, particularly dogs after the recent earthquakes.
Natural disaster is unpredictable and infectious diseases are almost inevitable due to lack clean water, vector-control, and health information, especially in least developed countries. So far STIDH is the only government tertiary hospital in Nepal serving patients of tropical infectious diseases and could be first-line of defense against potentially deadly infectious diseases such as SARS, highly pathogenic influenza, and Ebola, but we at STIDH also lack equipment, trained infectious disease specialists and clear political commitment.
The World Health Organization (WHO) can take the initiative to prevent dangerous outbreaks. WHO can help STIDH prevent and control infectious. This is important because Nepal lies in a tropical zone and new infectious diseases are being reported every year.
The author is with the Sukraraj Tropical and Infectious Disease Hospital
Related story
Underprepared infrastructure disappoints athletes, officials
