Hospitals Treating Dengue May Themselves Be Spreading It, NSTU Study Warns

The very hospitals treating dengue patients may be becoming possible 'hotspots' or sources for spreading the disease — that warning has emerged from a new study. Published in an international research volume brought out by IGI Global, the study analysed data from two hospital areas in Dhaka and found that dengue detection rates are higher among people living close to a hospital.

The study was conducted by researchers from Noakhali Science and Technology University (NSTU). Fahmida Alam Bintu, Murad Hossain Raju and Ayesha Ibnat, researchers in the university's Department of Environmental Science and Disaster Management, carried it out. It was based on the areas adjoining Dhaka Community Medical College Hospital in Bara Mogbazar and Mugda Medical College Hospital in Dhaka.

The study found that dengue detection rates are comparatively higher among people living near a hospital. As the distance from the hospital increases, the number of cases falls. According to the data, for every 100 metres of additional distance from a hospital, the likelihood of being diagnosed with dengue falls by about 5 percent.

According to the researchers, two factors may lie behind this picture. First, people living close to a hospital have more opportunity to get tested and be diagnosed with dengue. Second, and more worryingly, is the possibility of 'hospital amplification' — infection increasing around the hospital itself.

At the peak of the dengue season, when patient pressure on hospitals rises, the basic measures that protect patients from mosquito bites — such as using mosquito nets and fitting window screens — are often neglected. Yet a dengue patient can spread the virus through mosquitoes during the first week of illness. If protection is not ensured during that period, the hospital itself becomes a risk point for new infections.

In such a situation, mosquitoes in the hospital can bite an infected patient and become carriers of the virus. If those mosquitoes later bite the hospital's doctors, health workers, visitors and nearby residents, a risk of the infection spreading is created. In other words, a chain can form around the patient who came for treatment, putting healthy people around them at risk.

The study also found that if a person in the neighbouring house is infected with dengue, that person's own risk of infection rises about fivefold. According to the researchers, this finding is consistent with the Aedes mosquito's characteristic of flying only short distances. Because the mosquito cannot fly far, the people closest to an infected person carry the highest risk.

In addition, the research in the Mugda area identified the local drainage system and stagnant water caused by construction work as possible causes of new dengue hotspots forming in more distant areas. Stagnant water is a breeding ground for Aedes mosquitoes, and water collecting in this way at construction sites is an almost routine occurrence.

A survey of health workers in the study found that although their awareness and knowledge of dengue prevention are good, there are significant gaps in preventive measures at both the personal and institutional levels. In other words, the measures are known but not being taken in practice — and that gap is increasing the risk further.

The researchers advise that a hospital cannot be considered only a place of treatment; it must also be identified as a possible source of infection, and mosquito control there must be strengthened. They also stressed keeping dengue patients under treatment inside mosquito nets at all times and regularly spraying larvicide around hospitals.

These observations from the study clearly highlight the need for mosquito control in hospitals and their surrounding areas. The study also noted that using mosquito nets and removing stagnant water are essential to reducing the dengue risk around hospitals. However, there is also a view that the study's methods, sample and limitations should be considered before concluding that hospitals are one of the main sources of dengue spread.

At a time when the country's dengue outbreak is producing news of new patients and deaths every day, this study has pointed to an important weak spot in the prevention system. If treatment centres can be turned into centres of infection control, major progress against dengue could follow. The question now is how far the researchers' advice is implemented in hospital management.