Second National Communications There are several caveats for this study. Location of the hospitals as the sentinel sites for the cases may be not that favorable as there might be other hospitals that the patients went to for accessibility. The data gathered from the hospitals may not be complete. The NESSS started in 1988 and became operational in 1989. The period of analysis is short as for this reporting. Leptospirosis data was gathered starting 1998 as it was considered an emerging disease for inclusion only during that time. The data gathering personnel were given a short course in public health surveillance and practice (quality assurance) would be a challenge. Laboratory-diagnosed diseases (hepatitis A, hepatitis B, typhoid fever, cholera) were dependent on availability of reagents. It was also noted that clinically confirmed diseases were affected by changes in case definition which can cause confusion, although this are always regularly communicated to ESU staff. We should also consider the epidemiologic triad for disease occurrence (environment-agent-reservoir) with weather as being part of the environment factor. While we try to assume that only weather data affects disease occurrence to a significant extent, we may be assuming inadequately for we know that there are other factors to consider; so for the moment we will consider this. As we also have projection scenarios, it will not be accurate to say how the disease occurrence will go, and any projections using these assumptions may not have a high confidence. 5.4 Future Projections In the baseline historical data, we saw that relationships were confirmatory of the different disease conditions prevailing and the climate change impacts which we are likely experiencing today. Looking into the future then to project the effects with scenarios for 2020 and 2050 would be a good exercise. However, we will not be that confident as we still have to consider the epidemiologic triad as it goes into play. The following three diseases of Dengue, Leptospirosis and Malaria which had significant results will be the ones to be included in these projections. Our start year (Year 0) is 1989 so that 2020 would be year cell 32 and 2050 would be year cell 61. We see that with weather being the major variable affecting the disease, we have increasing values for the two diseases Dengue and Leptospirosis and a downward trend for Malaria. In related literature Nicaragua and Brazil has been having the medium term effects of communicable diseases over time, these countries have the same tropical climate and situations as ours. Medium term effects include increases in communicable diseases caused by ingestion of contaminated water (for example, cholera or hepatitis A) and contact with flood waters (for example, leptospirosis). Outbreaks of leptospirosis, a bacterial zoonosis, occurred after floods in Nicaragua and Brazil.41 41 (Trevejo RT, Rigau-Perez JG, Ashford DA, McClure EM, Jarquin-Gonzalez C, Amador JJ, et al. Epidemic leptospirosis associated with pulmonary hemorrhageNicaragua, 1995. J Infect Dis 1998; 178: 1457-1463 48