Monsoon Systems Impact in the Exacerbation of Malaria in Southern Sistan and Baluchestan Province with Emphasis on Chabahar city

Document Type : مقاله پژوهشی



1. Introduction
Malaria is a global public health challenge, with about one million deaths each year and a further 250 million new cases of malaria diagnosed annually. Interestingly, malaria have been distributed disproportionately such that the poorest countries in sub-Saharan Africa bearing about 85% of the burden of malaria morbidity and mortality in the world .However, more than half of the populations of the Eastern Mediterranean Region are at potential risk of contracting malaria. The Islamic Republic of Iran is one of the countries located in the Eastern Mediterranean Region with low malaria endemicity, with some regions having a reported API ranged from 0.14 to 8.74 per 1, 000 . The south-eastern areas of Iran, including Sistan & Baluchestan (S&B), Hormozgan and the tropical part of Kerman provinces accounting for around 95% of all malaria cases in the country (Raiesi, 2011).
Malaria is basically an Italian word which means bad weather and is meant a kind of disease that is with fever , which is the result of bad weather and swampy areas. Most outbreaks and spread of diseases such as malaria, in addition to economic, social and cultural issues are affected by environmental and geographical factors.
Malaria is a Infectious Diseases which is caused by celled parasites that infect human body through an anopheles mosquito. In human body the parasites grow to their next stage of development and multiply.
Malaria is Caused and transmitted by Anopheles Mosquito. Distribution and ecology of Anopheles Mosquito is strongly affected by temperature, humidity, evaporation, sweating and rain fall factors. The studies show that, proper temperature range for a malaria outbreak in southeastern Iran, ‎according to the insect species, is 25 to 35 degrees Celsius. Humidity is another factor affecting the ‎growth and spread of mosquitoes. Proper relative humidity range for a malaria outbreak in ‎southeastern Iran, according to the species of insects, is 50 to 80 percent. Spawning and early ‎release of Anopheles occurs in water that appears in the form of larvae. Since flying distance of ‎mosquitoes is limited and spawning is necessary to be done in ponds, there are numerous insects ‎around the places where there are water. Flying distance of mosquito species found in South and ‎South-East of Iran is considered 2Km so the water levels within 2 km of an area is appropriate for ‎the presence of Anopheles mosquitoes(Ahmadian Marj,2008).
People such as Ramage (1962) with studies on tropical cyclone, concluded in West Pakistan as a result ‎of severe warming of drought surface some energy transferred to the middle classes atmosphere and heat load ‎down. Pishaorti (1965) on the maps of air detect rain resulted from atmospheric turmoil and found that ‎the turmoil monsoon in the summer associated with the monsoon of low pressure.‎
Gilchrist (1977) claimed that during the summer monsoon, a strong field of thermal difference comes ‎when it changes is from the ocean to the land.‎
Huque (1977) knew Southeast Asia's monsoon as the result of combining the effects of dynamic ‎turbulences of seasonal changes in the position and density belt high pressure outside tropic in two hemispheres ‎and the confrontation of the thermodynamic between the continents and the oceans. RAO (1987) indicated ‎effect of reaction temperature between the water surface temperature and nearby air of the Arabian Sea and know ‎the development of the monsoon caused by thermal reaction above.‎
Research is on several aspects of the malaria, the past and present situation of malaria in Iran examined by the ‎Edrissian ( 2006).Reviews of a particular type of release of the malaria in the province of Sistan and ‎Baluchistan by Salehi and colleagues (2008). Schumann (2011) reviewed global climate change ‎and infectious diseases and the resulted if global climate change continue, it is likely that a range of deadly ‎diseases such as malaria spread or shift. Hoshvar (1986) in his book “introduction to medical geography of Iran” ‎assigned chapter to malaria and familiarity with it. Geographic information system GIS designed to control and ‎manage the disease malaria in kahnuj town by Zamani et al . Reviews of new prospects in the malaria ‎control conducted by shikhany, et al (2003). Najar Salighe (2006) explored the mechanisms of rain in the South ‎East of the country. In addition, he concluded in this area the influence of the moisture is from path A, B and C. In ‎path C, moisture is in the lower and median atmosphere, with low-pressure cycle monsoon takes place, causes the ‎sever cloudburst in hot zone.‎
Ahmadian Marj (2008) presented a good algorithm to determine the areas with the potential outbreak of malaria ‎using satellite images. The research indicated that a weather condition is effective directly on the amount of growth ‎and development of the mosquito Anopheles and ultimately malaria outbreaks.‎
2. Study Area
The study area includes beach areas in Sistan and Baluchestan area which is located in 26 and 30 in the north and 61:40 in the east which is a high danger area for malaria disease.In this study, we have tried to investigate the relationship between extended seasonal systems and Malaria disease in Chabahar province(Pourkermani and Zomorodian,1987).
3. Material and Methods
Annual data on malaria incidence during ( 2010-1991) Chabahar and data about rainfall and humidity for the June , July, August and September months were gathered through the weather station of Chabahar, by weather agency of Sistan and Baluchistan province.
The data of 850 hPa geopotential height and sea level data ranging from 0 to 80 and 0 to 120 North East were also studied. Those were considered as the upper atmosphere s data obtained from the United States National Oceanic and Atmospheric site (www.cdc.noaa. gov).
4. Results and Discussion
In the first phase, we in the Jun, July , august and September ,found days with humidity over 60% which there were 1858 days with humidity greater than 60 percent in this period, then the sum of relative humidity above 60 percent per year (wet of the day) and the statistics of patients were calculated.
The patient was given the same amount of years of relative humidity and illness statistics were increased compared with the previous year.
During the course of the disease process charting data (2010-1991) were reviewed.
Statistics show that with the increase of the humidity, the percent of people with the disease also increase.
The peripheral circulation method is used in this survey. In other words, the early years, simultaneously with high annual moisture and high rated of infected people with malaria were identified. Then the days with an average humidity of over 60% were obtained and the maps of geopotential height and sea level pressure related to these days were classified and their flow patterns were identified .For classification , all maps were standardized then standard matrix of 648 × 1617was based for Euclidian distance calculations. As before categorizing there is no idea about the number of groups, cluster analysis to categorize groups seems feasible. In this case, all points are compared to each other to reveal their similarity. And then all of them are clustered together according to similarity degree of the pressure points that show a pattern is detected. The four main patterns of sea level pressure and geopotential height patterns were obtained. By mapping software, Grads, the map of blowing humidity for the day with the highest precipitation and humidity was drawn.
5. Conclusion
Generally, malaria situation in terms of cases reported during (1991-2010) showed a decreasing ‎trend.‎
In the city of Chabahar the disease has been declining since about 10,555 in 1991 to 1,148 in 2010 ‎so. There is a positive and meaningful correlation between the annual incidence of the disease and ‎annual humidity at 0.05 Alpha level in Chabahar. The maps of pressure patterns revealed that the ‎entire period of (1991-2010) rainfall events in the region have circulating levels of 850 hPa pattern 3 ‎and circulating pattern of sea level type C.‎
The above mentioned patterns showed that the summer rains in south east of Iran are associated with forming and western expansion of Indian low - pressure monsoon and also frequency of their occurrence in the Arabian Sea region.
In all the years that statistics of disease has increased over the previous year, the study area is dominated by a strong low pressure system centered on Pakistan and some parts of it are spread to East and West. In all models, three core units, one located on the Ganges Valley, the other on Pakistan and there is often a low pressure on the Persian Gulf (fig. 9, 10(.
In most of the maps there are three Low pressure cores which one id dominated most of the Ganges Valley , the other in Pakistan and there is often a third core with little pressure on the Persian Gulf.
The monsoon systems in the region and its climate implication provides the rare conditions which is necessary for the growth and spread of mosquitoes, these conditions includes lowering the temperature of the earth Vabgyry Post marshy lands followed Widespread Larval abundance in the area, resulting in increased carrier is provided. Stats increase in malaria cases in the years that a strong monsoon system has since confirmed this.