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ORIGINAL ARTICLE  
Year : 2013  |  Volume : 6  |  Issue : 4  |  Page : 430-434
Epidemiology of malaria in Nikshahr, Sistan and Baluchestan province, Southeast Iran, during 2004-2010


1 Department of Medical Entomology, School of Health and Nutrition, Shiraz, Iran
2 Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran
3 Health Center of Nikshahr, Sistan and Baluchestan University of Medical Sciences, Sistan and Baluchestan, Iran

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Date of Web Publication26-Feb-2014
 

   Abstract 

Objective: Malaria is a major health problem in Nikshahr. In 2010, about 11.9% of the total malaria cases in Iran occurred in Nikshahr. The main purpose of this study was to survey the epidemiological features of malaria in Nikshahr, Southeast Iran, during a 7-year period, 2004-2010. Materials and Methods: The present survey is a descriptive study that involves positive cases of Malaria reported from the center of communicable diseases in Nikshahr. The data were entranced to a computer according to demographic and epidemiological characteristics of patients as well as plasmodium species; then they were analyzed by SPSS 16 software. Results: A total of 12233 cases were reported during 2004-2010 and three types of species of malaria parasite were detected. The highest positive number (2937) was reported in 2006 and the lowest number (221) in 2010. Malaria-positive cases of Nikshahr were mainly (60.2%) found among male individuals. The annual parasite incidence (API), which is the index of malaria incidence in the community, has decreased from 9.5 in 2004 to 1.09 in 2010. The slide positive rate among indigenous residents was significantly higher than that of the migrant population. Most (96.5%) of the malaria-positive cases were found among the Iranian population. About 0.3% of cases were identified to be mixed (falciparum and vivax), 98% Plasmodium vivax, and 1.7% Plasmodium falciparum. The largest number of malaria-positive cases occurred in October when the average percentage of humidity was 29.4 and the mean ambient temperature was 30.8°C. Conclusions: Several measures should ideally be implemented in an integrated pattern to contain the dissemination of malaria parasites and mosquito vectors; these include improvement of policies, regulations, and practices regarding malariological screening.

Keywords: Epidemiology, Iran, malaria, Nikshahr, Sistan and Baluchestan

How to cite this article:
Alipour H, Amiri SA, Delavari A, Amiri A. Epidemiology of malaria in Nikshahr, Sistan and Baluchestan province, Southeast Iran, during 2004-2010. Ann Trop Med Public Health 2013;6:430-4

How to cite this URL:
Alipour H, Amiri SA, Delavari A, Amiri A. Epidemiology of malaria in Nikshahr, Sistan and Baluchestan province, Southeast Iran, during 2004-2010. Ann Trop Med Public Health [serial online] 2013 [cited 2020 Aug 10];6:430-4. Available from: http://www.atmph.org/text.asp?2013/6/4/430/127790

   Introduction Top


Malaria is a resurgent malignant malady. This is by far the most important mosquito-borne blood parasitic infection of man in most of the tropical areas. [1] It is characterized by periodic fevers coinciding with the sudden release of malaria parasites from ruptured erythrocytes into the blood circulation. According to the World malaria report 2011, there were about 216 million cases of malaria (with an uncertainty range of 149 million to 274 million) and an estimated 655,000 deaths in 2010 (with an uncertainty range of 537,000 to 907,000). Malaria mortality rates have fallen by more than 25% globally since 2000 and by 33% in the WHO African Region. The number of laboratory confirmed autochthonous malaria cases have decreased from 11,923 in 2006 to 1847 in 2010. [2] Most deaths occur among children living in Africa where a child dies every minute from malaria. [1] Human malaria is transmitted naturally through exposure to the infective bites of female Anopheles mosquitoes. It is unstable (stability index<0.5) and mesoendemic in Iran. National Malaria Control Program reported 1847 malaria cases in 2010; among them 50% were imported. Seventeen percent of the total malaria cases were caused by falciparum malaria in Sistan and Baluchestan. [3],[4] The major peak of malaria transmission occurs between September and November. Both global warming and anthropogenic impacts are contributing to the causes of the resurgence of malaria in certain regions. [5],[6] The emergence of resistance to anti-malarial drugs as well as various insecticides also continues to hinder "averting a malaria disaster". [7],[8],[9] Human malaria is essentially a focal illness, since its transmission depends largely on local environmental and ecological conditions; hence, the impact of anthropogenic and climate changes will have a sweeping local influence on vectors. [10] Vector control is a crucial component of malaria control programs. In fact, three of the four basic technical elements outlined in the global malaria control strategy by WHO (1995) involve vector control. At least 65 different species of Anopheles are proven vectors of malaria worldwide, about two dozen of which are prevalent in Iran. [11] Although in each geographical region there are usually not more than three or four anopheline species that can be implicated as important vectors of human malarial parasites, it seems that there are more species of malaria vectors found in rural areas than in urban environments. The most indispensable requirement for Anopheles is always the presence of relatively clean water that is devoid of predators and competitors, to sustain viable development of the aquatic larval and pupal stages of the mosquitoes. Nikshahr is located in Sistan and Baluchestan province in the south east of Iran and its neighbor is Pakistan. More than 90% of positive cases of malaria disease are reported from Sistan and Baluchestan, Hormozgan and the south of Kerman provinces in the south east of Iran. [4] The aim of this study was to determine the epidemiological features of malaria disease in Nikshahr from April 2004 to March 2010.


   Materials and Methods Top


Nikshahr city (26°13’33”N 60°12’51”E) with a population of approximately 202624 is about 680 km to the south of Baluchestan and 510-meter altitude from the sea level. The county is subdivided into five districts: The Central District, Bent District, Fanuj District, Qasr-e Qand District, and has a subtropical climate and is prone to seasonal malaria transmission [Figure 1]. It has a fairly flat terrain with many natural springs, deep wells, and concrete pools for agricultural goals which are the main breeding sites for mosquitoes. Ambient air temperature oscillates between 3 and 49°C during the year. The annual average relative humidity is 36.8% and the average annual precipitation rate is about 150 mm. This district is sporadically covered with palm woods. A cluster of three cities, 16 rural districts and 816 villages with a total area of about 23,930 km 2 were selected for the study. All malaria cases are confirmed by microscopy or RDT kit [First Response Malaria Ag. (pLDH/HRP2) Combo Rapid Diagnostic Test, Cat No I16FRC30]. It is an ideal test for detection, confirmation and monitoring of treatment in a single test. The sensitivity and specificity has been found to be 100% by an independent WHO-FIND survey. The data collected from Communicable Diseases Control (CDC) of Nikshahr district include 20 Health Centers and 112 Health houses, during 2004-2010. Finally, data were categorized according to the demographic characteristics of patients and Plasmodium species and were then analyzed.
Figure 1: The map of the study area, Nikshahr, Sistan and Baluchestan province, southeast of Iran

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   Results Top


A preliminary survey of the number of malaria episodes in Nikshahr from 2004 to 2010 is depicted in [Figure 1]. It reflects the changing dynamics of infection with Plasmodium vivax and/or Plasmodium falciparum in Nikshahr over a 7-year period. In spite of yearly fluctuations, an overall downward trend in total malaria cases recorded at the County level over these years has been evident. Malaria-positive cases were mainly (60.2%) found among male individuals in the Nikshahr region of Sistan and Baluchestan province. The annual parasite incidence (API), which is a measure of malaria incidence in the community, has decreased from 9.5 to 1.09 (~85% decrease) from 2004 to 2010, respectively [Figure 2]. Most (95.2%) of the malaria-positive cases were found among Iranians and 80.3% were indigenous [Table 1]. About 0.3% of cases were mixed (falciparum and vivax), 98% were P. vivax and 1.7% were falciparums. P. falciparum has increased from 3.6% in 2004 to 5% in 2010 [Table 2]. A total of 9742 positive cases were locally transmitted and they were mostly reported among the resident population. The slide positivity rate among the Iranian population was significantly higher than that of the indigenous Afghan population [Table 1]. The largest number of malaria-positive cases occurred in the Fanuj during 2004-2010 [Figure 2]. Most positive cases were observed in October and December with 6188 cases (47.6%) during 2004-2010. The highest number of positive cases (2937) was seen in 2006 and this reduced to 221 cases in 2010. The prevalence of malaria among children under 5 years of age, children aged 5-15 and pregnant women were 7.2%, 32.6%, and 1.5%, respectively [Table 2].
Figure 2: Distribution frequency of malaria based on living area (Health Center) in Nikshahr County of Sistan and Baluchestan province, 2004-2010

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Table 1: Malaria epidemiologic indices in the Nikshahr County of Sistan and Bluchestan province in the years of 2004-2010

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Table 2: Malaria positive cases based on nationality and epidemiologic survey in the Nikshahr County of Sistan and Bluchestan province in the years of 2004-2010

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   Discussion Top


Malaria-related mortality is on the rise largely due to the resistance of parasites and mosquitoes to drugs and insecticides, respectively, and in part due to the anthropogenic and climatic impacts. [12],[13],[14] Although the number of clinical episodes of P. falciparum malaria is lower than that widely quoted for southeast regional provinces, [15] the morbidity due to malaria, particularly that of P. vivax in this area, has been greatly underestimated. The reason could be the difficulty in maintenance of the microscopes and the quality of microscopy in peripheral clinics. [16] Most rapid diagnostic tests do not detect vivax infections and those that do are expensive and cannot be afforded by clinicians in poor settings; that passive case detection is the mainstay of health care delivery system in Iran.

Malaria transmission is typically seasonal, long, and regular, according to the mean ambient temperature and percentage humidity patterns and presence of bodies of water around human settlements. Transmission is very much influenced by the local ecological situation of each village, nearby river, swamp, backwater and human ways of life-both on a small scale (near pits from which soil is taken for brick making, footprints in marshy grounds, etc.). In these conditions, the prevalence of Plasmodium is variable during the year, from about 20% during the dry season to more than 80% at the end of the rainy season in children under 5 years of age. The spring peak in malaria infections was also found in a study in Madagascar. [17] Nikshahr is located in Sistan and Baluchestan province where one of the highest prevalence rate of malaria has been recorded.

The finding of the present study showed that P. vivax was the most prevalent parasite. This is similar to the studies conducted in other parts of Iran. [18] P. vivax was observed in 97.5% of cases in Baboulsar during 1996-1997. [18] Ninety-eight percent of cases were positive for P. vivax at the Kermanshah study. [19] The analyzed data revealed that malaria had increasing and decreasing rates in Nikshahr District. Increasing rate in 2006 and 2007 was due to local transmission of the disease as well as immigration of Afghan people. This is in agreement with a previous study. [4] The total reported malaria cases in Iran reduced from 96,340 in 1991 to less than 1847 in 2010. [11] About 4.8% of malaria patients were among foreign immigrants (Afghani, Pakistan, and Bengali). However, in another study about 30-40% of malaria cases have been reported to be among foreign immigrants. [20] The main transmission route in this district is indigenous form (80.3%). Besides, local transmission was observed from 2004 to 2010 because of suitable ecological status of the region and effective presence of Anopheles mosquitoes. This underlines the importance of efforts to prevent the risk of malaria epidemic. The most affected age group was >15 years and many of them were male patients. Therefore, our concern should be on young males, that is the potentially working group. Occupational exposure due to men's work in agriculture is the main cause of higher affliction among men than women. In accordance with other studies, the most prevalence period of the disease has been observed to be the warmer months due to an increase in the number of mosquitoes. In the last study performed during 2005-2008 in Sistan and Baluchestan Province, 7807 out of a total of 28262 locally observed malaria cases were reported from Nikshahr City. [3] Malaria is getting the critical point at Systan and Baluchestan Province because of immigration from Pakistan and Afghanistan. Since malaria cases were also observed in pregnant women (1.5%), children under 5 years of age (7.2%) and children aged 5-15 years (32.6%), these should be regarded as the high-risk group for immediate intervention and implementation of prevention strategies. The annual parasite incidence (API), which is the index of malaria incidence in the community, has decreased from 9.5 in 2004 to 1.09 in 2010, that are related to an improved control system for elimination of malaria which includes screening for the disease as well as treatment within the first 48 hours [Figure 2]. Most of the malaria cases have been seen in Fanuj and Bent [Figure 3] because of the suitable ecological status of the region and effective presence of Anopheles mosquitoes. P. vivax has been the most prevalent malaria from 2004 to 2010, with an increasing trend from 2005. This trend indicated that the infection has been mostly transmitted indigenously. Due to the decrement of the number of Afghaian and Pakistanian migrants, the prevalence of P. falciparum has been reduced in this region. Instead, the prevalence of P. vivax has been increased. Over the last decade, the picture of distribution of malaria cases among different nationalities resident in Iran has changed. In 2001, over 50% of all malaria cases were among non-Iranian residents, [21] whereas currently only 5% of malaria cases are observed among non-Iranian residents in Nikshahr district. In fact, while Afghan migrants have left the country, cases of malaria have decreased in the Iranian population. Several measures should ideally be implemented in an integrated pattern to contain the unraveled dissemination of malaria parasites and mosquito vectors; these include improved policies, regulations and practices regarding malariological screening.
Figure 3: ABER and API Indexes in Nikshahr County, Sistan and Baluchestan province, southeast of Iran, during 2004-2010

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   Acknowledgment Top


This work was supported by the Shiraz University of Medical Sciences (SUMS) under the project number 90-01-04-3831. The authors are grateful to the financial support of vice-chancellor for research and technology at SUMS and also appreciate the assistance received from Nikshahr Health center.[22]

 
   References Top

1.WHO. World malaria report 2011. Geneva: World Health Organization Press; 2011.  Back to cited text no. 1
    
2.Available from: http://www.undp.org.ir/index.php/millennium-development-goals/480-15-february-2011-the-prevention-and-control-of-malaria-in-iran [Last accessed date Last Updated on Tuesday, 15 March 2011 15:43].  Back to cited text no. 2
    
3.Salehi M, Mokhtari M, Amirmajdi I, Eftekharzadeh Mashhadi Y, Hakemi H. Analysis of malaria epidemic features in Sistan and Baluchistan province, Southeast of Iran, 2005-2008. Iran Red Crescent Med J 2010;12:247-53.  Back to cited text no. 3
    
4.Moosa Kazemi SH, Vatandoost H, Raeisi A, Akbarzadeh K. Deltamethrin impregnated bed nets in a malaria control program in Chabahar, Southeast Baluchistan, I. R. Iran. Iran J Arthropod Borne Dis 2007;1:43-51.  Back to cited text no. 4
    
5.Rogers DJ, Randolph SE. The global spread of malaria in a future, warmer world. Science 2000;289:1763-6.  Back to cited text no. 5
    
6.Bouma MJ. Methodological problems and amendments to demonstrate effects of temperature on the epidemiology of malaria. A new perspective on the highland epidemics in Madagascar, 1972-89. Trans R Soc Trop Med Hyg 2003;97:133-9.  Back to cited text no. 6
    
7.White NJ, Nosten F, Looareesuwan S, Watkins WM, Marsh K, Snow RW, et al. Averting a malaria disaster. Lancet 1999;353:1965-7.  Back to cited text no. 7
    
8.Enayati AA, Vatandoost H, Ladonni H, Townson H, Hemingway J. Molecular evidence for a kdr-like pyrethroid resistance mechanism in the malaria vector mosquito Anopheles stephensi. Med Vet Entomol 2003;17:138-44.  Back to cited text no. 8
    
9.Alipour H, Ladonni H, Abaie MR, Moemenbellah-Fard MD, Fakoorziba MR. Laboratory efficacy tests of pyrethroid-treated bed nets on the malaria vector mosquito, Anopheles stephensi in a baited excito-repellency chamber. Pak J Biol Sci 2006;9:1877-83.  Back to cited text no. 9
    
10.Molyneux DH. Common themes in changing vector-borne disease scenarios. Trans R Soc Trop Med Hyg 2003;97:129-32.  Back to cited text no. 10
    
11.Eugene R. Shahgdian, A Key to the Anophelines of IRAN, Acta Medica Iranica 1960 Vol. III No. 3.  Back to cited text no. 11
    
12.Sedaghat MM, Harbach RE. An annotated checklist of the Anopheles mosquitoes (Diptera: Culicidae) in Iran. J Vector Ecol 2005;30:272-6.  Back to cited text no. 12
    
13.Vernick KD, Waters AP. Genomics and malaria control. N Engl J Med 2004;351:1901-4.  Back to cited text no. 13
    
14.Greenwood BM, Bojang K, Whitty CJ, Targett GA. Malaria. Lancet 2005;365:1487-98.  Back to cited text no. 14
    
15.White NJ, Nosten F, Looareesuwan S, Watkins WM, Marsh K, Snow RW, et al. Averting a malaria disaster. Lancet 1999;353:1965-7.  Back to cited text no. 15
    
16.Motabar M, Tabibzadeh I, Manouchehri AV. Malaria and its control in Iran. Trop Geogr Med 1975;27:71-8.  Back to cited text no. 16
    
17.Reyburn H, Mbakilwa H, Mwangi R, Mwerinde O, Olomi R, Drakeley C, et al. Rapid diagnostic tests compared with malaria microscopy for guiding outpatient treatment of febrile illness in Tanzania: Randomized trial. BMJ 2007;334:403.  Back to cited text no. 17
    
18.Bouma MJ. Methodological problems and amendments to demonstrate effects of temperature on the epidemiology of malaria. A new perspective on the highland epidemics in Madagascar 1972-89. Trans R Soc Trop Med Hyg 2003;97:133-9.  Back to cited text no. 18
    
19.Ghafari S, Kariminia H. Malaria in Mazandaran Province 1986-1996. J Mazandaran Med Sci Univ 1999;32:42-8.  Back to cited text no. 19
    
20.Rezavi M, Khodaei MA, Khazaeir M. Epidemilogy of Malaria in Kermanshah Province of Iran 1987-1996. Symp Parasitol Int 1998;47 (Suppl):160.  Back to cited text no. 20
    
21.Atta H, Zamani G. The progress of Roll Back Malaria in the Eastern Mediterranean Region over the past decade. East Mediterr Health J 2008;14:S82-9.  Back to cited text no. 21
    
22.Raeisi A, Nikpoor F, Kahkha RM, Faraji L. The trend of Malaria in I. R. Iran from 2002 to 2007. Hakim Res J 2009;12:35-41.  Back to cited text no. 22
    

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Correspondence Address:
Shokat Ali Amiri
Student Research Committee, Shiraz University of Medical Sciences, Shiraz
Iran
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/1755-6783.127790

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