Review Article
Volume 2 Issue 6 - 2018
Leptospirosis: An Emerging Infectious Disease Concern with Water Contamination
Muhammad Imran1,2* and Yan Jie1,2
1Department of Microbiology and Parasitology, School of Medicine, Zhejiang University Hangzhou China
2Division of Basic Medical Microbiology, State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital, Zhejiang University School of Medicine
*Corresponding Author: Muhammad Imran, Department of Microbiology and Parasitology, Zhejiang University, Hangzhou Zhejiang 310058, PR China.
Receive: September 24, 2018; Published: October 04, 2018
Contaminated water is mainly concern with a variety of diseases either it’s communicable or non-communicable. Water contamination occurs due to varieties of sources, one of main source of water contamination is animals. Many animals act as a carrier of various microorganisms, causes different diseases. Leptospirosis is one of those infection diseases, spreading by domestic and wild animals to individuals. Leptospirosis is possibly the most spreading zoonosis, worldwide. The causative agent of Leptospirosis is Leptospira species. This bacterium is largely found in the urine of animals and infected animal’s shed causes water contamination. In Pakistan, 2010 flood disaster causes a lot of loses along with the spreading of a numerous infection diseases including leptospirosis. It is one of the neglected zoonosis in developing countries, including Pakistan. Due to its wide range of symptoms its infection remains diagnostic. Leptospira spp. causes a variety of infections from flu-like sickness to Weil's syndrome with multi-organ dysfunction. This review could provide the useful information for peoples and researchers.
Keywords: Leptospirosis; Leptospira species; Pakistan; neglected zoonosis; developing countries
List of abbreviations: WHO = World health organization; HCV = Hepatitis C virus; ELISA = Enzyme-linked immunosorbent assay; GDP = Gross Domestic Product
Leptospirosis is a zoonotic disease caused by a various type of Leptospira species [1]. It belongs to spirochete family classified to various groups like non-virulent, intermediary, or virulent species [2] Leptospires survive longer in warm, moist, steamy and sub-tropical environments, but also persevere in moderate regions [3]. A virulent strain of Leptospira species causes infection can result in clinical signs of hemorrhage, fever, jaundice, meningitis, renal failure, and death. The server manifestation rate of leptospiral infection has 1 million incidences of yearly, worldwide and case casualty percentage from 5% to 20% [1]. This disease is spread by a person’s contact with urine and contaminated water and soil, while many domestic and wild animals are the main reservoirs of bacteria, which is the main source of causing infection in humans [4, 5]. The infection has a broad geographic distribution due to the huge variety of mammalian hosts that harbour and evacuate the bacterium from their renal tubules [6]. Acute renal failure, refractory hypotension, myocarditis, respiratory distress syndrome, have been quoted as a multi-organ dysfunction in human leptospirosis [7].
In human infection, Rodents like rats, mice and others are common factor. Infected animals remain asymptomatic and their urine contains infectious organism for its whole life [8]. Pets, like a dog also shed infectious bacterium and become a domestic transmission to individuals, even the dog immunized against Leptospira [9]. The well recognized endemicity of human infection is absorbed in the Indian subcontinent, Eastern Europe, Oceania, Southeast Asia and Caribbean and Latin America, while in European republics like Greece, Germany, Netherlands, Denmark, France and Portugal, its availability were noticed in lesser extent [8]. Thus fishermen, farmers, meat workers, miners, and sewer workers have usually been at extreme threat for infection.
In Pakistan, several diseases are common, like emerging infections, growing affliction of non-communicable diseases and increase in epidemic and endemic infectious diseases. It has been estimated that the infected rate of hepatitis C virus (HCV), increasing the threat of cancer and chronic liver disease are about 8–9 million individuals in Pakistan [10]. Another survey suggested that about 410 000 are newly infected every year, 620 000 individuals have tuberculosis, and nearly 59 000 dies from several kinds of diseases [11]. While in Baluchistan and rural districts adjacent the river Indus delta the malarial cases are about 500000, every year. The persons involved in agriculture, veterinarians, sewerage workers, pet shop owners, meat handlers, farm workers and animal slaughtering are more sensitive to leptospirosis, and up to some extant leptospirosis is considered a professionally related disease [12,13]. In developing countries, leptospirosis has been accepted as an emerging infectious disease. This disease is endemic and mostly found in tropical countries [14]. While in Pakistan the Leptospiral prevalence among the humans is completely mysterious and there is no documented report found on the incidence of leptospirosis. So on behalf of ignored disease, this review was written, which provided baseline information and awareness about leptospirosis and its causes for the people of Pakistan [15].
Main sources of bacterial and other infectious diseases in Pakistan
In Pakistan, various bacteriological contaminations was concerned with drinking water. [16]. several reports were conducted to notify the contaminated drinking water in Pakistan as given in Table 1. In most areas of Pakistan lakes, ground aquifers and rivers are mostly polluted with bacteriological contamination figure 1 [17]. Water samples from treatment plants and water supply networks were found polluted by total coliform and in few regions, it was noticed with fecal coliform [18,19]. Shar., et al. 2008b investigated 768 water samples in Khairpur (Sindh Province) and their results indicated that water contamination by fecal and total coliform were 73.83% and 45.70%, respectively [20]. Another report was conducted and in this report, the fecal and total coliforms were found 100% in the same city. The tested samples were calmed from distribution lines, consumer tips and from main reservoirs [21]. The major cities of Pakistan like Lahore (Punjab province), Karachi (Sindh Province) and Peshawar (Khyber Pakhtunkhwa Province) the drinking water condition is same. The bacteriological contamination was also noticed in these cities [22-26]. Another study was investigated among the main cities of the country and their results revealed that the E. coli and total coliforms were, 35% and 65 %, respectively. While for surface water the results were 100% for both bacterial contaminations [27].
Sampling location No. of samples % of samples References
Total Contm. with total coliform Contm. with fecal coliform Contm. with total coliform Contm. with fecal coliform
Rural areas of Punjab - - - 91.30–95.83 - (22)
Tap water Lahore city - - - 42.85 - (22)
Four villages in Peshawar 39 38   97.4 - (26)
Nine different localities in Lahore 2160 446b - 20.64b - (32)
Filtration plants, Islamabad 5 3 - 60 - (33)
Filtration plants, Rawalpindi 26 14 - 53.8 - (33)
Surface water samples from various sources in Pakistan 20 20 20 100 100 (16)
Groundwater samples from various sources in Pakistan 344 223 122 65 35 (16)
Fifteen tube wells around Nullah Lai Rawalpindi 15 14 - 93 - (34)
Groundwater, Karachi 115 - - 66.63 60.89 (35)
Tap water (treated) Karachi city 329 - 94 - 28.5 (36)
Well water, Karachi city 30   23   76 (36)
Khairpur city, Sindh 768 567 351 73.83 45.70 (20)
Khairpur city, Sindh 90 90 90 100 100 (21)
Rawalpindi different locations 8c 2 2 25 25 (18)
Westridge area water distribution network, Rawalpindi 8c 8 8 100 100 (37)
Tench area water distribution network, Rawalpindi 8c 8 7 100 87.5 (37)
Ratta Amral water distribution network, Rawalpindi 8c 6 6 75 75 (19)
Input water sources of Rawal Lake, Islamabad 4 4 4 100 100 (27)
Rawal Lake, Islamabad (at various depth) 9 9 6 100 66.6 (27)
Table 1: Drinking water contamination of different regions in Pakistan. The table is arranged from different studies found in Pakistan and arranged by year bases.
Figure 1 (a, b, c, d): In Pakistan Municipal wastewater, industrial wastewater is drained to the canal and rivers or other open land areas without any treatment which cause contamination of water.
In one of a recent study, the water of Rawal Lake, Islamabad was tested and feeding streams were found bacteriological contamination, it is a lake which provides drinking water to about 1.5 million individuals of Rawalpindi and surrounding areas [28].
Infections after the monsoon flood in northern areas of Khyber Pakhtunkhwa Pakistan
In 2010 summer session, northern areas of Khyber Pakhtunkhwa were affected with 312 mm of rain for 56 hours continuously, which result in 1600 losses throughout in area. Additionally, with the record-breaking flood, almost 14 million people were directly affected (figure 2a, 2b). All those regions which were exaggerated with deluge were considering a suitable medium for the various kinds of pathogens. Leptospirosis, skin and eye infections, malaria, Leishmaniasis, diarrhea, hepatitis and respiratory infections were observed among different peoples after the record-breaking flood. In spreading of these diseases among the individuals, the unhygienic conditions in camps were also contributed [28].
Figure 2 (a, b, c, d): a monsoon floor 2010 images of different affected regions.
Figure 3 (e, f g): Some random click from monsoon flood 2010 northern regions of Khyber Pakhtunkhwa, Pakistan (h) Pakistan rodent are present in farming regions, a common source of leptospirosis.
Study about leptospirosis in Pakistan
As we search and look back to the previous study about leptospirosis in Pakistan we found a few reports published online. One of the study is about the sero-surveillance of human leptospirosis, 100 humans (78 males; 22 females) blood samples were collected from Lahore city and its peri-urban areas and processed by cELISA Serion ELISA classic microtiter plate. The results of this study revealed 44% prevalence of human leptospirosis. Among 78 males and 22 females, 38 males (49%) and 06 females (27%) were found positive. Age wise sero-surveillance demonstrates 47% prevalence in adults and 35% in young ones. Season-wise 42%, 40%, 26% and 47% were observed in summer, fall, winter, and spring, respectively. It is concluded that highest prevalence was in male adults while spring and summer were more susceptible seasons having leptospirosis infection [15].
Another study was investigated for leptospiral serotype with agglutinating antibodies in human, rodents and also in domestic animals, 14 (25%) was positive out of 56 samples. In human samples, L. grippotyphosa and L. icterohemorrhagiae prevalent rate was (14.2%) and (10.7%), respectively. While in domestic animals L. Pomona, L. australis, Suncus murinus L. grippotyphosa, L. pyrogenes, R. norvegicus L. grippotyphosa, were detected as maximum serotype. And the total prevalence in commensal rat’s i-e A. rattus and ft.norvegicus was 100%. The final study results demonstrate that the main source of leptospirosis transmission among the human and domestic animals is rodents [29].
Leptospirosis has been broadly deliberate in several Asian countries excluding Pakistan. So inadequate literature study is available about the prevalence of leptospirosis [15]. Previously, Vitale., et al. (2004) and Cinco., et al. (2004) have already successfully used ELISA for diagnosis of leptospirosis. Sharma., et al. (2006) and Jalii., et al. (2000) reported 52.7% and 16.7% prevalence in India which have the similar socio-economic and climate condition as in Pakistan [15-37].
To control the threats of infectious disease need the observation and investigations, which leads to the response, the development in new technology could help in this platform to recover the evidence gaps and developed the local proficiencies in local government response very effective. The effort needed for the federal government laboratory, monitoring expertise, and public health departments to develop and help the provinces for diagnostic facilities, medications, active management, and immunization. Inter-provincial coordination Ministry might be an appropriate source. These various challenges need a health policy nationwide. More focus on these public health issues enhanced authority and resource division leads to the active commitment of all partners’ i-e public and private [30].
Various published reports show that rodents are mostly responsible for L. grippotyphosa and L. icterohemorrhagiae transmission among the human and animals, which act as a transporter and spread the bacteria to others. The infected men don’t transmit the bacteria to other man or animals. Animals are infected when they are grazing or contact with the infected rodent’s urine and the disease might be transmitted from infected to healthy animals. It has been reported previously that the rodents which are found in the farming regions and have a close interaction with animals act as a shipper and spread L. australis, L. pyrogens and L. Pomona infections in domestic animals [30].
It has been finally determined that the peoples whose are working in farming area, fishermen, sewer labors, butchers and the peoples working in sugarcane and rice areas, are the high-risk peoples who're are more visible to infected carriers and moist environment in this field tolerate Leptospira to survive for a long time out the host body.
The advances in the field of medicine for last few decades, medical problems arising from natural tragedies are quiet enormously common. In developing global the regions having limited resources and weak infrastructure like Pakistan, face a lot of challenging environments. The recent flood which has floated large portions of state only served to focus on the insufficiencies in the health strategies of the country. Only 2% of the state GDP has spent on the health sector, it has been noticed that more resources need to defend those caused by these ruins from the argumentative effects of the situations defined earlier [28]. This study provides the suitable information about the presence of leptospirosis in Pakistan. However, a wide range of studies needs to identify the magnitude of this infection disease, so that the health policy maker adopted a suitable way to control this infectious disease and its occurrence.
I would like to thanks to all co-authors.
Conflict of Interest
The authors declare no conflicts of interest.
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Citation: Muhammad Imran and Yan Jie. “Leptospirosis: An Emerging Infectious Disease Concern with Water Contamination”. Clinical Biotechnology and Microbiology 2.6 (2018): 542-549.
Copyright: © 2018 Muhammad Imran and Yan Jie. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.