Kenya needs to watch the incidence of leptospirosis

Abstract

Leptospirosis has received little attention from public health practitioners. And there is a likelihood that the spread and prevalence of the disease are high due scarcities of studies related to leptospirosis. As Kenya increases the acreage under rice, the country should monitor the incidences of leptospirosis. This is because evidence shows that the disease is prevalent in rice growing areas and as its transmission differs with rice cultivation practices.   Introduction Leptospirosis is a bacterial disease that attacks both man and animals. Transmission of Leptospiral bacteria may occur via direct contact with infected live or dead animals or exposure to urine, water or soil contaminated with the bacteria. The disease is fatal and can result in death.   Data shows that about 1 million people across the globe are infected with the disease annually. About a third to a half of these cases were severe. Leptospirosis is slowly becoming a re-emerging disease globally. Lately, several countries have reported outbreaks in various parts of the world.   Distribution of leptospirosis in Kenya  In Kenya, the disease has received little attention from public health practitioners. And there is a likelihood that the spread and prevalence of the disease are high due scarcities of studies related to leptospirosis. However, the few available studies have shown a high prevalence of the disease in Nyandarua and Turkana.   Nyandarua is a wet region, and Leptospira spp is known to be endemic in wet areas. On the other hand, the high temperatures prevalent in Turkana favour the survival of the bacteria. The disease killed six students and 12 Kenyans in total after the outbreak of the disease in 2004. The 2004 outbreak was not the only outbreak in the country.   Kenya reported the first case of leptospirosis in 1944. Since then, Kenya has conducted few studies in this area. It has led to less awareness of the disease among Kenyans and little scientific interest in leptospirosis. Available studies in the country have focused their attention on pigs and rodents.   Recent research in Garissa and Tana River showed that nearly half of the sampled rodents tested positive for leptospiral bacteria. Conspicuously, the two regions house the Hola and Bura irrigation schemes.   Expansion of rice fields in the country It is no doubt that the population of Kenya has doubled in the last three decades. Out of the country's desire to improve food security and feed its rapidly growing population, Kenyans have turned several previously arid and semi-arid lands (ASAL) into agricultural lands. Some into irrigated farmlands, while into ranches for cattle, sheep, goats and camels.   Scientific studies have shown that increased or intense agricultural activities may increase the number of synanthropic rodents. In 2022, Kenya announced plans to increase the acreage of land under irrigation. An ambitious goal outlined in Vision 2030 and spearheaded by the National Irrigation Authority.   Kenya wants to avoid overreliance on rain-fed agriculture, which has become unreliable due to erratic weather changes. The Government has launched several mega dams since it announced the plan early this year. Constructions of many others are underway, while some are awaiting commissioning.   For instance, in February 2022, the Government commenced the construction of the Mwache Irrigation dam in Kwale County. The dam will supply 186,000m3 of water for domestic use and irrigation of 2,600 acres of land in its environs. And on Oct 15 2022, President Dr William Ruto commissioned the Thiba dam in Kirinyanga County. The dam will boost the production of rice by 10,000 acres.   During its launch, the president announced a further plan to increase rice production in the Mwea Irrigation scheme by 86,000 metric tonnes. Before 2015, Kenya had only seven irrigation schemes. These schemes are Hola and Bura in Tana River, Ahero and West Kano in Kisumu, Bunyala in Siaya and Busia, Mwea in Kirinyanga and Pekerra in Baringo. However, the Government has launched several other projects like the Galana Kulalu Irrigation Scheme.   Kenya needs to watch the incidence of leptospirosis While these are noble initiatives, they could also be a source of vector-borne disease. Some diseases that thrive well under irrigated farmlands include Leptospirosis, Bilharzia due to water snails and malaria as the areas provide fertile breeding grounds for mosquitoes, only to mention a few.   As Kenya increases the acreage under rice, the country should monitor the incidences of leptospirosis. Evidence shows that the disease is prevalent in rice-growing areas, and its transmission differs with rice cultivation practices. For instance, using animals like water buffaloes in cultivating the paddies may increase the risk of transmission.   There is a possibility that the rains may wash the bacteria into these rice paddies and, therefore, contaminate the soil. Contaminated soils are a good reservoir for the disease, and walking barefoot on such soils may encourage disease transmission. Most irrigation schemes are in areas with favourable climatic conditions ideal for the flourishing of different types of Leptospira.   These include high rainfall, humid conditions, low concentration of human waste, alkaline PH, sediments in water, warm climatic conditions and high moisture content in the soil. With the increase in the number of irrigation schemes and particularly the rice paddies in the country, there is a need to understand the epidemiology of the Leptospira spp in irrigation schemes in Kenya. Such studies will help reduce the risk of transmission and the future outbreak of the disease