1

ARDHI UNIVERSITY

SCHOOL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY

DEPARTMENT OF ENVIRONMENTAL SCIENCE AND MANAGEMENT

ENVIRONMENTAL HEALTH AND EPIDEMIOLOGY

ASSIGNMENT ONE

20 APRL, 2015

2

ARDHI UNIVERSITY

SCHOOL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY

DEPARTMENT OF ENVIRONMENTAL SCIENCE AND MANAGEMENT

ENVIRONMENTAL HEALTH AND EPIDEMIOLOGY

ASSIGNMENT ONE

PARTICIPANTS

REG NO.

LUHIYE ISACK J 5757/T.2013

NDOMONDO ANDREW 5779/T.2013

ISMAIL MUHIDIN 5743/T.2013

BRYARUFU DATIVA

5734/T.2013

HERIETH LWASAYI

5755/T.2013

JACKLINE KASHINDE

5748/T.2013

AURELIUS MDEMU 5770/T.2013

20 APRL, 2015

i

ABSTRACT The study aimed to identify environmental hazardous that may lead to environmental diseases,

the sources, and transmissions of environmental diseases and how to eliminate the presence of

the health risk hazardous, control and the spread of environmental diseases.

The study focuses on how water supply and sewage system, environmental cleanliness and

wastes management and air pollution contribute in acceralating epidemiological diseases such as

malaria, typhoid, cholera, diarrhea, filarias, and giardiasis and so on.

The environmental situation that we observed at the case site (Sinza A & C) were not good since

it was observed that there were blockage of sewage system, presence of stagnant ponds, poor

waste management which provide prevalence of epidemiological diseases.

The two broad types of data source, the secondary and primary data sources were used in the

study. Site observation for gathering informationwas used to collect information.

The data will be analyzed using Microsoft word. However data presentation will also be done

through word process, the report also include figures, and plates used to assist in presentation of

information from the study.

According to the nature of the case study area and the environmental healthy hazardous we

recommend that designing of drainage system for storm water management, engineers have to

make a gentle slope in drainage system to allow free flowing water, the authority concern should

establish the programs for regular checking and cleaning of sewage and drainage system., and

epidemiological knowledge on the source, spread, effects, controlling and elimination of

epidemiological diseases should be provided to the people.

A visit to Sinza settlement has shown that there are environmental problems which need to be

handled by any relevant authority. The area requires an assessment pertaining to the prevailing

environmental conditions. However,Tandale, Kijitonyama and Mwananyamala, mwenge, survey

and Ubungo settlements which are nearby Sinza may have an impact on epidemiological

problems which may arise at Sinza area since the community of these areas interact each other.

ii

TABLE OF CONTENTS

ABSTRACT……………………………………………………………………………………....i

LIST OF FIGURE………………..………………………………………………………………iii

LIST OF PLATES………………………………………………………………………………..iv

CHAPTER ONE ............................................................................................................................ iii

INTRODUCTION .......................................................................................................................... 1

1.1Background ............................................................................................................................ 1

1.2 Objectives .............................................................................................................................. 2

1.3 Significance of the study ....................................................................................................... 2

1.4 The scope of the study ........................................................................................................... 2

CHAPTER TWO ............................................................................................................................ 3

METHODOLOGY ......................................................................................................................... 3

2.1 Description of the case study ................................................................................................ 3

2.2 Location of the study area ..................................................................................................... 3

2.3 Climatic Condition ................................................................................................................ 4

2.4 Data collection....................................................................................................................... 4

2.5 Site Visit and Observation..................................................................................................... 4

2.6 Data analysis ......................................................................................................................... 4

2.7 Data presentation ................................................................................................................... 4

CHAPTER THREE ........................................................................................................................ 5

3.1 Environmental condition at Sinza. ........................................................................................ 5

3.2 Sources and transmissions of environmental diseases .......................................................... 8

3.3.Elimination and control of communicable and environmental diseases ............................. 10

3.4 Solution to the Observed Environmental hazardous ........................................................... 12

CHAPTER FOUR ......................................................................................................................... 13

CONCLUSION AND RECOMMENDATION ............................................................................ 13

4.1 CONCLUSION ................................................................................................................... 13

4.2 RECOMMENDATION ...................................................................................................... 13

REFFERENCES ........................................................................................................................... 14

iii

LIST OF FIGURE Figure; 2.1 A map of Sinza ............................................................................................................. 3

Figure 3.1 Possible transmissions diseases from host to host ......................................................... 9

Figure 3.2 Possible transmissions of diseases from soil, animals to man....................................... 9

Figure 3.3 Possible transmissions of diseases from vector to man and from vectors, and water to

man. ............................................................................................................................................... 10

iv

LIST OF PLATES

Plate, 3.1 Poor solid wastes disposal at Sinza ................................................................................. 5

Plate, 3.2 Stagnant water in drainage system and in ponds at Sinza .............................................. 6

3.1.3 Poor sewage and sullage system ............................................................................................ 6

Plate 3.3 Poor sullage disposals into drainage and river at Sinza ................................................... 7

3.1.4 Water supply system passes through waste water stream ...................................................... 7

Plate 3.4 Exposed water supply pipes in waste water and storm water flow .................................. 7

Plate 3.5 Existence of long grasses in drainage system and around the residents .......................... 8

1

CHAPTER ONE

INTRODUCTION

1.1Background

Epidemiologyis the study of the spread, control, and prevention of disease in populations. Many

of our habits in the daily routine of life, from hand washing to waste disposal, reflect the

importance of this field. The application of this study is to the promotion of health, prevention

and control of health problems (Kebede2004).

The transmission of epidemiological disease is also rife among vulnerable communities because

they live in environments receptive to the breeding of insect vectors that carry parasites such as

malaria, filaria, trypanosomes, typhoid and cholera. Most of these need water for part of their

life-cycle. 300 million people suffer from malaria and in sub-Saharan Africa alone malaria kills

an estimated 1 million people per year, the large majority are children under five.(WHO, 2000).

Worldwide cholera affects 3–5 million people and causes 100,000–130,000 deaths per year.

Cholera has affected many African countries and the disease is among the major causes of

morbidity and mortality on the continent. The first cholera cases in Tanzania were reported in

1977 and since then cases and deaths have been reported each year (TFELTP, 2008).

Malaria has been a leading cause of morbidity and mortality in Tanzania, for many years,

accounting for over 40 per cent of overall outpatient attendances and 30 per cent of the national

disease burden.Although it increases during and soon after the rainy season.

TB continues to be a major public health problem, data from the Rufiji demographic

Surveillance System (RDSS) indicate that TB accounted for 7.0 per cent and 8.5 per cent of the

disease burden in 2000 and 2003, respectively, whereas WHO estimates that Tanzania has the

14th highest TB burden in the world. In 2006, the national prevalence was 459 per 100 000,

whereas incidence was 312 per 100 000 per year.15

TB case notification rates increased during

the 1990 s (Kwesigabo.etal, 2012,).

Malaria transmission in the urban area of Dar es Salaam is less intensive than in rural areas.

However, the initial process of urban expansion is accompanied by an increase in malaria rates at

the periphery of the city. This is driven by the establishment of new shantytown zones with open

2

sand pits and burrows and by the dangerous encounter at the urban fringe of a population with

low malaria immunity coming into contact with parasite carriers and thus provide favorable

condition for epidemiological diseases.

There is a lack of understanding of the complex interactions between human social structure, the

environment and the diseases infections, that’s why there is a need of understanding the study of

epidemiology.

1.2 Objectives

Main objectives

To conduct epidemiology study and identify environmental hazardous that may result to

environmental diseases.

Specific objectives

i. To identify environmental hazardous that may lead to environmental diseases.

ii. To identify the sources, and transmissions of environmental diseases(reservoir)

iii. To eliminate the presence of the health risk hazardous and to control the spread of

environmental diseases.

1.3 Significance of the study

The study will enable to acquire the knowledge on how the environmental hazardous may lead to

the healthy adverse effects and the way to eliminate and control of the environmental diseases.

1.4 The scope of the study

The study is based on studying epidemiological environmental disease; their sources, spread and

the control of epidemiological environmental disease .It is conducted in Dar es Salaam,

particularly at Sinza A and Sinza C.

3

CHAPTER TWO

METHODOLOGY

2.1 Description of the case study

Sinza is an administrative ward in the Kinondoni district of the Dar es Salaam region of

Tanzania. According to the 2012 census, the ward has a total population of 40546.

2.2 Location of the study area

Sinza is located at 6°47′08″S39°13′52″E, and itis bordered with Tandale and mwananyamala in

the east, awe in the west,Kijitonyama and makumbusho in the north and Ubungo ward in the

southern part as shown in the figure 2.1

Figure; 2.1A map of Sinza

4

2.3 Climatic Condition

Temperature and rainfall

The highest average temperature per month in Sinza is about 26 and the

lowest is about20 per year, the higher average rainfall is about 350mm per month on April to

May and the lowest is about100mm on January to February and June to October

(Http://worldwether online.com accessed on 11 April, 20015).

Soil type

The type of soil found at Sinza is clay soil with slightly sand which is characterized by having

low water permeability. Generally the evaluation of groundwater occurrences has indicated that

two types of aquifers characterize the area with sand, gravels and weathered limestone (Anthony

et al, 1999).

2.4 Data collection

Data collection in the study area where intended to know the following information

Identifying environmental hazardous that may lead to environmental diseases.

Identify the sources, and transmissions of environmental diseases (reservoir)

In this project the following were the methods used in data collection processes:

2.5 Site Visit and Observation

We visited different areas at Sinza wardand observed the existing situation. It was observed that

there were blockages of sewage system,poor solid waste Management, water supply system

passes through waste water stream, stagnant water and long grasses near home.

2.6 Data analysis

A computer program Microsoftword is used to make the analysis of data which were obtained

from the field.2.7 Data presentation

Data are going to be presented through word process; the report also will include figures, table

and plates which are used to assist in presentation or propagation of information from the study.

5

CHAPTER THREE

GENERAL FINDINGS

3.1 Environmental condition at Sinza

3.1.1 Improper solid waste management

Solid waste refers to the presence of the unwanted solid materials thrown to the environment; it

includes refuse papers, bottles and domestic solid products. The types of solid waste produced at

Sinza ward include food remains, plastic bags, cans, and bottles as illustrated in the plate 3.1.

a) Poor solid disposal around Sinza resident

b) Poor solid disposal around Sinza resident

Plate, 3.1: Poor solid wastes disposal at Sinza

The presence of solid waste may provide favorable condition for houseflies breeding and thus

cause the spreading of diseases such as cholera and diarrhea as long as solid wastes characterized

with unpleasant smell and presence of moist condition provide the habitat for houseflies. The

houseflies are able to cause these because are the carrier for pathogens of such epidemiological

diseases.

3.1.2 Poor drainage system

Drainage system is a process of conveying storm water or sewage from one place to a point of

disposal. A site visit at Sinza observed the presence of stagnant water due to poor drainage

6

systems and ponds which make water to stay for some days after raining as demonstrated in the

plates 3.2.

a) Stagnant water in a drainage system b) stagnant water in a pond

Plate, 3.2: Stagnant water in drainage system and in ponds at Sinza

Stagnant water provides better environments condition for the breeding and spread of vectors of

diseases such as mosquitoes, flies and snails. These may lead to the spread of malaria, bilharzia,

yellow fever, filariasis, dengue and the epidemic diseases such as cholera and diarrhoea.

3.1.3 Poor sewage and sullage system

Sullage water is the waste from households, sinks, shower, and baths but not toilets where

sewage is waste water and excrement conveyed in sewer. In a case study area it was observed the

presence of poor sewage and sullage system as showed in plate 3.3.

7

a) Sullage water around residents house

b) Sullage water introduced into a river

Plate 3.3: Poor sullage disposals into drainage and river at Sinza

The poor sewage and sullage system may lead to the epidemiological diseases such as cholera,

diarrhea, malaria, f ilariasis, and liver and kidney diseases due to contamination of such sewage

into river.

3.1.4 Water supply system passes through waste water stream

A site visit at Sinza observed the existence of some water system pipes pass through a waste

water stream as in figure 3.4.

a) Water pipes passé through waste water stream

b)Water supply pipelines within storm water

Plate 3.4: Exposed water supply pipes in waste water and storm water flow

Waste water stream carries pathogens and provides habitats and breading sites of infectious

agents, it may have health risk when the water pipes burst and result into the contamination of

8

infection agents with piped water. The contamination may lead to the outbreak of water borne

diseases such as typhoid, cholera, diarrhea, malaria, bilharzia, and filariasis.

3.1.5 Presence of long grasses near home

In a visit to Sinza, long grasses in a constructed drainage system and around Sinza resident were

observed as indicated in the figure3.5.

a) Long grasses in drainage system

b) Long grasses around Sinza resident

Plate 3.5: Existence of long grasses in drainage system and around the residents

The presence of growing grasses in drainage system restrict the normal water flow along the

drainage, this is due to accumulation of sands and debris .This situation provide favorable

condition for vector of diseases such as mosquitoes and snails, and thus may lead to the

occurrence of diseases like malaria,dengu fever,filariasis and bilharzia. However, the long

grasses around Sinza resident also provide good environment for breed and spread of rats, a

vector of plague.

3.2 Sources and transmissions of environmental diseases

Sources of environmental diseases

The sources of an infection can be an infected person or animal or soil. People and animals may

have clinical diseases, subclinical infection or carrier; on the other hand if there is a reservoir, it

9

should be considered as the source. When we referred to the environmental condition in our case

study, there were plenty of environmental risk factors; that may contribute to the occurrence of

an epidemic such as improper solid waste management, poor drainage system, and presence of

long grasses near home, water supply system passes through waste water stream and poor

sewage and sullage system.

Transmissions of communicable and environmental diseases

This is the passing of the diseases cause organisms from host to host. The transmission cycles

describes how an organism grows, multiplies and spread. In some cases man is the only host that

the disease spread from man to man for example measles.

Figure 3.1:Possible transmissions diseases from host to host

Source: Mausner and Bahn, 1985)

However, man can be the final host from whom the organism has no chance to pass further, for

instance Tetanus.

Figure 3.2: Possible transmissions of diseases from soil, animals to man

Source: Mausner and Bahn, 1985)

Man

Man

Animal

Soil

Man

10

Mosquito

Man Man

Water

Snail

Water

Man can be an integral part of transmission cycle as well as being the main reservoir e.g malaria

(simple cycle) and Schistosomiasis (complicated cycle).

Figure 3.3:Possible transmissions of diseases from vector to man and from vectors, and

water to man

Source: Mausner and Bahn, 1985)

For the case of Sinza, the possible routes of transmissions occurs when human beings:

Ingest contaminated water and food with pathogens through cockroaches and houseflies.

Dermal contact with vector of diseases through bites by mosquitoes, and rats

Inhalation of dust or contaminated air with pathogens for example viruses of influenza.

3.3. Elimination and control of communicable and environmental diseases

The environmental and communicable diseases can be controlled by preventing or destroying

their habitant and route of transmission as follows:

Attacking the source:

The treatment of the cases and carriers will depend on the reached cases. If there is a sign and

symptoms of any communicable and environmental disease, the case should be treated as

soon as possible.

11

Reservoir control is also used when a reservoir is the animal. Mass treatment, chemo

prophylaxis or immunization can be carried out. Other ways includes separating man from

animal or killing the animals and so destroying the reservoir e.g plague and rabies. This can

be done when there is an outbreak of rabies and there is a presence of wandering dogs.

Notification should be applied immediately to the local health authorities’ for instance,

DMO, after suspecting a patient suffering from an infectious disease so as measures can be

taken to prevent a particular disease not spreading. Some internationally modifiable disease

such as Cholera, Plague, Yellow fever.

Interrupting the route of transmission

The interrupting can be done as follows:

Improvement of environmental sanitation. Cleaning and removing all the grasses, stagnant

water basins which surrounding the environment thus favors the breeding sites for some

rodents and vermin (diseases causative agents)

Personal hygiene and behavior change. Facilitating the positive behavior change to the

community and ensuring that the personal hygiene is within to all people.

Protecting the host

Immunization. So that to increase host resistance by strengthening the internal defenses. It

has to be given to a high proportion of the people (80% coverage). The protective effect

obtained when a high proportion of the population has been immunized i.e herd immunity.

Herd immunity may be produced by many people having a disease (active natural

immunization) or giving immunization to most of population (active artificial immunization).

Chemo prophylaxis is a medication to prevent the development of infection; also given for

suppressing the disease like Malaria or preventing infection..

Person protection berries like shoes can be used especially for the children. The use of

repellents.

Mass education on various communicable and environmental diseases

12

Better nutrition to improve immunity

3.4 Solution to the Observed Environmental hazardous

Temporally solid wastes tank should be placed at Sinza resident to prevent the breeding and

spreading of vector of diseases such as house flies and cockroaches.

Covering of all ponds which may allow rainy water or running water from houses to stay

(stagnant water).This will help in preventing mosquitoes and snails to breed.

There should be regularly cleaning of drainage system at Sinza to remove sands and debris to

allow proper runoff in a drainage system.

Covering of all exposed out water supply pipe lines to remove the risk of portable water

contamination.

13

CHAPTER FOUR

CONCLUSIONS AND RECOMMENDATIONS

4.1 CONCLUSIONS

The study of Environmental epidemiology has great important to the community since it enables

scholars to identify and understand the source, and the mode oftransmissions as well as the

control and elimination ofepidemiological diseases such as

cholera,typhoid,malaria,filariasis,diarrhoea,yellow fever,plague.Contolling of epidemiological

diseases is possible through destroying the breeding sites of pathogens and destructing the

transmission route of vector of diseases.

4.2 RECOMMENDATIONS

According to the observation made at the case site Sinza we observed many environmental

hazardous that may result to epidemiological diseases and thus we recommend the following:

The authority concern should establish the temporally solid wastes storage tanks at

several areas around Sinza and having a regularly collection and disposing of solid

wastes by using a municipal truck.

In designing of drainage system for storm water management, engineers have to make a

gentle slope in drainage system to allow free flowing water.

The authority concern should establish the programs for regular checking and cleaning of

sewage and drainage system.

The authority for water supply (DAWASCO) has to make sure that all exposed water

supply pipe lines are properly covered.

Epidemiological knowledge on the source, spread, effects, controlling and elimination of

epidemiological diseases should be provided to the people not only at Sinza but also the

whole Dar es Salaam city.

14

REFFERENCES

1. Kebede, Y. 2004.Epidemiology. Ethiopia Public Health Training Initiative. Ethiopia.

2. Kwesigabo, G.etal.2012. Health challenges in Tanzania.Journal of Public Health Policy

(2012) 33, S23–S34. doi:10.1057/jphp.2012.47.

3. Mausner and Bahn. 1985. Epidemiology an Introductory. Press USA

4. The Tanzanian Field Epidemiology and Laboratory training Program. 2008.Program in

Applied Epidemiology and Public Health Laboratory Science.

5. World Health Organization and Water Supply and Sanitation Collaboration

Council.2000. World Water Day Report. (Document WHO/SDE/WSH/00.2).