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The unmeasured burden of malaria, typhoid, and dengue:

Malaria and typhoid are among the common causes of

febrile illness in children in South Asia. Outbreaks of

mosquito borne dengue fever and dengue haemor-

rhagic disease are also increasingly reported. 16 Malaria

is responsible for less than 5% of deaths in children in

South Asia but is a serious contributor to morbidity

and chronic anaemia. 2 Millions of South Asians have

debilitating typhoid and dengue infections every year,

but reliable data on the annual number of cases are

hard to come by because these diseases require labora-

tory confirmation, which is not routinely attempted.

Rates of typhoid fever as high as 980 per 100 000

population have been reported from urban slums in

Delhi, and Salmonella is the commonest bacterial

pathogen identified from bloodstream infections in

South Asia. 17–19 Infection rates in children under 5 years

of age are much higher than previously thought. 17 19

Public health approaches to infection control are

needed, especially as drug resistant malaria and

typhoid become increasingly common. An effective

vaccine against Salmonella typhi is available but not included in routine childhood immunisations.

The hepatitis B and C epidemics

High rates of hepatitis B infection in many South Asian countries are attributed to unsafe blood supply, reuse of contaminated syringes, lack of maternal screening to prevent perinatal transmission, and delay in the introduction of hepatitis B vaccine. India, Pakistan, and Bangladesh have the highest rates of infection, with prevalence ranging from 2% to 8% in different population groups.20 Prevalence rates in Sri Lanka are under 1%.21 Hepatitis C infections in South Asia are also rising, and chronic liver diseases increasingly burden the region’s health systems.21 22 Prevalence rates were estimated to be 1-2.4% in 1999.22 Infections seem to be acquired at an early age, and reuse of contaminated syringes is strongly implicated in transmission of hepatitis B and hepatitis C infection.

 

 

 

 Surveillance systems

Policy planners need to make evidence based decisions

for improving population health. The ability to

measure disease burden, the global effort for

eradication of polio, the recent outbreaks of severe

acute respiratory syndrome and avian influenza in

many Asian countries, and the plague scare in India

show the importance of establishing sustainable and

robust detection and early warning systems for

infectious diseases. Eradication or control requires the

ability to detect these diseases and use the information

for preventing further spread. Surveillance systems for

infectious diseases are, however, lacking in most of

South Asia. Requirements of notification for commu-

nicable diseases are rarely enforced, and most

healthcare activity takes place in the private sector —

information not usually captured by the rudimentary

government information systems for health manage-

ment. Epidemiologists and microbiologists are not

involved in disease control activities, and vital

registration systems for births and deaths are absent or

inadequate. Additionally, many disease outbreaks with

major consequences for public health and trade, such

as haemorrhagic fevers, influenza, and severe acute

respiratory syndrome, require sophisticated facilities

and expertise of the type available only in a well

equipped national reference laboratory. As the recent

outbreak of avian influenza in Pakistan’s poultry popu-

lation illustrates, absence of such facilities and dissemi-

nation of reliable information in a timely manner can

have devastating consequences for both public health

and industry.