Zambia Health Overview

Polio, typhoid, rabies and Hepatitis A vaccinations are recommended. Malaria is endemic in Zambia (prophylaxis is essential), and outbreaks of cholera and dysentery are common especially during the rainy season. Visitors to game parks are at risk of African trypanosomiasis (sleeping sickness), which is carried by tsetse flies; insect repellent is ineffective against tsetse flies. The country also has one of the highest rates of HIV/Aids infection worldwide. Avoid swimming or wading in bodies of fresh water, such as lakes, ponds, streams, or rivers due to the presence of bilharzia. Medical facilities in the country are under-developed and limited to the point that basic drugs and even clean needles are often not available. The small clinics in Lusaka are regarded as superior to the general hospitals, but clinics in rural areas are rarely stocked with anything more than aspirin or plasters. Full travel insurance, including cover for medical evacuation by air, is therefore essential and it is vital to bring a good first aid kit. Avoid food bought from local street vendors and ensure drinking water is filtered and boiled, or bought in sealed, branded bottles.


African Sleeping Sickness


Cause: Protozoan parasites Trypanosoma brucei (T. b.) gambiense and T. b. rhodesiense. Transmission: Infection with African trypanosomiasis (sleeping sickness) occurs through the bite of infected tsetse flies. Humans are the main reservoir host for T. b. gambiense. Domestic cattle and wild animals, including antelopes, are the main animal reservoir of T. b. rhodesiense. Nature of the disease: T. b. gambiense causes a chronic illness with onset of symptoms after a prolonged incubation period of weeks or months. T. b. rhodesiense causes a more acute illness, with onset a few days or weeks after the infected bite; often, there is a striking inoculation chancre. Initial clinical signs include severe headache, insomnia, enlarged lymph nodes, anaemia and rash. In the late stage of the disease, there is progressive loss of weight and involvement of the central nervous system. Without treatment, the disease is invariably fatal. Geographical distribution: T. b. gambiense is present in foci in the tropical countries of western and central Africa. T. b. rhodesiense occurs in east Africa, extending south as far as Botswana. Risk for travellers: Travellers are at risk of African sleeping sickness in endemic regions if they visit rural areas for hunting, fishing, safari trips, sailing or other activities in remote areas. Prophylaxis (protective treatment): None. Precautions: Travellers should be aware of the risk in endemic areas and as far as possible avoid any contact with tsetse flies. However, bites are difficult to avoid because tsetse flies can bite through clothing. Travellers should be warned that tsetse flies bite during the day and are not repelled by available insect-repellent products. The bite is painful, which helps to identify its origin, and travellers should seek medical attention promptly if symptoms develop subsequently. Source: WHO.


Schistosomiasis (bilharzia)


Cause: Several species of parasitic blood flukes (trematodes), of which the most important are Schistosoma mansoni, S. japonicum and S. haematobium. Transmission: Infection with bilharzia occurs in fresh water containing larval forms (cercariae) of schistosomes, which develop in snails. The free-swimming larvae penetrate the skin of individuals swimming or wading in water. Snails become infected as a result of excretion of eggs in human urine or faeces. Nature of the disease: Chronic conditions in which adult flukes live for many years in the veins (mesenteric or vesical) of the host where they produce eggs, which cause damage to the organs in which they are deposited. The symptoms of bilharzias depend on the main target organs affected by the different species, with S. mansoni and S. japonicum causing hepatic and intestinal signs and S. haematobium causing urinary dysfunction. The larvae of some schistosomes of birds and other animals may penetrate human skin and cause a self-limiting dermatitis, "swimmers itch". These larvae are unable to develop in humans. Geographical distribution: S. mansoni occurs in many countries of sub-Saharan Africa, in the Arabian peninsula, and in Brazil, Suriname and Venezuela. S. japonicum is found in China, in parts of Indonesia, and in the Philippines (but no longer in Japan). S. haematobium is present in sub-Saharan Africa and in eastern Mediterranean areas. Risk for travellers: In endemic areas, travellers are at risk to bilharzias while swimming or wading in fresh water. Prophylaxis (protective treatment): None. Precautions: Avoid direct contact (swimming or wading) with potentially contaminated fresh water in endemic areas. In case of accidental exposure, dry the skin vigorously to reduce penetration by cercariae. Avoid drinking, washing, or washing clothing in water that may contain cercariae. Water can be treated to remove or inactivate cercariae by paper filtering or use of iodine or chlorine. Source: WHO.


Rabies


Cause: The rabies virus, a rhabdovirus of the genus Lyssavirus. Transmission: Rabies is a zoonotic disease affecting a wide range of domestic and wild animals, including bats. Infection of humans usually occurs through the bite of an infected animal. The virus is present in the saliva. Any other contact involving penetration of the skin occurring in an area where rabies is present should be treated with caution. In developing countries transmission is usually from dogs. Person-to-person transmission has not been documented. Nature of the disease: An acute viral encephalomyelitis, which is almost invariably fatal. The initial signs include a sense of apprehension, headache, fever, malaise and sensory changes around the site of the animal bite. Excitability, hallucinations and aerophobia are common, followed in some cases by fear of water (hydrophobia) due to spasms of the swallowing muscles, progressing to delirium, convulsions and death a few days after onset. A less common form, paralytic rabies, is characterized by loss of sensation, weakness, pain and paralysis. Geographical distribution: Rabies is present in animals in many countries worldwide. Most cases of human infection occur in developing countries. Risk for travellers: In rabies-endemic areas, travellers may be at risk if there is contact with both wild and domestic animals, including dogs and cats. Prophylaxis (protective treatment): Vaccination for travellers with a foreseeable significant risk of exposure to rabies or travelling to a hyperendemic area where modern rabies vaccine may not be available. Precautions: Avoid contact with wild animals and stray domestic animals, particularly dogs and cats, in rabies-endemic areas. If bitten by an animal that is potentially infected with rabies, or after other suspect contact, immediately clean the wound thoroughly with disinfectant or with soap or detergent and water. Medical assistance should be sought immediately. The vaccination status of the animal involved should not be a criterion for withholding post-exposure treatment, unless the vaccination has been thoroughly documented and vaccine of known potency has been used. In the case of domestic animals, the suspect animal should be kept under observation for a period of 10 days. Rabies post-exposure treatment: In a rabies-endemic area, the circumstances of an animal bite, other contact with the animal, and the animal's behaviour and appearance may suggest that it is rabid. In such situations, medical advice should be obtained immediately. Post-exposure treatment to prevent the establishment of rabies infection involves first-aid treatment of the wound followed by administration of rabies vaccine and antirabies immunoglobulin in the case of a bite or exchange of saliva. The administration of vaccine, and immunoglobulin if required, must be carried out, or directly supervised, by a physician. Source: WHO.


Typhoid fever


Cause: Salmonella typhi, the typhoid bacillus, which infects only humans. Similar paratyphoid and enteric fevers are caused by other species of Salmonella, which infect domestic animals as well as humans. Transmission: Infection with typhoid fever is transmitted by consumption of contaminated food or water. Occasionally direct faecal-oral transmission may occur. Shellfish taken from sewage-polluted beds are an important source of infection. Infection occurs through eating fruit and vegetables fertilized by night soil and eaten raw, and milk and milk products that have been contaminated by those in contact with them. Flies may transfer infection to foods, resulting in contamination that may be sufficient to cause human infection. Pollution of water sources may produce epidemics of typhoid fever, when large numbers of people use the same source of drinking water. Nature of the disease: Typhoid fever is a systemic disease of varying severity. Severe cases are characterized by gradual onset of fever, headache, malaise, anorexia and insomnia. Constipation is more common than diarrhoea in adults and older children. Without treatment, the disease progresses with sustained fever, bradycardia, hepatosplenomegaly, abdominal symptoms and, in some cases, pneumonia. In white-skinned patients, pink spots (papules), which fade on pressure, appear on the skin of the trunk in up to 50% of cases. In the third week, untreated cases develop additional gastrointestinal and other complications, which may prove fatal. Around 2-5% of those who contract typhoid fever become chronic carriers, as bacteria persist in the biliary tract after symptoms have resolved. Geographical distribution: Worldwide. The disease occurs most commonly in association with poor standards of hygiene in food preparation and handling and where sanitary disposal of sewage is lacking. Risk for travellers: Generally low risk for travellers, except in parts of north and west Africa, in south Asia and in Peru. Elsewhere, travellers are usually at risk only when exposed to low standards of hygiene with respect to food handling, control of drinking water quality, and sewage disposal. Prophylaxis (protective treatment): Vaccination. Precautions: Observe all precautions against exposure to foodborne and waterborne infections. Source: WHO.


Malaria


General considerations: Malaria is a common and life-threatening disease in many tropical and subtropical areas. It is currently endemic in over 100 countries, which are visited by more than 125 million international travellers every year. Each year many international travellers fall ill with malaria while visiting countries where the disease is endemic, and well over 10,000 fall ill after returning home. Fever occurring in a traveller within three months of leaving a malaria-endemic area is a medical emergency and should be investigated urgently. Cause: Human malaria is caused by four different species of the protozoan parasite Plasmodium: Plasmodium falciparum, P. vivax, P. ovale and P. malariae. Transmission: The malaria parasite is transmitted by various species of Anopheles mosquitoes, which bite mainly between sunset and sunrise. Nature of the disease: Malaria is an acute febrile illness with an incubation period of 7 days or longer. Thus, a febrile illness developing less than one week after the first possible exposure is not malaria. The most severe form is caused by P. falciparum, in which variable clinical features include fever, chills, headache, muscular aching and weakness, vomiting, cough, diarrhoea and abdominal pain; other symptoms related to organ failure may supervene, such as: acute renal failure, generalized convulsions, circulatory collapse, followed by coma and death. It is estimated that about 1% of patients with P. falciparum infection die of the disease. The initial symptoms, which may be mild, may not be easy to recognize as being due to malaria. It is important that the possibility of falciparum malaria is considered in all cases of unexplained fever starting at any time between the seventh day of first possible exposure to malaria and three months (or, rarely, later) after the last possible exposure, and any individual who experiences a fever in this interval should immediately seek diagnosis and effective treatment. Early diagnosis and appropriate treatment can be life-saving. Falciparum malaria may be fatal if treatment is delayed beyond 24 hours. A blood sample should be examined for malaria parasites. If no parasites are found in the first blood film but symptoms persist, a series of blood samples should be taken and examined at 6-12-hour intervals. Pregnant women, young children and elderly travellers are particularly at risk. Malaria in pregnant travellers increases the risk of maternal death, miscarriage, stillbirth and neonatal death. The forms of malaria caused by other Plasmodium species are less severe and rarely life-threatening. Prevention and treatment of falciparum malaria are becoming more difficult because P. falciparum is increasingly resistant to various antimalarial drugs. Of the other malaria species, drug resistance has to date been reported for P. vivax, mainly from Indonesia (Irian Jaya) and Papua New Guinea, with more sporadic cases reported from Guyana. P. vivax with declining sensitivity has been reported for Brazil, Colombia, Guatemala, India, Myanmar, the Republic of Korea, and Thailand. P. malariae resistant to chloroquine has been reported from Indonesia. Geographical distribution: The risk for travellers of contracting malaria is highly variable from country to country and even between areas in a country. In many endemic countries of Latin America and the Caribbean, Asia and the Mediterranean region, the main urban areas, but not necessarily the outskirts of towns, are free of malaria transmission. However, malaria can occur in main urban areas in Africa and India. There is usually less risk of the disease at altitudes above 1,500 metres, but in favourable climatic conditions it can occur at altitudes up to almost 3,000 metres. The risk of infection may also vary according to the season, being highest at the end of the rainy season. There is no risk of malaria in many tourist destinations in South-East Asia, Latin America and the Caribbean. Source: WHO.


HIV/AIDS and Sexually Transmitted Diseases


The most important sexually transmitted diseases and infectious agents are HIV/AIDS, hepatitis B, syphilis, gonorrhoea, chlamydia infections, trichomoniasis, chancroid, genital herpes and genital warts. Transmission: Infection occurs during unprotected sexual intercourse. Hepatitis B, HIV and syphilis may also be transmitted in contaminated blood and blood products, by contaminated syringes and needles used for injection, and potentially by unsterilized instruments used for acupuncture, piercing and tattooing. Nature of the diseases: Most of the clinical manifestations are included in the following syndromes: genital ulcer, pelvic inflammatory disease, urethral discharge and vaginal discharge. However, many infections are asymptomatic. Sexually transmitted infections are a major cause of acute illness, infertility, long-term disability and death, with severe medical and psychological consequences for millions of men, women and children. Apart from being serious diseases in their own right, sexually transmitted infections increase the risk of HIV infection. The presence of an untreated disease (ulcerative or non-ulcerative) can increase by a factor of up to 10 the risk of becoming infected with HIV and transmitting the infection. On the other hand, early diagnosis and improved management of other sexually transmitted infections can reduce the incidence of HIV infection by up to 40%. Prevention and treatment of all sexually transmitted infections are therefore important for the prevention of HIV infection. Geographical distribution: Worldwide. Sexually transmitted infections have been known since ancient times; they remain a major public health problem, which was compounded by the appearance of HIV/AIDS around 1980. An estimated 340 million episodes of curable sexually transmitted infections (chlamydial infections, gonorrhoea, syphilis, trichomoniasis) occur throughout the world every year. Viral infections, which are more difficult to treat, are also very common in many populations. Genital herpes is becoming a major cause of genital ulcer, and subtypes of the human papillomavirus are associated with cervical cancer. Risk for travellers: For some travellers there may be an increased risk of infection. Lack of information about risk and preventive measures and the fact that travel and tourism enhance the probability of having sex with casual partners increase the risk of exposure to sexually transmitted infections. In some developed countries, a large proportion of sexually transmitted infections now occur as a result of unprotected sexual intercourse during international travel. In addition to transmission through sexual intercourse (both heterosexual and homosexual-anal, vaginal or oral), most of these infections can be passed on from an infected mother to her unborn or newborn baby. Hepatitis B, HIV and syphilis are also transmitted through transfusion of contaminated blood or blood products and the use of contaminated needles. There is no risk of acquiring any sexually transmitted infection from casual day-to-day contact at home, at work or socially. People run no risk of infection when sharing any means of communal transport (e.g. aircraft, boat, bus, car, train) with infected individuals. There is no evidence that HIV or other sexually transmitted infections can be acquired from insect bites. Prophylaxis: There is a vaccination against hepatitis B. No prophylaxis is available for any of the other sexually transmitted diseases. Precautions: Male or female condoms, when properly used, have proved to be effective in preventing the transmission of HIV and other sexually transmitted infections, and for reducing the risk of unwanted pregnancy. Latex rubber condoms are relatively inexpensive, are highly reliable and have virtually no side-effects. The transmission of HIV and other infections during sexual intercourse can be effectively prevented when high-quality condoms are used correctly and consistently. Studies on serodiscordant couples (only one of whom is HIV-positive) have shown that, with regular sexual intercourse over a period of two years, partners who consistently use condoms have a near-zero risk of HIV infection. A man should always use a condom during sexual intercourse, each time, from start to finish, and a woman should make sure that her partner uses one. A woman can also protect herself from sexually transmitted infections by using a female condom - essentially, a vaginal pouch, which is now commercially available in some countries. It is essential to avoid injecting drugs for non-medical purposes, and particularly to avoid any type of needle-sharing to reduce the risk of acquiring hepatitis, HIV, syphilis and other infections from contaminated needles and blood. Medical injections using unsterilized equipment are also a possible source of infection. If an injection is essential, the traveller should try to ensure that the needles and syringes come from a sterile package or have been sterilized properly by steam or boiling water for 20 minutes. Patients under medical care who require frequent injections, e.g. diabetics, should carry sufficient sterile needles and syringes for the duration of their trip and a doctor's authorization for their use. Unsterile dental and surgical instruments, needles used in acupuncture and tattooing, ear-piercing devices, and other skin-piercing instruments can likewise transmit infection and should be avoided. Treatment: Travellers with signs or symptoms of a sexually transmitted disease should cease all sexual activity and seek medical care immediately. The absence of symptoms does not guarantee absence of infection, and travellers exposed to unprotected sex should be tested for infection on returning home. HIV testing should always be voluntary and with counselling. The sexually transmitted infections caused by bacteria, e.g. chancroid, chlamydia, gonorrhoea and syphilis, can be treated successfully, but there is no single antimicrobial that is effective against more than one or two of them. Moreover, throughout the world, many of these bacteria are showing increased resistance to penicillin and other antimicrobials. Treatment for sexually transmitted viral infections, e.g. hepatitis B, genital herpes and genital warts, is unsatisfactory due to lack of specific medication, and cure is difficult to achieve. The same is true of HIV infection, which in its late stage causes AIDS and is thought to be invariably fatal. Antiretroviral drugs cannot completely eradicate the HIV virus; treatment is expensive and complex and most countries have only a few centres that are able to provide it. Source: WHO.


Hepatitis A


Cause: Hepatitis A virus, a member of the picornavirus family. Transmission: The virus is acquired directly from infected persons by the faecal-oral route or by close contact, or by consumption of contaminated food or drinking water. There is no insect vector or animal reservoir (although some non-human primates are sometimes infected). Nature of the disease: An acute viral hepatitis with abrupt onset of fever, malaise, nausea and abdominal discomfort, followed by the development of jaundice a few days later. Infection in very young children is usually mild or asymptomatic (e.g. causes no symptoms); older children are at risk of symptomatic disease. The disease is more severe in adults, with illness lasting several weeks and recovery taking several months; case-fatality is greater than 2% for those over 40 years of age and 4% for those over 60. Geographical distribution: Worldwide, but most common where sanitary conditions are poor and the safety of drinking water is not well controlled. Risk for travellers: Non-immune travellers to developing countries are at significant risk of infection. The risk is particularly high for travellers exposed to poor conditions of hygiene, sanitation and drinking water control. Prophylaxis (protective treatment): Vaccination. Precautions: Travellers who are non-immune to hepatitis A (i.e. have never had the disease and have not been vaccinated) should take particular care to avoid potentially contaminated food and water. Source: WHO.


Cholera


Cause: Vibrio cholerae bacteria, serogroups O1 and O139. Transmission: Infection occurs through ingestion of food or water contaminated directly or indirectly by faeces or vomit of infected persons. Cholera affects only humans; there is no insect vector or animal reservoir host. Nature of the disease: An acute enteric (intestine) disease varying in severity. Most infections are asymptomatic (i.e. do not cause any illness). In mild cases, diarrhoea occurs without other symptoms. In severe cases, there is sudden onset of profuse watery diarrhoea with nausea and vomiting and rapid development of dehydration. In severe untreated cases, death may occur within a few hours due to dehydration leading to circulatory collapse. Geographical distribution: Cholera occurs mainly in poor countries with inadequate sanitation and lack of clean drinking water and in war-torn countries where the infrastructure may have broken down. Many developing countries are affected, particularly those in Africa and Asia, and to a lesser extent those in central and south America. Risk for travellers: The risk of cholera is very low for most travellers, even in countries where cholera epidemics occur. Humanitarian relief workers in disaster areas and refugee camps are at risk.
Prophylaxis (protective treatment): Oral cholera vaccines for use by travellers and those in occupational risk groups are available in some countries. Precautions: As for other diarrhoeal diseases. All precautions should be taken to avoid consumption of potentially contaminated food, drink and drinking water. Oral rehydration salts should be carried to combat dehydration in case of severe diarrhoea. Source: WHO.